<?xml version="1.0" encoding="US-ASCII"?>
<!-- DFIN New ActiveDisclosure (SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date :2026-03-19T15:18:33.7824+00:00 -->
<!-- Copyright (c) 2026 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
<xsd:schema targetNamespace="http://fireflyspace.com/20251231" attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2024-01-31" xmlns:ecd-sub="http://xbrl.sec.gov/ecd-sub/2025" xmlns:ecd="http://xbrl.sec.gov/ecd/2025" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:dei="http://xbrl.sec.gov/dei/2025" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:cyd="http://xbrl.sec.gov/cyd/2025" xmlns:enum2="http://xbrl.org/2020/extensible-enumerations-2.0" xmlns:fly="http://fireflyspace.com/20251231" xmlns:srt="http://fasb.org/srt/2025" xmlns:us-gaap="http://fasb.org/us-gaap/2025" xmlns:currency="http://xbrl.sec.gov/currency/2025" xmlns:xlink="http://www.w3.org/1999/xlink">
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/instance"/>
  <xsd:import schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" namespace="http://www.xbrl.org/2003/linkbase"/>
  <xsd:import schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" namespace="http://xbrl.org/2005/xbrldt"/>
  <xsd:import schemaLocation="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd" namespace="http://xbrl.sec.gov/ecd/2025"/>
  <xsd:import schemaLocation="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd" namespace="http://fasb.org/us-gaap/2025"/>
  <xsd:import schemaLocation="https://www.xbrl.org/2020/extensible-enumerations-2.0.xsd" namespace="http://xbrl.org/2020/extensible-enumerations-2.0"/>
  <xsd:import schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd" namespace="http://www.xbrl.org/dtr/type/2024-01-31"/>
  <xsd:import schemaLocation="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd" namespace="http://fasb.org/srt/2025"/>
  <xsd:import schemaLocation="https://xbrl.sec.gov/currency/2025/currency-2025.xsd" namespace="http://xbrl.sec.gov/currency/2025"/>
  <xsd:import schemaLocation="https://xbrl.sec.gov/ecd/2025/ecd-sub-2025.xsd" namespace="http://xbrl.sec.gov/ecd-sub/2025"/>
  <xsd:import schemaLocation="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd" namespace="http://xbrl.sec.gov/cyd/2025"/>
  <xsd:import schemaLocation="https://xbrl.sec.gov/dei/2025/dei-2025.xsd" namespace="http://xbrl.sec.gov/dei/2025"/>
  <xsd:import schemaLocation="https://www.xbrl.org/2023/calculation-1.1.xsd" namespace="https://xbrl.org/2023/calculation-1.1"/>
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/Cover" id="Cover">
        <link:definition>75000 - Document - Cover</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheets" id="StatementConsolidatedBalanceSheets">
        <link:definition>75010 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" id="StatementConsolidatedBalanceSheetsParenthetical">
        <link:definition>75020 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss" id="StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss">
        <link:definition>75030 - Statement - Consolidated Statements of Net Loss and Comprehensive Loss</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows" id="StatementConsolidatedStatementsOfCashFlows">
        <link:definition>75040 - Statement - Consolidated Statements of Cash Flows</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfConvertiblePreferredStockAndStockholdersEquityDeficit" id="StatementConsolidatedStatementsOfConvertiblePreferredStockAndStockholdersEquityDeficit">
        <link:definition>75050 - Statement - Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance" id="DisclosureCybersecurityRiskManagementStrategyAndGovernance">
        <link:definition>995457 - Disclosure - Cybersecurity Risk Management, Strategy, and Governance</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentation" id="DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentation">
        <link:definition>995467 - Disclosure - The Company, Initial Public Offering, and Basis of Presentation</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies1" id="DisclosureSummaryOfSignificantAccountingPolicies1">
        <link:definition>995477 - Disclosure - Summary of Significant Accounting Policies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinations" id="DisclosureBusinessCombinations">
        <link:definition>995487 - Disclosure - Business Combinations</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenue" id="DisclosureRevenue">
        <link:definition>995497 - Disclosure - Revenue</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNet" id="DisclosurePropertyAndEquipmentNet">
        <link:definition>995507 - Disclosure - Property and Equipment, Net</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpenses" id="DisclosureAccruedExpenses">
        <link:definition>995517 - Disclosure - Accrued Expenses</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNet" id="DisclosureIntangibleAssetsNet">
        <link:definition>995527 - Disclosure - Intangible Assets, Net</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwill" id="DisclosureGoodwill">
        <link:definition>995537 - Disclosure - Goodwill</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurement" id="DisclosureFairValueMeasurement">
        <link:definition>995547 - Disclosure - Fair Value Measurement</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeases" id="DisclosureLeases">
        <link:definition>995557 - Disclosure - Leases</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayable1" id="DisclosureNotesPayable1">
        <link:definition>995567 - Disclosure - Notes Payable</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingencies" id="DisclosureCommitmentsAndContingencies">
        <link:definition>995577 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStock1" id="DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStock1">
        <link:definition>995587 - Disclosure - Stockholders' Equity (Deficit) and Redeemable Convertible Preferred Stock</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensation" id="DisclosureStockbasedCompensation">
        <link:definition>995597 - Disclosure - Stock-Based Compensation</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxes" id="DisclosureIncomeTaxes">
        <link:definition>995607 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactions" id="DisclosureRelatedPartyTransactions">
        <link:definition>995617 - Disclosure - Related Party Transactions</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShare" id="DisclosureNetLossPerShare">
        <link:definition>995627 - Disclosure - Net Loss Per Share</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformation1" id="DisclosureSegmentAndGeographicalInformation1">
        <link:definition>995637 - Disclosure - Segment and Geographical Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSubsequentEvents1" id="DisclosureSubsequentEvents1">
        <link:definition>995647 - Disclosure - Subsequent Events</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies" id="DisclosureSummaryOfSignificantAccountingPoliciesPolicies">
        <link:definition>995657 - Disclosure - Summary of Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables" id="DisclosureSummaryOfSignificantAccountingPoliciesTables">
        <link:definition>995667 - Disclosure - Summary of Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsTables" id="DisclosureBusinessCombinationsTables">
        <link:definition>995677 - Disclosure - Business Combinations (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueTables" id="DisclosureRevenueTables">
        <link:definition>995687 - Disclosure - Revenue (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetTables" id="DisclosurePropertyAndEquipmentNetTables">
        <link:definition>995697 - Disclosure - Property and Equipment, Net (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpensesTables" id="DisclosureAccruedExpensesTables">
        <link:definition>995707 - Disclosure - Accrued Expenses (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetTables" id="DisclosureIntangibleAssetsNetTables">
        <link:definition>995717 - Disclosure - Intangible Assets, Net (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillTables" id="DisclosureGoodwillTables">
        <link:definition>995727 - Disclosure - Goodwill (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementTables" id="DisclosureFairValueMeasurementTables">
        <link:definition>995737 - Disclosure - Fair Value Measurement (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesTables" id="DisclosureLeasesTables">
        <link:definition>995747 - Disclosure - Leases (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableTables" id="DisclosureNotesPayableTables">
        <link:definition>995757 - Disclosure - Notes Payable (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersDeficitAndRedeemableConvertiblePreferredStockTables" id="DisclosureStockholdersDeficitAndRedeemableConvertiblePreferredStockTables">
        <link:definition>995767 - Disclosure - Stockholders Deficit and Redeemable Convertible Preferred Stock (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationTables" id="DisclosureStockbasedCompensationTables">
        <link:definition>995777 - Disclosure - Stock-Based Compensation (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesTables" id="DisclosureIncomeTaxesTables">
        <link:definition>995787 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsTables" id="DisclosureRelatedPartyTransactionsTables">
        <link:definition>995797 - Disclosure - Related Party Transactions (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareTables" id="DisclosureNetLossPerShareTables">
        <link:definition>995807 - Disclosure - Net Loss Per Share (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationTables" id="DisclosureSegmentAndGeographicalInformationTables">
        <link:definition>995817 - Disclosure - Segment and Geographical Information (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentationDetails" id="DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentationDetails">
        <link:definition>995827 - Disclosure - The Company, Initial Public Offering, and Basis of Presentation (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails" id="DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails">
        <link:definition>995837 - Disclosure - Summary of Significant Accounting Policies (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfPropertyAndEquipmentUsefulLivesDetails" id="DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfPropertyAndEquipmentUsefulLivesDetails">
        <link:definition>995847 - Disclosure - Summary of Significant Accounting Policies - Schedule of property and equipment useful lives (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfConcentrationOfCreditRiskDetails" id="DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfConcentrationOfCreditRiskDetails">
        <link:definition>995857 - Disclosure - Summary of Significant Accounting Policies - Schedule of Concentration of Credit Risk (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsAdditionalInformationDetails" id="DisclosureBusinessCombinationsAdditionalInformationDetails">
        <link:definition>995867 - Disclosure - Business Combinations (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfConsiderationPaidAndTheFairValueOfAssetsAcquiredAndLiabilitiesAssumedDetails" id="DisclosureBusinessCombinationsScheduleOfConsiderationPaidAndTheFairValueOfAssetsAcquiredAndLiabilitiesAssumedDetails">
        <link:definition>995877 - Disclosure - Business Combinations - Schedule of Consideration Paid and The Fair Value of Assets Acquired, and Liabilities Assumed (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfFairValueOfAcquiredIdentifiableIntangibleAssetsDetails" id="DisclosureBusinessCombinationsScheduleOfFairValueOfAcquiredIdentifiableIntangibleAssetsDetails">
        <link:definition>995887 - Disclosure - Business Combinations - Schedule of Fair Value of Acquired Identifiable Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfNetImpactOfAcquisitionDetails" id="DisclosureBusinessCombinationsScheduleOfNetImpactOfAcquisitionDetails">
        <link:definition>995897 - Disclosure - Business Combinations - Schedule of Net Impact of Acquisition (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfUnauditedProFormaInformationDetails" id="DisclosureBusinessCombinationsScheduleOfUnauditedProFormaInformationDetails">
        <link:definition>995907 - Disclosure - Business Combinations - Schedule of Unaudited Pro Forma Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDisaggregatedRevenueDetails" id="DisclosureRevenueScheduleOfDisaggregatedRevenueDetails">
        <link:definition>995917 - Disclosure - Revenue - Schedule of Disaggregated Revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfContractAssetsDetails" id="DisclosureRevenueScheduleOfContractAssetsDetails">
        <link:definition>995927 - Disclosure - Revenue - Schedule of Contract Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueAdditionalInformationDetails" id="DisclosureRevenueAdditionalInformationDetails">
        <link:definition>995937 - Disclosure - Revenue (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDeferredRevenueDetails" id="DisclosureRevenueScheduleOfDeferredRevenueDetails">
        <link:definition>995947 - Disclosure - Revenue - Schedule of Deferred Revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails" id="DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails">
        <link:definition>995957 - Disclosure - Property and Equipment, Net - Schedule of Property and Equipment, Net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetAdditionalInformationDetails" id="DisclosurePropertyAndEquipmentNetAdditionalInformationDetails">
        <link:definition>995967 - Disclosure - Property and Equipment, Net (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpensesDetails" id="DisclosureAccruedExpensesDetails">
        <link:definition>995977 - Disclosure - Accrued Expenses (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfIntangibleAssetsGrossCarryingAmountAndAccumulatedAmortizationDetails" id="DisclosureIntangibleAssetsNetScheduleOfIntangibleAssetsGrossCarryingAmountAndAccumulatedAmortizationDetails">
        <link:definition>995987 - Disclosure - Intangible Assets, Net - Schedule of intangible assets gross carrying amount and accumulated amortization (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfFutureAmortizationExpenseOnIntangibleAssetsDetails" id="DisclosureIntangibleAssetsNetScheduleOfFutureAmortizationExpenseOnIntangibleAssetsDetails">
        <link:definition>995997 - Disclosure - Intangible Assets, Net - Schedule of future amortization expense on intangible assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetAdditionalInformationDetails" id="DisclosureIntangibleAssetsNetAdditionalInformationDetails">
        <link:definition>996007 - Disclosure - Intangible Assets, Net (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillScheduleOfChangesInTheCarryingAmountOfGoodwillDetails" id="DisclosureGoodwillScheduleOfChangesInTheCarryingAmountOfGoodwillDetails">
        <link:definition>996017 - Disclosure - Goodwill - Schedule of Changes in the Carrying Amount of Goodwill (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillAdditionalInformationDetails" id="DisclosureGoodwillAdditionalInformationDetails">
        <link:definition>996027 - Disclosure - Goodwill (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementAdditionalInformationDetails" id="DisclosureFairValueMeasurementAdditionalInformationDetails">
        <link:definition>996037 - Disclosure - Fair Value Measurement (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementPresentTheKeyInputsAppliedInTheValuationsWarrantsDetails" id="DisclosureFairValueMeasurementPresentTheKeyInputsAppliedInTheValuationsWarrantsDetails">
        <link:definition>996047 - Disclosure - Fair Value Measurement - Present the Key Inputs Applied In the Valuations Warrants (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfPresentsTheKeyInputsAppliedInTheValuationsDetails" id="DisclosureFairValueMeasurementScheduleOfPresentsTheKeyInputsAppliedInTheValuationsDetails">
        <link:definition>996057 - Disclosure - Fair Value Measurement - Schedule of Presents the Key Inputs Applied in the Valuations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfCarryingValueOfTheTermLoansApproximatedTheirEstimatedFairValueDetails" id="DisclosureFairValueMeasurementScheduleOfCarryingValueOfTheTermLoansApproximatedTheirEstimatedFairValueDetails">
        <link:definition>996067 - Disclosure - Fair Value Measurement - Schedule of Carrying Value of The Term Loans Approximated Their Estimated Fair Value (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfLeaseExpenseDetails" id="DisclosureLeasesScheduleOfLeaseExpenseDetails">
        <link:definition>996077 - Disclosure - Leases - Schedule of Lease Expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfOperatingAndFinanceLeaseRightofuseAssetsAndLiabilitiesDetails" id="DisclosureLeasesScheduleOfOperatingAndFinanceLeaseRightofuseAssetsAndLiabilitiesDetails">
        <link:definition>996087 - Disclosure - Leases - Schedule of Operating and Finance Lease Right-of-use Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfLeaseTermAndDiscountRateDetails" id="DisclosureLeasesScheduleOfLeaseTermAndDiscountRateDetails">
        <link:definition>996097 - Disclosure - Leases - Schedule of Lease Term and Discount Rate (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentsDetails" id="DisclosureLeasesScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentsDetails">
        <link:definition>996107 - Disclosure - Leases - Schedule of Reconciles the Undiscounted Future Minimum Lease Payments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesAdditionalInformationDetails" id="DisclosureLeasesAdditionalInformationDetails">
        <link:definition>996117 - Disclosure - Leases (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAdditionalInformationDetails" id="DisclosureNotesPayableAdditionalInformationDetails">
        <link:definition>996127 - Disclosure - Notes Payable (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtDetails" id="DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtDetails">
        <link:definition>996137 - Disclosure - Notes Payable - Net Carrying Amount of the Company's outstanding debt (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtParentheticalDetails" id="DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtParentheticalDetails">
        <link:definition>996147 - Disclosure - Notes Payable - Net Carrying Amount of the Company's outstanding debt (Parenthetical) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableInterestExpenseRelatedToTheTermLoansDetails" id="DisclosureNotesPayableInterestExpenseRelatedToTheTermLoansDetails">
        <link:definition>996157 - Disclosure - Notes Payable - Interest Expense Related to the Term Loans (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAndWarrantsPrincipalPaymentsUnderTheTermLoansDetails" id="DisclosureNotesPayableAndWarrantsPrincipalPaymentsUnderTheTermLoansDetails">
        <link:definition>996167 - Disclosure - Notes Payable and Warrants - Principal Payments Under the Term Loans (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayablePrincipalPaymentsUnderTheTermLoansParentheticalDetails" id="DisclosureNotesPayablePrincipalPaymentsUnderTheTermLoansParentheticalDetails">
        <link:definition>996177 - Disclosure - Notes Payable - Principal Payments Under the Term Loans (Parenthetical) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesDetails" id="DisclosureCommitmentsAndContingenciesDetails">
        <link:definition>996187 - Disclosure - Commitments and Contingencies (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockDetails" id="DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockDetails">
        <link:definition>996197 - Disclosure - Stockholders' Equity (Deficit) and Redeemable Convertible Preferred Stock (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockAdditionalInformationDetails" id="DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockAdditionalInformationDetails">
        <link:definition>996207 - Disclosure - Stockholders' Equity (Deficit) and Redeemable Convertible Preferred Stock (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationAdditionalInformationDetails" id="DisclosureStockbasedCompensationAdditionalInformationDetails">
        <link:definition>996217 - Disclosure - Stock-Based Compensation (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfRestrictedStockActivityDetails" id="DisclosureStockbasedCompensationSummaryOfRestrictedStockActivityDetails">
        <link:definition>996227 - Disclosure - Stock-Based Compensation - Summary of restricted stock activity (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfStockOptionActivityDetails" id="DisclosureStockbasedCompensationSummaryOfStockOptionActivityDetails">
        <link:definition>996237 - Disclosure - Stock-Based Compensation - Summary of stock option activity (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfWeightedAverageAssumptionsUsedInTheEstimatedGrantDateFairValueCalculationsDetails" id="DisclosureStockbasedCompensationScheduleOfWeightedAverageAssumptionsUsedInTheEstimatedGrantDateFairValueCalculationsDetails">
        <link:definition>996247 - Disclosure - Stock-Based Compensation - Schedule of weighted average assumptions used in the estimated grant date fair value calculations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfStockbasedCompensationExpenseRelatedToOptionsAndRsusDetails" id="DisclosureStockbasedCompensationScheduleOfStockbasedCompensationExpenseRelatedToOptionsAndRsusDetails">
        <link:definition>996257 - Disclosure - Stock-Based Compensation - Schedule of stock-based compensation expense related to options and RSUs (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeBeforeIncomeTaxDetails" id="DisclosureIncomeTaxesScheduleOfIncomeBeforeIncomeTaxDetails">
        <link:definition>996267 - Disclosure - Income Taxes - Schedule of Income before Income Tax (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeTaxExpenseDetails" id="DisclosureIncomeTaxesScheduleOfIncomeTaxExpenseDetails">
        <link:definition>996277 - Disclosure - Income Taxes - Schedule of Income Tax Expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails" id="DisclosureIncomeTaxesAdditionalInformationDetails">
        <link:definition>996287 - Disclosure - Income Taxes (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfEffectiveIncomeTaxReconciliationDetails" id="DisclosureIncomeTaxesScheduleOfEffectiveIncomeTaxReconciliationDetails">
        <link:definition>996297 - Disclosure - Income Taxes - Schedule of Effective Income Tax Reconciliation (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfProvisionForEffectiveIncomeTaxReconciliationDetails" id="DisclosureIncomeTaxesScheduleOfProvisionForEffectiveIncomeTaxReconciliationDetails">
        <link:definition>996307 - Disclosure - Income Taxes - Schedule of Provision for Effective Income Tax Reconciliation (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxPaidByJurisdicationDetails" id="DisclosureIncomeTaxesSummaryOfIncomeTaxPaidByJurisdicationDetails">
        <link:definition>996317 - Disclosure - Income Taxes - Summary of Income Tax Paid by Jurisdication (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfCarryforwardsThatGaveRiseToSignificantPortionsOfDeferredTaxesDetails" id="DisclosureIncomeTaxesSummaryOfCarryforwardsThatGaveRiseToSignificantPortionsOfDeferredTaxesDetails">
        <link:definition>996327 - Disclosure - Income Taxes - Summary of Carryforwards That Gave Rise to Significant Portions of Deferred Taxes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfUnrecognizedTaxBenefitsDetails" id="DisclosureIncomeTaxesSummaryOfUnrecognizedTaxBenefitsDetails">
        <link:definition>996337 - Disclosure - Income Taxes - Summary of Unrecognized Tax Benefits (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails" id="DisclosureRelatedPartyTransactionsAdditionalInformationDetails">
        <link:definition>996347 - Disclosure - Related Party Transactions (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsScheduleOfRelatedPartyTransactionsDetails" id="DisclosureRelatedPartyTransactionsScheduleOfRelatedPartyTransactionsDetails">
        <link:definition>996357 - Disclosure - Related Party Transactions - Schedule of Related Party Transactions (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails" id="DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails">
        <link:definition>996367 - Disclosure - Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetails" id="DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetails">
        <link:definition>996377 - Disclosure - Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationAdditionalInformationDetails" id="DisclosureSegmentAndGeographicalInformationAdditionalInformationDetails">
        <link:definition>996387 - Disclosure - Segment and Geographical Information (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationScheduleOfSegmentReportingInformationBySegmentDetails" id="DisclosureSegmentAndGeographicalInformationScheduleOfSegmentReportingInformationBySegmentDetails">
        <link:definition>996397 - Disclosure - Segment and Geographical Information - Schedule of Segment Reporting Information, by Segment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails" id="DisclosureSubsequentEventsAdditionalInformationDetails">
        <link:definition>996407 - Disclosure - Subsequent Events (Additional Information) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbase id="lnk">
        <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple"/>
        <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple"/>
        <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple"/>
        <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple"/>
        <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple"/>
        <link:arcroleRef arcroleURI="http://www.esma.europa.eu/xbrl/esef/arcrole/wider-narrower" xlink:href="http://www.xbrl.org/lrr/arcrole/esma-arcrole-2018-11-21.xsd#wider-narrower" xlink:type="simple"/>
        <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/Cover" xlink:href="fly-20251231.xsd#Cover" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheets" xlink:href="fly-20251231.xsd#StatementConsolidatedBalanceSheets" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" xlink:href="fly-20251231.xsd#StatementConsolidatedBalanceSheetsParenthetical" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss" xlink:href="fly-20251231.xsd#StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfConvertiblePreferredStockAndStockholdersEquityDeficit" xlink:href="fly-20251231.xsd#StatementConsolidatedStatementsOfConvertiblePreferredStockAndStockholdersEquityDeficit" xlink:type="simple"/>
        <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:href="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd#IndividualsOnly" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance" xlink:href="fly-20251231.xsd#DisclosureCybersecurityRiskManagementStrategyAndGovernance" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsTables" xlink:href="fly-20251231.xsd#DisclosureBusinessCombinationsTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesTables" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentationDetails" xlink:href="fly-20251231.xsd#DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfPropertyAndEquipmentUsefulLivesDetails" xlink:href="fly-20251231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfPropertyAndEquipmentUsefulLivesDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfConcentrationOfCreditRiskDetails" xlink:href="fly-20251231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfConcentrationOfCreditRiskDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureBusinessCombinationsAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfConsiderationPaidAndTheFairValueOfAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:href="fly-20251231.xsd#DisclosureBusinessCombinationsScheduleOfConsiderationPaidAndTheFairValueOfAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfFairValueOfAcquiredIdentifiableIntangibleAssetsDetails" xlink:href="fly-20251231.xsd#DisclosureBusinessCombinationsScheduleOfFairValueOfAcquiredIdentifiableIntangibleAssetsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfNetImpactOfAcquisitionDetails" xlink:href="fly-20251231.xsd#DisclosureBusinessCombinationsScheduleOfNetImpactOfAcquisitionDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfUnauditedProFormaInformationDetails" xlink:href="fly-20251231.xsd#DisclosureBusinessCombinationsScheduleOfUnauditedProFormaInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDisaggregatedRevenueDetails" xlink:href="fly-20251231.xsd#DisclosureRevenueScheduleOfDisaggregatedRevenueDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDeferredRevenueDetails" xlink:href="fly-20251231.xsd#DisclosureRevenueScheduleOfDeferredRevenueDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails" xlink:href="fly-20251231.xsd#DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfIntangibleAssetsGrossCarryingAmountAndAccumulatedAmortizationDetails" xlink:href="fly-20251231.xsd#DisclosureIntangibleAssetsNetScheduleOfIntangibleAssetsGrossCarryingAmountAndAccumulatedAmortizationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureFairValueMeasurementAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementPresentTheKeyInputsAppliedInTheValuationsWarrantsDetails" xlink:href="fly-20251231.xsd#DisclosureFairValueMeasurementPresentTheKeyInputsAppliedInTheValuationsWarrantsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfPresentsTheKeyInputsAppliedInTheValuationsDetails" xlink:href="fly-20251231.xsd#DisclosureFairValueMeasurementScheduleOfPresentsTheKeyInputsAppliedInTheValuationsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfCarryingValueOfTheTermLoansApproximatedTheirEstimatedFairValueDetails" xlink:href="fly-20251231.xsd#DisclosureFairValueMeasurementScheduleOfCarryingValueOfTheTermLoansApproximatedTheirEstimatedFairValueDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureLeasesAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureNotesPayableAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtDetails" xlink:href="fly-20251231.xsd#DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtParentheticalDetails" xlink:href="fly-20251231.xsd#DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtParentheticalDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAndWarrantsPrincipalPaymentsUnderTheTermLoansDetails" xlink:href="fly-20251231.xsd#DisclosureNotesPayableAndWarrantsPrincipalPaymentsUnderTheTermLoansDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayablePrincipalPaymentsUnderTheTermLoansParentheticalDetails" xlink:href="fly-20251231.xsd#DisclosureNotesPayablePrincipalPaymentsUnderTheTermLoansParentheticalDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesDetails" xlink:href="fly-20251231.xsd#DisclosureCommitmentsAndContingenciesDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockDetails" xlink:href="fly-20251231.xsd#DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureStockbasedCompensationAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfRestrictedStockActivityDetails" xlink:href="fly-20251231.xsd#DisclosureStockbasedCompensationSummaryOfRestrictedStockActivityDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfStockOptionActivityDetails" xlink:href="fly-20251231.xsd#DisclosureStockbasedCompensationSummaryOfStockOptionActivityDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfWeightedAverageAssumptionsUsedInTheEstimatedGrantDateFairValueCalculationsDetails" xlink:href="fly-20251231.xsd#DisclosureStockbasedCompensationScheduleOfWeightedAverageAssumptionsUsedInTheEstimatedGrantDateFairValueCalculationsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfStockbasedCompensationExpenseRelatedToOptionsAndRsusDetails" xlink:href="fly-20251231.xsd#DisclosureStockbasedCompensationScheduleOfStockbasedCompensationExpenseRelatedToOptionsAndRsusDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfEffectiveIncomeTaxReconciliationDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesScheduleOfEffectiveIncomeTaxReconciliationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxPaidByJurisdicationDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesSummaryOfIncomeTaxPaidByJurisdicationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureRelatedPartyTransactionsAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsScheduleOfRelatedPartyTransactionsDetails" xlink:href="fly-20251231.xsd#DisclosureRelatedPartyTransactionsScheduleOfRelatedPartyTransactionsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails" xlink:href="fly-20251231.xsd#DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetails" xlink:href="fly-20251231.xsd#DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureSegmentAndGeographicalInformationAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationScheduleOfSegmentReportingInformationBySegmentDetails" xlink:href="fly-20251231.xsd#DisclosureSegmentAndGeographicalInformationScheduleOfSegmentReportingInformationBySegmentDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureSubsequentEventsAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.xsd#eedm" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows" xlink:href="fly-20251231.xsd#StatementConsolidatedStatementsOfCashFlows" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpensesDetails" xlink:href="fly-20251231.xsd#DisclosureAccruedExpensesDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfFutureAmortizationExpenseOnIntangibleAssetsDetails" xlink:href="fly-20251231.xsd#DisclosureIntangibleAssetsNetScheduleOfFutureAmortizationExpenseOnIntangibleAssetsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentsDetails" xlink:href="fly-20251231.xsd#DisclosureLeasesScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeBeforeIncomeTaxDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesScheduleOfIncomeBeforeIncomeTaxDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeTaxExpenseDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesScheduleOfIncomeTaxExpenseDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfProvisionForEffectiveIncomeTaxReconciliationDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesScheduleOfProvisionForEffectiveIncomeTaxReconciliationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel" xlink:type="simple"/>
        <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTerseLabel" xlink:type="simple"/>
        <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTotalLabel" xlink:type="simple"/>
        <link:roleRef roleURI="http://www.xbrl.org/2009/role/netLabel" xlink:href="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd#netLabel" xlink:type="simple"/>
        <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements" xlink:href="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd#InsiderTradingArrangements" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentation" xlink:href="fly-20251231.xsd#DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentation" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies1" xlink:href="fly-20251231.xsd#DisclosureSummaryOfSignificantAccountingPolicies1" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinations" xlink:href="fly-20251231.xsd#DisclosureBusinessCombinations" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenue" xlink:href="fly-20251231.xsd#DisclosureRevenue" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNet" xlink:href="fly-20251231.xsd#DisclosurePropertyAndEquipmentNet" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpenses" xlink:href="fly-20251231.xsd#DisclosureAccruedExpenses" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNet" xlink:href="fly-20251231.xsd#DisclosureIntangibleAssetsNet" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwill" xlink:href="fly-20251231.xsd#DisclosureGoodwill" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurement" xlink:href="fly-20251231.xsd#DisclosureFairValueMeasurement" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeases" xlink:href="fly-20251231.xsd#DisclosureLeases" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayable1" xlink:href="fly-20251231.xsd#DisclosureNotesPayable1" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingencies" xlink:href="fly-20251231.xsd#DisclosureCommitmentsAndContingencies" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStock1" xlink:href="fly-20251231.xsd#DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStock1" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensation" xlink:href="fly-20251231.xsd#DisclosureStockbasedCompensation" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxes" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxes" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactions" xlink:href="fly-20251231.xsd#DisclosureRelatedPartyTransactions" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShare" xlink:href="fly-20251231.xsd#DisclosureNetLossPerShare" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformation1" xlink:href="fly-20251231.xsd#DisclosureSegmentAndGeographicalInformation1" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSubsequentEvents1" xlink:href="fly-20251231.xsd#DisclosureSubsequentEvents1" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies" xlink:href="fly-20251231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesPolicies" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables" xlink:href="fly-20251231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueTables" xlink:href="fly-20251231.xsd#DisclosureRevenueTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetTables" xlink:href="fly-20251231.xsd#DisclosurePropertyAndEquipmentNetTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpensesTables" xlink:href="fly-20251231.xsd#DisclosureAccruedExpensesTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetTables" xlink:href="fly-20251231.xsd#DisclosureIntangibleAssetsNetTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillTables" xlink:href="fly-20251231.xsd#DisclosureGoodwillTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementTables" xlink:href="fly-20251231.xsd#DisclosureFairValueMeasurementTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesTables" xlink:href="fly-20251231.xsd#DisclosureLeasesTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableTables" xlink:href="fly-20251231.xsd#DisclosureNotesPayableTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersDeficitAndRedeemableConvertiblePreferredStockTables" xlink:href="fly-20251231.xsd#DisclosureStockholdersDeficitAndRedeemableConvertiblePreferredStockTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationTables" xlink:href="fly-20251231.xsd#DisclosureStockbasedCompensationTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsTables" xlink:href="fly-20251231.xsd#DisclosureRelatedPartyTransactionsTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareTables" xlink:href="fly-20251231.xsd#DisclosureNetLossPerShareTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationTables" xlink:href="fly-20251231.xsd#DisclosureSegmentAndGeographicalInformationTables" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfContractAssetsDetails" xlink:href="fly-20251231.xsd#DisclosureRevenueScheduleOfContractAssetsDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureRevenueAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosurePropertyAndEquipmentNetAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureIntangibleAssetsNetAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillScheduleOfChangesInTheCarryingAmountOfGoodwillDetails" xlink:href="fly-20251231.xsd#DisclosureGoodwillScheduleOfChangesInTheCarryingAmountOfGoodwillDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillAdditionalInformationDetails" xlink:href="fly-20251231.xsd#DisclosureGoodwillAdditionalInformationDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfLeaseExpenseDetails" xlink:href="fly-20251231.xsd#DisclosureLeasesScheduleOfLeaseExpenseDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfOperatingAndFinanceLeaseRightofuseAssetsAndLiabilitiesDetails" xlink:href="fly-20251231.xsd#DisclosureLeasesScheduleOfOperatingAndFinanceLeaseRightofuseAssetsAndLiabilitiesDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfLeaseTermAndDiscountRateDetails" xlink:href="fly-20251231.xsd#DisclosureLeasesScheduleOfLeaseTermAndDiscountRateDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableInterestExpenseRelatedToTheTermLoansDetails" xlink:href="fly-20251231.xsd#DisclosureNotesPayableInterestExpenseRelatedToTheTermLoansDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfCarryforwardsThatGaveRiseToSignificantPortionsOfDeferredTaxesDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesSummaryOfCarryforwardsThatGaveRiseToSignificantPortionsOfDeferredTaxesDetails" xlink:type="simple"/>
        <link:roleRef roleURI="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfUnrecognizedTaxBenefitsDetails" xlink:href="fly-20251231.xsd#DisclosureIncomeTaxesSummaryOfUnrecognizedTaxBenefitsDetails" xlink:type="simple"/>
        <link:labelLink xlink:role="http://www.xbrl.org/2003/role/link" xlink:title="labelLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="us-gaap_SoftwareDevelopmentMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AggregateOfNumberOfWarrantsToPurchase" xlink:label="fly_AggregateOfNumberOfWarrantsToPurchase"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability" xlink:label="us-gaap_FinanceLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsGrossAbstract" xlink:label="us-gaap_DeferredTaxAssetsGrossAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TimeDepositsMember" xlink:label="fly_TimeDepositsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeemedSharesIssuedPricePerShare" xlink:label="fly_DeemedSharesIssuedPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AverageValuePerUnitAsPerMonteCarloSimulations" xlink:label="fly_AverageValuePerUnitAsPerMonteCarloSimulations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" xlink:label="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="us-gaap_DeferredTaxAssetsNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SMINoteMember" xlink:label="fly_SMINoteMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DiscountForLackOfMarketability" xlink:label="fly_DiscountForLackOfMarketability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfPreferredStockDividend" xlink:label="fly_IssuanceOfPreferredStockDividend"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationIncurredCost" xlink:label="fly_BusinessCombinationIncurredCost"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:label="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxUncertaintiesAbstract" xlink:label="us-gaap_IncomeTaxUncertaintiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockVotingRights" xlink:label="us-gaap_PreferredStockVotingRights"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerAbstract" xlink:label="us-gaap_RevenueFromContractWithCustomerAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SecuredOverFinancingRateMember" xlink:label="fly_SecuredOverFinancingRateMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligation" xlink:label="us-gaap_ContractualObligation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantsMember" xlink:label="fly_SeriesJWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:label="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfShareSold" xlink:label="fly_NumberOfShareSold"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TaxReconciliationNotRequired" xlink:label="fly_TaxReconciliationNotRequired"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Rule10B51ArrModifiedFlag" xlink:label="fly_Rule10B51ArrModifiedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashNoncurrent" xlink:label="us-gaap_RestrictedCashNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PricePerSquareFoot" xlink:label="fly_PricePerSquareFoot"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract" xlink:label="us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansHeldForSaleMaturityDate" xlink:label="us-gaap_LoansHeldForSaleMaturityDate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" xlink:label="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember" xlink:label="us-gaap_VehiclesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PayablesAndAccrualsAbstract" xlink:label="us-gaap_PayablesAndAccrualsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PropertyAndEquipmentAdditionsInAccountsPayable" xlink:label="fly_PropertyAndEquipmentAdditionsInAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_UnauditedProFormaInformationMember" xlink:label="fly_UnauditedProFormaInformationMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantsMember" xlink:label="fly_CommonStockWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="us-gaap_OperatingLossCarryforwardsTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag" xlink:label="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExtinguishmentOfDebtAmount" xlink:label="us-gaap_ExtinguishmentOfDebtAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems" xlink:label="us-gaap_SubsequentEventLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementThirdPartyEngagedFlag" xlink:label="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentsIncorporatedByReferenceTextBlock" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="us-gaap_IncomeTaxAuthorityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCancelableSubscriptionBasedServicesMember" xlink:label="fly_NonCancelableSubscriptionBasedServicesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CumulativeOwnershipPeriod" xlink:label="fly_CumulativeOwnershipPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes" xlink:label="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantMember" xlink:label="fly_SeriesJWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember" xlink:label="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember" xlink:label="us-gaap_RelatedPartyMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConversionOfStockAmountConverted1" xlink:label="us-gaap_ConversionOfStockAmountConverted1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ShareRepurchaseProgramAxis" xlink:label="srt_ShareRepurchaseProgramAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CurrencyAxis" xlink:label="srt_CurrencyAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FireflyMember" xlink:label="fly_FireflyMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain" xlink:label="us-gaap_VestingDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="us-gaap_DisaggregationOfRevenueTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionNameDomain" xlink:label="us-gaap_SaleLeasebackTransactionNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceTable" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="us-gaap_TrademarksAndTradeNamesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeFinanceLeaseDescriptionAbstract" xlink:label="us-gaap_LesseeFinanceLeaseDescriptionAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssued1" xlink:label="us-gaap_StockIssued1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpecificAdditionalInterestRate" xlink:label="fly_SpecificAdditionalInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember" xlink:label="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommodityContractAssetCurrent" xlink:label="us-gaap_CommodityContractAssetCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:label="us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidFederalAfterRefundReceived" xlink:label="us-gaap_IncomeTaxPaidFederalAfterRefundReceived"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsOnNotesPayable" xlink:label="fly_PaymentsOnNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OptionIndexedToIssuersEquityShares" xlink:label="us-gaap_OptionIndexedToIssuersEquityShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DomesticCountryMember" xlink:label="us-gaap_DomesticCountryMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ShareRepurchaseProgramDomain" xlink:label="srt_ShareRepurchaseProgramDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InterestExpenseContractual" xlink:label="fly_InterestExpenseContractual"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageFairValuePerWarrant" xlink:label="fly_WeightedAverageFairValuePerWarrant"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAveragePricePerShare" xlink:label="fly_WeightedAveragePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTable" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain" xlink:label="srt_ConsolidationItemsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsFromRepaymentOfEmployeeNote" xlink:label="fly_ProceedsFromRepaymentOfEmployeeNote"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IncreaseDecreaseAccountsPayableRelatedParties" xlink:label="fly_IncreaseDecreaseAccountsPayableRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsLineItems" xlink:label="us-gaap_OtherCommitmentsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccretionExpense" xlink:label="us-gaap_AccretionExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="dei_EntityWellKnownSeasonedIssuer"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonAccruingOrignalIssuePricePerShare" xlink:label="fly_PercentageOfNonAccruingOrignalIssuePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiability" xlink:label="us-gaap_ContractWithCustomerLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems" xlink:label="us-gaap_LesseeLeaseDescriptionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LeaseRemainingLeaseTerm" xlink:label="fly_LeaseRemainingLeaseTerm"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestExpense" xlink:label="us-gaap_FinanceLeaseInterestExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInterestExpense" xlink:label="fly_Non-CashInterestExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonRule10B51ArrModifiedFlag" xlink:label="fly_NonRule10B51ArrModifiedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValue" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskRoleOfManagementTextBlock" xlink:label="cyd_CybersecurityRiskRoleOfManagementTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardAmount" xlink:label="us-gaap_TaxCreditCarryforwardAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BelcanLLCMember" xlink:label="fly_BelcanLLCMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingFairValue" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="us-gaap_DeferredIncomeTaxLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandSeventeenEquityIncentivePlanMember" xlink:label="fly_TwoThousandSeventeenEquityIncentivePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" xlink:label="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy" xlink:label="us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CumulativeOwnershipPercentage" xlink:label="fly_CumulativeOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IncreaseDecreaseInAdvancedPayments" xlink:label="fly_IncreaseDecreaseInAdvancedPayments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="us-gaap_DeferredTaxAssetsGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:label="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermLoanMember" xlink:label="fly_TermLoanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType" xlink:label="dei_DocumentType"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="us-gaap_IncomeTaxesPaidNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromCommissionsReceived" xlink:label="us-gaap_ProceedsFromCommissionsReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PropertyAndEquipmentUsefulLivesTableTextBlock" xlink:label="fly_PropertyAndEquipmentUsefulLivesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:label="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FollowOnOpportunitiesMember" xlink:label="fly_FollowOnOpportunitiesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueAxis" xlink:label="us-gaap_ValuationTechniqueAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeOperating" xlink:label="us-gaap_InterestIncomeOperating"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerOneMember" xlink:label="fly_CustomerOneMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractorsAndOutsideServices" xlink:label="fly_ContractorsAndOutsideServices"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2025/currency-2025.xsd#currency_USD" xlink:label="currency_USD"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="us-gaap_OperatingCostsAndExpenses"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PreferredStockIssuedAtAPurchasePrice" xlink:label="fly_PreferredStockIssuedAtAPurchasePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IPOScenarioMember" xlink:label="fly_IPOScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExitFeePercentage" xlink:label="fly_ExitFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesSeed-1PreferredStockMember" xlink:label="fly_ConvertibleSeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAbstract" xlink:label="us-gaap_LiabilitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BaseRateMember" xlink:label="us-gaap_BaseRateMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:label="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeInRight-Of-UseAssets" xlink:label="fly_ChangeInRight-Of-UseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetPurchase" xlink:label="us-gaap_ContractWithCustomerAssetPurchase"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFinStmtErrorCorrectionFlag" xlink:label="dei_DocumentFinStmtErrorCorrectionFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CallOptionMember" xlink:label="us-gaap_CallOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationCancellationFeePercentage" xlink:label="fly_ContractualObligationCancellationFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ITRelatedEquipmentMember" xlink:label="fly_ITRelatedEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BlackScholesMertonModelMember" xlink:label="us-gaap_BlackScholesMertonModelMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfRelatedPartyDebt" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock" xlink:label="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeOfControlScenarioMember" xlink:label="fly_ChangeOfControlScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableOtherCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableOtherCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MajoritySponsorMember" xlink:label="fly_MajoritySponsorMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="srt_EquityMethodInvesteeNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain" xlink:label="us-gaap_AssetAcquisitionDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CostOfSalePolicyTextBlock" xlink:label="fly_CostOfSalePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConversionOfStockSharesConverted1" xlink:label="us-gaap_ConversionOfStockSharesConverted1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember" xlink:label="us-gaap_AccountsReceivableMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock" xlink:label="us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockOptionMember" xlink:label="us-gaap_StockOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DavidWheelerMember" xlink:label="fly_DavidWheelerMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SwinglineLoans" xlink:label="fly_SwinglineLoans"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="us-gaap_DeferredRevenueCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_GainOnSettlementOfContingentLiabilities" xlink:label="fly_GainOnSettlementOfContingentLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerFourMember" xlink:label="fly_CustomerFourMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="us-gaap_OperatingLossCarryforwardsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantExercisePriceDecrease" xlink:label="us-gaap_WarrantExercisePriceDecrease"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebt" xlink:label="us-gaap_InterestExpenseDebt"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerTwoMember" xlink:label="fly_CustomerTwoMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsDomain" xlink:label="us-gaap_OtherCommitmentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="us-gaap_StateAndLocalJurisdictionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain" xlink:label="srt_NameOfMajorCustomerDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashMember" xlink:label="us-gaap_CashMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CashProceeds" xlink:label="fly_CashProceeds"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsTable" xlink:label="us-gaap_OtherCommitmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCashInterestIncome" xlink:label="fly_NonCashInterestIncome"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeInFairValueOfWarrantLiability" xlink:label="fly_ChangeInFairValueOfWarrantLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PurchaseAccountingMember" xlink:label="fly_PurchaseAccountingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermBLoansMember" xlink:label="fly_TermBLoansMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:label="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NotesPayableNoncurrent-RelatedParties" xlink:label="fly_NotesPayableNoncurrent-RelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsPolicy" xlink:label="us-gaap_BusinessCombinationsPolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsPerShareDeclared" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantsToPurchaseAnAggregate" xlink:label="fly_WarrantsToPurchaseAnAggregate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Weighted-AverageRemainingContractualTermUnvested" xlink:label="fly_Weighted-AverageRemainingContractualTermUnvested"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockWarrantsMember" xlink:label="fly_SeriesJPreferredStockWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeed-1PreferredStockMember" xlink:label="fly_SeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-2PreferredStockMember" xlink:label="fly_SeriesD-2PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonRecourseEmployeeLoans" xlink:label="fly_NonRecourseEmployeeLoans"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="us-gaap_OperatingLossCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseNoncurrent" xlink:label="us-gaap_PrepaidExpenseNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="us-gaap_RestrictedCashAndCashEquivalents"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashEquivalentsCurrent" xlink:label="us-gaap_RestrictedCashEquivalentsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeasesPolicyTextBlock" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsToAcquireTimeDeposits" xlink:label="fly_PaymentsToAcquireTimeDeposits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairMarketValueOfSharePercentage" xlink:label="fly_FairMarketValueOfSharePercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_StockIssuedDuringPeriodSharesStockDividend" xlink:label="fly_StockIssuedDuringPeriodSharesStockDividend"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorFirmId" xlink:label="dei_AuditorFirmId"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityReverseStockSplit" xlink:label="us-gaap_StockholdersEquityReverseStockSplit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTextBlock" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredTaxAssetsCapitalizedResearchCosts" xlink:label="fly_DeferredTaxAssetsCapitalizedResearchCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SubordinatedConvertiblePromissoryNoteMember" xlink:label="fly_SubordinatedConvertiblePromissoryNoteMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashCurrent" xlink:label="us-gaap_RestrictedCashCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TestStandsMember" xlink:label="fly_TestStandsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativePremiumPaid" xlink:label="us-gaap_DerivativePremiumPaid"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LeasesTextBlock" xlink:label="fly_LeasesTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleNotesMember" xlink:label="fly_ConvertibleNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" xlink:label="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable" xlink:label="us-gaap_LesseeLeaseDescriptionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageFairValuePerShare" xlink:label="fly_WeightedAverageFairValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonCompoundingRate" xlink:label="fly_PercentageOfNonCompoundingRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LongTermDebtNet" xlink:label="fly_LongTermDebtNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesNoncurrentAbstract" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SharesOutstandingPercentage" xlink:label="fly_SharesOutstandingPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationalAndOfferingCostsExpense" xlink:label="us-gaap_OrganizationalAndOfferingCostsExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementScenarioAxis" xlink:label="srt_StatementScenarioAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" xlink:label="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems" xlink:label="dei_DocumentInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityAbstract" xlink:label="us-gaap_TemporaryEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription" xlink:label="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesLeasingArrangements" xlink:label="us-gaap_DeferredTaxLiabilitiesLeasingArrangements"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPayableCurrentAndNoncurrent" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SaleAndLeasebackTransactionsMember" xlink:label="fly_SaleAndLeasebackTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationTotalConsiderationPaid" xlink:label="fly_BusinessCombinationTotalConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock" xlink:label="us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantsToPurchaseSeriesJPreferredStockMember" xlink:label="fly_WarrantsToPurchaseSeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain" xlink:label="us-gaap_ValuationTechniqueDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="us-gaap_SeriesAPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfDebtInExchangeOfSoftwareLicenses" xlink:label="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="us-gaap_LeaseholdImprovementsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine2" xlink:label="dei_EntityAddressAddressLine2"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="us-gaap_FairValueDisclosuresTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AllowanceForCreditLossesPolicyTextBlock" xlink:label="fly_AllowanceForCreditLossesPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PreferredStockConvertedToCommonSharesMember" xlink:label="fly_PreferredStockConvertedToCommonSharesMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PrepaidAsset" xlink:label="fly_PrepaidAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingOtherItemAmount" xlink:label="us-gaap_SegmentReportingOtherItemAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingMember" xlink:label="us-gaap_BuildingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueOther" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentRepaidPrincipal" xlink:label="us-gaap_DebtInstrumentRepaidPrincipal"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock" xlink:label="us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerMember" xlink:label="fly_CustomerMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FinancingAgreementMember" xlink:label="fly_FinancingAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_GSPrecisionMember" xlink:label="fly_GSPrecisionMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AEIndustrialMember" xlink:label="fly_AEIndustrialMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValuePerShareMarketableSecurity" xlink:label="fly_FairValuePerShareMarketableSecurity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BacklogMember" xlink:label="fly_BacklogMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsAxis" xlink:label="us-gaap_OtherCommitmentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashFDICInsuredAmount" xlink:label="us-gaap_CashFDICInsuredAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementMaximumValueRecognized" xlink:label="fly_ShareBasedCompensationArrangementMaximumValueRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockOutstandingCommonWarrantsExercised" xlink:label="fly_CommonStockOutstandingCommonWarrantsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CompensationRelatedCostsAbstract" xlink:label="us-gaap_CompensationRelatedCostsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteAbstract" xlink:label="us-gaap_StockholdersEquityNoteAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentIncreaseAccruedInterest" xlink:label="us-gaap_DebtInstrumentIncreaseAccruedInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:label="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPaidNet" xlink:label="us-gaap_InterestPaidNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonWarrantsMember" xlink:label="fly_CommonWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_IcfrAuditorAttestationFlag" xlink:label="dei_IcfrAuditorAttestationFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationAsset" xlink:label="us-gaap_BusinessCombinationContingentConsiderationAsset"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantMember" xlink:label="fly_CommonStockWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetRentableArea" xlink:label="us-gaap_NetRentableArea"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NotesPayablePolicyTextBlock" xlink:label="fly_NotesPayablePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableConvertiblePreferredStockMember" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ScheduleOfRedeemableConvertiblePreferredStock" xlink:label="fly_ScheduleOfRedeemableConvertiblePreferredStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingAxis" xlink:label="us-gaap_VestingAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValueInputsDiscountRate" xlink:label="fly_FairValueInputsDiscountRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedeemableConvertiblePreferredStocksMember" xlink:label="fly_RedeemableConvertiblePreferredStocksMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCancelableServiceContractCommitmentsMember" xlink:label="fly_NonCancelableServiceContractCommitmentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueOptionPricingModelMember" xlink:label="us-gaap_ValuationTechniqueOptionPricingModelMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2025/currency-2025.xsd#currency_AllCurrenciesDomain" xlink:label="currency_AllCurrenciesDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCash" xlink:label="us-gaap_RestrictedCash"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember" xlink:label="us-gaap_RestrictedStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueArrangementByTypeTable" xlink:label="us-gaap_DeferredRevenueArrangementByTypeTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis" xlink:label="us-gaap_VariableRateAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AdvancedPaymentsPolicyTextBlock" xlink:label="fly_AdvancedPaymentsPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerThreeMember" xlink:label="fly_CustomerThreeMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfReservedSharesIncreaseApproximately" xlink:label="fly_NumberOfReservedSharesIncreaseApproximately"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InternalUseSoftwareMember" xlink:label="fly_InternalUseSoftwareMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CoverAbstract" xlink:label="dei_CoverAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:label="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Weighted-AverageDiscountRate" xlink:label="fly_Weighted-AverageDiscountRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredRevenuePolicyTextBlock" xlink:label="fly_DeferredRevenuePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock" xlink:label="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalLeaseObligationsIncurred" xlink:label="us-gaap_CapitalLeaseObligationsIncurred"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember" xlink:label="us-gaap_SalesRevenueNetMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="srt_ScenarioUnspecifiedDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RPMCallOptionMember" xlink:label="fly_RPMCallOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EquityMethodInvestmentMember" xlink:label="fly_EquityMethodInvestmentMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LaunchRevenueMember" xlink:label="fly_LaunchRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:label="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LesseeOperatingTotalLeaseLiability" xlink:label="fly_LesseeOperatingTotalLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityLiquidationPreference" xlink:label="us-gaap_TemporaryEquityLiquidationPreference"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationNumberOfLaunches" xlink:label="fly_ContractualObligationNumberOfLaunches"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable" xlink:label="us-gaap_SubsequentEventTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract" xlink:label="us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OperatingLeaseRight-Of-UseAssetDecreased" xlink:label="fly_OperatingLeaseRight-Of-UseAssetDecreased"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:label="us-gaap_DeferredCostsCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="us-gaap_DeferredTaxAssetsOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:label="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesOther" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="us-gaap_GainLossOnDispositionOfAssets1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationCashConsiderationPaid" xlink:label="fly_BusinessCombinationCashConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesCPurchaseAgreementMember" xlink:label="fly_SeriesCPurchaseAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="us-gaap_NonrecurringAdjustmentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:label="us-gaap_RevenueRemainingPerformanceObligation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesIntegratedFlag" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments" xlink:label="us-gaap_ShortTermInvestments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsFromNotesPayableRelatedParties" xlink:label="fly_ProceedsFromNotesPayableRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockMember" xlink:label="us-gaap_ConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements" xlink:label="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherNotesMember" xlink:label="fly_OtherNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractWithCustomerLossProvision" xlink:label="fly_ContractWithCustomerLossProvision"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BrokerageCommissionsRevenue" xlink:label="us-gaap_BrokerageCommissionsRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueOptionChangesInFairValueGainLoss1" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" xlink:label="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentForPurchaseAndLeasebackAgreements" xlink:label="fly_PaymentForPurchaseAndLeasebackAgreements"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpaceflightMember" xlink:label="fly_SpaceflightMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="us-gaap_EarningsPerShareTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationGoodwillAbstract" xlink:label="us-gaap_BusinessCombinationGoodwillAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesOther" xlink:label="us-gaap_DeferredTaxLiabilitiesOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember" xlink:label="us-gaap_ComputerEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateInventoryCapitalizedInterestCosts" xlink:label="us-gaap_RealEstateInventoryCapitalizedInterestCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPreferredStockCash" xlink:label="us-gaap_DividendsPreferredStockCash"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost" xlink:label="us-gaap_OperatingLeaseCost"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredTaxLiabilitiesRightOfUseAssets" xlink:label="fly_DeferredTaxLiabilitiesRightOfUseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasicLineItems" xlink:label="us-gaap_EarningsPerShareBasicLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DiscountsOnUnderwriting" xlink:label="fly_DiscountsOnUnderwriting"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationPriceOfAcquisitionExpected" xlink:label="us-gaap_BusinessCombinationPriceOfAcquisitionExpected"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember" xlink:label="us-gaap_ConstructionInProgressMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfReservedSharesIncrease" xlink:label="fly_NumberOfReservedSharesIncrease"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationEquityConsiderationPaid" xlink:label="fly_BusinessCombinationEquityConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:label="us-gaap_SaleLeasebackTransactionDescriptionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating" xlink:label="us-gaap_InterestExpenseNonoperating"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" xlink:label="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EventProbabilityPercentage" xlink:label="fly_EventProbabilityPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenue" xlink:label="us-gaap_DeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeBasisSpreadOnVariableRate" xlink:label="us-gaap_DerivativeBasisSpreadOnVariableRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FinanceLeaseLiabilityTotalPayments" xlink:label="fly_FinanceLeaseLiabilityTotalPayments"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:label="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_VotingPowerPercentage" xlink:label="fly_VotingPowerPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination" xlink:label="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FormerGainContingencyRecognizedInCurrentPeriod" xlink:label="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsOfDebtIssuanceCostsRelatedParties" xlink:label="fly_PaymentsOfDebtIssuanceCostsRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantLiabilitiesPolicyTextBlock" xlink:label="fly_WarrantLiabilitiesPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AssetsAndLiabilitiesLesseeTableTextBlock" xlink:label="fly_AssetsAndLiabilitiesLesseeTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="us-gaap_ConcentrationRiskPercentage1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DevelopedTechnologyMember" xlink:label="fly_DevelopedTechnologyMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherArrangementsMember" xlink:label="fly_OtherArrangementsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-4PreferredStockMember" xlink:label="fly_SeriesD-4PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExerciseOfCommonWarrantsIntoCommonStock" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="us-gaap_MoneyMarketFundsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="us-gaap_TemporaryEquitySharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SaleAndLeasebackPolicyTextBlock" xlink:label="fly_SaleAndLeasebackPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable" xlink:label="dei_DocumentInformationTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" xlink:label="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="us-gaap_LettersOfCreditOutstandingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare" xlink:label="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValuePerShareNonMarketableSecurity" xlink:label="fly_FairValuePerShareNonMarketableSecurity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="us-gaap_IncomeStatementLocationAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueAdjustment" xlink:label="us-gaap_LiabilitiesFairValueAdjustment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromNotesPayable" xlink:label="us-gaap_ProceedsFromNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValueAssumption" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueAssumption"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccountsPayableCurrentRelatedParties" xlink:label="fly_AccountsPayableCurrentRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeDomain" xlink:label="fly_SponsorTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TrancheObligationsMember" xlink:label="fly_TrancheObligationsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="us-gaap_FairValueByAssetClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:label="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DepositoryRiskMember" xlink:label="fly_DepositoryRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:label="us-gaap_DeferredRevenueNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsDeferredIncome" xlink:label="us-gaap_DeferredTaxAssetsDeferredIncome"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentAnnualReport" xlink:label="dei_DocumentAnnualReport"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredTaxAssetsInterestLimitationCarryforwards" xlink:label="fly_DeferredTaxAssetsInterestLimitationCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="us-gaap_MachineryAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis" xlink:label="srt_MajorCustomersAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermNotesPayable" xlink:label="us-gaap_LongTermNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedwireCorporationMember" xlink:label="fly_RedwireCorporationMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesD-1PreferredStockMember" xlink:label="fly_ConvertibleSeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="us-gaap_LiabilitiesFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeAxis" xlink:label="fly_SponsorTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentMember" xlink:label="us-gaap_PropertyPlantAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeasePrincipalPayments" xlink:label="us-gaap_FinanceLeasePrincipalPayments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForFees" xlink:label="us-gaap_PaymentsForFees"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstanding" xlink:label="us-gaap_WarrantsAndRightsOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:label="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="us-gaap_AmortizationOfFinancingCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DefaultScenarioMember" xlink:label="fly_DefaultScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="us-gaap_NonrecurringAdjustmentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaintainMinimumInterestReserveAmount" xlink:label="fly_MaintainMinimumInterestReserveAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAnnualPrincipalPayment" xlink:label="us-gaap_DebtInstrumentAnnualPrincipalPayment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:label="us-gaap_RevenueFromContractWithCustomerTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfShortTermInvestments" xlink:label="us-gaap_ProceedsFromSaleOfShortTermInvestments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityVoluntaryFilers" xlink:label="dei_EntityVoluntaryFilers"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueArrangementLineItems" xlink:label="us-gaap_DeferredRevenueArrangementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccruedPayrollCurrent" xlink:label="fly_AccruedPayrollCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesDPreferredStockMember" xlink:label="us-gaap_SeriesDPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventsAbstract" xlink:label="us-gaap_SubsequentEventsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock" xlink:label="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestExpenseInvestmentAdvisoryFees" xlink:label="us-gaap_NoninterestExpenseInvestmentAdvisoryFees"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:label="us-gaap_ConcentrationRiskCreditRisk"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CompensationRelatedCostsPolicyTextBlock" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis" xlink:label="srt_ConsolidationItemsAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherRevenueMember" xlink:label="fly_OtherRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositLiabilitiesAccruedInterest" xlink:label="us-gaap_DepositLiabilitiesAccruedInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProbabilityWeightedFairValuePerCommonWarrant" xlink:label="fly_ProbabilityWeightedFairValuePerCommonWarrant"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RightOfUseAssetObtainedInForLeaseLiability" xlink:label="fly_RightOfUseAssetObtainedInForLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived" xlink:label="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AverageFairValuePerWarrant" xlink:label="fly_AverageFairValuePerWarrant"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostAbstract" xlink:label="us-gaap_LeaseCostAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesAuthorized" xlink:label="us-gaap_TemporaryEquitySharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationIntegrationRelatedCosts" xlink:label="us-gaap_BusinessCombinationIntegrationRelatedCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RestrictedCashMember" xlink:label="fly_RestrictedCashMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember" xlink:label="us-gaap_OperatingSegmentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandAndLandImprovementsMember" xlink:label="us-gaap_LandAndLandImprovementsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IPOClosingPreferredStockDividendMember" xlink:label="fly_IPOClosingPreferredStockDividendMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionAxis" xlink:label="us-gaap_AssetAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ClassA1PreferredStockMember" xlink:label="fly_ClassA1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorName" xlink:label="dei_AuditorName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="us-gaap_ProceedsFromLinesOfCredit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsFiniteLivedPolicy" xlink:label="us-gaap_IntangibleAssetsFiniteLivedPolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerFiveMember" xlink:label="fly_CustomerFiveMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermALoansMember" xlink:label="fly_TermALoansMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsOfUnderwritngDiscounts" xlink:label="fly_ProceedsOfUnderwritngDiscounts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:label="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Weighted-AverageRemainingLeaseTermYears" xlink:label="fly_Weighted-AverageRemainingLeaseTermYears"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossRelatedToLitigationSettlement" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock" xlink:label="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockMember" xlink:label="fly_SeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost" xlink:label="us-gaap_LeaseCost"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpacecraftSolutionsRevenueMember" xlink:label="fly_SpacecraftSolutionsRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationAnnualInstallments" xlink:label="fly_ContractualObligationAnnualInstallments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableAllowance" xlink:label="us-gaap_LoansAndLeasesReceivableAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RentIncraeseAnuallyInPercent" xlink:label="fly_RentIncraeseAnuallyInPercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtCurrent" xlink:label="us-gaap_DebtCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="us-gaap_CashAndCashEquivalentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeedPreferredStockMember" xlink:label="fly_SeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold" xlink:label="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureTextBlockAbstract" xlink:label="us-gaap_DisclosureTextBlockAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayable" xlink:label="us-gaap_NotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostTableTextBlock" xlink:label="us-gaap_LeaseCostTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnamortizedDebtIssuanceExpense" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorLocation" xlink:label="dei_AuditorLocation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="us-gaap_DevelopedTechnologyRightsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" xlink:label="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" xlink:label="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaterialMember" xlink:label="fly_MaterialMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForMortgageDeposits" xlink:label="us-gaap_PaymentsForMortgageDeposits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="us-gaap_IncomeTaxAuthorityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesAbstract" xlink:label="us-gaap_DeferredTaxLiabilitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLeaseIncomeTableTextBlock" xlink:label="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="us-gaap_IncomeStatementLocationDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaterialsAndConsumables" xlink:label="fly_MaterialsAndConsumables"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations" xlink:label="us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="us-gaap_FurnitureAndFixturesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaidInKindInterest" xlink:label="us-gaap_PaidInKindInterest"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInventoryWrite-Off" xlink:label="fly_Non-CashInventoryWrite-Off"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnbilledReceivablesCurrent" xlink:label="us-gaap_UnbilledReceivablesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InterestExpenseOnPurchaseAndLeasebackAgreement" xlink:label="fly_InterestExpenseOnPurchaseAndLeasebackAgreement"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetNet" xlink:label="us-gaap_ContractWithCustomerAssetNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingNumber" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesSeedPreferredStockMember" xlink:label="fly_ConvertibleSeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PrepaidPurchaseCredit" xlink:label="fly_PrepaidPurchaseCredit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfNotesPayable" xlink:label="us-gaap_RepaymentsOfNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease" xlink:label="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExerciseOfCommonWarrantsIntoCommonStockShares" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStockShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorOpinionTextBlock" xlink:label="dei_AuditorOpinionTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConsultingAgreementMember" xlink:label="fly_ConsultingAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:label="us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueByArrangementDisclosureTextBlock" xlink:label="us-gaap_DeferredRevenueByArrangementDisclosureTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="us-gaap_DisaggregationOfRevenueLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="us-gaap_AccruedProfessionalFeesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SelfInsuranceReserve" xlink:label="us-gaap_SelfInsuranceReserve"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="us-gaap_ScheduleOfStockByClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AreaOfLand" xlink:label="us-gaap_AreaOfLand"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted Average Grant Date Fair Value, Vested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Sale of Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Proceeds from Sale of Property, Plant, and Equipment, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">International</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Income Taxes, Foreign</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SoftwareDevelopmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Software Development [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SoftwareDevelopmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Software</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AggregateOfNumberOfWarrantsToPurchase_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Aggregate of number of Warrants to purchase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AggregateOfNumberOfWarrantsToPurchase_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Aggregate of number of Warrants to purchase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGrossAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Gross [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGrossAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Related Party Transactions [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Related Party Transactions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Incorporation, State or Country Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Incorporation, State or Country Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2029</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares issued (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TimeDepositsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Time Deposits [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TimeDepositsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Time Deposits [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TimeDepositsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Time Deposits [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accounts Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Reduction in accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Increase (Decrease) in Accounts Payable, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Decrease in contingent liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Long-Term Debt Instruments [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Company's outstanding debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCurrentReportingStatus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Current Reporting Status</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCurrentReportingStatus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Current Reporting Status</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeemedSharesIssuedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deemed Shares Issued Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeemedSharesIssuedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deemed Shares Issued Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeemedSharesIssuedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deemed issue prices</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Expenses [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpensesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AverageValuePerUnitAsPerMonteCarloSimulations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Average value per unit as per Monte Carlo simulations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AverageValuePerUnitAsPerMonteCarloSimulations_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Average value per unit as per Monte Carlo simulations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AverageValuePerUnitAsPerMonteCarloSimulations_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Average value per unit as per Monte Carlo simulations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 2 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel2Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 2</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Canceled in Period, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Canceled in Period, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-Average Exercise Price, Options canceled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Net of Valuation Allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred tax assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SMINoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">SMI Note</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SMINoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SMI Note [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SMINoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SMI Note</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and Contingencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DiscountForLackOfMarketability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Discount For Lack Of Marketability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DiscountForLackOfMarketability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Discount For Lack Of Marketability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DiscountForLackOfMarketability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discount for lack of marketability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfPreferredStockDividend_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance of Preferred Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfPreferredStockDividend_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of Preferred Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfPreferredStockDividend_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of Preferred Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Temporary equity, par or stated value per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationIncurredCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Incurred Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationIncurredCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Incurred Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationIncurredCost_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Incurred Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted Average Number Basic And Diluted Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number Basic And Diluted Shares Outstanding [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average common shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxUncertaintiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Uncertainties [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product and Service [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockVotingRights_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Voting Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockVotingRights_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred Stock Voting Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Period Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Fiscal Period Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Interest Rate, Stated Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SecuredOverFinancingRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Secured Over Financing Rate [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SecuredOverFinancingRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Secured Over Financing Rate [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SecuredOverFinancingRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SOFR Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityShellCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Shell Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityShellCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Shell Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Temporary equity, Shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractualObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Obligation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractualObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual obligation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Accrued Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment Reporting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and cash equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cash and Cash Equivalent, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding Reconciliation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Denominator:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Maturities of Long-Term Debt [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Principal Payments under Term Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Notes Payable, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Notes payable, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes payable, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series J Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series J Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series J Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management, Strategy, and Governance [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares, issued (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Board of Directors Oversight [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfShareSold_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number Of Share Sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfShareSold_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Share Sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfShareSold_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number Of Share Sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TaxReconciliationNotRequired_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tax Reconciliation Not Required</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TaxReconciliationNotRequired_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tax Reconciliation Not Required</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Class [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Rule10B51ArrModifiedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Rule 10b5 1 Arr Modified [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Rule10B51ArrModifiedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Rule 10b5-1 Arrangement Modified [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Rule10B51ArrModifiedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Rule 10b5-1 Arrangement Modified</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PricePerSquareFoot_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Price per Square foot</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PricePerSquareFoot_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Price per Square foot</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additions based on tax positions related to current year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use asset acquired in exchange for operating lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Right-of-Use Asset Obtained in Exchange for Operating Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Businesses, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price of acquisition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statement [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Net Impact of Acquisition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Separately Recognized Transaction [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFilerCategory_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Filer Category</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFilerCategory_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Filer Category</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities, non-current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Operating Lease Liabilities Non Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Operating Lease Liabilities Non Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LoansHeldForSaleMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Loan, Held-for-Sale, Maturity Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LoansHeldForSaleMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term loan maturity date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Indefinite-Lived</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total acquired intangible assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Summary of Income Tax Paid by Jurisdication [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Summary of Income Tax Paid by Jurisdication [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Income Tax Paid by Jurisdication</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities, temporary equity, and stockholders' equity (deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VehiclesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vehicles [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VehiclesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vehicles</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Liability Assumed, Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PayablesAndAccrualsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payables and Accruals [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PropertyAndEquipmentAdditionsInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment additions in accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PropertyAndEquipmentAdditionsInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property and Equipment Additions in Accounts Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PropertyAndEquipmentAdditionsInAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Property and Equipment Additions in Accounts Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year Three</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2028</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-Average Exercise Price Vested and exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_UnauditedProFormaInformationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unaudited Pro Forma Information</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_UnauditedProFormaInformationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unaudited Pro Forma Information [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_UnauditedProFormaInformationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Unaudited Pro Forma Information [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Lived Tangible Asset [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Three</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2028</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common Stock Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net change in the valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwardsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SciTecMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">SciTec [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SciTecMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">SciTec [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SciTecMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SciTec</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Valuation Allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ExtinguishmentOfDebtAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Extinguishment fees</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ExtinguishmentOfDebtAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Extinguishment of Debt, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax benefit at statutory rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">State income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssuedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssuedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Seven Point Seventy One Percent Due Two Thousand Twenty Nine [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Seven Point Seventy One Percent Due Two Thousand Twenty Nine [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">7.71% due 2029</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Third Party Engaged [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Documents Incorporated by Reference [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Goodwill, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Goodwill, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Goodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Goodwill, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effective tax rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Effective income tax rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line of Credit Facility, Increase (Decrease), Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Line of Credit Facility, Increase (Decrease), Net, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of Credit Facility, Increase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Jurisdiction [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Amortization Expense, Next Rolling 12 Months</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCancelableSubscriptionBasedServicesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-Cancelable Subscription-Based Services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCancelableSubscriptionBasedServicesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non-Cancelable Subscription-Based Services [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCancelableSubscriptionBasedServicesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-Cancelable Subscription-Based Services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash, Cash Equivalents, and Short-Term Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CumulativeOwnershipPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cumulative Ownership Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CumulativeOwnershipPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cumulative Ownership Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CumulativeOwnershipPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative ownership period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets acquired and liabilities assumed</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less) [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accured Interest From Subordinated Convertible Promissory Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accured Interest From Subordinated Convertible Promissory Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accured Interest From Subordinated Convertible Promissory Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable, Allowance for Credit Loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Accounts Receivable, Allowance for Credit Loss, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Accounts Receivable, Allowance for Credit Loss, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts Receivable, Allowance for Credit Loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Liability Assumed, Lease Obligation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series J Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series J Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series J Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total debt, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFinanceCostsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Issuance Costs, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other Than Options, Cancelled in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other Than Options, Cancelled in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Options Outstanding, Options canceled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Five Omnibus Incentive Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Twenty Five Omnibus Incentive Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025 Omnibus Incentive Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related Party [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockAmountConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Conversion of Stock, Amount Converted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockAmountConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of Preferred Stock to common stock upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayableAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Asset, Useful Life</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Useful Life</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ShareRepurchaseProgramAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Repurchase Program [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_CurrencyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Currency [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FireflyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Firefly</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FireflyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Firefly [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FireflyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Firefly [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Options Outstanding, Options granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disaggregation of Revenue [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleLeasebackTransactionNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale Leaseback Transaction, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management, Strategy, and Governance [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Computation of Basic and Diluted Net Loss Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TrademarksAndTradeNamesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trademarks and Trade Names [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TrademarksAndTradeNamesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trade name and trademarks</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeFinanceLeaseDescriptionAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Finance Lease, Description [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeFinanceLeaseDescriptionAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance lease expense:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance of Preferred Stock and Preference Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from the issuance of Class C preferred stock, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from issuance of Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment, Name [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss per share attributable to common stockholders - basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disaggregation of Revenue [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Disaggregated Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prior year true-ups</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Shares, Outstanding ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Shares, Outstanding beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average grant date fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Initial fair value of warrants at issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpecificAdditionalInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Specific Additional Interest Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpecificAdditionalInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Specific Additional Interest Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpecificAdditionalInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Specific additional interest rate of premium</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Asset, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Income (Expense), Nonoperating</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Interest Income (Expense), Nonoperating, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Interest expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest income (expense), net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Interest expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevolvingCreditFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revolving Credit Facility [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevolvingCreditFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revolving Credit Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding borrowings on Revolving Credit Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Outstanding borrowings on Revolving Credit Facility [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Outstanding borrowings on Revolving Credit Facility [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Penalties expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Income Tax Penalties Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accounts Receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Accounts receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accounts receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Adjustments to reconcile net loss to net cash used in operating activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2030</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommodityContractAssetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commodity Contract Asset, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommodityContractAssetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total contract assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EntityWideRevenueMajorCustomerLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue, Major Customer [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual purchase price for Series J Preferred Stock (per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidFederalAfterRefundReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Paid, Federal, after Refund Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidFederalAfterRefundReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Income Tax Paid, Federal, after Refund Received, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidFederalAfterRefundReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">United States - federal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOnNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payments on Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOnNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments on Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOnNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments on Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOnNotesPayable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments on notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OptionIndexedToIssuersEquityShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Option Indexed to Issuer's Equity, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OptionIndexedToIssuersEquityShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of the Shares Underlying the RPM Call Option</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DomesticCountryMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Domestic Tax Jurisdiction [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DomesticCountryMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Domestic Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ShareRepurchaseProgramDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Repurchase Program [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InterestExpenseContractual_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense Contractual</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InterestExpenseContractual_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest Expense Contractual</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InterestExpenseContractual_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Expense Contractual</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageFairValuePerWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Fair Value Per Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageFairValuePerWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted Average Fair Value Per Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageFairValuePerWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average value per Series J Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAveragePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAveragePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted Average Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAveragePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average Series D Preferred Stock price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes for tax positions of prior years</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments of Debt Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Costs associated with the credit facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments of debt issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Standards Update [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidation Items [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Attributable to Parent [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders' equity (deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntitySmallBusiness_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Small Business</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntitySmallBusiness_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Small Business</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsFromRepaymentOfEmployeeNote_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Repayment Of Employee Note</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsFromRepaymentOfEmployeeNote_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds From Repayment Of Employee Note</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsFromRepaymentOfEmployeeNote_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from repayment of employee note</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accrued Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings (Accumulated Deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Retained Earnings (Accumulated Deficit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IncreaseDecreaseAccountsPayableRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase Decrease Accounts Payable Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IncreaseDecreaseAccountsPayableRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase Decrease Accounts Payable Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IncreaseDecreaseAccountsPayableRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Commitments [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Commitments [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccretionExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accretion expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccretionExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accretion Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Well-known Seasoned Issuer</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net operating loss carryforwards, expiration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Aggregate Purchased price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock, Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Public offering price (in USD per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate intrinsic value of the options exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Foreign Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">International</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-Based Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonAccruingOrignalIssuePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Non Accruing Orignal Issue Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonAccruingOrignalIssuePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage Of Non Accruing Orignal Issue Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonAccruingOrignalIssuePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of Non Accruing Deemed Issue Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of units subject to purchase by majority sponsor</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement Option Fair Value Outstanding Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement Option Fair Value Outstanding Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeasesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Leases [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonClassAMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Class A [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonClassAMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Class A</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract liabilities (current and non-current)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Contract with Customer, Liability, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeaseDescriptionLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Lease, Description [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amendment Flag</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amendment Flag</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LeaseRemainingLeaseTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease Remaining Lease Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LeaseRemainingLeaseTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Lease Remaining Lease Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LeaseRemainingLeaseTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Remaining lease term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Product and Service [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax benefit at statutory rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Number of Securities Called by Warrants or Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Interest Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest on lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Loss Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities, temporary equity, and stockholders' equity (deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Postal Zip Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Postal Zip Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts Receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used in operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Cash flows from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cash flows from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Cash flows from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Operating Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non-Cash Interest Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-Cash Interest Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInterestExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash interest expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Pro Forma Earnings Per Share, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pro forma net loss per common share, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonRule10B51ArrModifiedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non Rule 10b5 1Arr Modified [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonRule10B51ArrModifiedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non-Rule 10b5-1 Arrangement Modified [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonRule10B51ArrModifiedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-Rule 10b5-1 Arrangement Modified</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common&#160;Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement Option Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement Option Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Value of forward obligation (per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Inventory, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventory</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskRoleOfManagementTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Role of Management [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research credit carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TaxCreditCarryforwardAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tax Credit Carryforward, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-Average Exercise Price, Options granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2028</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Three</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Less: Accumulated depreciation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BelcanLLCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Belcan, LLC [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BelcanLLCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Belcan, LLC [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BelcanLLCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Belcan, LLC</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Paid, by Individual Jurisdiction [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Interest Rate, Effective Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effective interest rate of the term loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Value of RPM Option</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement Option Outstanding Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement Option Outstanding Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Address Line One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Address Line One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred tax liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel">Total deferred tax liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of assumptions fair value of options granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandSeventeenEquityIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Seventeen Equity Incentive Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandSeventeenEquityIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Seventeen Equity Incentive Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandSeventeenEquityIncentivePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2017 Equity Incentive Plans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss per common share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Carrying Amount, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Temporary equity, Carrying value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Supplemental Cash Flow Information [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Supplemental disclosures of cash flow information</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Five Employee Stock Purchase Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Twenty Five Employee Stock Purchase Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025 Employee Stock Purchase Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill and Intangible Assets Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders' Equity Note, Redeemable Preferred Stock, Issue, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CumulativeOwnershipPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cumulative Ownership Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CumulativeOwnershipPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cumulative Ownership Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CumulativeOwnershipPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative ownership percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Right-of-Use Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets - operating leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Operating lease right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, Undiscounted Excess Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: Imputed interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Less: Imputed interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IncreaseDecreaseInAdvancedPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Advanced payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IncreaseDecreaseInAdvancedPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) In Advanced Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IncreaseDecreaseInAdvancedPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase (Decrease) In Advanced Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gross deferred tax assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermLoanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Term Loan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermLoanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Term Loan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermLoanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term Loan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Other Asset, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentType_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Type</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentType_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Type</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxesPaidNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Taxes Paid, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxesPaidNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total income tax payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GrossProfit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gross profit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GrossProfit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gross Profit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromCommissionsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Commissions Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromCommissionsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds of commission received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Central Index Key</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Central Index Key</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PropertyAndEquipmentUsefulLivesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of property and equipment useful lives</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PropertyAndEquipmentUsefulLivesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property and Equipment Useful Lives TableText Block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PropertyAndEquipmentUsefulLivesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Property and equipment useful lives</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FollowOnOpportunitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Follow on opportunities[Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FollowOnOpportunitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Follow on opportunities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FollowOnOpportunitiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Follow-on opportunities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationTechniqueAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Approach and Technique [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net increase in cash and cash equivalents and restricted cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Adjustment of Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of warrant liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAdjustmentOfWarrants_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Change in fair value of warrant liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeOperating_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Income, Operating</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeOperating_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Interest Income, Operating, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeOperating_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Compensation Arrangement with Individual, Common Stock Reserved for Future Issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock available for issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer One [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer One Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer 1</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractorsAndOutsideServices_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractors and Outside Services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractorsAndOutsideServices_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contractors and Outside Services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractorsAndOutsideServices_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractors and outside services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractorsAndOutsideServices_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contractors and outside services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_lbl" xlink:role="http://www.xbrl.org/2003/role/label">APIC, Share-Based Payment Arrangement, Option, Increase for Cost Recognition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, par or stated value per share (in USD per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common stock retained par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="currency_USD_lbl" xlink:role="http://www.xbrl.org/2003/role/label">United States of America, Dollars</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="currency_USD_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Standards Update [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred project costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Deferred Tax Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingCostsAndExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Costs and Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingCostsAndExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Operating Costs and Expenses, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingCostsAndExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expenses- related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PreferredStockIssuedAtAPurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock Issued at a Purchase Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PreferredStockIssuedAtAPurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Preferred Stock Issued at a Purchase Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IPOScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">IPO Scenario [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IPOScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">IPO Scenario [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IPOScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">IPO Scenario</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExitFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exit Fee Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExitFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exit Fee Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExitFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exit fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesSeed-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Series Seed-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesSeed-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Convertible Series Seed-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesSeed-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Series Seed-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BaseRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Base Rate [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BaseRateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Base rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-Average Remaining Contractual Term, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Operating Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Components of Deferred Tax Assets and Liabilities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeInRight-Of-UseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change in Right-Of-Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeInRight-Of-UseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Change in Right-Of-Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeInRight-Of-UseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetPurchase_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition of contract assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetPurchase_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Asset, Purchase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFinStmtErrorCorrectionFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Financial Statement Error Correction [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CallOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Call Option</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CallOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Call Option [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationCancellationFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contractual Obligation, Cancellation Fee Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationCancellationFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Obligation, Cancellation Fee Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationCancellationFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual obligation, cancellation fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, share exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Number of Options Outstanding, Options exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Number of Options Outstanding, Options exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ITRelatedEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">IT Related Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ITRelatedEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">IT Related Equipment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ITRelatedEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">IT related equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BlackScholesMertonModelMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Technique, Black-Scholes-Merton Model [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BlackScholesMertonModelMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Black-Scholes option-pricing valuation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Settlements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Repayments of Related Party Debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Repayments of debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Eight Point Thirty One Percent Due Two Thousand Thirty One [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Eight Point Thirty One Percent Due Two Thousand Thirty One [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">8.31% due 2031</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of reconciles the undiscounted future minimum lease payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Reconciles the Undiscounted Future Minimum Lease Payment Table Text Block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of Reconciles the Undiscounted Future Minimum Lease Payment Table Text Block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Fiscal Year End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current Fiscal Year End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Long-Term Debt Instruments [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Long-Term Debt Instruments [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeOfControlScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change of Control Scenario [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeOfControlScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Change of Control Scenario [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeOfControlScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change of Control Scenario</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerRelationshipsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Relationships [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerRelationshipsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer Relationships</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableOtherCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, State or Province</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, State or Province</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MajoritySponsorMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Majority Sponsor [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MajoritySponsorMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Majority Sponsor [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MajoritySponsorMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Majority Sponsor Top-Up</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Number of shares, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Number of shares, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Options Outstanding, Unvested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Conversion of Convertible Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of Redeemable Convertible Preferred Stock to common stock in connection with initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock upon settlement of Preferred Stock Dividends</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance of Common Stock Upon Settlement of Preferred Stock Dividends, Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of Common Stock Upon Settlement of Preferred Stock Dividends, Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_EquityMethodInvesteeNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetAcquisitionDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Acquisition [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Preferred stock ending balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Preferred stock beginning balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares outstanding (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and Development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of reserved shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Capital Shares Reserved for Future Issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common stock available for issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Liability, Revenue Recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Recognize Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Transaction Cost, Excluding Separately Recognized Transaction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transaction Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CostOfSalePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost of Sale Policy text block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CostOfSalePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cost of Sale Policy text block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CostOfSalePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost of Sales</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of Preferred Stock to common stock, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Conversion of Stock, Shares Converted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts Receivable [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesMPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series M Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesMPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series M Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesMPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series M Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesMPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible Series M Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, after Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Stock Options Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Options Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Call Option derecognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Carryforwards That Gave Rise to Significant Portions of Deferred Taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Deferred Tax Assets and Liabilities [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Concentration of Credit Risk</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Unamortized Discount (Premium), Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Debt Instrument, Unamortized Discount (Premium), Net, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Less: Unamortized issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unamortized issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Option [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Option [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Event</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DavidWheelerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">David Wheeler</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DavidWheelerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">David Wheeler [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DavidWheelerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">David Wheeler [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SwinglineLoans_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sublimit for swingline loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SwinglineLoans_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Swingline Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SwinglineLoans_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Swingline Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Revenue, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other noncurrent assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement by Share Based Payment Award, Options Available for Grant, Exercised in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement by Share Based Payment Award, Options Available for Grant, Exercised in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Options Available for Grant, Options exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_GainOnSettlementOfContingentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain on settlement of contingent liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_GainOnSettlementOfContingentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Gain on settlement of contingent liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerFourMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Four [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerFourMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer Four [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerFourMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer 4</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwardsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Prepaid Expense and Other Asset, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid expenses and other current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantExercisePriceDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant, Exercise Price, Decrease</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantExercisePriceDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant Exercise Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Basis of Presentation and Significant Accounting Policies [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Significant Accounting Policies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value of RSUs vested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense, Debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total interest expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Expense Debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer two Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Two [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer 2</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Commitments [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Commitments [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StateAndLocalJurisdictionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">State and Local Jurisdiction [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StateAndLocalJurisdictionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State and Local</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_NameOfMajorCustomerDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_NameOfMajorCustomerDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CashProceeds_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Proceeds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CashProceeds_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash Proceeds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CashProceeds_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash proceeds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Commitments [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Commitments [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Consideration Transferred</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total consideration, net of cash acquired</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Combination Consideration Transferred</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redeemable convertible preferred stock, $0.0001 par value; 100,000 and 51,033 shares authorized as of September 30, 2025 and December 31, 2024, respectively; 0 and 41,588 shares issued and outstanding as of September 30, 2025 and December 31, 2024, respectively; $0 and $1,227,158 liquidation preference as of September 30, 2025 and December 31, 2024, respectively</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCashInterestIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash interest income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCashInterestIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Cash Interest Income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCashInterestIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non Cash Interest Income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCashInterestIncome_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Non-cash interest income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Value, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Preferred stock value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redeemable convertible preferred shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Consideration Transferred, Equity Interest, Share Issued, Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business acquisition in common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Equity (issuance of common stock)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeInFairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of warrant liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeInFairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change in fair value of warrant liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeInFairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Change in fair value of warrant liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ChangeInFairValueOfWarrantLiability_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Change in fair value of warrant liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Selling, General and Administrative Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Selling, General and Administrative Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractors and outside services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Selling, general and administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Selling, general and administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PurchaseAccountingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Purchase Accounting [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PurchaseAccountingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase Accounting [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PurchaseAccountingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase Accounting [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line of Credit Facility, Fair Value of Amount Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount drawn under the revolving credit facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted Average Grant Date Fair Value, Granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancialInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermBLoansMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Term B Loans [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermBLoansMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Term B Loans [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermBLoansMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term B Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization of Intangible Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonClassBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Class B [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonClassBMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Class B</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 3 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 3</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total net assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NotesPayableNoncurrent-RelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes payable, less current portion - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NotesPayableNoncurrent-RelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable, Noncurrent - Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NotesPayableNoncurrent-RelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Notes Payable, Noncurrent - Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Property, Plant and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Combination</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationsPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Dividends Per Share, Declared</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred Stock Dividends Per Share Declared</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantsToPurchaseAnAggregate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants to Purchase An Aggregate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantsToPurchaseAnAggregate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrants to Purchase An Aggregate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantsToPurchaseAnAggregate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants to purchase an aggregate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock upon settlement of Preferred Stock Dividends (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance of common stock upon settlement of Preferred Stock Dividends, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of common stock upon settlement of Preferred Stock Dividends, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Weighted-AverageRemainingContractualTermUnvested_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted-Average Remaining Contractual Term Unvested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Weighted-AverageRemainingContractualTermUnvested_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted-Average Remaining Contractual Term Unvested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJPreferredStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series J Preferred Stock Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJPreferredStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series J Preferred Stock Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJPreferredStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series J Preferred Stock Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJPreferredStockWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Warrants for Series J Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesSeed-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series Seed-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesSeed-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series Seed-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesSeed-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series Seed-1 Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-2PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series D-2 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-2PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series D-2 Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-2PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series D-2 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonRecourseEmployeeLoans_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-recourse employee loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonRecourseEmployeeLoans_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Recourse Employee Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonRecourseEmployeeLoans_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non Recourse Employee Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transactions [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net operating loss carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable, after Allowance for Credit Loss, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts receivable, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accounts receivable, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Accounts receivable, net- related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Expense, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Prepaid Expense, Noncurrent, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Advanced payments, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashAndCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash and Cash Equivalent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashAndCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Restricted Cash and Cash Equivalent, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashAndCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total cash and cash equivalents and restricted cash at the end of the period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashEquivalentsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash Equivalent, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashEquivalentsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash, non-current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and contingencies (See Note 10)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Leases [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Separately Recognized Transaction, Acquisition-Related Cost, Incurred</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recognized Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Weighted Average Grant Date Fair Value, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Weighted Average Grant Date Fair Value, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-Average Exercise Price Unvested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock under equity plan (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsToAcquireTimeDeposits_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchases of time deposits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsToAcquireTimeDeposits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments To Acquire Time Deposits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsToAcquireTimeDeposits_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments To Acquire Time Deposits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsToAcquireTimeDeposits_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of time deposits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Selling, general and administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">General and Administrative Expense [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairMarketValueOfSharePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Market Value Of Share Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairMarketValueOfSharePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair Market Value Of Share Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairMarketValueOfSharePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair market value of share, Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_StockIssuedDuringPeriodSharesStockDividend_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_StockIssuedDuringPeriodSharesStockDividend_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock Issued During Period Shares Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_StockIssuedDuringPeriodSharesStockDividend_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash dividends paid on Preferred stock (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorFirmId_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Firm ID</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock, Percentage of Ownership after Transaction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of shares acquired</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityReverseStockSplit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders' Equity, Reverse Stock Split</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityReverseStockSplit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock reverse split</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Changes in the Carrying Amount of Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Goodwill [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxAssetsCapitalizedResearchCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Capitalized Research Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxAssetsCapitalizedResearchCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Tax Assets Capitalized Research Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxAssetsCapitalizedResearchCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capitalized research costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SubordinatedConvertiblePromissoryNoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subordinated Convertible Promissory Note [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SubordinatedConvertiblePromissoryNoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subordinated Convertible Promissory Note [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SubordinatedConvertiblePromissoryNoteMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Subordinated Convertible Promissory Note [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Benchmark [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TestStandsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Test stands [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TestStandsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Test stands Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TestStandsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Test stands</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativePremiumPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Initial insurance premium</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativePremiumPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative, Premium Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LeasesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Leases Text Block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LeasesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Leases Text Block</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LeasesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Notes [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Convertible Notes [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options Available for Grant, Grants in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share-Based Compensation Arrangement by Share-Based Payment Award, Options Available for Grant, Grants in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Options Available for Grant, Options granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance lease liability, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Finance lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeLeaseDescriptionTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Lease, Description [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Weighted Average Discount Rate, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageFairValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Fair Value Per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageFairValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted Average Fair Value Per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WeightedAverageFairValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted Value per Common Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonCompoundingRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Non Compounding Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonCompoundingRate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage Of Non Compounding Rate.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LongTermDebtNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term debt, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LongTermDebtNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LongTermDebtNet_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Long Term Debt Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LongTermDebtNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Long-term debt, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Noncurrent [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Noncurrent:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Capital Expenditures Incurred but Not yet Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash additions of property, plant and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Property and equipment additions in accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Cash and Cash Equivalent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and cash equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Cash, net of cash acquired</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SharesOutstandingPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Outstanding Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SharesOutstandingPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Shares Outstanding Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SharesOutstandingPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares outstanding percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Term Debt, Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Positions or Committees Responsible [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationalAndOfferingCostsExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Offering and Organizational Costs, Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationalAndOfferingCostsExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Offering and Organizational Costs, Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationalAndOfferingCostsExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Weighted average common shares outstanding - basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill, Acquired During Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition through business combinations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_StatementScenarioAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scenario [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Permanent Items, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective Income Tax Rate Reconciliation, Permanent Items, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Permanent items</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentInformationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Information [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentInformationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Information [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Temporary equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line of Credit Facility, Revolving Credit Conversion to Term Loan, Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term loan description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Effective Income Tax Reconciliation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesLeasingArrangements_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred lease liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesLeasingArrangements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Leasing Arrangements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Lived Tangible Asset [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SaleAndLeasebackTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale and Leaseback Transactions [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SaleAndLeasebackTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sale and Leaseback Transactions [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SaleAndLeasebackTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale and Leaseback Transactions Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Events [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Events</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transactions Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party Transactions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Variable Rate [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Variable Rate [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationTotalConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationTotalConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Total Consideration Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationTotalConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Total Consideration Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationTotalConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in valuation allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pro forma net loss per common share, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Pro Forma Earnings Per Share, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Income and Interest Expense Disclosure [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Interest Expense Related to the Term Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Basis of Accounting, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basis of Presentation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Stockholders' Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesCPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series C Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesCPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible Series C Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesCPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series C Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement Option Outstanding Fair Value Majority Sponsor</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement Option Outstanding Fair Value Majority Sponsor</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Value of Majority Sponsor Top-Up</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantsToPurchaseSeriesJPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants to Purchase Series J Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantsToPurchaseSeriesJPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrants to Purchase Series J Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantsToPurchaseSeriesJPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants to Purchase Series J Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationTechniqueDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Approach and Technique [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesAPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series A Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesAPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesAPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible Series A Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UseOfEstimates_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Use of Estimates, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UseOfEstimates_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Use of Estimates</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance of Debt in Exchange of Software Licenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of Debt in Exchange of Software Licenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of debt in exchange of software licenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2030</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseholdImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Leasehold Improvements [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseholdImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Leasehold improvements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine2_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Address Line Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine2_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Address Line Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Disclosures [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Measurement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Consideration Transferred [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consideration paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance Of Underwriting Discounts And Commissions And Other Offering Costs Value During Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance Of Underwriting Discounts And Commissions And Other Offering Costs Value During Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance Of Underwriting Discounts And Commissions And Other Offering Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AllowanceForCreditLossesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Allowance for Credit Losses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AllowanceForCreditLossesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Allowance For Credit Losses [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AllowanceForCreditLossesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Allowance For Credit Losses [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Noncash Investing and Financing Items [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Supplemental non-cash investing and financing activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Non-cash investing and financing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2029</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Unrecognized Tax Benefits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PreferredStockConvertedToCommonSharesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Preferred Stock Converted To Common Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PreferredStockConvertedToCommonSharesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock Converted To Common Shares [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PreferredStockConvertedToCommonSharesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock (as converted to common shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PrepaidAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PrepaidAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prepaid Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PrepaidAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingOtherItemAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting, Other Segment Item, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingOtherItemAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other segment items</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingOtherItemAmount_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other segment items</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Operating Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Other assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BuildingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Building [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BuildingMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Buildings</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CreditFacilityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CreditFacilityAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment, Ownership Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding common stock owning percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost of Product and Service Sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost of sales</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cost of Product and Service Sold, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CostOfGoodsAndServicesSold_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cost of sales</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current State and Local Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentRepaidPrincipal_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding principal amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentRepaidPrincipal_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Repaid, Principal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Description and Basis of Presentation [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">The Company, Initial Public Offering, and Basis of Presentation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Expertise of Management Responsible [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FinancingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financing Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FinancingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Financing Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FinancingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financing Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_GSPrecisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">G.S. Precision [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_GSPrecisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">G.S. Precision [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_GSPrecisionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">G.S. Precision</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AEIndustrialMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">AE Industrial [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AEIndustrialMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">AE Industrial [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AEIndustrialMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">AE Industrial</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValuePerShareMarketableSecurity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Per Share Marketable Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValuePerShareMarketableSecurity_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair Value Per Share Marketable Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValuePerShareMarketableSecurity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Value per Common Warrant on a marketable basis</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related and Nonrelated Parties [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related and Nonrelated Parties [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BacklogMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Backlog [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BacklogMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Backlog</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BacklogMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Backlog</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, City or Town</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, City or Town</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Commitments [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherCommitmentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Commitments [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Contingent Consideration, Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Business Combination, Contingent Consideration, Liability, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contingent liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashFDICInsuredAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, FDIC Insured Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashFDICInsuredAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash, FDIC Insured Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_SecurityExchangeName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Security Exchange Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_SecurityExchangeName_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Security Exchange Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CreditFacilityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CreditFacilityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument Carrying Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment, gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Auction Market Preferred Securities, Stock Series [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementMaximumValueRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement Maximum Value Recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementMaximumValueRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement Maximum Value Recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementMaximumValueRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount subject to the Majority Sponsor Top-Up</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible Assets, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Intangible Assets Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss before provision for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Loss before income tax benefit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockOutstandingCommonWarrantsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common stock, Outstanding Common Warrants Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockOutstandingCommonWarrantsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock, Outstanding Common Warrants Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockOutstandingCommonWarrantsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, outstanding common warrants exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2030</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationRelatedCostsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Compensation Related Costs [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders' Equity Note [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentIncreaseAccruedInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Increase, Accrued Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentIncreaseAccruedInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Goodwill and Intangible Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Balance, end of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Balance, beginning of period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestPaidNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Paid, Excluding Capitalized Interest, Operating Activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestPaidNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash paid for interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transfers between levels within the fair value hierarchy</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common Warrants [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonWarrantsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Warrant or Right, Exercise Price of Warrants or Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total share-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Noncash or Part Noncash Acquisition, Fixed Assets Acquired</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment acquired through loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentPeriodEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Period End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentPeriodEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Period End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_IcfrAuditorAttestationFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">ICFR Auditor Attestation Flag</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Contingent Consideration, Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Business Combination, Contingent Consideration, Asset, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationContingentConsiderationAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business acquisition total consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common Stock Warrant [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CommonStockWarrantMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Options Outstanding, Vested and exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line of Credit Facility, Commitment Fee Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitment fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain (Loss) on Disposition of Property Plant Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gain (Loss) on Disposition of Property Plant Equipment, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on disposal of fixed assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">(Gain) loss on disposal of fixed assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetRentableArea_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Rentable Area</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetRentableArea_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Rentable Area</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NotesPayablePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NotesPayablePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NotesPayablePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Notes Payable [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted Average Life</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Financial Position [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock Units (RSUs) [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">RSUs [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue Recognition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Redeemable Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfRedeemableConvertiblePreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfRedeemableConvertiblePreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfRedeemableConvertiblePreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule Of Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Security, Excluded EPS Calculation [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Security, Excluded EPS Calculation [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValueInputsDiscountRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discount factor</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValueInputsDiscountRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Inputs Discount Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValueInputsDiscountRate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair Value Inputs Discount Factor</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RedeemableConvertiblePreferredStocksMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Redeemable Convertible Preferred Stocks [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RedeemableConvertiblePreferredStocksMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Redeemable Convertible Preferred Stocks</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RedeemableConvertiblePreferredStocksMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redeemable convertible preferred stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCancelableServiceContractCommitmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-Cancelable Service Contract Commitments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCancelableServiceContractCommitmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non-Cancelable Service Contract Commitments [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NonCancelableServiceContractCommitmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-Cancelable Service Contract Commitments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management, Strategy, and Governance [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance Leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax rate change</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instruments [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Four Point Five Zero Percent Due Two Thousand Twenty six [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Four Point Five Zero Percent Due Two Thousand Twenty six [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">4.50% due 2026</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationTechniqueOptionPricingModelMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Valuation Technique, Option Pricing Model [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ValuationTechniqueOptionPricingModelMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Forward pricing valuation model</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Deferred Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Loss Contingency, Estimate of Possible Loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss contingency, estimate of possible loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion, Converted Instrument, Warrants or Options Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issued to the lenders series J warrants to purchase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="currency_AllCurrenciesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">All Currencies [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accruals and reserves</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCash_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCash_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Restricted Cash, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCash_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCash_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Restricted cash balances</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueArrangementByTypeTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Arrangement, by Type [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Right-of-Use Asset, Amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of ROU assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Amortization of right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Variable Rate [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VariableRateAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Variable Rate [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Indefinite-Lived Intangible Assets, Major Class Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gross Carrying Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Finite-Lived Intangible Assets, Gross, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted average common shares outstanding - diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity File Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity File Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AdvancedPaymentsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Advanced Payments [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AdvancedPaymentsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Advanced Payments [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AdvancedPaymentsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Advanced Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerThreeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Three [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerThreeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer Three Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerThreeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer 3</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfReservedSharesIncreaseApproximately_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Reserved Shares, Increase approximately</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfReservedSharesIncreaseApproximately_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number Of Reserved Shares, Increase approximately</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfReservedSharesIncreaseApproximately_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number Of Reserved Shares, Increase approximately</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Other Reconciling Items, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InternalUseSoftwareMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Internal Use Software [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InternalUseSoftwareMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Internal Use Software</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InternalUseSoftwareMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Internal-use software</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CoverAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cover [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Intangible Asset, Acquired, Indefinite-Lived [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Fair Value of Acquired Identifiable Intangible Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Weighted-AverageDiscountRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted-average discount rate:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Weighted-AverageDiscountRate_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted-average discount rate:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredRevenuePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredRevenuePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredRevenuePolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Revenue [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Carrying Value of The Term Loans Approximated Their Estimated Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Number of shares, Canceled / forfeited</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares, Canceled / forfeited</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalLeaseObligationsIncurred_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease Obligation Incurred</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalLeaseObligationsIncurred_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment acquired through finance leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Liability Assumed, Other Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue Benchmark [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue Benchmark [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scenario [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RPMCallOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">RPM Call Option [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RPMCallOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">RPM Call Option [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RPMCallOptionMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">RPM Call Option</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number of Operating Segments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of operating segments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EquityMethodInvestmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EquityMethodInvestmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity Method Investment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EquityMethodInvestmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Method Investment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LaunchRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Launch Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LaunchRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Launch Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LaunchRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Launch Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment and Geographical Information</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesBPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series B Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesBPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series B Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesBPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible Series B Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonvested Restricted Stock Shares Activity [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of restricted stock activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LesseeOperatingTotalLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Total Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LesseeOperatingTotalLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Lessee Operating Total Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LesseeOperatingTotalLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total lease payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_LesseeOperatingTotalLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Lessee Operating Total Lease Liability, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Acquisitions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock related to business combinations (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer, Including Assessed Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Liquidation Preference</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate Liquidation Preferences</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding stock options, vesting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationNumberOfLaunches_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contractual Obligation, Number Of Launches</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationNumberOfLaunches_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Obligation, Number Of Launches</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationNumberOfLaunches_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss contingency, number of launch</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Geographic Areas, Revenues from External Customers [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business combination post-acquisition income and loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Pro Forma Income (Loss), after Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OperatingLeaseRight-Of-UseAssetDecreased_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Right-of-Use Asset Decreased</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OperatingLeaseRight-Of-UseAssetDecreased_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Operating Lease, Right-of-Use Asset Decreased</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OperatingLeaseRight-Of-UseAssetDecreased_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets - operating leases decreases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share Based Compensation, Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCostsCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCostsCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Costs, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCostsCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred contract costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Federal, State and Local, Tax Expense (Benefit) [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Liability Assumed, Accounts Payable, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Finite-Lived Intangible Assets, Net, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Finite-Lived Intangible Assets, Net, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Finite-Lived Intangible Assets, Net, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Carrying Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total future amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments to Additional Paid in Capital, Warrant Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase of an Aggregate of Common Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on extinguishment of debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain (Loss) on Extinguishment of Debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gain (Loss) on Extinguishment of Debt, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Loss on extinguishment of debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Loss on extinguishment of debt</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Option, Nonvested, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Share-Based Compensation Arrangement by Share-Based Payment Award, Option, Nonvested, Weighted Average Exercise Price, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Share-Based Compensation Arrangement by Share-Based Payment Award, Option, Nonvested, Weighted Average Exercise Price, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Useful Life</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated Useful Lives</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">New Accounting Pronouncements, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recent Accounting Pronouncements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnDispositionOfAssets1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain (Loss) on Disposition of Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnDispositionOfAssets1_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gain (Loss) on Disposition of Assets, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnDispositionOfAssets1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on sale of fixed assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossOnDispositionOfAssets1_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">(Gain) loss on disposal of fixed assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Conversion of Convertible Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of Redeemable Convertible Preferred Stock to common stock in connection with initial public offering (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationCashConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Cash Consideration Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationCashConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Cash Consideration Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationCashConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Comprehensive Income (Loss) [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of net loss and comprehensive loss on date of acquisition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesCPurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series C Purchase Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesCPurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series C Purchase Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesCPurchaseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series C Purchase Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonrecurringAdjustmentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Nonrecurring Adjustment [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Income Taxes, Domestic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">United States</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecognized compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Common stock, shares, outstanding, beginning balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Common stock, shares, outstanding, ending balance (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares, outstanding (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Operating lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liability, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Depreciation, Depletion and Amortization, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation, Depletion and Amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation and amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue, Remaining Performance Obligation, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue, remaining performance obligation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Processes Integrated [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Transition Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Transition Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net deferred tax assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Short-Term Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Short-Term Investments, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expenses- related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total operating expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsFromNotesPayableRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Notes Payable, Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsFromNotesPayableRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds From Notes Payable, Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsFromNotesPayableRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from notes payable - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Three</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2028</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Income Tax Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Cash Flows [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum Cash Balance for Purchase and Leaseback Agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Minimum Cash Balance for Purchase and Leaseback Agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum cash balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other notes [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other notes [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherNotesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other notes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractWithCustomerLossProvision_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Loss Provision</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractWithCustomerLossProvision_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract With Customer Loss Provision</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractWithCustomerLossProvision_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract With Customer Loss Provision</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Federal Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Federal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, New Issues</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of stock, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of stock option activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Option, Activity [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BrokerageCommissionsRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Brokerage Commissions Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BrokerageCommissionsRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amount of commission</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recognized loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Option, Changes in Fair Value, Gain (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Businesses, Net of Cash Acquired</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Payments to Acquire Businesses, Net of Cash Acquired, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business combinations, net of acquired cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Acquisition of business, net of acquired cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Exercise of Common Stock Warrants to Common Stock in Connection With Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Net Exercise of Common Stock Warrants to Common Stock in Connection With Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net exercise of Common Warrants to common stock in connection with initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders' Equity (Deficit) and Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentForPurchaseAndLeasebackAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payment for Purchase and Leaseback Agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentForPurchaseAndLeasebackAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payment for Purchase and Leaseback Agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentForPurchaseAndLeasebackAgreements_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payment for purchase and leaseback agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpaceflightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Spaceflight [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpaceflightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Spaceflight [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpaceflightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Spaceflight</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">13.875% due 2028</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Thirteen Point Eight Hundred Seventy Five Percent Due Two Thousand Twenty Eight [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Thirteen Point Eight Hundred Seventy Five Percent Due Two Thousand Twenty Eight [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Loss Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits that Would Impact Effective Tax Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecognized tax benefits effective tax rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Unrecognized tax benefits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationGoodwillAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Goodwill [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of the RSU activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesOther_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComputerEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Computer Equipment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComputerEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Computer Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Processes Integrated [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Consolidated net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net loss and comprehensive loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate intrinsic value of the options outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RealEstateInventoryCapitalizedInterestCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Real Estate Inventory, Capitalized Interest Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RealEstateInventoryCapitalizedInterestCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Real Estate Inventory, Capitalized Interest Costs, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RealEstateInventoryCapitalizedInterestCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Real Estate Inventory, Capitalized Interest Costs, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RealEstateInventoryCapitalizedInterestCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capitalized interest in connection with construction in progress</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPreferredStockCash_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Dividends, Preferred Stock, Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DividendsPreferredStockCash_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dividends, Preferred Stock, Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxLiabilitiesRightOfUseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities Right of Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxLiabilitiesRightOfUseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Tax Liabilities Right of Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxLiabilitiesRightOfUseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dividend yield</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasicLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasicLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible assets, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Intangible Assets, Net (Excluding Goodwill)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Intangible Assets, Net (Excluding Goodwill), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DiscountsOnUnderwriting_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Discounts on Underwriting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DiscountsOnUnderwriting_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Discounts on Underwriting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DiscountsOnUnderwriting_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discounts on Underwriting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ASSETS</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationPriceOfAcquisitionExpected_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business aquisition, aggregate purchase price upon closing</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationPriceOfAcquisitionExpected_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Price of Acquisition, Expected</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Risk-free rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Risk-free interest rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConstructionInProgressMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Construction in Progress [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConstructionInProgressMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Construction in progress [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfReservedSharesIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Reserved Shares, Increase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfReservedSharesIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number Of Reserved Shares, Increase</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_NumberOfReservedSharesIncrease_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increment in reserved shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationEquityConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Equity Consideration Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationEquityConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Equity Consideration Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationEquityConsiderationPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Year Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Fiscal Year Focus</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion, Converted Instrument, Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred Stock settled shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Benchmark [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Flows from investing activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Accounts payable- related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleLeasebackTransactionDescriptionAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale Leaseback Transaction, Description [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseNonoperating_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense, Nonoperating</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseNonoperating_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Finance and interest expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseNonoperating_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Interest Expense, Nonoperating, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseNonoperating_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Interest expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestExpenseNonoperating_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reductions as a result of a lapse of applicable statute of limitations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Income before Income Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments of Ordinary Dividends, Preferred Stock and Preference Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payment of IPO Closing Preferred Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">IPO Closing Preferred Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Cash dividends paid on Preferred stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payment of initial public offering closing Preferred Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EventProbabilityPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Event Probability Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EventProbabilityPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Event Probability Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_EventProbabilityPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Event weighting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Contract Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Federal Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Federal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Advanced payments, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Total deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock under equity plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeBasisSpreadOnVariableRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Variable rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeBasisSpreadOnVariableRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative, Basis Spread on Variable Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of future amortization expense on intangible assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets Amortization Expense [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Measurements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FinanceLeaseLiabilityTotalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Total Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FinanceLeaseLiabilityTotalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Finance Lease Liability Total Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FinanceLeaseLiabilityTotalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total lease payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FinanceLeaseLiabilityTotalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Finance Lease Liability Total Payments, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series D-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series D-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible Series D-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series D-1 Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits [Roll Forward]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Stock Options Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Share exercised over allotment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromStockOptionsExercised_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from exercise of stock options</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Disclosures [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_VotingPowerPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Voting Power</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_VotingPowerPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Voting Power Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_VotingPowerPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Voting Power Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Acquisitions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock related to business combinations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity issued for business combination</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non-cash Investing and Financing Activities Equity Issued for Business Combination</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-cash Investing and Financing Activities Equity Issued for Business Combination</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock, Consideration Received on Transaction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate purchase price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Series D-1 Preferred Stock funding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss) Available to Common Stockholders, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net loss attributable to common shareholders, basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Liability Assumed, Deferred Revenue, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contingent liabilities gain recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Former Gain Contingency, Recognized in Current Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Pro Forma Income (Loss) from Continuing Operations, after Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pro forma net loss and comprehensive loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Unaudited Pro Forma Information</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOfDebtIssuanceCostsRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments Of Debt Issuance Costs, Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOfDebtIssuanceCostsRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments Of Debt Issuance Costs, Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOfDebtIssuanceCostsRelatedParties_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments of debt issuance costs - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PaymentsOfDebtIssuanceCostsRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of debt in exchange of software licenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantLiabilitiesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Liabilities [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantLiabilitiesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant Liabilities [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_WarrantLiabilitiesPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, after Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AssetsAndLiabilitiesLesseeTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets And Liabilities Lessee [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AssetsAndLiabilitiesLesseeTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Assets And Liabilities Lessee [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AssetsAndLiabilitiesLesseeTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Operating and Finance Lease Right-of-Use Assets and Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecognized compensation cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total financial assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Assets, Fair Value Disclosure, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Liability Assumed, Deferred Tax Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk, Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Credit Risk Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DevelopedTechnologyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Developed Technology [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DevelopedTechnologyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Developed Technology [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DevelopedTechnologyMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Developed technology</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Revenues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenues</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Revenues_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Revenues, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Revenues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used in investing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherArrangementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Arrangements [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherArrangementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other Arrangements [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherArrangementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Arrangements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Weighted Average Remaining Lease Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Title of 12(b) Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of 12(b) Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-4PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series D-4 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-4PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series D-4 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-4PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series D-4 Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net exercise of Common Warrants into common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exercise of Common Warrants into Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exercise of Common Warrants into Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Paid, by Individual Jurisdiction [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted Average Grant Date Fair Value, Canceled / Forfeited</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Money Market Funds [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Money market funds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related and Nonrelated Parties [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related and Nonrelated Parties [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2030</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Maturity, after Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Shares Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Temporary equity, Shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SaleAndLeasebackPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale and Leaseback [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SaleAndLeasebackPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sale and Leaseback [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SaleAndLeasebackPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sales and Leaseback</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total debt, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Carrying Amount Net Of Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt Instrument Carrying Amount Net Of Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentInformationTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Information [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentInformationTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Information [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other liabilities, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Right-of-Use Asset, after Accumulated Amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Finance Lease, Right-of-Use Asset, after Accumulated Amortization, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets - finance leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Finance lease right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments to Additional Paid in Capital Share Based Compensation Stock Options Requisite Service Period Recognition, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Adjustments to Additional Paid in Capital Share Based Compensation Stock Options Requisite Service Period Recognition, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in operating assets and liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Property and Equipment, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LettersOfCreditOutstandingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Letters of Credit Outstanding, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LettersOfCreditOutstandingAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Letters of credit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Weighted Average Exercise Price , Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Weighted Average Exercise Price, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Non Accruing Dividend Deemed Issue Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage Of Non Accruing Dividend Deemed Issue Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of Non Accruing Dividend Deemed Issue Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Recurring and Nonrecurring [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Combinations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unrecognized Tax Benefits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending Balance at December 31</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning Balance at January 1</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecognized tax benefits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid-in Capital [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional Paid-in Capital, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on derivatives</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValuePerShareNonMarketableSecurity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Per Share Non Marketable Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValuePerShareNonMarketableSecurity_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair Value Per Share Non Marketable Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValuePerShareNonMarketableSecurity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Value per Common Warrant on a non-marketable basis</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trading Symbol</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trading Symbol</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investments, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and Equipment, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueAdjustment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Fair Value Adjustment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueAdjustment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value warrant liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transaction [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party Transaction [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Proceeds from Notes Payable, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Finite-Lived Intangible Assets [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of intangible assets gross carrying amount and accumulated amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueAssumption_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Black-Scholes value (per share)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueAssumption_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement Option Fair Value Assumption</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueAssumption_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement Option Fair Value Assumption</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Flows from financing activities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term (years)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Accrued Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Accrued Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable and Accrued Liabilities Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityExTransitionPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Ex Transition Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityExTransitionPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Ex Transition Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccountsPayableCurrentRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable Current Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccountsPayableCurrentRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accounts Payable Current Related Parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccountsPayableCurrentRelatedParties_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Less: Imputed interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, Undiscounted Excess Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: Imputed interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SponsorTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sponsor Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SponsorTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sponsor Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Components [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Components [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Standards Update 2023-09 Prospective [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ASU 2023-09</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accounts Payable, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total other expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non operating Income Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Component [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Component [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TrancheObligationsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">tranche obligations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TrancheObligationsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Tranche Obligations [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TrancheObligationsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Tranche Obligations [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Activity [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of stock-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByAssetClassAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Class [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Reconciles the Undiscounted Future Minimum Lease Payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DepositoryRiskMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depository Risk [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DepositoryRiskMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Depository Risk [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill and Intangible Assets Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Revenue, Noncurrent, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsDeferredIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Deferred Income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsDeferredIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Consideration Paid and The Fair Value of Assets Acquired, and Liabilities Assumed</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentAnnualReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Annual Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxAssetsInterestLimitationCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest limitation carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxAssetsInterestLimitationCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Interest Limitation Carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DeferredTaxAssetsInterestLimitationCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred Tax Assets Interest Limitation Carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Percentage Bearing Fixed Interest, Percentage Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate for term loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">IPO [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">IPO</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Machinery and Equipment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Machinery and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MajorCustomersAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MajorCustomersAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Notes Payable, Noncurrent, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Notes payable, non-current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes payable, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Interest-Bearing</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest reserve accounts</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation, Depletion and Amortization, Nonproduction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Depreciation, Depletion and Amortization, Nonproduction, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation and amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepreciationAndAmortization_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Depreciation and amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance Of Underwriting Discounts And Commissions And Other Offering Costs Shares During Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance Of Underwriting Discounts And Commissions And Other Offering Costs Shares During Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance Of Underwriting Discounts And Commissions And Other Offering Costs, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RedwireCorporationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Redwire Corporation [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RedwireCorporationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Redwire Corporation [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RedwireCorporationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redwire Corporation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesD-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Series D-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesD-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Series D-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesD-1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Convertible Series D-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maximum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Liabilities, Fair Value Disclosure, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total financial liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-Average Exercise Price, Options exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Accumulated Amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Amortization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Expense, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Prepaid Expense, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Advanced payments, current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Value, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, $0.0001 par value, 1,000,000 and 154,397 shares authorized as of September 30, 2025 and December 31, 2024, respectively; 148,138 and 13,241 shares issued and outstanding as of September 30, 2025 and December 31, 2024, respectively</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SponsorTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sponsor Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SponsorTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sponsor Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss) Available to Common Stockholders, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net loss available to common stockholders, diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Principal Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Principal payments on finance leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForFees_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments for Other Fees</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForFees_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Annual fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForFees_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">lender fees</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants and Rights Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WarrantsAndRightsOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Including Portion Attributable to Noncontrolling Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Equity, ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Equity, beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total stockholders' equity (deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock Dividends, Income Statement Impact</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: dividends accrued on preferred stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Less: Accretion of dividends</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Less: Accretion of dividends</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Operating Loss Carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Tax Assets, Operating Loss Carryforwards, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net operating loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of Long-Lived Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfFinancingCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization of Debt Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AmortizationOfFinancingCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of debt issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DefaultScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Default Scenario</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DefaultScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Default Scenario [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_DefaultScenarioMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Default Scenario [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonrecurringAdjustmentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Nonrecurring Adjustment [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityPublicFloat_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Public Float</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Right of Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Right of Use Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Volatility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Expected volatility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, shares authorized (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaintainMinimumInterestReserveAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maintain Minimum Interest Reserve Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaintainMinimumInterestReserveAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Maintain Minimum Interest Reserve Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaintainMinimumInterestReserveAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maintain minimum interest reserve amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentAnnualPrincipalPayment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Repayment of debts</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentAnnualPrincipalPayment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Annual Principal Payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transaction [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RelatedPartyTransactionLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party Transaction [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Combination [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityRegistrantName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Registrant Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityRegistrantName_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Registrant Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Intangible assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Goodwill and Intangible Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Tax Liabilities, Goodwill and Intangible Assets, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of short-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleOfShortTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Sale of Short-Term Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Voluntary Filers</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerConcentrationRiskMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Concentration Risk [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CustomerConcentrationRiskMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer Concentration Risk [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueArrangementLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Arrangement [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Other expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Nonoperating Income (Expense), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other income (expense), net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid in Capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional paid-in capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred State and Local Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccruedPayrollCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payroll-related expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccruedPayrollCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Payroll Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AccruedPayrollCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued Payroll Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesDPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series D Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesDPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series D Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Events [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Presents The Key Inputs Applied In The Valuation [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule Of Presents The KeyInputs Applied In The Valuation [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Presents the Key Inputs Applied in the Valuations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cybersecurity Risk Management Positions or Committees Responsible [Flag]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Provision for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Income tax benefit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Income tax benefit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Effective income tax rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance of Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from the issuance of Common stock, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from issuance of common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoninterestExpenseInvestmentAdvisoryFees_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment Advisory Fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoninterestExpenseInvestmentAdvisoryFees_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consulting and advisory services fees</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Tables Present the Key Inputs Applied In the Valuations Warrants</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Common Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Common Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskCreditRisk_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk, Credit Risk, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskCreditRisk_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration of Credit Risk</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConcentrationRiskCreditRisk_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Allowance for Credit Losses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Remaining Lease Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Lease Remaining Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Compensation Related Costs, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-Based Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidation Items [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_OtherRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Purchases of property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares, Granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepositLiabilitiesAccruedInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deposit Liabilities, Accrued Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DepositLiabilitiesAccruedInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProbabilityWeightedFairValuePerCommonWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Probability Weighted Fair Value Per Common Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProbabilityWeightedFairValuePerCommonWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Probability Weighted Fair Value Per Common Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProbabilityWeightedFairValuePerCommonWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total probability weighted value per Common Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RightOfUseAssetObtainedInForLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Right Of Use Asset ObtainedIn For LeaseLiability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RightOfUseAssetObtainedInForLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Right Of Use Asset ObtainedIn For LeaseLiability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RightOfUseAssetObtainedInForLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right of use For lease liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Paid, State and Local, after Refund Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Income Tax Paid, State and Local, after Refund Received, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">United States - state and local</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected term (in years)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred income taxe</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock, Number of Shares Issued in Transaction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares issued in transaction</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Number of shares sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2029</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AverageFairValuePerWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Average Fair Value Per Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AverageFairValuePerWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Average Fair Value Per Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_AverageFairValuePerWarrant_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Average value per Series J Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, New Issues</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of stock, net (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common Stock, Initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease, Cost [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Temporary equity, shares authorized (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares, Vested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Number of shares, Vested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationIntegrationRelatedCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Integration-Related Cost, Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationIntegrationRelatedCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition related costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RestrictedCashMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RestrictedCashMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Restricted Cash [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RestrictedCashMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss per share attributable to common stockholders - diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Auction Market Preferred Securities, Stock Series, Title [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Segment Reporting Information, by Segment [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Segment Reporting Information, by Segment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Segments [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Segments [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LandAndLandImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Land and Land Improvements [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LandAndLandImprovementsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Land and land improvements [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IPOClosingPreferredStockDividendMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">IPO Closing Preferred Stock Dividend [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IPOClosingPreferredStockDividendMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">IPO Closing Preferred Stock Dividend [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_IPOClosingPreferredStockDividendMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">IPO Closing Preferred Stock Dividend</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetAcquisitionAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Acquisition [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ClassA1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Class A-1 Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ClassA1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class A-1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ClassA1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class A-1 Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated Useful Lives, Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">City Area Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">City Area Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Pro Forma Information, Pro Forma Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business combination post-acquisition revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Pro forma revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Net of Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Comprehensive Income (Loss), Net of Tax, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net income and comprehensive income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance lease liability, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Finance lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Lines of Credit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Proceeds from Lines of Credit, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from Revolving Credit Facility</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument, Face Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Principal amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsFiniteLivedPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Intangible Assets, Finite-Lived, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IntangibleAssetsFiniteLivedPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Intangible Assets, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Line of Credit Facility, Maximum Borrowing Capacity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum borrowing capacity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessAcquisitionLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Combination [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerFiveMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Customer Five [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerFiveMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Customer Five [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_CustomerFiveMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer 5</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermALoansMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Term A Loans [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermALoansMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Term A Loans [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_TermALoansMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term A Loans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Thereafter</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finite-Lived Intangible Assets, Amortization Expense, Rolling after Year Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets, Tax Credit Carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Tax Assets, Tax Credit Carryforwards, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsOfUnderwritngDiscounts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds Of Underwritng Discounts</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsOfUnderwritngDiscounts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds Of Underwritng Discounts</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ProceedsOfUnderwritngDiscounts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds of underwritng discounts</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on derivatives</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Revenue by Major Customers, by Reporting Segments [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Weighted-AverageRemainingLeaseTermYears_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted-average remaining lease term (years):</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Weighted-AverageRemainingLeaseTermYears_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted-average remaining lease term (years):</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Gain (Loss) from Litigation Settlement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gain (Loss) from Litigation Settlement, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain from settlement of contingent liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Noncash or Part Noncash Acquisition, Intangible Assets Acquired</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition of internal-use software licenses and obligations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Weighted Average Remaining Lease Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Summary of Tax Credit Carryforwards [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Carryforwards</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingInformationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting Information [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingInformationLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment Reporting Information [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series J Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series J Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesJPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series J Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease, Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpacecraftSolutionsRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Spacecraft Solutions Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpacecraftSolutionsRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Spacecraft Solutions Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SpacecraftSolutionsRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Spacecraft Solutions Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Uncertain tax position liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Uncertain Tax Position Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Uncertain Tax Position Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationAnnualInstallments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contractual Obligation, Annual Installments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationAnnualInstallments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Obligation, Annual Installments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractualObligationAnnualInstallments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual obligation, annual installments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Property and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Right-of-Use Asset Obtained in Exchange for Finance Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use asset acquired in exchange for finance lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">International</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Foreign Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LoansAndLeasesReceivableAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Loans and Leases Receivable, Allowance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LoansAndLeasesReceivableAllowance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Allowance for credit losses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RentIncraeseAnuallyInPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Rent Incraese anually in Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RentIncraeseAnuallyInPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Rent Incraese anually in Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_RentIncraeseAnuallyInPercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Rent Incraese annual by Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Debt, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: Current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesSeedPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series Seed Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesSeedPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series Seed Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesSeedPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series Seed Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee Benefits and Share-Based Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Noncash Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Compensation Expense, Excluding Cost of Good and Service Sold</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments of Stock Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payments of offering costs associated with IPO</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Costs associated with initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating leases</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Weighted Average Discount Rate, Percent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Operating lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liability, less current portion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 1 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 1</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfStockLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureTextBlockAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disclosure Text Block [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash provided by financing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Notes Payable, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Notes payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lease, Cost [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Lease Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unamortized debt issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unamortized Debt Issuance Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorLocation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Location</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DevelopedTechnologyRightsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Developed Technology Rights [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DevelopedTechnologyRightsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Developed technology</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Assets Weighted Average</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Assets Weighted Average</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total probability weighted average value per Series J Warrant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Option, Increase for Cost Recognition, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share-Based Payment Arrangement, Option, Increase for Cost Recognition, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense) [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other income (expense):</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Other expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Contract [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaterialMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Material</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaterialMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Material [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaterialMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Material Member</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForMortgageDeposits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments for Mortgage Deposits</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsForMortgageDeposits_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments on mortgage principal</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Receivable, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired, Investment in Debt and Equity Securities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxAuthorityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Jurisdiction [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Interactive Data Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Interactive Data Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities, Gross [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredTaxLiabilitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Lease term and discount rate</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Lease Income [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaterialsAndConsumables_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Materials and Consumables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaterialsAndConsumables_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Materials and Consumables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaterialsAndConsumables_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Materials and consumables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_MaterialsAndConsumables_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Materials and consumables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contractual Interest Expense on Prepetition Liabilities Not Recognized in Statement of Operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contractual interest expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Furniture and Fixtures [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FurnitureAndFixturesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Furniture and fixtures</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Preferred Stock, Shares Issued upon Conversion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible preferred stock, shares issued upon conversion</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaidInKindInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Paid-in-Kind Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaidInKindInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capitalized interest (paid-in-kind)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInventoryWrite-Off_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non-Cash Inventory Write-Off</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInventoryWrite-Off_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-Cash Inventory Write-Off</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_Non-CashInventoryWrite-Off_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-cash inventory write-off</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnbilledReceivablesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unbilled Receivables, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UnbilledReceivablesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unbilled receivables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InterestExpenseOnPurchaseAndLeasebackAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense On Purchase and Leaseback Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InterestExpenseOnPurchaseAndLeasebackAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest Expense On Purchase and Leaseback Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_InterestExpenseOnPurchaseAndLeasebackAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expense on purchase and leaseback agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Asset, after Allowance for Credit Loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Contract with Customer, Asset, after Allowance for Credit Loss, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerAssetNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement Option Outstanding Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement Option Outstanding Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesSeedPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Series Seed Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesSeedPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Convertible Series Seed Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConvertibleSeriesSeedPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Series Seed Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Tax Identification Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Tax Identification Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PrepaidPurchaseCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid purchase credit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PrepaidPurchaseCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Purchase Credit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_PrepaidPurchaseCredit_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Prepaid Purchase Credit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Share price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Repayments of Notes Payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Repayment of notes payable - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RepaymentsOfNotesPayable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Repayment of notes payable - related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Debt, Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Term Debt, Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract With Customer Loss Provision Period Increase Decrease</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Loss Provision Period Increase Decrease</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract With Customer Loss Provision Period Increase Decrease</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments to Additional Paid in Capital, Increase in Carrying Amount of Redeemable Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accretion of redeemable convertible preferred stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Preferred stock, carrying amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance or Sale of Equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Proceeds from Issuance or Sale of Equity, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Local Phone Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Local Phone Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStockShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exercise Of Common Warrants Into Common Stock Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStockShares_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exercise Of Common Warrants Into Common Stock Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStockShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net exercise of Common Warrants to common stock in connection with initial public offering, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AuditorOpinionTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Opinion [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease, Liability, to be Paid, Year Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2027</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConsultingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consulting Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConsultingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Consulting Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ConsultingAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consulting Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligationPercentage_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue, Remaining Performance Obligation, Percentage</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Policies [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueByArrangementDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue, by Arrangement, Disclosure [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueByArrangementDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Deferred Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisaggregationOfRevenueLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disaggregation of Revenue [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer, Excluding Assessed Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net sales- related parties</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2009/role/netLabel">Total Net Sales</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-3PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series D-3 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-3PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series D-3 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-3PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Convertible Series D-3 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_SeriesD-3PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series D-3 Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Lessee, Operating Lease, Liability, to be Paid, Year Four</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2029</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfStockDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ClassOfStockDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Options Available for Grant, Begining Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Options Available for Grant, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Professional Fees, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Professional services expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement by Share Based Payment Award, Options Available for Grant, Canceled in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share Based Compensation Arrangement by Share Based Payment Award, Options Available for Grant, Canceled in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Options Available for Grant, Options canceled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss) Available to Common Stockholders, Diluted [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Numerator:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Accounts Payable and Accrued Liabilities [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Accrued Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SelfInsuranceReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Self Insurance Reserve</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SelfInsuranceReserve_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Insurance premium reserve</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfStockByClassTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock, Class of Stock [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Emerging Growth Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityEmergingGrowthCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Emerging Growth Company</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Indefinite-Lived Intangible Assets [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AreaOfLand_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Area Of Land</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AreaOfLand_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Area of Land</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Goodwill</link:label>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SoftwareDevelopmentMember" xlink:to="us-gaap_SoftwareDevelopmentMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AggregateOfNumberOfWarrantsToPurchase" xlink:to="fly_AggregateOfNumberOfWarrantsToPurchase_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskByTypeAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiability" xlink:to="us-gaap_FinanceLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsGrossAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityIncorporationStateCountryCode" xlink:to="dei_EntityIncorporationStateCountryCode_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesIssued" xlink:to="us-gaap_PreferredStockSharesIssued_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TimeDepositsMember" xlink:to="fly_TimeDepositsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsPayable" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:to="us-gaap_ScheduleOfDebtInstrumentsTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCurrentReportingStatus" xlink:to="dei_EntityCurrentReportingStatus_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DeemedSharesIssuedPricePerShare" xlink:to="fly_DeemedSharesIssuedPricePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpensesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AverageValuePerUnitAsPerMonteCarloSimulations" xlink:to="fly_AverageValuePerUnitAsPerMonteCarloSimulations_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel2Member" xlink:to="us-gaap_FairValueInputsLevel2Member_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" xlink:to="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNet" xlink:to="us-gaap_DeferredTaxAssetsNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SMINoteMember" xlink:to="fly_SMINoteMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DiscountForLackOfMarketability" xlink:to="fly_DiscountForLackOfMarketability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IssuanceOfPreferredStockDividend" xlink:to="fly_IssuanceOfPreferredStockDividend_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:to="us-gaap_TemporaryEquityParOrStatedValuePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationIncurredCost" xlink:to="fly_BusinessCombinationIncurredCost_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:to="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxUncertaintiesAbstract" xlink:to="us-gaap_IncomeTaxUncertaintiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductOrServiceAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockVotingRights" xlink:to="us-gaap_PreferredStockVotingRights_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalPeriodFocus" xlink:to="dei_DocumentFiscalPeriodFocus_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_RevenueFromContractWithCustomerAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SecuredOverFinancingRateMember" xlink:to="fly_SecuredOverFinancingRateMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityShellCompany" xlink:to="dei_EntityShellCompany_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquitySharesOutstanding" xlink:to="us-gaap_TemporaryEquitySharesOutstanding_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractualObligation" xlink:to="us-gaap_ContractualObligation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAccruedLiabilitiesCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:to="us-gaap_SegmentReportingPolicyPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:to="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableCurrent" xlink:to="us-gaap_NotesPayableCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesJWarrantsMember" xlink:to="fly_SeriesJWarrantsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:to="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NumberOfShareSold" xlink:to="fly_NumberOfShareSold_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TaxReconciliationNotRequired" xlink:to="fly_TaxReconciliationNotRequired_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Rule10B51ArrModifiedFlag" xlink:to="fly_Rule10B51ArrModifiedFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashNoncurrent" xlink:to="us-gaap_RestrictedCashNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PricePerSquareFoot" xlink:to="fly_PricePerSquareFoot_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract" xlink:to="us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesGross" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock" xlink:to="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantMember" xlink:to="us-gaap_WarrantMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFilerCategory" xlink:to="dei_EntityFilerCategory_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansHeldForSaleMaturityDate" xlink:to="us-gaap_LoansHeldForSaleMaturityDate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" xlink:to="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VehiclesMember" xlink:to="us-gaap_VehiclesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_PayablesAndAccrualsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PropertyAndEquipmentAdditionsInAccountsPayable" xlink:to="fly_PropertyAndEquipmentAdditionsInAccountsPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_UnauditedProFormaInformationMember" xlink:to="fly_UnauditedProFormaInformationMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CommonStockWarrantsMember" xlink:to="fly_CommonStockWarrantsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:to="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_OperatingLossCarryforwardsTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SciTecMember" xlink:to="fly_SciTecMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag" xlink:to="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:to="us-gaap_CashAndCashEquivalentsFairValueDisclosure_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ExtinguishmentOfDebtAmount" xlink:to="us-gaap_ExtinguishmentOfDebtAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssuedPricePerShare" xlink:to="us-gaap_SharesIssuedPricePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" xlink:to="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventLineItems" xlink:to="us-gaap_SubsequentEventLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag" xlink:to="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentsIncorporatedByReferenceTextBlock" xlink:to="dei_DocumentsIncorporatedByReferenceTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet" xlink:to="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxAuthorityAxis" xlink:to="us-gaap_IncomeTaxAuthorityAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NonCancelableSubscriptionBasedServicesMember" xlink:to="fly_NonCancelableSubscriptionBasedServicesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:to="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CumulativeOwnershipPeriod" xlink:to="fly_CumulativeOwnershipPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes" xlink:to="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesJWarrantMember" xlink:to="fly_SeriesJWarrantMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFinanceCostsNet" xlink:to="us-gaap_DeferredFinanceCostsNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" xlink:to="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember" xlink:to="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyMember" xlink:to="us-gaap_RelatedPartyMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockAmountConverted1" xlink:to="us-gaap_ConversionOfStockAmountConverted1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_NotesPayableAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ShareRepurchaseProgramAxis" xlink:to="srt_ShareRepurchaseProgramAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_CurrencyAxis" xlink:to="srt_CurrencyAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FireflyMember" xlink:to="fly_FireflyMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VestingDomain" xlink:to="us-gaap_VestingDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisaggregationOfRevenueTable" xlink:to="us-gaap_DisaggregationOfRevenueTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleLeasebackTransactionNameDomain" xlink:to="us-gaap_SaleLeasebackTransactionNameDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable" xlink:to="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TrademarksAndTradeNamesMember" xlink:to="us-gaap_TrademarksAndTradeNamesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeFinanceLeaseDescriptionAbstract" xlink:to="us-gaap_LesseeFinanceLeaseDescriptionAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:to="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasic" xlink:to="us-gaap_EarningsPerShareBasic_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:to="us-gaap_DisaggregationOfRevenueTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssued1" xlink:to="us-gaap_StockIssued1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SpecificAdditionalInterestRate" xlink:to="fly_SpecificAdditionalInterestRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:to="us-gaap_InterestIncomeExpenseNonoperatingNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevolvingCreditFacilityMember" xlink:to="us-gaap_RevolvingCreditFacilityMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember" xlink:to="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommodityContractAssetCurrent" xlink:to="us-gaap_CommodityContractAssetCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_EntityWideRevenueMajorCustomerLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPaidFederalAfterRefundReceived" xlink:to="us-gaap_IncomeTaxPaidFederalAfterRefundReceived_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PaymentsOnNotesPayable" xlink:to="fly_PaymentsOnNotesPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OptionIndexedToIssuersEquityShares" xlink:to="us-gaap_OptionIndexedToIssuersEquityShares_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DomesticCountryMember" xlink:to="us-gaap_DomesticCountryMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ShareRepurchaseProgramDomain" xlink:to="srt_ShareRepurchaseProgramDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_InterestExpenseContractual" xlink:to="fly_InterestExpenseContractual_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_WeightedAverageFairValuePerWarrant" xlink:to="fly_WeightedAverageFairValuePerWarrant_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_WeightedAveragePricePerShare" xlink:to="fly_WeightedAveragePricePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationTable" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsDomain" xlink:to="srt_ConsolidationItemsDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntitySmallBusiness" xlink:to="dei_EntitySmallBusiness_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ProceedsFromRepaymentOfEmployeeNote" xlink:to="fly_ProceedsFromRepaymentOfEmployeeNote_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IncreaseDecreaseAccountsPayableRelatedParties" xlink:to="fly_IncreaseDecreaseAccountsPayableRelatedParties_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_OtherCommitmentsLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccretionExpense" xlink:to="us-gaap_AccretionExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockMember" xlink:to="us-gaap_PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityWellKnownSeasonedIssuer" xlink:to="dei_EntityWellKnownSeasonedIssuer_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockPricePerShare" xlink:to="us-gaap_SaleOfStockPricePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentForeignTaxExpenseBenefit" xlink:to="us-gaap_CurrentForeignTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PercentageOfNonAccruingOrignalIssuePricePerShare" xlink:to="fly_PercentageOfNonAccruingOrignalIssuePricePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LeasesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonClassAMember" xlink:to="us-gaap_CommonClassAMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiability" xlink:to="us-gaap_ContractWithCustomerLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_LesseeLeaseDescriptionLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_LeaseRemainingLeaseTerm" xlink:to="fly_LeaseRemainingLeaseTerm_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductsAndServicesDomain" xlink:to="srt_ProductsAndServicesDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseInterestExpense" xlink:to="us-gaap_FinanceLeaseInterestExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerSharePolicyTextBlock" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressPostalZipCode" xlink:to="dei_EntityAddressPostalZipCode_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:to="us-gaap_TradeAndOtherAccountsReceivablePolicy_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:to="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Non-CashInterestExpense" xlink:to="fly_Non-CashInterestExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic" xlink:to="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NonRule10B51ArrModifiedFlag" xlink:to="fly_NonRule10B51ArrModifiedFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementOptionFairValue" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskRoleOfManagementTextBlock" xlink:to="cyd_CybersecurityRiskRoleOfManagementTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TaxCreditCarryforwardAmount" xlink:to="us-gaap_TaxCreditCarryforwardAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BelcanLLCMember" xlink:to="fly_BelcanLLCMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine1" xlink:to="dei_EntityAddressAddressLine1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilities" xlink:to="us-gaap_DeferredIncomeTaxLiabilities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TwoThousandSeventeenEquityIncentivePlanMember" xlink:to="fly_TwoThousandSeventeenEquityIncentivePlanMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPolicyTextBlock" xlink:to="us-gaap_IncomeTaxPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:to="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag" xlink:to="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" xlink:to="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:to="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy" xlink:to="us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CumulativeOwnershipPercentage" xlink:to="fly_CumulativeOwnershipPercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseRightOfUseAsset" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IncreaseDecreaseInAdvancedPayments" xlink:to="fly_IncreaseDecreaseInAdvancedPayments_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsGross" xlink:to="us-gaap_DeferredTaxAssetsGross_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:to="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TermLoanMember" xlink:to="fly_TermLoanMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxesPaidNet" xlink:to="us-gaap_IncomeTaxesPaidNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_GrossProfit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_TypeOfArrangementAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromCommissionsReceived" xlink:to="us-gaap_ProceedsFromCommissionsReceived_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PropertyAndEquipmentUsefulLivesTableTextBlock" xlink:to="fly_PropertyAndEquipmentUsefulLivesTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:to="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FollowOnOpportunitiesMember" xlink:to="fly_FollowOnOpportunitiesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationTechniqueAxis" xlink:to="us-gaap_ValuationTechniqueAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventTypeDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAdjustmentOfWarrants" xlink:to="us-gaap_FairValueAdjustmentOfWarrants_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestIncomeOperating" xlink:to="us-gaap_InterestIncomeOperating_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:to="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CustomerOneMember" xlink:to="fly_CustomerOneMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ContractorsAndOutsideServices" xlink:to="fly_ContractorsAndOutsideServices_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="currency_USD" xlink:to="currency_USD_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_TypeOfAdoptionMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingCostsAndExpenses" xlink:to="us-gaap_OperatingCostsAndExpenses_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PreferredStockIssuedAtAPurchasePrice" xlink:to="fly_PreferredStockIssuedAtAPurchasePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IPOScenarioMember" xlink:to="fly_IPOScenarioMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ExitFeePercentage" xlink:to="fly_ExitFeePercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ConvertibleSeriesSeed-1PreferredStockMember" xlink:to="fly_ConvertibleSeriesSeed-1PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAbstract" xlink:to="us-gaap_LiabilitiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BaseRateMember" xlink:to="us-gaap_BaseRateMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:to="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ChangeInRight-Of-UseAssets" xlink:to="fly_ChangeInRight-Of-UseAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerAssetPurchase" xlink:to="us-gaap_ContractWithCustomerAssetPurchase_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFinStmtErrorCorrectionFlag" xlink:to="dei_DocumentFinStmtErrorCorrectionFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CallOptionMember" xlink:to="us-gaap_CallOptionMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ContractualObligationCancellationFeePercentage" xlink:to="fly_ContractualObligationCancellationFeePercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ITRelatedEquipmentMember" xlink:to="fly_ITRelatedEquipmentMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BlackScholesMertonModelMember" xlink:to="us-gaap_BlackScholesMertonModelMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" xlink:to="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfRelatedPartyDebt" xlink:to="us-gaap_RepaymentsOfRelatedPartyDebt_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" xlink:to="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock" xlink:to="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ChangeOfControlScenarioMember" xlink:to="fly_ChangeOfControlScenarioMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerRelationshipsMember" xlink:to="us-gaap_CustomerRelationshipsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableOtherCurrentAndNoncurrent" xlink:to="us-gaap_AccountsPayableOtherCurrentAndNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressStateOrProvince" xlink:to="dei_EntityAddressStateOrProvince_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_MajoritySponsorMember" xlink:to="fly_MajoritySponsorMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:to="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" xlink:to="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_EquityMethodInvesteeNameDomain" xlink:to="srt_EquityMethodInvesteeNameDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetAcquisitionDomain" xlink:to="us-gaap_AssetAcquisitionDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesOutstanding" xlink:to="us-gaap_PreferredStockSharesOutstanding_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:to="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:to="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CostOfSalePolicyTextBlock" xlink:to="fly_CostOfSalePolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConversionOfStockSharesConverted1" xlink:to="us-gaap_ConversionOfStockSharesConverted1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableMember" xlink:to="us-gaap_AccountsReceivableMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesMPreferredStockMember" xlink:to="fly_SeriesMPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock" xlink:to="us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockOptionMember" xlink:to="us-gaap_StockOptionMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DavidWheelerMember" xlink:to="fly_DavidWheelerMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SwinglineLoans" xlink:to="fly_SwinglineLoans_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueCurrent" xlink:to="us-gaap_DeferredRevenueCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsNoncurrent" xlink:to="us-gaap_OtherAssetsNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" xlink:to="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_GainOnSettlementOfContingentLiabilities" xlink:to="fly_GainOnSettlementOfContingentLiabilities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CustomerFourMember" xlink:to="fly_CustomerFourMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_OperatingLossCarryforwardsLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantExercisePriceDecrease" xlink:to="us-gaap_WarrantExercisePriceDecrease_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseDebt" xlink:to="us-gaap_InterestExpenseDebt_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CustomerTwoMember" xlink:to="fly_CustomerTwoMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsDomain" xlink:to="us-gaap_OtherCommitmentsDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StateAndLocalJurisdictionMember" xlink:to="us-gaap_StateAndLocalJurisdictionMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="srt_NameOfMajorCustomerDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashMember" xlink:to="us-gaap_CashMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CashProceeds" xlink:to="fly_CashProceeds_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsTable" xlink:to="us-gaap_OtherCommitmentsTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationConsiderationTransferred1" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:to="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NonCashInterestIncome" xlink:to="fly_NonCashInterestIncome_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:to="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ChangeInFairValueOfWarrantLiability" xlink:to="fly_ChangeInFairValueOfWarrantLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SellingGeneralAndAdministrativeExpense" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PurchaseAccountingMember" xlink:to="fly_PurchaseAccountingMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" xlink:to="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_FinancialInstrumentAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrentAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TermBLoansMember" xlink:to="fly_TermBLoansMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonClassBMember" xlink:to="us-gaap_CommonClassBMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel3Member" xlink:to="us-gaap_FairValueInputsLevel3Member_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_SegmentReportingAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NotesPayableNoncurrent-RelatedParties" xlink:to="fly_NotesPayableNoncurrent-RelatedParties_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:to="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationsPolicy" xlink:to="us-gaap_BusinessCombinationsPolicy_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsPerShareDeclared" xlink:to="us-gaap_PreferredStockDividendsPerShareDeclared_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_WarrantsToPurchaseAnAggregate" xlink:to="fly_WarrantsToPurchaseAnAggregate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" xlink:to="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Weighted-AverageRemainingContractualTermUnvested" xlink:to="fly_Weighted-AverageRemainingContractualTermUnvested_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesJPreferredStockWarrantsMember" xlink:to="fly_SeriesJPreferredStockWarrantsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesSeed-1PreferredStockMember" xlink:to="fly_SeriesSeed-1PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesD-2PreferredStockMember" xlink:to="fly_SeriesD-2PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NonRecourseEmployeeLoans" xlink:to="fly_NonRecourseEmployeeLoans_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_RelatedPartyTransactionsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLossCarryforwards" xlink:to="us-gaap_OperatingLossCarryforwards_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseNoncurrent" xlink:to="us-gaap_PrepaidExpenseNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashAndCashEquivalents" xlink:to="us-gaap_RestrictedCashAndCashEquivalents_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashEquivalentsCurrent" xlink:to="us-gaap_RestrictedCashEquivalentsCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeLeasesPolicyTextBlock" xlink:to="us-gaap_LesseeLeasesPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts" xlink:to="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PaymentsToAcquireTimeDeposits" xlink:to="fly_PaymentsToAcquireTimeDeposits_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralAndAdministrativeExpenseMember" xlink:to="us-gaap_GeneralAndAdministrativeExpenseMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FairMarketValueOfSharePercentage" xlink:to="fly_FairMarketValueOfSharePercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_StockIssuedDuringPeriodSharesStockDividend" xlink:to="fly_StockIssuedDuringPeriodSharesStockDividend_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiability" xlink:to="us-gaap_OperatingLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorFirmId" xlink:to="dei_AuditorFirmId_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" xlink:to="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityReverseStockSplit" xlink:to="us-gaap_StockholdersEquityReverseStockSplit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfGoodwillTextBlock" xlink:to="us-gaap_ScheduleOfGoodwillTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DeferredTaxAssetsCapitalizedResearchCosts" xlink:to="fly_DeferredTaxAssetsCapitalizedResearchCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SubordinatedConvertiblePromissoryNoteMember" xlink:to="fly_SubordinatedConvertiblePromissoryNoteMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCashCurrent" xlink:to="us-gaap_RestrictedCashCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TestStandsMember" xlink:to="fly_TestStandsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativePremiumPaid" xlink:to="us-gaap_DerivativePremiumPaid_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_LeasesTextBlock" xlink:to="fly_LeasesTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ConvertibleNotesMember" xlink:to="fly_ConvertibleNotesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" xlink:to="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityCurrent" xlink:to="us-gaap_FinanceLeaseLiabilityCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeLeaseDescriptionTable" xlink:to="us-gaap_LesseeLeaseDescriptionTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_WeightedAverageFairValuePerShare" xlink:to="fly_WeightedAverageFairValuePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PercentageOfNonCompoundingRate" xlink:to="fly_PercentageOfNonCompoundingRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_LongTermDebtNet" xlink:to="fly_LongTermDebtNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_LiabilitiesNoncurrentAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:to="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProfitLoss" xlink:to="us-gaap_ProfitLoss_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SharesOutstandingPercentage" xlink:to="fly_SharesOutstandingPercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="us-gaap_LongtermDebtTypeDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationalAndOfferingCostsExpense" xlink:to="us-gaap_OrganizationalAndOfferingCostsExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAcquiredDuringPeriod" xlink:to="us-gaap_GoodwillAcquiredDuringPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_StatementScenarioAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" xlink:to="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentInformationLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquityAbstract" xlink:to="us-gaap_TemporaryEquityAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription" xlink:to="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesLeasingArrangements" xlink:to="us-gaap_DeferredTaxLiabilitiesLeasingArrangements_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPayableCurrentAndNoncurrent" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock" xlink:to="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SaleAndLeasebackTransactionsMember" xlink:to="fly_SaleAndLeasebackTransactionsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsTextBlock" xlink:to="us-gaap_SubsequentEventsTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:to="us-gaap_RelatedPartyTransactionsDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableRateDomain" xlink:to="us-gaap_VariableRateDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationTotalConsiderationPaid" xlink:to="fly_BusinessCombinationTotalConsiderationPaid_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" xlink:to="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock" xlink:to="us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:to="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementOfStockholdersEquityAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeriesCPreferredStockMember" xlink:to="us-gaap_SeriesCPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_WarrantsToPurchaseSeriesJPreferredStockMember" xlink:to="fly_WarrantsToPurchaseSeriesJPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="us-gaap_ValuationTechniqueDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeriesAPreferredStockMember" xlink:to="us-gaap_SeriesAPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses" xlink:to="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseholdImprovementsMember" xlink:to="us-gaap_LeaseholdImprovementsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine2" xlink:to="dei_EntityAddressAddressLine2_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueDisclosuresTextBlock" xlink:to="us-gaap_FairValueDisclosuresTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="us-gaap_BusinessCombinationConsiderationTransferredAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" xlink:to="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AllowanceForCreditLossesPolicyTextBlock" xlink:to="fly_AllowanceForCreditLossesPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsCurrent" xlink:to="us-gaap_OtherAssetsCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashInvestingAndFinancingItemsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:to="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PreferredStockConvertedToCommonSharesMember" xlink:to="fly_PreferredStockConvertedToCommonSharesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PrepaidAsset" xlink:to="fly_PrepaidAsset_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingOtherItemAmount" xlink:to="us-gaap_SegmentReportingOtherItemAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameDomain" xlink:to="us-gaap_PlanNameDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BuildingMember" xlink:to="us-gaap_BuildingMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostOfGoodsAndServicesSold" xlink:to="us-gaap_CostOfGoodsAndServicesSold_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock" xlink:to="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueOther" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRepaidPrincipal" xlink:to="us-gaap_DebtInstrumentRepaidPrincipal_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock" xlink:to="us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock" xlink:to="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CustomerMember" xlink:to="fly_CustomerMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FinancingAgreementMember" xlink:to="fly_FinancingAgreementMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_GSPrecisionMember" xlink:to="fly_GSPrecisionMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AEIndustrialMember" xlink:to="fly_AEIndustrialMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FairValuePerShareMarketableSecurity" xlink:to="fly_FairValuePerShareMarketableSecurity_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BacklogMember" xlink:to="fly_BacklogMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressCityOrTown" xlink:to="dei_EntityAddressCityOrTown_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCommitmentsAxis" xlink:to="us-gaap_OtherCommitmentsAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashFDICInsuredAmount" xlink:to="us-gaap_CashFDICInsuredAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_SecurityExchangeName" xlink:to="dei_SecurityExchangeName_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_CreditFacilityDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" xlink:to="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementMaximumValueRecognized" xlink:to="fly_ShareBasedCompensationArrangementMaximumValueRecognized_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:to="us-gaap_IntangibleAssetsDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CommonStockOutstandingCommonWarrantsExercised" xlink:to="fly_CommonStockOutstandingCommonWarrantsExercised_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="us-gaap_ConcentrationRiskTypeDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CompensationRelatedCostsAbstract" xlink:to="us-gaap_CompensationRelatedCostsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_StockholdersEquityNoteAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentIncreaseAccruedInterest" xlink:to="us-gaap_DebtInstrumentIncreaseAccruedInterest_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:to="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPaidNet" xlink:to="us-gaap_InterestPaidNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeMember" xlink:to="srt_RangeMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CommonWarrantsMember" xlink:to="fly_CommonWarrantsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1" xlink:to="us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentPeriodEndDate" xlink:to="dei_DocumentPeriodEndDate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_IcfrAuditorAttestationFlag" xlink:to="dei_IcfrAuditorAttestationFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationContingentConsiderationAsset" xlink:to="us-gaap_BusinessCombinationContingentConsiderationAsset_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CommonStockWarrantMember" xlink:to="fly_CommonStockWarrantMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:to="us-gaap_LineOfCreditFacilityCommitmentFeePercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetRentableArea" xlink:to="us-gaap_NetRentableArea_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NotesPayablePolicyTextBlock" xlink:to="fly_NotesPayablePolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:to="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockUnitsRSUMember" xlink:to="us-gaap_RestrictedStockUnitsRSUMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRecognitionPolicyTextBlock" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RedeemableConvertiblePreferredStockMember" xlink:to="us-gaap_RedeemableConvertiblePreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ScheduleOfRedeemableConvertiblePreferredStock" xlink:to="fly_ScheduleOfRedeemableConvertiblePreferredStock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VestingAxis" xlink:to="us-gaap_VestingAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_StatementClassOfStockAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FairValueInputsDiscountRate" xlink:to="fly_FairValueInputsDiscountRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_RedeemableConvertiblePreferredStocksMember" xlink:to="fly_RedeemableConvertiblePreferredStocksMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NonCancelableServiceContractCommitmentsMember" xlink:to="fly_NonCancelableServiceContractCommitmentsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:to="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" xlink:to="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationTechniqueOptionPricingModelMember" xlink:to="us-gaap_ValuationTechniqueOptionPricingModelMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:to="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:to="us-gaap_LossContingencyEstimateOfPossibleLoss_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" xlink:to="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="currency_AllCurrenciesDomain" xlink:to="currency_AllCurrenciesDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCash" xlink:to="us-gaap_RestrictedCash_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueArrangementByTypeTable" xlink:to="us-gaap_DeferredRevenueArrangementByTypeTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:to="us-gaap_FinanceLeaseRightOfUseAssetAmortization_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_VariableRateAxis" xlink:to="us-gaap_VariableRateAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFileNumber" xlink:to="dei_EntityFileNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AdvancedPaymentsPolicyTextBlock" xlink:to="fly_AdvancedPaymentsPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CustomerThreeMember" xlink:to="fly_CustomerThreeMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NumberOfReservedSharesIncreaseApproximately" xlink:to="fly_NumberOfReservedSharesIncreaseApproximately_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_InternalUseSoftwareMember" xlink:to="fly_InternalUseSoftwareMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CoverAbstract" xlink:to="dei_CoverAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:to="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Weighted-AverageDiscountRate" xlink:to="fly_Weighted-AverageDiscountRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DeferredRevenuePolicyTextBlock" xlink:to="fly_DeferredRevenuePolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock" xlink:to="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalLeaseObligationsIncurred" xlink:to="us-gaap_CapitalLeaseObligationsIncurred_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SalesRevenueNetMember" xlink:to="us-gaap_SalesRevenueNetMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="srt_ScenarioUnspecifiedDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_RPMCallOptionMember" xlink:to="fly_RPMCallOptionMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfOperatingSegments" xlink:to="us-gaap_NumberOfOperatingSegments_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_EquityMethodInvestmentMember" xlink:to="fly_EquityMethodInvestmentMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_LaunchRevenueMember" xlink:to="fly_LaunchRevenueMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingDisclosureTextBlock" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:to="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeriesBPreferredStockMember" xlink:to="us-gaap_SeriesBPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock" xlink:to="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_LesseeOperatingTotalLeaseLiability" xlink:to="fly_LesseeOperatingTotalLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:to="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquityLiquidationPreference" xlink:to="us-gaap_TemporaryEquityLiquidationPreference_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ContractualObligationNumberOfLaunches" xlink:to="fly_ContractualObligationNumberOfLaunches_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_SubsequentEventTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract" xlink:to="us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:to="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_OperatingLeaseRight-Of-UseAssetDecreased" xlink:to="fly_OperatingLeaseRight-Of-UseAssetDecreased_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:to="us-gaap_DeferredCostsCurrentAndNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOther" xlink:to="us-gaap_DeferredTaxAssetsOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:to="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesOther" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnDispositionOfAssets1" xlink:to="us-gaap_GainLossOnDispositionOfAssets1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationCashConsiderationPaid" xlink:to="fly_BusinessCombinationCashConsiderationPaid_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" xlink:to="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesCPurchaseAgreementMember" xlink:to="fly_SeriesCPurchaseAgreementMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonrecurringAdjustmentAxis" xlink:to="us-gaap_NonrecurringAdjustmentAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligation" xlink:to="us-gaap_RevenueRemainingPerformanceObligation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementProcessesIntegratedFlag" xlink:to="cyd_CybersecurityRiskManagementProcessesIntegratedFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentTransitionReport" xlink:to="dei_DocumentTransitionReport_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:to="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermInvestments" xlink:to="us-gaap_ShortTermInvestments_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_OperatingExpenses_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpense" xlink:to="us-gaap_ResearchAndDevelopmentExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ProceedsFromNotesPayableRelatedParties" xlink:to="fly_ProceedsFromNotesPayableRelatedParties_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredStockMember" xlink:to="us-gaap_ConvertiblePreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements" xlink:to="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_OtherNotesMember" xlink:to="fly_OtherNotesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ContractWithCustomerLossProvision" xlink:to="fly_ContractWithCustomerLossProvision_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BrokerageCommissionsRevenue" xlink:to="us-gaap_BrokerageCommissionsRevenue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueOptionChangesInFairValueGainLoss1" xlink:to="us-gaap_FairValueOptionChangesInFairValueGainLoss1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" xlink:to="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PaymentForPurchaseAndLeasebackAgreements" xlink:to="fly_PaymentForPurchaseAndLeasebackAgreements_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SpaceflightMember" xlink:to="fly_SpaceflightMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" xlink:to="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareTextBlock" xlink:to="us-gaap_EarningsPerShareTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesIssued" xlink:to="us-gaap_SharesIssued_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:to="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationGoodwillAbstract" xlink:to="us-gaap_BusinessCombinationGoodwillAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesOther" xlink:to="us-gaap_DeferredTaxLiabilitiesOther_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComputerEquipmentMember" xlink:to="us-gaap_ComputerEquipmentMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock" xlink:to="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RealEstateInventoryCapitalizedInterestCosts" xlink:to="us-gaap_RealEstateInventoryCapitalizedInterestCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DividendsPreferredStockCash" xlink:to="us-gaap_DividendsPreferredStockCash_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseCost" xlink:to="us-gaap_OperatingLeaseCost_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DeferredTaxLiabilitiesRightOfUseAssets" xlink:to="fly_DeferredTaxLiabilitiesRightOfUseAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareBasicLineItems" xlink:to="us-gaap_EarningsPerShareBasicLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DiscountsOnUnderwriting" xlink:to="fly_DiscountsOnUnderwriting_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationPriceOfAcquisitionExpected" xlink:to="us-gaap_BusinessCombinationPriceOfAcquisitionExpected_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConstructionInProgressMember" xlink:to="us-gaap_ConstructionInProgressMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_NumberOfReservedSharesIncrease" xlink:to="fly_NumberOfReservedSharesIncrease_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationEquityConsiderationPaid" xlink:to="fly_BusinessCombinationEquityConsiderationPaid_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentFiscalYearFocus" xlink:to="dei_DocumentFiscalYearFocus_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrent" xlink:to="us-gaap_AccountsPayableCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:to="us-gaap_SaleLeasebackTransactionDescriptionAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseNonoperating" xlink:to="us-gaap_InterestExpenseNonoperating_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:to="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" xlink:to="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ResearchAndDevelopmentExpenseMember" xlink:to="us-gaap_ResearchAndDevelopmentExpenseMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_EventProbabilityPercentage" xlink:to="fly_EventProbabilityPercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:to="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenue" xlink:to="us-gaap_DeferredRevenue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:to="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeBasisSpreadOnVariableRate" xlink:to="us-gaap_DerivativeBasisSpreadOnVariableRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FinanceLeaseLiabilityTotalPayments" xlink:to="fly_FinanceLeaseLiabilityTotalPayments_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesD-1PreferredStockMember" xlink:to="fly_SeriesD-1PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:to="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromStockOptionsExercised" xlink:to="us-gaap_ProceedsFromStockOptionsExercised_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_VotingPowerPercentage" xlink:to="fly_VotingPowerPercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:to="us-gaap_StockIssuedDuringPeriodValueAcquisitions_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination" xlink:to="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod" xlink:to="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" xlink:to="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:to="us-gaap_BusinessAcquisitionProFormaInformationTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PaymentsOfDebtIssuanceCostsRelatedParties" xlink:to="fly_PaymentsOfDebtIssuanceCostsRelatedParties_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeInstrumentRiskAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_WarrantLiabilitiesPolicyTextBlock" xlink:to="fly_WarrantLiabilitiesPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AssetsAndLiabilitiesLesseeTableTextBlock" xlink:to="fly_AssetsAndLiabilitiesLesseeTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsFairValueDisclosure" xlink:to="us-gaap_AssetsFairValueDisclosure_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskPercentage1" xlink:to="us-gaap_ConcentrationRiskPercentage1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DevelopedTechnologyMember" xlink:to="fly_DevelopedTechnologyMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Revenues" xlink:to="us-gaap_Revenues_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_OtherArrangementsMember" xlink:to="fly_OtherArrangementsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_Security12bTitle" xlink:to="dei_Security12bTitle_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesD-4PreferredStockMember" xlink:to="fly_SeriesD-4PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ExerciseOfCommonWarrantsIntoCommonStock" xlink:to="fly_ExerciseOfCommonWarrantsIntoCommonStock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" xlink:to="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MoneyMarketFundsMember" xlink:to="us-gaap_MoneyMarketFundsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureTextBlock" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquitySharesIssued" xlink:to="us-gaap_TemporaryEquitySharesIssued_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SaleAndLeasebackPolicyTextBlock" xlink:to="fly_SaleAndLeasebackPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" xlink:to="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentInformationTable" xlink:to="dei_DocumentInformationTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseRightOfUseAsset" xlink:to="us-gaap_FinanceLeaseRightOfUseAsset_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" xlink:to="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LettersOfCreditOutstandingAmount" xlink:to="us-gaap_LettersOfCreditOutstandingAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare" xlink:to="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationDisclosureTextBlock" xlink:to="us-gaap_BusinessCombinationDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FairValuePerShareNonMarketableSecurity" xlink:to="fly_FairValuePerShareNonMarketableSecurity_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementLocationAxis" xlink:to="us-gaap_IncomeStatementLocationAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:to="us-gaap_EquityMethodInvestmentsFairValueDisclosure_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesFairValueAdjustment" xlink:to="us-gaap_LiabilitiesFairValueAdjustment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromNotesPayable" xlink:to="us-gaap_ProceedsFromNotesPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementOptionFairValueAssumption" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValueAssumption_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityExTransitionPeriod" xlink:to="dei_EntityExTransitionPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AccountsPayableCurrentRelatedParties" xlink:to="fly_AccountsPayableCurrentRelatedParties_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SponsorTypeDomain" xlink:to="fly_SponsorTypeDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableCurrentAndNoncurrent" xlink:to="us-gaap_AccountsPayableCurrentAndNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_NonoperatingIncomeExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_EquityComponentDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TrancheObligationsMember" xlink:to="fly_TrancheObligationsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueByAssetClassAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:to="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DepositoryRiskMember" xlink:to="fly_DepositoryRiskMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueNoncurrent" xlink:to="us-gaap_DeferredRevenueNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsDeferredIncome" xlink:to="us-gaap_DeferredTaxAssetsDeferredIncome_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:to="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentAnnualReport" xlink:to="dei_DocumentAnnualReport_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DeferredTaxAssetsInterestLimitationCarryforwards" xlink:to="fly_DeferredTaxAssetsInterestLimitationCarryforwards_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:to="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IPOMember" xlink:to="us-gaap_IPOMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MachineryAndEquipmentMember" xlink:to="us-gaap_MachineryAndEquipmentMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_MajorCustomersAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermNotesPayable" xlink:to="us-gaap_LongTermNotesPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent" xlink:to="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationAndAmortization" xlink:to="us-gaap_DepreciationAndAmortization_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" xlink:to="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_RedwireCorporationMember" xlink:to="fly_RedwireCorporationMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ConvertibleSeriesD-1PreferredStockMember" xlink:to="fly_ConvertibleSeriesD-1PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesFairValueDisclosure" xlink:to="us-gaap_LiabilitiesFairValueDisclosure_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeAxis" xlink:to="srt_RangeAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseCurrent" xlink:to="us-gaap_PrepaidExpenseCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SponsorTypeAxis" xlink:to="fly_SponsorTypeAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentMember" xlink:to="us-gaap_PropertyPlantAndEquipmentMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeasePrincipalPayments" xlink:to="us-gaap_FinanceLeasePrincipalPayments_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForFees" xlink:to="us-gaap_PaymentsForFees_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantsAndRightsOutstanding" xlink:to="us-gaap_WarrantsAndRightsOutstanding_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:to="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfFinancingCosts" xlink:to="us-gaap_AmortizationOfFinancingCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_DefaultScenarioMember" xlink:to="fly_DefaultScenarioMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonrecurringAdjustmentDomain" xlink:to="us-gaap_NonrecurringAdjustmentDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPublicFloat" xlink:to="dei_EntityPublicFloat_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_MaintainMinimumInterestReserveAmount" xlink:to="fly_MaintainMinimumInterestReserveAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAnnualPrincipalPayment" xlink:to="us-gaap_DebtInstrumentAnnualPrincipalPayment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_RelatedPartyTransactionLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:to="us-gaap_RevenueFromContractWithCustomerTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureTextBlock" xlink:to="us-gaap_DebtDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:to="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfShortTermInvestments" xlink:to="us-gaap_ProceedsFromSaleOfShortTermInvestments_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityVoluntaryFilers" xlink:to="dei_EntityVoluntaryFilers_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerConcentrationRiskMember" xlink:to="us-gaap_CustomerConcentrationRiskMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueArrangementLineItems" xlink:to="us-gaap_DeferredRevenueArrangementLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapital" xlink:to="us-gaap_AdditionalPaidInCapital_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AccruedPayrollCurrent" xlink:to="fly_AccruedPayrollCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeriesDPreferredStockMember" xlink:to="us-gaap_SeriesDPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock" xlink:to="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_IncomeTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoninterestExpenseInvestmentAdvisoryFees" xlink:to="us-gaap_NoninterestExpenseInvestmentAdvisoryFees_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskCreditRisk" xlink:to="us-gaap_ConcentrationRiskCreditRisk_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" xlink:to="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CompensationRelatedCostsPolicyTextBlock" xlink:to="us-gaap_CompensationRelatedCostsPolicyTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsAxis" xlink:to="srt_ConsolidationItemsAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_OtherRevenueMember" xlink:to="fly_OtherRevenueMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepositLiabilitiesAccruedInterest" xlink:to="us-gaap_DepositLiabilitiesAccruedInterest_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ProbabilityWeightedFairValuePerCommonWarrant" xlink:to="fly_ProbabilityWeightedFairValuePerCommonWarrant_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_RightOfUseAssetObtainedInForLeaseLiability" xlink:to="fly_RightOfUseAssetObtainedInForLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived" xlink:to="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_AverageFairValuePerWarrant" xlink:to="fly_AverageFairValuePerWarrant_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_LeaseCostAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TemporaryEquitySharesAuthorized" xlink:to="us-gaap_TemporaryEquitySharesAuthorized_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationIntegrationRelatedCosts" xlink:to="us-gaap_BusinessCombinationIntegrationRelatedCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_BusinessCombinationsAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_RestrictedCashMember" xlink:to="fly_RestrictedCashMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarningsPerShareDiluted" xlink:to="us-gaap_EarningsPerShareDiluted_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" xlink:to="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingSegmentsMember" xlink:to="us-gaap_OperatingSegmentsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LandAndLandImprovementsMember" xlink:to="us-gaap_LandAndLandImprovementsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_IPOClosingPreferredStockDividendMember" xlink:to="fly_IPOClosingPreferredStockDividendMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetAcquisitionAxis" xlink:to="us-gaap_AssetAcquisitionAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ClassA1PreferredStockMember" xlink:to="fly_ClassA1PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CityAreaCode" xlink:to="dei_CityAreaCode_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:to="us-gaap_BusinessAcquisitionsProFormaRevenue_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorName" xlink:to="dei_AuditorName_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromLinesOfCredit" xlink:to="us-gaap_ProceedsFromLinesOfCredit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsFiniteLivedPolicy" xlink:to="us-gaap_IntangibleAssetsFiniteLivedPolicy_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_CustomerFiveMember" xlink:to="fly_CustomerFiveMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_TermALoansMember" xlink:to="fly_TermALoansMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:to="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ProceedsOfUnderwritngDiscounts" xlink:to="fly_ProceedsOfUnderwritngDiscounts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Weighted-AverageRemainingLeaseTermYears" xlink:to="fly_Weighted-AverageRemainingLeaseTermYears_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossRelatedToLitigationSettlement" xlink:to="us-gaap_GainLossRelatedToLitigationSettlement_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1" xlink:to="us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock" xlink:to="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingInformationLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesJPreferredStockMember" xlink:to="fly_SeriesJPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_LeaseCost_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SpacecraftSolutionsRevenueMember" xlink:to="fly_SpacecraftSolutionsRevenueMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ContractualObligationAnnualInstallments" xlink:to="fly_ContractualObligationAnnualInstallments_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:to="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LoansAndLeasesReceivableAllowance" xlink:to="us-gaap_LoansAndLeasesReceivableAllowance_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_RentIncraeseAnuallyInPercent" xlink:to="fly_RentIncraeseAnuallyInPercent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtCurrent" xlink:to="us-gaap_DebtCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsMember" xlink:to="us-gaap_RetainedEarningsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_CashAndCashEquivalentsAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesSeedPreferredStockMember" xlink:to="fly_SeriesSeedPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:to="us-gaap_EmployeeBenefitsAndShareBasedCompensation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold" xlink:to="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfStockIssuanceCosts" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueInputsLevel1Member" xlink:to="us-gaap_FairValueInputsLevel1Member_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ClassOfStockLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisclosureTextBlockAbstract" xlink:to="us-gaap_DisclosureTextBlockAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_NotesPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCostTableTextBlock" xlink:to="us-gaap_LeaseCostTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnamortizedDebtIssuanceExpense" xlink:to="us-gaap_UnamortizedDebtIssuanceExpense_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorLocation" xlink:to="dei_AuditorLocation_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DevelopedTechnologyRightsMember" xlink:to="us-gaap_DevelopedTechnologyRightsMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" xlink:to="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" xlink:to="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_DerivativeContractTypeDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_MaterialMember" xlink:to="fly_MaterialMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForMortgageDeposits" xlink:to="us-gaap_PaymentsForMortgageDeposits_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxAuthorityDomain" xlink:to="us-gaap_IncomeTaxAuthorityDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityInteractiveDataCurrent" xlink:to="dei_EntityInteractiveDataCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock" xlink:to="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementLocationDomain" xlink:to="us-gaap_IncomeStatementLocationDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_MaterialsAndConsumables" xlink:to="fly_MaterialsAndConsumables_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations" xlink:to="us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FurnitureAndFixturesMember" xlink:to="us-gaap_FurnitureAndFixturesMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" xlink:to="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaidInKindInterest" xlink:to="us-gaap_PaidInKindInterest_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_Non-CashInventoryWrite-Off" xlink:to="fly_Non-CashInventoryWrite-Off_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnbilledReceivablesCurrent" xlink:to="us-gaap_UnbilledReceivablesCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_InterestExpenseOnPurchaseAndLeasebackAgreement" xlink:to="fly_InterestExpenseOnPurchaseAndLeasebackAgreement_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerAssetNet" xlink:to="us-gaap_ContractWithCustomerAssetNet_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementOptionOutstandingNumber" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ConvertibleSeriesSeedPreferredStockMember" xlink:to="fly_ConvertibleSeriesSeedPreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityTaxIdentificationNumber" xlink:to="dei_EntityTaxIdentificationNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_PrepaidPurchaseCredit" xlink:to="fly_PrepaidPurchaseCredit_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharePrice" xlink:to="us-gaap_SharePrice_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfNotesPayable" xlink:to="us-gaap_RepaymentsOfNotesPayable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease" xlink:to="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LocalPhoneNumber" xlink:to="dei_LocalPhoneNumber_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ExerciseOfCommonWarrantsIntoCommonStockShares" xlink:to="fly_ExerciseOfCommonWarrantsIntoCommonStockShares_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorOpinionTextBlock" xlink:to="dei_AuditorOpinionTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ConsultingAgreementMember" xlink:to="fly_ConsultingAgreementMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:to="us-gaap_RevenueRemainingPerformanceObligationPercentage_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_AccountingPoliciesAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueByArrangementDisclosureTextBlock" xlink:to="us-gaap_DeferredRevenueByArrangementDisclosureTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisaggregationOfRevenueLineItems" xlink:to="us-gaap_DisaggregationOfRevenueLineItems_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_SeriesD-3PreferredStockMember" xlink:to="fly_SeriesD-3PreferredStockMember_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ClassOfStockDomain_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedProfessionalFeesCurrent" xlink:to="us-gaap_AccruedProfessionalFeesCurrent_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" xlink:to="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" xlink:to="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SelfInsuranceReserve" xlink:to="us-gaap_SelfInsuranceReserve_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_ScheduleOfStockByClassTable_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityEmergingGrowthCompany" xlink:to="dei_EntityEmergingGrowthCompany_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AreaOfLand" xlink:to="us-gaap_AreaOfLand_lbl"/>
          <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_lbl"/>
        </link:labelLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/Cover" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems" xlink:label="dei_DocumentInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType" xlink:label="dei_DocumentType"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable" xlink:label="dei_DocumentInformationTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentAnnualReport" xlink:label="dei_DocumentAnnualReport"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine2" xlink:label="dei_EntityAddressAddressLine2"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="dei_EntityWellKnownSeasonedIssuer"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityVoluntaryFilers" xlink:label="dei_EntityVoluntaryFilers"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_IcfrAuditorAttestationFlag" xlink:label="dei_IcfrAuditorAttestationFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFinStmtErrorCorrectionFlag" xlink:label="dei_DocumentFinStmtErrorCorrectionFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentsIncorporatedByReferenceTextBlock" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorOpinionTextBlock" xlink:label="dei_AuditorOpinionTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorName" xlink:label="dei_AuditorName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorLocation" xlink:label="dei_AuditorLocation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorFirmId" xlink:label="dei_AuditorFirmId"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CoverAbstract" xlink:label="dei_CoverAbstract"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentType" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_CommonClassAMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentPeriodEndDate" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationTable" xlink:to="dei_DocumentInformationLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_CommonClassBMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentAnnualReport" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentTransitionReport" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityFileNumber" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityRegistrantName" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityIncorporationStateCountryCode" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityTaxIdentificationNumber" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressAddressLine1" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressAddressLine2" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressCityOrTown" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressStateOrProvince" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressPostalZipCode" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_CityAreaCode" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_LocalPhoneNumber" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_Security12bTitle" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_TradingSymbol" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_SecurityExchangeName" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCurrentReportingStatus" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityInteractiveDataCurrent" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityFilerCategory" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntitySmallBusiness" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityEmergingGrowthCompany" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityExTransitionPeriod" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityShellCompany" order="24" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCommonStockSharesOutstanding" order="25" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCentralIndexKey" order="26" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AmendmentFlag" order="27" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentFiscalPeriodFocus" order="28" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentFiscalYearFocus" order="29" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_CurrentFiscalYearEndDate" order="30" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityWellKnownSeasonedIssuer" order="31" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityVoluntaryFilers" order="32" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_IcfrAuditorAttestationFlag" order="33" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentFinStmtErrorCorrectionFlag" order="34" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityPublicFloat" order="35" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentsIncorporatedByReferenceTextBlock" order="36" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorOpinionTextBlock" order="37" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorName" order="38" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorLocation" order="39" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorFirmId" order="40" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_CoverAbstract" xlink:to="dei_DocumentInformationTable" order="49.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheets" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityAbstract" xlink:label="us-gaap_TemporaryEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember" xlink:label="us-gaap_RelatedPartyMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments" xlink:label="us-gaap_ShortTermInvestments"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccountsPayableCurrentRelatedParties" xlink:label="fly_AccountsPayableCurrentRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseNoncurrent" xlink:label="us-gaap_PrepaidExpenseNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashCurrent" xlink:label="us-gaap_RestrictedCashCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:label="us-gaap_DeferredRevenueNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashNoncurrent" xlink:label="us-gaap_RestrictedCashNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermNotesPayable" xlink:label="us-gaap_LongTermNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NotesPayableNoncurrent-RelatedParties" xlink:label="fly_NotesPayableNoncurrent-RelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="us-gaap_DeferredRevenueCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstanding" xlink:label="us-gaap_WarrantsAndRightsOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AssetsAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_CommonStockValue" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccountsPayableCurrent" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TemporaryEquityAbstract" xlink:to="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsCurrentAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_AdditionalPaidInCapital" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_ShortTermInvestments" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="fly_AccountsPayableCurrentRelatedParties" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_PrepaidExpenseNoncurrent" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_RestrictedCashCurrent" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_DeferredRevenueNoncurrent" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AccountsReceivableNetCurrent" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_RestrictedCashNoncurrent" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LongTermNotesPayable" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_PrepaidExpenseCurrent" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityCurrent" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="fly_NotesPayableNoncurrent-RelatedParties" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_OtherAssetsCurrent" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_DeferredRevenueCurrent" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_FinanceLeaseRightOfUseAsset" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_WarrantsAndRightsOutstanding" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrent" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_NotesPayableCurrent" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_OtherLiabilitiesNoncurrent" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_OtherLiabilitiesCurrent" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_Goodwill" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_Liabilities" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrent" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_OtherAssetsNoncurrent" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_CommitmentsAndContingencies" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_Assets" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_TemporaryEquityAbstract" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableConvertiblePreferredStockMember" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesAuthorized" xlink:label="us-gaap_TemporaryEquitySharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="us-gaap_TemporaryEquitySharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityLiquidationPreference" xlink:label="us-gaap_TemporaryEquityLiquidationPreference"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquityParOrStatedValuePerShare" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_RedeemableConvertiblePreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquitySharesAuthorized" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquitySharesIssued" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquitySharesOutstanding" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquityLiquidationPreference" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesIssued" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:label="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementAbstract" xlink:label="us-gaap_IncomeStatementAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeInFairValueOfWarrantLiability" xlink:label="fly_ChangeInFairValueOfWarrantLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeOperating" xlink:label="us-gaap_InterestIncomeOperating"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossRelatedToLitigationSettlement" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpense" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareBasic" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_StatementTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="fly_ChangeInFairValueOfWarrantLiability" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CostOfGoodsAndServicesSold" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_GrossProfit" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_InterestIncomeOperating" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpenses" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OperatingExpensesAbstract" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_InterestIncomeExpenseNonoperatingNet" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OperatingIncomeLoss" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_GainLossRelatedToLitigationSettlement" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_OtherNonoperatingIncomeExpense" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpense" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLoss" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EarningsPerShareAbstract" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPaidNet" xlink:label="us-gaap_InterestPaidNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:label="us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="us-gaap_GainLossOnDispositionOfAssets1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PropertyAndEquipmentAdditionsInAccountsPayable" xlink:label="fly_PropertyAndEquipmentAdditionsInAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsToAcquireTimeDeposits" xlink:label="fly_PaymentsToAcquireTimeDeposits"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IncreaseDecreaseInAdvancedPayments" xlink:label="fly_IncreaseDecreaseInAdvancedPayments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaidInKindInterest" xlink:label="us-gaap_PaidInKindInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination" xlink:label="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeasePrincipalPayments" xlink:label="us-gaap_FinanceLeasePrincipalPayments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfDebtInExchangeOfSoftwareLicenses" xlink:label="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfShortTermInvestments" xlink:label="us-gaap_ProceedsFromSaleOfShortTermInvestments"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IncreaseDecreaseAccountsPayableRelatedParties" xlink:label="fly_IncreaseDecreaseAccountsPayableRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromNotesPayable" xlink:label="us-gaap_ProceedsFromNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInterestExpense" xlink:label="fly_Non-CashInterestExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_5"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCashInterestIncome" xlink:label="fly_NonCashInterestIncome"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsFromNotesPayableRelatedParties" xlink:label="fly_ProceedsFromNotesPayableRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInventoryWrite-Off" xlink:label="fly_Non-CashInventoryWrite-Off"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashCurrent" xlink:label="us-gaap_RestrictedCashCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeInRight-Of-UseAssets" xlink:label="fly_ChangeInRight-Of-UseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfNotesPayable" xlink:label="us-gaap_RepaymentsOfNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssued1" xlink:label="us-gaap_StockIssued1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashEquivalentsCurrent" xlink:label="us-gaap_RestrictedCashEquivalentsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsOnNotesPayable" xlink:label="fly_PaymentsOnNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1" xlink:label="us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:label="us-gaap_RestrictedCashAndCashEquivalents"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForMortgageDeposits" xlink:label="us-gaap_PaymentsForMortgageDeposits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalLeaseObligationsIncurred" xlink:label="us-gaap_CapitalLeaseObligationsIncurred"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExerciseOfCommonWarrantsIntoCommonStock" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsOfDebtIssuanceCostsRelatedParties" xlink:label="fly_PaymentsOfDebtIssuanceCostsRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfPreferredStockDividend" xlink:label="fly_IssuanceOfPreferredStockDividend"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsFromRepaymentOfEmployeeNote" xlink:label="fly_ProceedsFromRepaymentOfEmployeeNote"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConversionOfStockAmountConverted1" xlink:label="us-gaap_ConversionOfStockAmountConverted1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="us-gaap_ProceedsFromLinesOfCredit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_DepreciationDepletionAndAmortization" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_InterestPaidNet" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_CapitalExpendituresIncurredButNotYetPaid" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_ProfitLoss" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_GainLossOnDispositionOfAssets1" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="fly_PropertyAndEquipmentAdditionsInAccountsPayable" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="fly_PaymentsToAcquireTimeDeposits" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="fly_IncreaseDecreaseInAdvancedPayments" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_ShareBasedCompensation" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_PaidInKindInterest" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_FairValueAdjustmentOfWarrants" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_FinanceLeasePrincipalPayments" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromSaleOfShortTermInvestments" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="fly_IncreaseDecreaseAccountsPayableRelatedParties" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromNotesPayable" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="fly_Non-CashInterestExpense" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashOrPartNoncashAcquisitionIntangibleAssetsAcquired1" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_5" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="fly_NonCashInterestIncome" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="fly_ProceedsFromNotesPayableRelatedParties" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="fly_Non-CashInventoryWrite-Off" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_RestrictedCashCurrent" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="fly_ChangeInRight-Of-UseAssets" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_RepaymentsOfNotesPayable" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_StockIssued1" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_RestrictedCashEquivalentsCurrent" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingLeaseLiability" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="fly_PaymentsOnNotesPayable" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_RestrictedCashAndCashEquivalents" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInDeferredRevenue" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_PaymentsForMortgageDeposits" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_CapitalLeaseObligationsIncurred" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="fly_ExerciseOfCommonWarrantsIntoCommonStock" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_NoncashInvestingAndFinancingItemsAbstract" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="fly_PaymentsOfDebtIssuanceCostsRelatedParties" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="fly_IssuanceOfPreferredStockDividend" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="fly_ProceedsFromRepaymentOfEmployeeNote" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NoncashInvestingAndFinancingItemsAbstract" xlink:to="us-gaap_ConversionOfStockAmountConverted1" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromLinesOfCredit" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_ProceedsFromStockOptionsExercised" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfConvertiblePreferredStockAndStockholdersEquityDeficit" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-4PreferredStockMember" xlink:label="fly_SeriesD-4PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" xlink:label="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" xlink:label="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesOther" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueOther" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_StockIssuedDuringPeriodSharesStockDividend" xlink:label="fly_StockIssuedDuringPeriodSharesStockDividend"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" xlink:label="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_24"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConversionOfStockAmountConverted1" xlink:label="us-gaap_ConversionOfStockAmountConverted1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConversionOfStockSharesConverted1" xlink:label="us-gaap_ConversionOfStockSharesConverted1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExerciseOfCommonWarrantsIntoCommonStock" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExerciseOfCommonWarrantsIntoCommonStockShares" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStockShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding_30"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_31"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding_32"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_PreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AdditionalPaidInCapitalMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_RetainedEarningsMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-4PreferredStockMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesAcquisitions" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueAcquisitions" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_StockIssuedDuringPeriodSharesStockDividend" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_24" order="24" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConversionOfStockAmountConverted1" order="25" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConversionOfStockSharesConverted1" order="26" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ExerciseOfCommonWarrantsIntoCommonStock" order="27" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ExerciseOfCommonWarrantsIntoCommonStockShares" order="28" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLoss" order="29" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding_30" order="30" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_31" order="31" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PreferredStockSharesOutstanding_32" order="32" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd#ecd_AllIndividualsMember" xlink:label="ecd_AllIndividualsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DavidWheelerMember" xlink:label="fly_DavidWheelerMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd#ecd_InsiderTradingArrLineItems" xlink:label="ecd_InsiderTradingArrLineItems"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Rule10B51ArrModifiedFlag" xlink:label="fly_Rule10B51ArrModifiedFlag"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonRule10B51ArrModifiedFlag" xlink:label="fly_NonRule10B51ArrModifiedFlag"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ecd_AllIndividualsMember" xlink:to="fly_DavidWheelerMember" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ecd_InsiderTradingArrLineItems" xlink:to="fly_Rule10B51ArrModifiedFlag" order="14.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="ecd_InsiderTradingArrLineItems" xlink:to="fly_NonRule10B51ArrModifiedFlag" order="15.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceTable" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:label="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:label="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:label="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesIntegratedFlag" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:label="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskRoleOfManagementTextBlock" xlink:label="cyd_CybersecurityRiskRoleOfManagementTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementThirdPartyEngagedFlag" xlink:label="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag" xlink:label="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:to="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:to="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskManagementProcessesIntegratedFlag" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:to="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:to="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskRoleOfManagementTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentation" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock" xlink:label="us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_BusinessDescriptionAndBasisOfPresentationTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies1" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinations" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_BusinessCombinationDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenue" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerAbstract" xlink:label="us-gaap_RevenueFromContractWithCustomerAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerTextBlock" xlink:label="us-gaap_RevenueFromContractWithCustomerTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_RevenueFromContractWithCustomerTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNet" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpenses" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureTextBlockAbstract" xlink:label="us-gaap_DisclosureTextBlockAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureTextBlockAbstract" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNet" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_IntangibleAssetsDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwill" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationGoodwillAbstract" xlink:label="us-gaap_BusinessCombinationGoodwillAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationGoodwillAbstract" xlink:to="us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurement" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="us-gaap_FairValueDisclosuresTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueDisclosuresTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeases" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LeasesTextBlock" xlink:label="fly_LeasesTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="fly_LeasesTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayable1" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_DebtDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingencies" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStock1" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteAbstract" xlink:label="us-gaap_StockholdersEquityNoteAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensation" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxes" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="us-gaap_IncomeTaxDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactions" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="us-gaap_RelatedPartyTransactionsDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_RelatedPartyTransactionsDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShare" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="us-gaap_EarningsPerShareTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformation1" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_SegmentReportingDisclosureTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSubsequentEvents1" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventsAbstract" xlink:label="us-gaap_SubsequentEventsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventsTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AllowanceForCreditLossesPolicyTextBlock" xlink:label="fly_AllowanceForCreditLossesPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AdvancedPaymentsPolicyTextBlock" xlink:label="fly_AdvancedPaymentsPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeasesPolicyTextBlock" xlink:label="us-gaap_LesseeLeasesPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SaleAndLeasebackPolicyTextBlock" xlink:label="fly_SaleAndLeasebackPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsFiniteLivedPolicy" xlink:label="us-gaap_IntangibleAssetsFiniteLivedPolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:label="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:label="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NotesPayablePolicyTextBlock" xlink:label="fly_NotesPayablePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantLiabilitiesPolicyTextBlock" xlink:label="fly_WarrantLiabilitiesPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:label="us-gaap_FairValueMeasurementPolicyPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredRevenuePolicyTextBlock" xlink:label="fly_DeferredRevenuePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsPolicy" xlink:label="us-gaap_BusinessCombinationsPolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CostOfSalePolicyTextBlock" xlink:label="fly_CostOfSalePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:label="us-gaap_ConcentrationRiskCreditRisk"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy" xlink:label="us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CompensationRelatedCostsPolicyTextBlock" xlink:label="us-gaap_CompensationRelatedCostsPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="us-gaap_IncomeTaxPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingPolicyPolicyTextBlock" xlink:label="us-gaap_SegmentReportingPolicyPolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_BasisOfAccountingPolicyPolicyTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_UseOfEstimates" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_TradeAndOtherAccountsReceivablePolicy" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_AllowanceForCreditLossesPolicyTextBlock" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_AdvancedPaymentsPolicyTextBlock" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_LesseeLeasesPolicyTextBlock" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_SaleAndLeasebackPolicyTextBlock" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_IntangibleAssetsFiniteLivedPolicy" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_NotesPayablePolicyTextBlock" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_WarrantLiabilitiesPolicyTextBlock" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_FairValueMeasurementPolicyPolicyTextBlock" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_DeferredRevenuePolicyTextBlock" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_BusinessCombinationsPolicy" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_CostOfSalePolicyTextBlock" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ConcentrationRiskCreditRisk" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_StockholdersEquityNoteRedeemablePreferredStockIssuePolicy" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_CompensationRelatedCostsPolicyTextBlock" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_IncomeTaxPolicyTextBlock" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_SegmentReportingPolicyPolicyTextBlock" order="24" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock" order="25" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" order="26" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock" xlink:label="us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PropertyAndEquipmentUsefulLivesTableTextBlock" xlink:label="fly_PropertyAndEquipmentUsefulLivesTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="fly_PropertyAndEquipmentUsefulLivesTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpaceflightMember" xlink:label="fly_SpaceflightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:label="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SpaceflightMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionProFormaInformationTextBlock" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerAbstract" xlink:label="us-gaap_RevenueFromContractWithCustomerAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTableTextBlock" xlink:label="us-gaap_DisaggregationOfRevenueTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:label="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueByArrangementDisclosureTextBlock" xlink:label="us-gaap_DeferredRevenueByArrangementDisclosureTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_DisaggregationOfRevenueTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_DeferredRevenueByArrangementDisclosureTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpensesTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PayablesAndAccrualsAbstract" xlink:label="us-gaap_PayablesAndAccrualsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_ScheduleOfAccountsPayableAndAccruedLiabilitiesTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:label="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTextBlock" xlink:label="us-gaap_ScheduleOfGoodwillTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_ScheduleOfGoodwillTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock" xlink:label="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock" xlink:label="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_ScheduleOfCarryingValuesAndEstimatedFairValuesOfDebtInstrumentsTableTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostTableTextBlock" xlink:label="us-gaap_LeaseCostTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AssetsAndLiabilitiesLesseeTableTextBlock" xlink:label="fly_AssetsAndLiabilitiesLesseeTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLeaseIncomeTableTextBlock" xlink:label="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock" xlink:label="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:label="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LeaseCostTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="fly_AssetsAndLiabilitiesLesseeTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_OperatingLeaseLeaseIncomeTableTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock" xlink:label="us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_ScheduleOfDebtInstrumentsTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_InterestIncomeAndInterestExpenseDisclosureTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersDeficitAndRedeemableConvertiblePreferredStockTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteAbstract" xlink:label="us-gaap_StockholdersEquityNoteAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ScheduleOfRedeemableConvertiblePreferredStock" xlink:label="fly_ScheduleOfRedeemableConvertiblePreferredStock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="fly_ScheduleOfRedeemableConvertiblePreferredStock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CompensationRelatedCostsAbstract" xlink:label="us-gaap_CompensationRelatedCostsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" xlink:label="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CompensationRelatedCostsAbstract" xlink:to="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CompensationRelatedCostsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CompensationRelatedCostsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CompensationRelatedCostsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CompensationRelatedCostsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" xlink:label="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" xlink:label="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock" xlink:label="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_StatementTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationTables" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonWarrantsMember" xlink:label="fly_CommonWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsOfUnderwritngDiscounts" xlink:label="fly_ProceedsOfUnderwritngDiscounts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DiscountsOnUnderwriting" xlink:label="fly_DiscountsOnUnderwriting"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromCommissionsReceived" xlink:label="us-gaap_ProceedsFromCommissionsReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationalAndOfferingCostsExpense" xlink:label="us-gaap_OrganizationalAndOfferingCostsExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BrokerageCommissionsRevenue" xlink:label="us-gaap_BrokerageCommissionsRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositLiabilitiesAccruedInterest" xlink:label="us-gaap_DepositLiabilitiesAccruedInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityReverseStockSplit" xlink:label="us-gaap_StockholdersEquityReverseStockSplit"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:to="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="fly_CommonWarrantsMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_StatementLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ProceedsOfUnderwritngDiscounts" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_DiscountsOnUnderwriting" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProceedsFromCommissionsReceived" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OrganizationalAndOfferingCostsExpense" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_BrokerageCommissionsRevenue" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DepositLiabilitiesAccruedInterest" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EmployeeBenefitsAndShareBasedCompensation" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityReverseStockSplit" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:label="us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain" xlink:label="srt_NameOfMajorCustomerDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerMember" xlink:label="fly_CustomerMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember" xlink:label="us-gaap_SalesRevenueNetMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis" xlink:label="srt_MajorCustomersAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:label="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockMember" xlink:label="us-gaap_ConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCash" xlink:label="us-gaap_RestrictedCash"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DepositoryRiskMember" xlink:label="fly_DepositoryRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember" xlink:label="us-gaap_AccountsReceivableMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashFDICInsuredAmount" xlink:label="us-gaap_CashFDICInsuredAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="us-gaap_ConcentrationRiskPercentage1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_CommonStockSharesIssued" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="us-gaap_CustomerConcentrationRiskMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_SalesRevenueNetMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_NameOfMajorCustomerDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ConvertiblePreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_RestrictedCash" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="fly_DepositoryRiskMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_AccountsReceivableMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="srt_MajorCustomersAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_EntityWideRevenueMajorCustomerLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_CashFDICInsuredAmount" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_ConcentrationRiskPercentage1" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="srt_RangeAxis" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="6.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="7.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfPropertyAndEquipmentUsefulLivesDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="us-gaap_MachineryAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TestStandsMember" xlink:label="fly_TestStandsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingMember" xlink:label="us-gaap_BuildingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="us-gaap_FurnitureAndFixturesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember" xlink:label="us-gaap_ComputerEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="us-gaap_SoftwareDevelopmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember" xlink:label="us-gaap_VehiclesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="us-gaap_LeaseholdImprovementsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_MachineryAndEquipmentMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_TestStandsMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="srt_RangeAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_BuildingMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_FurnitureAndFixturesMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_ComputerEquipmentMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_SoftwareDevelopmentMember" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_VehiclesMember" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="6.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_LeaseholdImprovementsMember" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="7.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfConcentrationOfCreditRiskDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:label="us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="us-gaap_ConcentrationRiskPercentage1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain" xlink:label="srt_NameOfMajorCustomerDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerOneMember" xlink:label="fly_CustomerOneMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract" xlink:label="us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:label="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember" xlink:label="us-gaap_SalesRevenueNetMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis" xlink:label="srt_MajorCustomersAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerTwoMember" xlink:label="fly_CustomerTwoMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember" xlink:label="us-gaap_AccountsReceivableMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerThreeMember" xlink:label="fly_CustomerThreeMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerFourMember" xlink:label="fly_CustomerFourMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerFiveMember" xlink:label="fly_CustomerFiveMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_ConcentrationRiskPercentage1" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerOneMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="us-gaap_CustomerConcentrationRiskMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract" xlink:to="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_SalesRevenueNetMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_NameOfMajorCustomerDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="srt_MajorCustomersAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerTwoMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_AccountsReceivableMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByTypeAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerThreeMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerFourMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_EntityWideRevenueMajorCustomerLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerFiveMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashMember" xlink:label="us-gaap_CashMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="us-gaap_NonrecurringAdjustmentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="us-gaap_NonrecurringAdjustmentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_UnauditedProFormaInformationMember" xlink:label="fly_UnauditedProFormaInformationMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="us-gaap_CashAndCashEquivalentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpaceflightMember" xlink:label="fly_SpaceflightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationIntegrationRelatedCosts" xlink:label="us-gaap_BusinessCombinationIntegrationRelatedCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationAsset" xlink:label="us-gaap_BusinessCombinationContingentConsiderationAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationIncurredCost" xlink:label="fly_BusinessCombinationIncurredCost"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="us-gaap_CashMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonrecurringAdjustmentAxis" xlink:to="us-gaap_NonrecurringAdjustmentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonrecurringAdjustmentDomain" xlink:to="fly_UnauditedProFormaInformationMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_CashAndCashEquivalentsAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SpaceflightMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationIntegrationRelatedCosts" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_NonrecurringAdjustmentAxis" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationAsset" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaRevenue" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_BusinessCombinationIncurredCost" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfConsiderationPaidAndTheFairValueOfAssetsAcquiredAndLiabilitiesAssumedDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationCashConsiderationPaid" xlink:label="fly_BusinessCombinationCashConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpaceflightMember" xlink:label="fly_SpaceflightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationEquityConsiderationPaid" xlink:label="fly_BusinessCombinationEquityConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationTotalConsiderationPaid" xlink:label="fly_BusinessCombinationTotalConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:label="us-gaap_DeferredCostsCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="fly_BusinessCombinationCashConsiderationPaid" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationConsiderationTransferredAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SpaceflightMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="fly_BusinessCombinationEquityConsiderationPaid" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="fly_BusinessCombinationTotalConsiderationPaid" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_DeferredCostsCurrentAndNoncurrent" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" order="24" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" order="25" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfFairValueOfAcquiredIdentifiableIntangibleAssetsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="us-gaap_TrademarksAndTradeNamesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DevelopedTechnologyMember" xlink:label="fly_DevelopedTechnologyMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BacklogMember" xlink:label="fly_BacklogMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FollowOnOpportunitiesMember" xlink:label="fly_FollowOnOpportunitiesMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_TrademarksAndTradeNamesMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_DevelopedTechnologyMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_BacklogMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_CustomerRelationshipsMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_FollowOnOpportunitiesMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfNetImpactOfAcquisitionDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfUnauditedProFormaInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="us-gaap_NonrecurringAdjustmentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="us-gaap_NonrecurringAdjustmentDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_UnauditedProFormaInformationMember" xlink:label="fly_UnauditedProFormaInformationMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="us-gaap_BusinessCombinationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonrecurringAdjustmentAxis" xlink:to="us-gaap_NonrecurringAdjustmentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonrecurringAdjustmentDomain" xlink:to="fly_UnauditedProFormaInformationMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_NonrecurringAdjustmentAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaRevenue" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDisaggregatedRevenueDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerAbstract" xlink:label="us-gaap_RevenueFromContractWithCustomerAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="us-gaap_DisaggregationOfRevenueTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LaunchRevenueMember" xlink:label="fly_LaunchRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="us-gaap_DisaggregationOfRevenueLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpacecraftSolutionsRevenueMember" xlink:label="fly_SpacecraftSolutionsRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherRevenueMember" xlink:label="fly_OtherRevenueMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductsAndServicesDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_DisaggregationOfRevenueTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisaggregationOfRevenueTable" xlink:to="srt_ProductOrServiceAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_LaunchRevenueMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisaggregationOfRevenueLineItems" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisaggregationOfRevenueTable" xlink:to="us-gaap_DisaggregationOfRevenueLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_SpacecraftSolutionsRevenueMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_OtherRevenueMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfContractAssetsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnbilledReceivablesCurrent" xlink:label="us-gaap_UnbilledReceivablesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:label="us-gaap_DeferredCostsCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommodityContractAssetCurrent" xlink:label="us-gaap_CommodityContractAssetCurrent"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_UnbilledReceivablesCurrent" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_DeferredCostsCurrentAndNoncurrent" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_CommodityContractAssetCurrent" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerAbstract" xlink:label="us-gaap_RevenueFromContractWithCustomerAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:label="us-gaap_RevenueRemainingPerformanceObligation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage" xlink:label="us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetPurchase" xlink:label="us-gaap_ContractWithCustomerAssetPurchase"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerAssetNet" xlink:label="us-gaap_ContractWithCustomerAssetNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractWithCustomerLossProvision" xlink:label="fly_ContractWithCustomerLossProvision"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease" xlink:label="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiability" xlink:label="us-gaap_ContractWithCustomerLiability"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_RevenueRemainingPerformanceObligation" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_RevenueRemainingPerformanceObligationPercentage" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_ContractWithCustomerAssetPurchase" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_ContractWithCustomerAssetNet" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="fly_ContractWithCustomerLossProvision" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_ContractWithCustomerLiability" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDeferredRevenueDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerAbstract" xlink:label="us-gaap_RevenueFromContractWithCustomerAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueArrangementByTypeTable" xlink:label="us-gaap_DeferredRevenueArrangementByTypeTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LaunchRevenueMember" xlink:label="fly_LaunchRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueArrangementLineItems" xlink:label="us-gaap_DeferredRevenueArrangementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenue" xlink:label="us-gaap_DeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpacecraftSolutionsRevenueMember" xlink:label="fly_SpacecraftSolutionsRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherRevenueMember" xlink:label="fly_OtherRevenueMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductsAndServicesDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RevenueFromContractWithCustomerAbstract" xlink:to="us-gaap_DeferredRevenueArrangementByTypeTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_LaunchRevenueMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredRevenueArrangementByTypeTable" xlink:to="srt_ProductOrServiceAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredRevenueArrangementLineItems" xlink:to="us-gaap_DeferredRevenue" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_SpacecraftSolutionsRevenueMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredRevenueArrangementByTypeTable" xlink:to="us-gaap_DeferredRevenueArrangementLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_OtherRevenueMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="us-gaap_MachineryAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TestStandsMember" xlink:label="fly_TestStandsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingMember" xlink:label="us-gaap_BuildingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandAndLandImprovementsMember" xlink:label="us-gaap_LandAndLandImprovementsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember" xlink:label="us-gaap_ConstructionInProgressMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="us-gaap_FurnitureAndFixturesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember" xlink:label="us-gaap_ComputerEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="us-gaap_SoftwareDevelopmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember" xlink:label="us-gaap_VehiclesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="us-gaap_LeaseholdImprovementsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ITRelatedEquipmentMember" xlink:label="fly_ITRelatedEquipmentMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentGross" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_MachineryAndEquipmentMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_TestStandsMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_BuildingMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_LandAndLandImprovementsMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_ConstructionInProgressMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_FurnitureAndFixturesMember" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_ComputerEquipmentMember" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_SoftwareDevelopmentMember" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_VehiclesMember" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_LeaseholdImprovementsMember" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_ITRelatedEquipmentMember" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Depreciation" xlink:label="us-gaap_Depreciation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateInventoryCapitalizedInterestCosts" xlink:label="us-gaap_RealEstateInventoryCapitalizedInterestCosts"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_Depreciation" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_RealEstateInventoryCapitalizedInterestCosts" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpensesDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PayablesAndAccrualsAbstract" xlink:label="us-gaap_PayablesAndAccrualsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccruedPayrollCurrent" xlink:label="fly_AccruedPayrollCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="us-gaap_AccruedProfessionalFeesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPayableCurrentAndNoncurrent" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="fly_AccruedPayrollCurrent" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_AccruedProfessionalFeesCurrent" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PayablesAndAccrualsAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfIntangibleAssetsGrossCarryingAmountAndAccumulatedAmortizationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InternalUseSoftwareMember" xlink:label="fly_InternalUseSoftwareMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:label="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="us-gaap_TrademarksAndTradeNamesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="us-gaap_DevelopedTechnologyRightsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BacklogMember" xlink:label="fly_BacklogMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FollowOnOpportunitiesMember" xlink:label="fly_FollowOnOpportunitiesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_InternalUseSoftwareMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_TrademarksAndTradeNamesMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:to="srt_RangeAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_DevelopedTechnologyRightsMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_CustomerRelationshipsMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_BacklogMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_FollowOnOpportunitiesMember" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="6.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="7.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfFutureAmortizationExpenseOnIntangibleAssetsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:label="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_AmortizationOfIntangibleAssets" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillScheduleOfChangesInTheCarryingAmountOfGoodwillDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill_2"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_Goodwill" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_GoodwillAcquiredDuringPeriod" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="us-gaap_Goodwill_2" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureGoodwillAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended"/>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain" xlink:label="us-gaap_VestingDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TrancheObligationsMember" xlink:label="fly_TrancheObligationsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingAxis" xlink:label="us-gaap_VestingAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantMember" xlink:label="fly_CommonStockWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeDomain" xlink:label="fly_SponsorTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MajoritySponsorMember" xlink:label="fly_MajoritySponsorMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeAxis" xlink:label="fly_SponsorTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantMember" xlink:label="fly_SeriesJWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantsToPurchaseAnAggregate" xlink:label="fly_WarrantsToPurchaseAnAggregate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CallOptionMember" xlink:label="us-gaap_CallOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AggregateOfNumberOfWarrantsToPurchase" xlink:label="fly_AggregateOfNumberOfWarrantsToPurchase"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AverageValuePerUnitAsPerMonteCarloSimulations" xlink:label="fly_AverageValuePerUnitAsPerMonteCarloSimulations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueAdjustment" xlink:label="us-gaap_LiabilitiesFairValueAdjustment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueOptionChangesInFairValueGainLoss1" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockOutstandingCommonWarrantsExercised" xlink:label="fly_CommonStockOutstandingCommonWarrantsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityMethodInvestmentsFairValueDisclosure" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VestingDomain" xlink:to="fly_TrancheObligationsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VestingAxis" xlink:to="us-gaap_VestingDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_CommonStockWarrantMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_SponsorTypeDomain" xlink:to="fly_MajoritySponsorMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_PreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_SponsorTypeAxis" xlink:to="fly_SponsorTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJWarrantMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WarrantsToPurchaseAnAggregate" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_CallOptionMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AggregateOfNumberOfWarrantsToPurchase" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_VestingAxis" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="fly_SponsorTypeAxis" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CashAndCashEquivalentsFairValueDisclosure" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementLineItems" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PreferredStockValue" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AverageValuePerUnitAsPerMonteCarloSimulations" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LiabilitiesFairValueAdjustment" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueOptionChangesInFairValueGainLoss1" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_CommonStockOutstandingCommonWarrantsExercised" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementPresentTheKeyInputsAppliedInTheValuationsWarrantsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AverageFairValuePerWarrant" xlink:label="fly_AverageFairValuePerWarrant"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantMember" xlink:label="fly_CommonStockWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="srt_ScenarioUnspecifiedDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeOfControlScenarioMember" xlink:label="fly_ChangeOfControlScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantMember" xlink:label="fly_SeriesJWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EventProbabilityPercentage" xlink:label="fly_EventProbabilityPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IPOScenarioMember" xlink:label="fly_IPOScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementScenarioAxis" xlink:label="srt_StatementScenarioAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DefaultScenarioMember" xlink:label="fly_DefaultScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageFairValuePerWarrant" xlink:label="fly_WeightedAverageFairValuePerWarrant"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" xlink:label="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValuePerShareMarketableSecurity" xlink:label="fly_FairValuePerShareMarketableSecurity"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DiscountForLackOfMarketability" xlink:label="fly_DiscountForLackOfMarketability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValuePerShareNonMarketableSecurity" xlink:label="fly_FairValuePerShareNonMarketableSecurity"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageFairValuePerShare" xlink:label="fly_WeightedAverageFairValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProbabilityWeightedFairValuePerCommonWarrant" xlink:label="fly_ProbabilityWeightedFairValuePerCommonWarrant"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AverageFairValuePerWarrant" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_CommonStockWarrantMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="fly_ChangeOfControlScenarioMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJWarrantMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_EventProbabilityPercentage" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="fly_IPOScenarioMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_ScenarioUnspecifiedDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="fly_DefaultScenarioMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="srt_StatementScenarioAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WeightedAverageFairValuePerWarrant" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_FairValuePerShareMarketableSecurity" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_DiscountForLackOfMarketability" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_FairValuePerShareNonMarketableSecurity" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WeightedAverageFairValuePerShare" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ProbabilityWeightedFairValuePerCommonWarrant" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfPresentsTheKeyInputsAppliedInTheValuationsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueAxis" xlink:label="us-gaap_ValuationTechniqueAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain" xlink:label="us-gaap_ValuationTechniqueDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BlackScholesMertonModelMember" xlink:label="us-gaap_BlackScholesMertonModelMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantMember" xlink:label="fly_SeriesJWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueOptionPricingModelMember" xlink:label="us-gaap_ValuationTechniqueOptionPricingModelMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAveragePricePerShare" xlink:label="fly_WeightedAveragePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValueAssumption" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueAssumption"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingNumber" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingFairValue" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementMaximumValueRecognized" xlink:label="fly_ShareBasedCompensationArrangementMaximumValueRecognized"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValueInputsDiscountRate" xlink:label="fly_FairValueInputsDiscountRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValue" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ValuationTechniqueAxis" xlink:to="us-gaap_ValuationTechniqueDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="us-gaap_BlackScholesMertonModelMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_ValuationTechniqueAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_SharePrice" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJWarrantMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="us-gaap_ValuationTechniqueOptionPricingModelMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_WeightedAveragePricePerShare" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="srt_RangeAxis" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="6.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValueAssumption" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="7.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingNumber" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementMaximumValueRecognized" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_FairValueInputsDiscountRate" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValue" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfCarryingValueOfTheTermLoansApproximatedTheirEstimatedFairValueDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashMember" xlink:label="us-gaap_CashMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RPMCallOptionMember" xlink:label="fly_RPMCallOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="us-gaap_FairValueDisclosuresAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="us-gaap_CashAndCashEquivalentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeDomain" xlink:label="fly_SponsorTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MajoritySponsorMember" xlink:label="fly_MajoritySponsorMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeAxis" xlink:label="fly_SponsorTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantsMember" xlink:label="fly_SeriesJWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RestrictedCashMember" xlink:label="fly_RestrictedCashMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="us-gaap_LiabilitiesFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TimeDepositsMember" xlink:label="fly_TimeDepositsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="us-gaap_MoneyMarketFundsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonWarrantsMember" xlink:label="fly_CommonWarrantsMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="us-gaap_CashMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_AssetsFairValueDisclosure" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" xlink:to="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_RPMCallOptionMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_CashAndCashEquivalentsAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_SponsorTypeDomain" xlink:to="fly_MajoritySponsorMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_SponsorTypeAxis" xlink:to="fly_SponsorTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" xlink:to="fly_SeriesJWarrantsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="fly_RestrictedCashMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_LiabilitiesFairValueDisclosure" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_TimeDepositsMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="us-gaap_MoneyMarketFundsMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="fly_CommonWarrantsMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FinancialInstrumentAxis" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="fly_SponsorTypeAxis" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfLeaseExpenseDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeFinanceLeaseDescriptionAbstract" xlink:label="us-gaap_LesseeFinanceLeaseDescriptionAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostAbstract" xlink:label="us-gaap_LeaseCostAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestExpense" xlink:label="us-gaap_FinanceLeaseInterestExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost" xlink:label="us-gaap_OperatingLeaseCost"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost" xlink:label="us-gaap_LeaseCost"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeFinanceLeaseDescriptionAbstract" xlink:to="us-gaap_FinanceLeaseRightOfUseAssetAmortization" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_LesseeFinanceLeaseDescriptionAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeFinanceLeaseDescriptionAbstract" xlink:to="us-gaap_FinanceLeaseInterestExpense" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_OperatingLeaseCost" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_LeaseCost" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfOperatingAndFinanceLeaseRightofuseAssetsAndLiabilitiesDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAbstract" xlink:label="us-gaap_LiabilitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesNoncurrentAbstract" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostAbstract" xlink:label="us-gaap_LeaseCostAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_AssetsAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesAbstract" xlink:to="us-gaap_LiabilitiesNoncurrentAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityCurrent" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_FinanceLeaseRightOfUseAsset" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_LiabilitiesAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfLeaseTermAndDiscountRateDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Weighted-AverageDiscountRate" xlink:label="fly_Weighted-AverageDiscountRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostAbstract" xlink:label="us-gaap_LeaseCostAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Weighted-AverageRemainingLeaseTermYears" xlink:label="fly_Weighted-AverageRemainingLeaseTermYears"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_Weighted-AverageDiscountRate" xlink:to="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="fly_Weighted-AverageRemainingLeaseTermYears" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_Weighted-AverageRemainingLeaseTermYears" xlink:to="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_Weighted-AverageDiscountRate" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="fly_Weighted-AverageDiscountRate" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="fly_Weighted-AverageRemainingLeaseTermYears" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCostAbstract" xlink:label="us-gaap_LeaseCostAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LesseeOperatingTotalLeaseLiability" xlink:label="fly_LesseeOperatingTotalLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FinanceLeaseLiabilityTotalPayments" xlink:label="fly_FinanceLeaseLiabilityTotalPayments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability" xlink:label="us-gaap_FinanceLeaseLiability"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeaseCostAbstract" xlink:to="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="fly_LesseeOperatingTotalLeaseLiability" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="fly_FinanceLeaseLiabilityTotalPayments" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_OperatingLeaseLiability" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiability" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionNameDomain" xlink:label="us-gaap_SaleLeasebackTransactionNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SaleAndLeasebackTransactionsMember" xlink:label="fly_SaleAndLeasebackTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeasesAbstract" xlink:label="us-gaap_LeasesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable" xlink:label="us-gaap_LesseeLeaseDescriptionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems" xlink:label="us-gaap_LesseeLeaseDescriptionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:label="us-gaap_SaleLeasebackTransactionDescriptionAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LeaseRemainingLeaseTerm" xlink:label="fly_LeaseRemainingLeaseTerm"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RentIncraeseAnuallyInPercent" xlink:label="fly_RentIncraeseAnuallyInPercent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OperatingLeaseRight-Of-UseAssetDecreased" xlink:label="fly_OperatingLeaseRight-Of-UseAssetDecreased"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RightOfUseAssetObtainedInForLeaseLiability" xlink:label="fly_RightOfUseAssetObtainedInForLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AreaOfLand" xlink:label="us-gaap_AreaOfLand"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetRentableArea" xlink:label="us-gaap_NetRentableArea"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PricePerSquareFoot" xlink:label="fly_PricePerSquareFoot"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayable" xlink:label="us-gaap_NotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermNotesPayable" xlink:label="us-gaap_LongTermNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentForPurchaseAndLeasebackAgreements" xlink:label="fly_PaymentForPurchaseAndLeasebackAgreements"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InterestExpenseOnPurchaseAndLeasebackAgreement" xlink:label="fly_InterestExpenseOnPurchaseAndLeasebackAgreement"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements" xlink:label="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SaleLeasebackTransactionNameDomain" xlink:to="fly_SaleAndLeasebackTransactionsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_LesseeLeaseDescriptionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionTable" xlink:to="srt_RangeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:to="us-gaap_SaleLeasebackTransactionNameDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_LeaseRemainingLeaseTerm" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionTable" xlink:to="us-gaap_SaleLeasebackTransactionDescriptionAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionTable" xlink:to="us-gaap_LesseeLeaseDescriptionLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_RentIncraeseAnuallyInPercent" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_OperatingLeaseRight-Of-UseAssetDecreased" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_RightOfUseAssetObtainedInForLeaseLiability" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_OperatingLeaseLiability" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" order="6.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_AreaOfLand" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="7.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_NetRentableArea" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_PricePerSquareFoot" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_NotesPayable" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_NotesPayableCurrent" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_LongTermNotesPayable" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_PaymentForPurchaseAndLeasebackAgreements" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_InterestExpenseOnPurchaseAndLeasebackAgreement" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FinancingAgreementMember" xlink:label="fly_FinancingAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermALoansMember" xlink:label="fly_TermALoansMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SecuredOverFinancingRateMember" xlink:label="fly_SecuredOverFinancingRateMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis" xlink:label="us-gaap_VariableRateAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantsToPurchaseSeriesJPreferredStockMember" xlink:label="fly_WarrantsToPurchaseSeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermBLoansMember" xlink:label="fly_TermBLoansMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesDPreferredStockMember" xlink:label="us-gaap_SeriesDPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansHeldForSaleMaturityDate" xlink:label="us-gaap_LoansHeldForSaleMaturityDate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermLoanMember" xlink:label="fly_TermLoanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativePremiumPaid" xlink:label="us-gaap_DerivativePremiumPaid"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleNotesMember" xlink:label="fly_ConvertibleNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription" xlink:label="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="us-gaap_LettersOfCreditOutstandingAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExitFeePercentage" xlink:label="fly_ExitFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SwinglineLoans" xlink:label="fly_SwinglineLoans"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeBasisSpreadOnVariableRate" xlink:label="us-gaap_DerivativeBasisSpreadOnVariableRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForFees" xlink:label="us-gaap_PaymentsForFees"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SelfInsuranceReserve" xlink:label="us-gaap_SelfInsuranceReserve"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InterestExpenseContractual" xlink:label="fly_InterestExpenseContractual"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaintainMinimumInterestReserveAmount" xlink:label="fly_MaintainMinimumInterestReserveAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentRepaidPrincipal" xlink:label="us-gaap_DebtInstrumentRepaidPrincipal"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentIncreaseAccruedInterest" xlink:label="us-gaap_DebtInstrumentIncreaseAccruedInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpecificAdditionalInterestRate" xlink:label="fly_SpecificAdditionalInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebt" xlink:label="us-gaap_InterestExpenseDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnamortizedDebtIssuanceExpense" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="us-gaap_AmortizationOfFinancingCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentFaceAmount" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_DebtInstrumentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="fly_FinancingAgreementMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_LongtermDebtTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_TermALoansMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VariableRateDomain" xlink:to="fly_SecuredOverFinancingRateMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VariableRateAxis" xlink:to="us-gaap_VariableRateDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_WarrantsToPurchaseSeriesJPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="srt_RangeAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_TermBLoansMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesDPreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LoansHeldForSaleMaturityDate" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_TypeOfArrangementAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_TermLoanMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DerivativePremiumPaid" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_ConvertibleNotesMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_CreditFacilityAxis" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LettersOfCreditOutstandingAmount" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_VariableRateAxis" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_ExitFeePercentage" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentLineItems" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" order="6.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_SwinglineLoans" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DerivativeBasisSpreadOnVariableRate" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityCommitmentFeePercentage" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_PaymentsForFees" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_SelfInsuranceReserve" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_InterestExpenseContractual" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtPercentageBearingFixedInterestRate" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_MaintainMinimumInterestReserveAmount" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentRepaidPrincipal" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentIncreaseAccruedInterest" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_SpecificAdditionalInterestRate" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_InterestExpenseDebt" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" order="24" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" order="25" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_UnamortizedDebtIssuanceExpense" order="26" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_AmortizationOfFinancingCosts" order="27" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet" order="28" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" order="29" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtCurrent" xlink:label="us-gaap_DebtCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherNotesMember" xlink:label="fly_OtherNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LongTermDebtNet" xlink:label="fly_LongTermDebtNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember" xlink:label="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentCarryingAmount" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_DebtInstrumentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_LongtermDebtTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DeferredFinanceCostsNet" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtCurrent" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_OtherNotesMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_LongTermDebtNet" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtParentheticalDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_DebtInstrumentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_CreditFacilityAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" order="3.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" order="4.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" order="5.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" order="6.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableInterestExpenseRelatedToTheTermLoansDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations" xlink:label="us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="us-gaap_AmortizationOfFinancingCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebt" xlink:label="us-gaap_InterestExpenseDebt"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_ContractualInterestExpenseOnPrepetitionLiabilitiesNotRecognizedInStatementOfOperations" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_DebtInstrumentLineItems" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_AmortizationOfFinancingCosts" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_InterestExpenseDebt" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAndWarrantsPrincipalPaymentsUnderTheTermLoansDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermLoanMember" xlink:label="fly_TermLoanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_DebtInstrumentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="fly_TermLoanMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentCarryingAmount" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayablePrincipalPaymentsUnderTheTermLoansParentheticalDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableAbstract" xlink:label="us-gaap_NotesPayableAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NotesPayableAbstract" xlink:to="us-gaap_DebtInstrumentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_CreditFacilityAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsLineItems" xlink:label="us-gaap_OtherCommitmentsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsDomain" xlink:label="us-gaap_OtherCommitmentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCancelableServiceContractCommitmentsMember" xlink:label="fly_NonCancelableServiceContractCommitmentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsTable" xlink:label="us-gaap_OtherCommitmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsAxis" xlink:label="us-gaap_OtherCommitmentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCancelableSubscriptionBasedServicesMember" xlink:label="fly_NonCancelableSubscriptionBasedServicesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossRelatedToLitigationSettlement" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FormerGainContingencyRecognizedInCurrentPeriod" xlink:label="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationNumberOfLaunches" xlink:label="fly_ContractualObligationNumberOfLaunches"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligation" xlink:label="us-gaap_ContractualObligation"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationCancellationFeePercentage" xlink:label="fly_ContractualObligationCancellationFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationAnnualInstallments" xlink:label="fly_ContractualObligationAnnualInstallments"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsDomain" xlink:to="fly_NonCancelableServiceContractCommitmentsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsTable" xlink:to="us-gaap_OtherCommitmentsAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsAxis" xlink:to="us-gaap_OtherCommitmentsDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:to="us-gaap_OtherCommitmentsTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsDomain" xlink:to="fly_NonCancelableSubscriptionBasedServicesMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsTable" xlink:to="us-gaap_OtherCommitmentsLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_GainLossRelatedToLitigationSettlement" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="fly_ContractualObligationNumberOfLaunches" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_ContractualObligation" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="fly_ContractualObligationCancellationFeePercentage" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_LossContingencyEstimateOfPossibleLoss" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="fly_ContractualObligationAnnualInstallments" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ShareRepurchaseProgramAxis" xlink:label="srt_ShareRepurchaseProgramAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ShareRepurchaseProgramDomain" xlink:label="srt_ShareRepurchaseProgramDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedeemableConvertiblePreferredStocksMember" xlink:label="fly_RedeemableConvertiblePreferredStocksMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteAbstract" xlink:label="us-gaap_StockholdersEquityNoteAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="us-gaap_ScheduleOfStockByClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeedPreferredStockMember" xlink:label="fly_SeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesAuthorized" xlink:label="us-gaap_TemporaryEquitySharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeed-1PreferredStockMember" xlink:label="fly_SeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="us-gaap_TemporaryEquitySharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="us-gaap_SeriesAPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockMember" xlink:label="fly_SeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-2PreferredStockMember" xlink:label="fly_SeriesD-2PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableConvertiblePreferredStockMember" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ShareRepurchaseProgramAxis" xlink:to="srt_ShareRepurchaseProgramDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ShareRepurchaseProgramDomain" xlink:to="fly_RedeemableConvertiblePreferredStocksMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_ScheduleOfStockByClassTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquityParOrStatedValuePerShare" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeedPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquitySharesAuthorized" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeed-1PreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="srt_ShareRepurchaseProgramAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquitySharesIssued" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_ClassOfStockLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquitySharesOutstanding" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquityCarryingAmountAttributableToParent" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJPreferredStockMember" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-2PreferredStockMember" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_RedeemableConvertiblePreferredStockMember" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesCPurchaseAgreementMember" xlink:label="fly_SeriesCPurchaseAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityNoteAbstract" xlink:label="us-gaap_StockholdersEquityNoteAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="us-gaap_ScheduleOfStockByClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfShareSold" xlink:label="fly_NumberOfShareSold"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeedPreferredStockMember" xlink:label="fly_SeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-2PreferredStockMember" xlink:label="fly_SeriesD-2PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CashProceeds" xlink:label="fly_CashProceeds"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="us-gaap_SeriesAPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IPOClosingPreferredStockDividendMember" xlink:label="fly_IPOClosingPreferredStockDividendMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockMember" xlink:label="us-gaap_ConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeed-1PreferredStockMember" xlink:label="fly_SeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockMember" xlink:label="fly_SeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PreferredStockIssuedAtAPurchasePrice" xlink:label="fly_PreferredStockIssuedAtAPurchasePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes" xlink:label="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesDPreferredStockMember" xlink:label="us-gaap_SeriesDPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeemedSharesIssuedPricePerShare" xlink:label="fly_DeemedSharesIssuedPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPreferredStockCash" xlink:label="us-gaap_DividendsPreferredStockCash"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonCompoundingRate" xlink:label="fly_PercentageOfNonCompoundingRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MajoritySponsorMember" xlink:label="fly_MajoritySponsorMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedeemableConvertiblePreferredStocksMember" xlink:label="fly_RedeemableConvertiblePreferredStocksMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare" xlink:label="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonAccruingOrignalIssuePricePerShare" xlink:label="fly_PercentageOfNonAccruingOrignalIssuePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityLiquidationPreference" xlink:label="us-gaap_TemporaryEquityLiquidationPreference"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccretionExpense" xlink:label="us-gaap_AccretionExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockVotingRights" xlink:label="us-gaap_PreferredStockVotingRights"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsPerShareDeclared" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantExercisePriceDecrease" xlink:label="us-gaap_WarrantExercisePriceDecrease"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OptionIndexedToIssuersEquityShares" xlink:label="us-gaap_OptionIndexedToIssuersEquityShares"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PrepaidPurchaseCredit" xlink:label="fly_PrepaidPurchaseCredit"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="fly_SeriesCPurchaseAgreementMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_ScheduleOfStockByClassTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_WarrantMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_NumberOfShareSold" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeedPreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_IPOMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_TypeOfArrangementAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-2PreferredStockMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_ClassOfStockLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_CashProceeds" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_IPOClosingPreferredStockDividendMember" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SharesIssued" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ConvertiblePreferredStockMember" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SharePrice" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeed-1PreferredStockMember" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJPreferredStockMember" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PreferredStockIssuedAtAPurchasePrice" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesDPreferredStockMember" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_DeemedSharesIssuedPricePerShare" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DividendsPreferredStockCash" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PercentageOfNonCompoundingRate" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_MajoritySponsorMember" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CommonStockSharesIssued" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_RedeemableConvertiblePreferredStocksMember" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PercentageOfNonAccruingOrignalIssuePricePerShare" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SharesIssuedPricePerShare" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquityLiquidationPreference" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_AccretionExpense" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockVotingRights" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockDividendsPerShareDeclared" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_WarrantExercisePriceDecrease" order="24" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CommonStockValue" order="25" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockSharesIssued" order="26" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="27" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockValue" order="28" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_OptionIndexedToIssuersEquityShares" order="29" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PrepaidPurchaseCredit" order="30" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract" xlink:label="us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandSeventeenEquityIncentivePlanMember" xlink:label="fly_TwoThousandSeventeenEquityIncentivePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockOptionMember" xlink:label="us-gaap_StockOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember" xlink:label="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" xlink:label="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfReservedSharesIncrease" xlink:label="fly_NumberOfReservedSharesIncrease"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherArrangementsMember" xlink:label="fly_OtherArrangementsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfReservedSharesIncreaseApproximately" xlink:label="fly_NumberOfReservedSharesIncreaseApproximately"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_VotingPowerPercentage" xlink:label="fly_VotingPowerPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SharesOutstandingPercentage" xlink:label="fly_SharesOutstandingPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairMarketValueOfSharePercentage" xlink:label="fly_FairMarketValueOfSharePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableAllowance" xlink:label="us-gaap_LoansAndLeasesReceivableAllowance"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonRecourseEmployeeLoans" xlink:label="fly_NonRecourseEmployeeLoans"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PrepaidAsset" xlink:label="fly_PrepaidAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableOtherCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableOtherCurrentAndNoncurrent"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedArrangementsToObtainGoodsAndServicesAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_PlanNameAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_TwoThousandSeventeenEquityIncentivePlanMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_StockOptionMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharesIssued" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_NumberOfReservedSharesIncrease" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="3.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_OtherArrangementsMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_NumberOfReservedSharesIncreaseApproximately" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_VotingPowerPercentage" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_SharesOutstandingPercentage" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_FairMarketValueOfSharePercentage" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ProceedsFromStockOptionsExercised" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_LoansAndLeasesReceivableAllowance" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_NonRecourseEmployeeLoans" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_PrepaidAsset" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AccountsPayableOtherCurrentAndNoncurrent" order="24" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfRestrictedStockActivityDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember" xlink:label="us-gaap_RestrictedStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_4"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_9"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockMember" order="3.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_4" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_9" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfStockOptionActivityDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockOptionMember" xlink:label="us-gaap_StockOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" xlink:label="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_4"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_9"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" xlink:label="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_16"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Weighted-AverageRemainingContractualTermUnvested" xlink:label="fly_Weighted-AverageRemainingContractualTermUnvested"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_22"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_StockOptionMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="3.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_4" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_9" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_16" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" order="19" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_Weighted-AverageRemainingContractualTermUnvested" order="20" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" order="21" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_22" order="22" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" order="23" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfWeightedAverageAssumptionsUsedInTheEstimatedGrantDateFairValueCalculationsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="3.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfStockbasedCompensationExpenseRelatedToOptionsAndRsusDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="us-gaap_IncomeStatementLocationAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="us-gaap_IncomeStatementLocationDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_IncomeStatementLocationAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementLocationAxis" xlink:to="us-gaap_IncomeStatementLocationDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementLocationDomain" xlink:to="us-gaap_ResearchAndDevelopmentExpenseMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementLocationDomain" xlink:to="us-gaap_GeneralAndAdministrativeExpenseMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeBeforeIncomeTaxDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeTaxExpenseDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:label="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:to="us-gaap_DeferredForeignIncomeTaxExpenseBenefit" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:to="us-gaap_CurrentForeignTaxExpenseBenefit" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CurrentFederalStateAndLocalTaxExpenseBenefitAbstract" xlink:to="us-gaap_CurrentIncomeTaxExpenseBenefit" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="us-gaap_OperatingLossCarryforwardsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="us-gaap_IncomeTaxAuthorityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="us-gaap_IncomeTaxAuthorityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CurrencyAxis" xlink:label="srt_CurrencyAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2025/currency-2025.xsd#currency_AllCurrenciesDomain" xlink:label="currency_AllCurrenciesDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain" xlink:label="us-gaap_AssetAcquisitionDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PurchaseAccountingMember" xlink:label="fly_PurchaseAccountingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="us-gaap_OperatingLossCarryforwardsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2025/currency-2025.xsd#currency_USD" xlink:label="currency_USD"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionAxis" xlink:label="us-gaap_AssetAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DomesticCountryMember" xlink:label="us-gaap_DomesticCountryMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="us-gaap_StateAndLocalJurisdictionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="us-gaap_OperatingLossCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardAmount" xlink:label="us-gaap_TaxCreditCarryforwardAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CumulativeOwnershipPercentage" xlink:label="fly_CumulativeOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CumulativeOwnershipPeriod" xlink:label="fly_CumulativeOwnershipPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_IncomeTaxAuthorityAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxAuthorityAxis" xlink:to="us-gaap_IncomeTaxAuthorityDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_CurrencyAxis" xlink:to="currency_AllCurrenciesDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetAcquisitionDomain" xlink:to="fly_PurchaseAccountingMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="currency_AllCurrenciesDomain" xlink:to="currency_USD" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_OperatingLossCarryforwardsTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetAcquisitionAxis" xlink:to="us-gaap_AssetAcquisitionDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxAuthorityDomain" xlink:to="us-gaap_DomesticCountryMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxAuthorityDomain" xlink:to="us-gaap_StateAndLocalJurisdictionMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_AssetAcquisitionAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="srt_CurrencyAxis" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_OperatingLossCarryforwards" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_OperatingLossCarryforwardsLineItems" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_TaxCreditCarryforwardAmount" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="fly_CumulativeOwnershipPercentage" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="fly_CumulativeOwnershipPeriod" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_UnrecognizedTaxBenefits" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfEffectiveIncomeTaxReconciliationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTable" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationTable" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfProvisionForEffectiveIncomeTaxReconciliationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" xlink:label="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TaxReconciliationNotRequired" xlink:label="fly_TaxReconciliationNotRequired"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="fly_TaxReconciliationNotRequired" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxPaidByJurisdicationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidFederalAfterRefundReceived" xlink:label="us-gaap_IncomeTaxPaidFederalAfterRefundReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="us-gaap_IncomeTaxDisclosureAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived" xlink:label="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="us-gaap_IncomeTaxesPaidNet"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxPaidFederalAfterRefundReceived" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxDisclosureAbstract" xlink:to="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" xlink:to="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxesPaidNet" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfCarryforwardsThatGaveRiseToSignificantPortionsOfDeferredTaxesDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsGrossAbstract" xlink:label="us-gaap_DeferredTaxAssetsGrossAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:label="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesAbstract" xlink:label="us-gaap_DeferredTaxLiabilitiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredTaxLiabilitiesRightOfUseAssets" xlink:label="fly_DeferredTaxLiabilitiesRightOfUseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" xlink:label="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredTaxAssetsCapitalizedResearchCosts" xlink:label="fly_DeferredTaxAssetsCapitalizedResearchCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:label="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" xlink:label="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesOther" xlink:label="us-gaap_DeferredTaxLiabilitiesOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="us-gaap_DeferredIncomeTaxLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxLiabilitiesLeasingArrangements" xlink:label="us-gaap_DeferredTaxLiabilitiesLeasingArrangements"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeferredTaxAssetsInterestLimitationCarryforwards" xlink:label="fly_DeferredTaxAssetsInterestLimitationCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsDeferredIncome" xlink:label="us-gaap_DeferredTaxAssetsDeferredIncome"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="us-gaap_DeferredTaxAssetsOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="us-gaap_DeferredTaxAssetsGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="us-gaap_DeferredTaxAssetsNet"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxAssetsGrossAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="fly_DeferredTaxLiabilitiesRightOfUseAssets" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsTaxCreditCarryforwards" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentsOfDeferredTaxAssetsAndLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="fly_DeferredTaxAssetsCapitalizedResearchCosts" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesOther" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="us-gaap_DeferredIncomeTaxLiabilities" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedTotalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesLeasingArrangements" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxLiabilitiesAbstract" xlink:to="us-gaap_DeferredTaxAssetsLiabilitiesNet" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="fly_DeferredTaxAssetsInterestLimitationCarryforwards" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsDeferredIncome" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsOther" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsGross" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DeferredTaxAssetsGrossAbstract" xlink:to="us-gaap_DeferredTaxAssetsNet" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfUnrecognizedTaxBenefitsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxUncertaintiesAbstract" xlink:label="us-gaap_IncomeTaxUncertaintiesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:label="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:label="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" xlink:label="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits_5"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeTaxUncertaintiesAbstract" xlink:to="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:to="us-gaap_UnrecognizedTaxBenefits" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:to="us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:to="us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:to="us-gaap_UnrecognizedTaxBenefits_5" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="srt_EquityMethodInvesteeNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConsultingAgreementMember" xlink:label="fly_ConsultingAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EquityMethodInvestmentMember" xlink:label="fly_EquityMethodInvestmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-4PreferredStockMember" xlink:label="fly_SeriesD-4PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAnnualPrincipalPayment" xlink:label="us-gaap_DebtInstrumentAnnualPrincipalPayment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfRelatedPartyDebt" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExtinguishmentOfDebtAmount" xlink:label="us-gaap_ExtinguishmentOfDebtAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestExpenseInvestmentAdvisoryFees" xlink:label="us-gaap_NoninterestExpenseInvestmentAdvisoryFees"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="srt_EquityMethodInvesteeNameDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="fly_ConsultingAgreementMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_EquityMethodInvesteeNameDomain" xlink:to="fly_EquityMethodInvestmentMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-4PreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_TypeOfArrangementAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DebtInstrumentAnnualPrincipalPayment" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_StatementLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RepaymentsOfRelatedPartyDebt" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ExtinguishmentOfDebtAmount" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NoninterestExpenseInvestmentAdvisoryFees" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NonoperatingIncomeExpense" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsScheduleOfRelatedPartyTransactionsDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="us-gaap_RelatedPartyTransactionsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AEIndustrialMember" xlink:label="fly_AEIndustrialMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_GSPrecisionMember" xlink:label="fly_GSPrecisionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="us-gaap_OperatingCostsAndExpenses"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedwireCorporationMember" xlink:label="fly_RedwireCorporationMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BelcanLLCMember" xlink:label="fly_BelcanLLCMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember" xlink:label="us-gaap_RelatedPartyMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsAbstract" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_AEIndustrialMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_AccountsPayableCurrentAndNoncurrent" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_GSPrecisionMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_RelatedPartyTransactionLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_OperatingCostsAndExpenses" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_RedwireCorporationMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_BelcanLLCMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasicLineItems" xlink:label="us-gaap_EarningsPerShareBasicLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ClassA1PreferredStockMember" xlink:label="fly_ClassA1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareBasicLineItems" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_ClassA1PreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_NetIncomeLoss" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareBasicLineItems" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:to="us-gaap_EarningsPerShareBasicLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_EarningsPerShareBasic" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="2.0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesSeedPreferredStockMember" xlink:label="fly_ConvertibleSeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesSeed-1PreferredStockMember" xlink:label="fly_ConvertibleSeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="us-gaap_SeriesAPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockWarrantsMember" xlink:label="fly_SeriesJPreferredStockWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantsMember" xlink:label="fly_SeriesJWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantsMember" xlink:label="fly_CommonStockWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesD-1PreferredStockMember" xlink:label="fly_ConvertibleSeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="us-gaap_EmployeeStockOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SubordinatedConvertiblePromissoryNoteMember" xlink:label="fly_SubordinatedConvertiblePromissoryNoteMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleNotesMember" xlink:label="fly_ConvertibleNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SMINoteMember" xlink:label="fly_SMINoteMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PreferredStockConvertedToCommonSharesMember" xlink:label="fly_PreferredStockConvertedToCommonSharesMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleSeriesSeedPreferredStockMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleSeriesSeed-1PreferredStockMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesD-1PreferredStockMember" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesD-3PreferredStockMember" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesMPreferredStockMember" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesJPreferredStockWarrantsMember" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesJWarrantsMember" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_CommonStockWarrantsMember" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleSeriesD-1PreferredStockMember" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_EmployeeStockOptionMember" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="13" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SubordinatedConvertiblePromissoryNoteMember" order="14" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleNotesMember" order="15" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_WarrantMember" order="16" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SMINoteMember" order="17" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_PreferredStockConvertedToCommonSharesMember" order="18" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentMember" xlink:label="us-gaap_PropertyPlantAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaterialMember" xlink:label="fly_MaterialMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="us-gaap_FairValueByAssetClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_MaterialMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_NumberOfOperatingSegments" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_FairValueByAssetClassAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_SegmentReportingInformationLineItems" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationScheduleOfSegmentReportingInformationBySegmentDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain" xlink:label="srt_ConsolidationItemsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember" xlink:label="us-gaap_OperatingSegmentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingAbstract" xlink:label="us-gaap_SegmentReportingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis" xlink:label="srt_ConsolidationItemsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold" xlink:label="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaterialsAndConsumables" xlink:label="fly_MaterialsAndConsumables"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractorsAndOutsideServices" xlink:label="fly_ContractorsAndOutsideServices"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeOperating" xlink:label="us-gaap_InterestIncomeOperating"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating" xlink:label="us-gaap_InterestExpenseNonoperating"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_GainOnSettlementOfContingentLiabilities" xlink:label="fly_GainOnSettlementOfContingentLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingOtherItemAmount" xlink:label="us-gaap_SegmentReportingOtherItemAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidationItemsDomain" xlink:to="us-gaap_OperatingSegmentsMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="srt_ConsolidationItemsAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="srt_ConsolidationItemsAxis" xlink:to="srt_ConsolidationItemsDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_Revenues" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_SegmentReportingInformationLineItems" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_CostOfGoodsAndServicesSold" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="fly_MaterialsAndConsumables" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="fly_ContractorsAndOutsideServices" order="4" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_DepreciationAndAmortization" order="5" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_InterestIncomeOperating" order="6" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_InterestExpenseNonoperating" order="7" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_FairValueAdjustmentOfWarrants" order="8" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" order="9" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="fly_GainOnSettlementOfContingentLiabilities" order="10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingOtherItemAmount" order="11" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_NetIncomeLoss" order="12" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel"/>
        </link:presentationLink>
        <link:presentationLink xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails" xlink:title="presentationLink" xlink:type="extended">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems" xlink:label="us-gaap_SubsequentEventLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationPriceOfAcquisitionExpected" xlink:label="us-gaap_BusinessCombinationPriceOfAcquisitionExpected"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BaseRateMember" xlink:label="us-gaap_BaseRateMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis" xlink:label="us-gaap_VariableRateAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable" xlink:label="us-gaap_SubsequentEventTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventsAbstract" xlink:label="us-gaap_SubsequentEventsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SecuredOverFinancingRateMember" xlink:label="fly_SecuredOverFinancingRateMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FireflyMember" xlink:label="fly_FireflyMember"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventLineItems" xlink:to="us-gaap_BusinessCombinationPriceOfAcquisitionExpected" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VariableRateDomain" xlink:to="us-gaap_BaseRateMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VariableRateAxis" xlink:to="us-gaap_VariableRateDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_SubsequentEventTypeAxis" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeDomain" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventsAbstract" xlink:to="us-gaap_SubsequentEventTable" order="0" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_VariableRateDomain" xlink:to="fly_SecuredOverFinancingRateMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="fly_FireflyMember" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_VariableRateAxis" order="1" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_CreditFacilityAxis" order="2" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
          <link:presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_SubsequentEventLineItems" order="3" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/label"/>
        </link:presentationLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/Cover">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems" xlink:label="dei_DocumentInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable" xlink:label="dei_DocumentInformationTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType" xlink:label="dei_DocumentType"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassAMember" xlink:label="us-gaap_CommonClassAMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate" xlink:label="dei_DocumentPeriodEndDate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonClassBMember" xlink:label="us-gaap_CommonClassBMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentAnnualReport" xlink:label="dei_DocumentAnnualReport"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport" xlink:label="dei_DocumentTransitionReport"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber" xlink:label="dei_EntityFileNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode" xlink:label="dei_EntityIncorporationStateCountryCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber" xlink:label="dei_EntityTaxIdentificationNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1" xlink:label="dei_EntityAddressAddressLine1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine2" xlink:label="dei_EntityAddressAddressLine2"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown" xlink:label="dei_EntityAddressCityOrTown"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince" xlink:label="dei_EntityAddressStateOrProvince"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode" xlink:label="dei_EntityAddressPostalZipCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode" xlink:label="dei_CityAreaCode"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber" xlink:label="dei_LocalPhoneNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle" xlink:label="dei_Security12bTitle"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName" xlink:label="dei_SecurityExchangeName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus" xlink:label="dei_EntityCurrentReportingStatus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent" xlink:label="dei_EntityInteractiveDataCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory" xlink:label="dei_EntityFilerCategory"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness" xlink:label="dei_EntitySmallBusiness"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany" xlink:label="dei_EntityEmergingGrowthCompany"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityExTransitionPeriod" xlink:label="dei_EntityExTransitionPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany" xlink:label="dei_EntityShellCompany"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="dei_DocumentFiscalPeriodFocus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus" xlink:label="dei_DocumentFiscalYearFocus"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="dei_EntityWellKnownSeasonedIssuer"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityVoluntaryFilers" xlink:label="dei_EntityVoluntaryFilers"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_IcfrAuditorAttestationFlag" xlink:label="dei_IcfrAuditorAttestationFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFinStmtErrorCorrectionFlag" xlink:label="dei_DocumentFinStmtErrorCorrectionFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityPublicFloat" xlink:label="dei_EntityPublicFloat"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentsIncorporatedByReferenceTextBlock" xlink:label="dei_DocumentsIncorporatedByReferenceTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorOpinionTextBlock" xlink:label="dei_AuditorOpinionTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorName" xlink:label="dei_AuditorName"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorLocation" xlink:label="dei_AuditorLocation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AuditorFirmId" xlink:label="dei_AuditorFirmId"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentInformationTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentType" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="dei_DocumentInformationTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_CommonClassAMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentPeriodEndDate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_CommonClassBMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentAnnualReport" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentTransitionReport" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityFileNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityRegistrantName" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityIncorporationStateCountryCode" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityTaxIdentificationNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressAddressLine1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressAddressLine2" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressCityOrTown" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressStateOrProvince" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityAddressPostalZipCode" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_CityAreaCode" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_LocalPhoneNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_Security12bTitle" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="16" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_TradingSymbol" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_SecurityExchangeName" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCurrentReportingStatus" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="19" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityInteractiveDataCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="20" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityFilerCategory" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="21" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntitySmallBusiness" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="22" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityEmergingGrowthCompany" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="23" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityExTransitionPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="24" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityShellCompany" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="25" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCommonStockSharesOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="26" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityCentralIndexKey" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="27" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AmendmentFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="28" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentFiscalPeriodFocus" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="29" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentFiscalYearFocus" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="30" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_CurrentFiscalYearEndDate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="31" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityWellKnownSeasonedIssuer" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="32" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityVoluntaryFilers" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="33" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_IcfrAuditorAttestationFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="34" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentFinStmtErrorCorrectionFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="35" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_EntityPublicFloat" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="36" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_DocumentsIncorporatedByReferenceTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="37" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorOpinionTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="38" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorName" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="39" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorLocation" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="40" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="dei_DocumentInformationLineItems" xlink:to="dei_AuditorFirmId" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheets">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="us-gaap_LiabilitiesCurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="us-gaap_AssetsCurrentAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityAbstract" xlink:label="us-gaap_TemporaryEquityAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember" xlink:label="us-gaap_RelatedPartyMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments" xlink:label="us-gaap_ShortTermInvestments"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccountsPayableCurrentRelatedParties" xlink:label="fly_AccountsPayableCurrentRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseNoncurrent" xlink:label="us-gaap_PrepaidExpenseNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashCurrent" xlink:label="us-gaap_RestrictedCashCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:label="us-gaap_DeferredRevenueNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashNoncurrent" xlink:label="us-gaap_RestrictedCashNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermNotesPayable" xlink:label="us-gaap_LongTermNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NotesPayableNoncurrent-RelatedParties" xlink:label="fly_NotesPayableNoncurrent-RelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="us-gaap_DeferredRevenueCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstanding" xlink:label="us-gaap_WarrantsAndRightsOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AssetsAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_CommonStockValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesCurrentAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccountsPayableCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TemporaryEquityAbstract" xlink:to="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsCurrentAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_AdditionalPaidInCapital" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_ShortTermInvestments" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="fly_AccountsPayableCurrentRelatedParties" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_PrepaidExpenseNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_RestrictedCashCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_DeferredRevenueNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AccountsReceivableNetCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_RestrictedCashNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LongTermNotesPayable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_PrepaidExpenseCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_FinanceLeaseLiabilityCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="fly_NotesPayableNoncurrent-RelatedParties" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_OtherAssetsCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_DeferredRevenueCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_FinanceLeaseRightOfUseAsset" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_WarrantsAndRightsOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_NotesPayableCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_OtherLiabilitiesNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_OtherLiabilitiesCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_Goodwill" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_Liabilities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_OtherAssetsNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_CommitmentsAndContingencies" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_Assets" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_TemporaryEquityAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableConvertiblePreferredStockMember" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesAuthorized" xlink:label="us-gaap_TemporaryEquitySharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="us-gaap_TemporaryEquitySharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityLiquidationPreference" xlink:label="us-gaap_TemporaryEquityLiquidationPreference"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquityParOrStatedValuePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_RedeemableConvertiblePreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquitySharesAuthorized" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquitySharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquitySharesOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TemporaryEquityLiquidationPreference" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="us-gaap_OperatingExpensesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:label="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="us-gaap_EarningsPerShareAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeInFairValueOfWarrantLiability" xlink:label="fly_ChangeInFairValueOfWarrantLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeOperating" xlink:label="us-gaap_InterestIncomeOperating"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossRelatedToLitigationSettlement" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareBasic" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="fly_ChangeInFairValueOfWarrantLiability" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CostOfGoodsAndServicesSold" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_GrossProfit" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_InterestIncomeOperating" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpenses" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OperatingExpensesAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_InterestIncomeExpenseNonoperatingNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OperatingIncomeLoss" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_GainLossRelatedToLitigationSettlement" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_OtherNonoperatingIncomeExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_IncomeTaxExpenseBenefit" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLoss" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EarningsPerShareAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfConvertiblePreferredStockAndStockholdersEquityDeficit">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="us-gaap_PreferredStockSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember" xlink:label="us-gaap_RetainedEarningsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-4PreferredStockMember" xlink:label="fly_SeriesD-4PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" xlink:label="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" xlink:label="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" xlink:label="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesOther" xlink:label="us-gaap_StockIssuedDuringPeriodSharesOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueOther" xlink:label="us-gaap_StockIssuedDuringPeriodValueOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_StockIssuedDuringPeriodSharesStockDividend" xlink:label="fly_StockIssuedDuringPeriodSharesStockDividend"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" xlink:label="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" xlink:label="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConversionOfStockAmountConverted1" xlink:label="us-gaap_ConversionOfStockAmountConverted1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConversionOfStockSharesConverted1" xlink:label="us-gaap_ConversionOfStockSharesConverted1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExerciseOfCommonWarrantsIntoCommonStock" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExerciseOfCommonWarrantsIntoCommonStockShares" xlink:label="fly_ExerciseOfCommonWarrantsIntoCommonStockShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementEquityComponentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PreferredStockSharesOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AdditionalPaidInCapitalMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_RetainedEarningsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-4PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognition" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesAcquisitions" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueAcquisitions" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesOther" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueOther" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="16" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalIncreaseInCarryingAmountOfRedeemablePreferredStock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_StockIssuedDuringPeriodSharesStockDividend" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="19" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="20" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="21" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="22" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="23" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="25" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConversionOfStockAmountConverted1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="26" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConversionOfStockSharesConverted1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="27" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ExerciseOfCommonWarrantsIntoCommonStock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="28" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ExerciseOfCommonWarrantsIntoCommonStockShares" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="29" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetIncomeLoss" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd#ecd_AllIndividualsMember" xlink:label="ecd_AllIndividualsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DavidWheelerMember" xlink:label="fly_DavidWheelerMember"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ecd_AllIndividualsMember" xlink:to="fly_DavidWheelerMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCybersecurityRiskManagementStrategyAndGovernance">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceTable" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:label="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:label="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:label="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:label="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesIntegratedFlag" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" xlink:label="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock" xlink:label="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskRoleOfManagementTextBlock" xlink:label="cyd_CybersecurityRiskRoleOfManagementTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementThirdPartyEngagedFlag" xlink:label="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag" xlink:label="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock" xlink:label="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock" xlink:label="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/cyd/2025/cyd-2025.xsd#cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag" xlink:label="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:to="cyd_CybersecurityRiskManagementStrategyAndGovernanceTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:to="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskManagementProcessesIntegratedFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceAbstract" xlink:to="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskProcessForInformingBoardCommitteeOrSubcommitteeResponsibleForOversightTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementStrategyAndGovernanceLineItems" xlink:to="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskManagementProcessesIntegratedTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskRoleOfManagementTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskManagementThirdPartyEngagedFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskThirdPartyOversightAndIdentificationProcessesFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantFlag" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementExpertiseOfManagementResponsibleTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskManagementProcessesForAssessingIdentifyingAndManagingThreatsTextBlock" xlink:to="cyd_CybersecurityRiskMateriallyAffectedOrReasonablyLikelyToMateriallyAffectRegistrantTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskProcessForInformingManagementOrCommitteesResponsibleTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="cyd_CybersecurityRiskBoardOfDirectorsOversightTextBlock" xlink:to="cyd_CybersecurityRiskManagementPositionsOrCommitteesResponsibleReportToBoardFlag" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsTables">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpaceflightMember" xlink:label="fly_SpaceflightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:label="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" xlink:label="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaInformationTextBlock" xlink:label="us-gaap_BusinessAcquisitionProFormaInformationTextBlock"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SpaceflightMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfComprehensiveIncomeLossTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionProFormaInformationTextBlock" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesTables">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" xlink:label="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:label="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" xlink:label="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:label="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock" xlink:label="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SummaryOfTaxCreditCarryforwardsTextBlock" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureTheCompanyInitialPublicOfferingAndBasisOfPresentationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:label="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonWarrantsMember" xlink:label="fly_CommonWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsOfUnderwritngDiscounts" xlink:label="fly_ProceedsOfUnderwritngDiscounts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DiscountsOnUnderwriting" xlink:label="fly_DiscountsOnUnderwriting"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromCommissionsReceived" xlink:label="us-gaap_ProceedsFromCommissionsReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OrganizationalAndOfferingCostsExpense" xlink:label="us-gaap_OrganizationalAndOfferingCostsExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BrokerageCommissionsRevenue" xlink:label="us-gaap_BrokerageCommissionsRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" xlink:label="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositLiabilitiesAccruedInterest" xlink:label="us-gaap_DepositLiabilitiesAccruedInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation" xlink:label="us-gaap_EmployeeBenefitsAndShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityReverseStockSplit" xlink:label="us-gaap_StockholdersEquityReverseStockSplit"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_StatementEquityComponentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="fly_CommonWarrantsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProceedsFromIssuanceInitialPublicOffering" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ProceedsOfUnderwritngDiscounts" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_DiscountsOnUnderwriting" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProceedsFromCommissionsReceived" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OrganizationalAndOfferingCostsExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_BrokerageCommissionsRevenue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DepositLiabilitiesAccruedInterest" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EmployeeBenefitsAndShareBasedCompensation" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityReverseStockSplit" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="us-gaap_AccountingPoliciesAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:label="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:label="us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain" xlink:label="srt_NameOfMajorCustomerDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerMember" xlink:label="fly_CustomerMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember" xlink:label="us-gaap_SalesRevenueNetMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis" xlink:label="srt_MajorCustomersAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain" xlink:label="srt_NameOfMajorCustomerDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockMember" xlink:label="us-gaap_ConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCash" xlink:label="us-gaap_RestrictedCash"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DepositoryRiskMember" xlink:label="fly_DepositoryRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember" xlink:label="us-gaap_AccountsReceivableMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashFDICInsuredAmount" xlink:label="us-gaap_CashFDICInsuredAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="us-gaap_ConcentrationRiskPercentage1"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskTypeDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_CommonStockSharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="us-gaap_CustomerConcentrationRiskMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_SalesRevenueNetMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_NameOfMajorCustomerDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_NameOfMajorCustomerDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ConvertiblePreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_RestrictedCash" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="fly_DepositoryRiskMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_AccountsReceivableMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="srt_MajorCustomersAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_EntityWideRevenueMajorCustomerLineItems" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_CashFDICInsuredAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_StatementEquityComponentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_ConcentrationRiskPercentage1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="srt_RangeAxis" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfPropertyAndEquipmentUsefulLivesDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="us-gaap_MachineryAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TestStandsMember" xlink:label="fly_TestStandsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingMember" xlink:label="us-gaap_BuildingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="us-gaap_FurnitureAndFixturesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember" xlink:label="us-gaap_ComputerEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="us-gaap_SoftwareDevelopmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember" xlink:label="us-gaap_VehiclesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="us-gaap_LeaseholdImprovementsMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_MachineryAndEquipmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLifeDescriptionOfTermExtensibleEnumeration" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_TestStandsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="srt_RangeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_BuildingMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_FurnitureAndFixturesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_ComputerEquipmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_SoftwareDevelopmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_VehiclesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_LeaseholdImprovementsMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesScheduleOfConcentrationOfCreditRiskDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:label="us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:label="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="us-gaap_ConcentrationRiskByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="us-gaap_ConcentrationRiskTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="us-gaap_ConcentrationRiskPercentage1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_NameOfMajorCustomerDomain" xlink:label="srt_NameOfMajorCustomerDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerOneMember" xlink:label="fly_CustomerOneMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="us-gaap_CustomerConcentrationRiskMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SalesRevenueNetMember" xlink:label="us-gaap_SalesRevenueNetMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MajorCustomersAxis" xlink:label="srt_MajorCustomersAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerTwoMember" xlink:label="fly_CustomerTwoMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember" xlink:label="us-gaap_AccountsReceivableMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerThreeMember" xlink:label="fly_CustomerThreeMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerFourMember" xlink:label="fly_CustomerFourMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CustomerFiveMember" xlink:label="fly_CustomerFiveMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EntityWideRevenueMajorCustomerLineItems" xlink:to="us-gaap_ConcentrationRiskPercentage1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerOneMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="us-gaap_CustomerConcentrationRiskMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_SalesRevenueNetMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_NameOfMajorCustomerDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="srt_MajorCustomersAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerTwoMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_AccountsReceivableMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerThreeMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerFourMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="fly_CustomerFiveMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashMember" xlink:label="us-gaap_CashMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="us-gaap_NonrecurringAdjustmentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="us-gaap_NonrecurringAdjustmentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="us-gaap_NonrecurringAdjustmentDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_UnauditedProFormaInformationMember" xlink:label="fly_UnauditedProFormaInformationMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="us-gaap_CashAndCashEquivalentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpaceflightMember" xlink:label="fly_SpaceflightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="us-gaap_PaymentsToAcquireBusinessesGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationIntegrationRelatedCosts" xlink:label="us-gaap_BusinessCombinationIntegrationRelatedCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationAsset" xlink:label="us-gaap_BusinessCombinationContingentConsiderationAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" xlink:label="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" xlink:label="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts" xlink:label="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationIncurredCost" xlink:label="fly_BusinessCombinationIncurredCost"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="us-gaap_CashMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_NonrecurringAdjustmentAxis" xlink:to="us-gaap_NonrecurringAdjustmentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_NonrecurringAdjustmentAxis" xlink:to="us-gaap_NonrecurringAdjustmentDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonrecurringAdjustmentDomain" xlink:to="fly_UnauditedProFormaInformationMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_CashAndCashEquivalentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SpaceflightMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_PaymentsToAcquireBusinessesGross" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementEquityComponentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationIntegrationRelatedCosts" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_NonrecurringAdjustmentAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationAsset" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaRevenue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAdditionalDisclosuresAcquisitionCosts" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_BusinessCombinationIncurredCost" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfConsiderationPaidAndTheFairValueOfAssetsAcquiredAndLiabilitiesAssumedDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:label="us-gaap_BusinessCombinationConsiderationTransferredAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationCashConsiderationPaid" xlink:label="fly_BusinessCombinationCashConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpaceflightMember" xlink:label="fly_SpaceflightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" xlink:label="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationEquityConsiderationPaid" xlink:label="fly_BusinessCombinationEquityConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationTotalConsiderationPaid" xlink:label="fly_BusinessCombinationTotalConsiderationPaid"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCostsCurrentAndNoncurrent" xlink:label="us-gaap_DeferredCostsCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" xlink:label="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="fly_BusinessCombinationCashConsiderationPaid" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationConsiderationTransferredAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SpaceflightMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="fly_BusinessCombinationEquityConsiderationPaid" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationConsiderationTransferredAbstract" xlink:to="fly_BusinessCombinationTotalConsiderationPaid" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_DeferredCostsCurrentAndNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="16" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="19" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="20" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="21" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="22" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="23" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="24" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="25" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetAbstract" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfFairValueOfAcquiredIdentifiableIntangibleAssetsDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="us-gaap_TrademarksAndTradeNamesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DevelopedTechnologyMember" xlink:label="fly_DevelopedTechnologyMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BacklogMember" xlink:label="fly_BacklogMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FollowOnOpportunitiesMember" xlink:label="fly_FollowOnOpportunitiesMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_TrademarksAndTradeNamesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_DevelopedTechnologyMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_BacklogMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_CustomerRelationshipsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_FollowOnOpportunitiesMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfNetImpactOfAcquisitionDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SciTecMember" xlink:label="fly_SciTecMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="us-gaap_BusinessAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="fly_SciTecMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTax" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureBusinessCombinationsScheduleOfUnauditedProFormaInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentAxis" xlink:label="us-gaap_NonrecurringAdjustmentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonrecurringAdjustmentDomain" xlink:label="us-gaap_NonrecurringAdjustmentDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_UnauditedProFormaInformationMember" xlink:label="fly_UnauditedProFormaInformationMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue" xlink:label="us-gaap_BusinessAcquisitionsProFormaRevenue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" xlink:label="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" xlink:label="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_NonrecurringAdjustmentAxis" xlink:to="us-gaap_NonrecurringAdjustmentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NonrecurringAdjustmentDomain" xlink:to="fly_UnauditedProFormaInformationMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_NonrecurringAdjustmentAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaRevenue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDisaggregatedRevenueDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="us-gaap_DisaggregationOfRevenueLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="us-gaap_DisaggregationOfRevenueTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LaunchRevenueMember" xlink:label="fly_LaunchRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpacecraftSolutionsRevenueMember" xlink:label="fly_SpacecraftSolutionsRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherRevenueMember" xlink:label="fly_OtherRevenueMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DisaggregationOfRevenueLineItems" xlink:to="us-gaap_DisaggregationOfRevenueTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductsAndServicesDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductsAndServicesDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DisaggregationOfRevenueTable" xlink:to="srt_ProductOrServiceAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_LaunchRevenueMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DisaggregationOfRevenueLineItems" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_SpacecraftSolutionsRevenueMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_OtherRevenueMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRevenueScheduleOfDeferredRevenueDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueArrangementLineItems" xlink:label="us-gaap_DeferredRevenueArrangementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueArrangementByTypeTable" xlink:label="us-gaap_DeferredRevenueArrangementByTypeTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis" xlink:label="srt_ProductOrServiceAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain" xlink:label="srt_ProductsAndServicesDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LaunchRevenueMember" xlink:label="fly_LaunchRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenue" xlink:label="us-gaap_DeferredRevenue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpacecraftSolutionsRevenueMember" xlink:label="fly_SpacecraftSolutionsRevenueMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherRevenueMember" xlink:label="fly_OtherRevenueMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DeferredRevenueArrangementLineItems" xlink:to="us-gaap_DeferredRevenueArrangementByTypeTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductsAndServicesDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_LaunchRevenueMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DeferredRevenueArrangementByTypeTable" xlink:to="srt_ProductOrServiceAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DeferredRevenueArrangementLineItems" xlink:to="us-gaap_DeferredRevenue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_SpacecraftSolutionsRevenueMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ProductsAndServicesDomain" xlink:to="fly_OtherRevenueMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="us-gaap_MachineryAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TestStandsMember" xlink:label="fly_TestStandsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BuildingMember" xlink:label="us-gaap_BuildingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandAndLandImprovementsMember" xlink:label="us-gaap_LandAndLandImprovementsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember" xlink:label="us-gaap_ConstructionInProgressMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="us-gaap_FurnitureAndFixturesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember" xlink:label="us-gaap_ComputerEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="us-gaap_SoftwareDevelopmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VehiclesMember" xlink:label="us-gaap_VehiclesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="us-gaap_LeaseholdImprovementsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ITRelatedEquipmentMember" xlink:label="fly_ITRelatedEquipmentMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentGross" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_MachineryAndEquipmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_TestStandsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_BuildingMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_LandAndLandImprovementsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_ConstructionInProgressMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_FurnitureAndFixturesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_ComputerEquipmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_SoftwareDevelopmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_VehiclesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_LeaseholdImprovementsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_ITRelatedEquipmentMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfIntangibleAssetsGrossCarryingAmountAndAccumulatedAmortizationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:label="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InternalUseSoftwareMember" xlink:label="fly_InternalUseSoftwareMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="us-gaap_TrademarksAndTradeNamesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="us-gaap_DevelopedTechnologyRightsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BacklogMember" xlink:label="fly_BacklogMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FollowOnOpportunitiesMember" xlink:label="fly_FollowOnOpportunitiesMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_InternalUseSoftwareMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_TrademarksAndTradeNamesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable" xlink:to="srt_RangeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_DevelopedTechnologyRightsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_CustomerRelationshipsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_BacklogMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="fly_FollowOnOpportunitiesMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentsFairValueDisclosure" xlink:label="us-gaap_EquityMethodInvestmentsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain" xlink:label="us-gaap_VestingDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TrancheObligationsMember" xlink:label="fly_TrancheObligationsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingAxis" xlink:label="us-gaap_VestingAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain" xlink:label="us-gaap_VestingDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantMember" xlink:label="fly_CommonStockWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="us-gaap_SubsidiarySaleOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeDomain" xlink:label="fly_SponsorTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MajoritySponsorMember" xlink:label="fly_MajoritySponsorMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockMember" xlink:label="us-gaap_PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeAxis" xlink:label="fly_SponsorTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeDomain" xlink:label="fly_SponsorTypeDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantMember" xlink:label="fly_SeriesJWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantsToPurchaseAnAggregate" xlink:label="fly_WarrantsToPurchaseAnAggregate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CallOptionMember" xlink:label="us-gaap_CallOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AggregateOfNumberOfWarrantsToPurchase" xlink:label="fly_AggregateOfNumberOfWarrantsToPurchase"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AverageValuePerUnitAsPerMonteCarloSimulations" xlink:label="fly_AverageValuePerUnitAsPerMonteCarloSimulations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueAdjustment" xlink:label="us-gaap_LiabilitiesFairValueAdjustment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueOptionChangesInFairValueGainLoss1" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockOutstandingCommonWarrantsExercised" xlink:label="fly_CommonStockOutstandingCommonWarrantsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityMethodInvestmentsFairValueDisclosure" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_VestingDomain" xlink:to="fly_TrancheObligationsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_VestingAxis" xlink:to="us-gaap_VestingDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_VestingAxis" xlink:to="us-gaap_VestingDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_CommonStockWarrantMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_IPOMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="fly_SponsorTypeDomain" xlink:to="fly_MajoritySponsorMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="fly_SponsorTypeAxis" xlink:to="fly_SponsorTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="fly_SponsorTypeAxis" xlink:to="fly_SponsorTypeDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJWarrantMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WarrantsToPurchaseAnAggregate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="us-gaap_CallOptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementEquityComponentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AggregateOfNumberOfWarrantsToPurchase" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FinancialInstrumentAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_VestingAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="fly_SponsorTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CashAndCashEquivalentsFairValueDisclosure" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_SubsidiarySaleOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PreferredStockValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AverageValuePerUnitAsPerMonteCarloSimulations" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LiabilitiesFairValueAdjustment" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueOptionChangesInFairValueGainLoss1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_CommonStockOutstandingCommonWarrantsExercised" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementPresentTheKeyInputsAppliedInTheValuationsWarrantsDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AverageFairValuePerWarrant" xlink:label="fly_AverageFairValuePerWarrant"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementScenarioAxis" xlink:label="srt_StatementScenarioAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="srt_ScenarioUnspecifiedDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScenarioUnspecifiedDomain" xlink:label="srt_ScenarioUnspecifiedDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantMember" xlink:label="fly_CommonStockWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeOfControlScenarioMember" xlink:label="fly_ChangeOfControlScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantMember" xlink:label="fly_SeriesJWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EventProbabilityPercentage" xlink:label="fly_EventProbabilityPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IPOScenarioMember" xlink:label="fly_IPOScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DefaultScenarioMember" xlink:label="fly_DefaultScenarioMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageFairValuePerWarrant" xlink:label="fly_WeightedAverageFairValuePerWarrant"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" xlink:label="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValuePerShareMarketableSecurity" xlink:label="fly_FairValuePerShareMarketableSecurity"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DiscountForLackOfMarketability" xlink:label="fly_DiscountForLackOfMarketability"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValuePerShareNonMarketableSecurity" xlink:label="fly_FairValuePerShareNonMarketableSecurity"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAverageFairValuePerShare" xlink:label="fly_WeightedAverageFairValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProbabilityWeightedFairValuePerCommonWarrant" xlink:label="fly_ProbabilityWeightedFairValuePerCommonWarrant"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_AverageFairValuePerWarrant" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_ScenarioUnspecifiedDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_StatementScenarioAxis" xlink:to="srt_ScenarioUnspecifiedDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_CommonStockWarrantMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="fly_ChangeOfControlScenarioMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJWarrantMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_EventProbabilityPercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="fly_IPOScenarioMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FinancialInstrumentAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ScenarioUnspecifiedDomain" xlink:to="fly_DefaultScenarioMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="srt_StatementScenarioAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WeightedAverageFairValuePerWarrant" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_FairValuePerShareMarketableSecurity" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_DiscountForLackOfMarketability" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_FairValuePerShareNonMarketableSecurity" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_WeightedAverageFairValuePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="fly_ProbabilityWeightedFairValuePerCommonWarrant" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfPresentsTheKeyInputsAppliedInTheValuationsDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="us-gaap_BusinessAcquisitionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueAxis" xlink:label="us-gaap_ValuationTechniqueAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain" xlink:label="us-gaap_ValuationTechniqueDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueDomain" xlink:label="us-gaap_ValuationTechniqueDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BlackScholesMertonModelMember" xlink:label="us-gaap_BlackScholesMertonModelMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember" xlink:label="us-gaap_CommonStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantMember" xlink:label="fly_SeriesJWarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationTechniqueOptionPricingModelMember" xlink:label="us-gaap_ValuationTechniqueOptionPricingModelMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WeightedAveragePricePerShare" xlink:label="fly_WeightedAveragePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValueAssumption" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueAssumption"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingNumber" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingFairValue" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementMaximumValueRecognized" xlink:label="fly_ShareBasedCompensationArrangementMaximumValueRecognized"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairValueInputsDiscountRate" xlink:label="fly_FairValueInputsDiscountRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValue" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValue"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" xlink:label="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" xlink:label="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_ValuationTechniqueAxis" xlink:to="us-gaap_ValuationTechniqueDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_ValuationTechniqueAxis" xlink:to="us-gaap_ValuationTechniqueDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="us-gaap_BlackScholesMertonModelMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_ValuationTechniqueAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_SharePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJWarrantMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ValuationTechniqueDomain" xlink:to="us-gaap_ValuationTechniqueOptionPricingModelMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementEquityComponentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_WeightedAveragePricePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="srt_RangeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValueAssumption" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementMaximumValueRecognized" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_FairValueInputsDiscountRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureFairValueMeasurementScheduleOfCarryingValueOfTheTermLoansApproximatedTheirEstimatedFairValueDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashMember" xlink:label="us-gaap_CashMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="us-gaap_FinancialInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" xlink:label="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="us-gaap_FairValueInputsLevel1Member"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RPMCallOptionMember" xlink:label="fly_RPMCallOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis" xlink:label="us-gaap_CashAndCashEquivalentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeDomain" xlink:label="fly_SponsorTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MajoritySponsorMember" xlink:label="fly_MajoritySponsorMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SponsorTypeAxis" xlink:label="fly_SponsorTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantsMember" xlink:label="fly_SeriesJWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RestrictedCashMember" xlink:label="fly_RestrictedCashMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="us-gaap_LiabilitiesFairValueDisclosure"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="us-gaap_FairValueInputsLevel2Member"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TimeDepositsMember" xlink:label="fly_TimeDepositsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="us-gaap_MoneyMarketFundsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="us-gaap_FairValueInputsLevel3Member"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonWarrantsMember" xlink:label="fly_CommonWarrantsMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="us-gaap_CashMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FinancialInstrumentAxis" xlink:to="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_AssetsFairValueDisclosure" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" xlink:to="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" xlink:to="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_RPMCallOptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_CashAndCashEquivalentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="fly_SponsorTypeDomain" xlink:to="fly_MajoritySponsorMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="fly_SponsorTypeAxis" xlink:to="fly_SponsorTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesTitleDomain" xlink:to="fly_SeriesJWarrantsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CashAndCashEquivalentsAxis" xlink:to="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="fly_RestrictedCashMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_LiabilitiesFairValueDisclosure" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:to="fly_TimeDepositsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="us-gaap_MoneyMarketFundsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember" xlink:to="fly_CommonWarrantsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FinancialInstrumentAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="fly_SponsorTypeAxis" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems" xlink:label="us-gaap_LesseeLeaseDescriptionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable" xlink:label="us-gaap_LesseeLeaseDescriptionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionNameDomain" xlink:label="us-gaap_SaleLeasebackTransactionNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SaleAndLeasebackTransactionsMember" xlink:label="fly_SaleAndLeasebackTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" xlink:label="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember" xlink:label="srt_MinimumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:label="us-gaap_SaleLeasebackTransactionDescriptionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionNameDomain" xlink:label="us-gaap_SaleLeasebackTransactionNameDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LeaseRemainingLeaseTerm" xlink:label="fly_LeaseRemainingLeaseTerm"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RentIncraeseAnuallyInPercent" xlink:label="fly_RentIncraeseAnuallyInPercent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OperatingLeaseRight-Of-UseAssetDecreased" xlink:label="fly_OperatingLeaseRight-Of-UseAssetDecreased"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RightOfUseAssetObtainedInForLeaseLiability" xlink:label="fly_RightOfUseAssetObtainedInForLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability" xlink:label="us-gaap_OperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AreaOfLand" xlink:label="us-gaap_AreaOfLand"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetRentableArea" xlink:label="us-gaap_NetRentableArea"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PricePerSquareFoot" xlink:label="fly_PricePerSquareFoot"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayable" xlink:label="us-gaap_NotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermNotesPayable" xlink:label="us-gaap_LongTermNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentForPurchaseAndLeasebackAgreements" xlink:label="fly_PaymentForPurchaseAndLeasebackAgreements"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InterestExpenseOnPurchaseAndLeasebackAgreement" xlink:label="fly_InterestExpenseOnPurchaseAndLeasebackAgreement"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements" xlink:label="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_LesseeLeaseDescriptionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SaleLeasebackTransactionNameDomain" xlink:to="fly_SaleAndLeasebackTransactionsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_LesseeOperatingLeaseRemainingLeaseTerm" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_LesseeLeaseDescriptionTable" xlink:to="srt_RangeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MinimumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:to="us-gaap_SaleLeasebackTransactionNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:to="us-gaap_SaleLeasebackTransactionNameDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_LeaseRemainingLeaseTerm" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_LesseeLeaseDescriptionTable" xlink:to="us-gaap_SaleLeasebackTransactionDescriptionAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_RentIncraeseAnuallyInPercent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_OperatingLeaseRight-Of-UseAssetDecreased" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_RightOfUseAssetObtainedInForLeaseLiability" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_OperatingLeaseLiability" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_AreaOfLand" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_NetRentableArea" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_PricePerSquareFoot" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_NotesPayable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_NotesPayableCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_LongTermNotesPayable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_PaymentForPurchaseAndLeasebackAgreements" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_InterestExpenseOnPurchaseAndLeasebackAgreement" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FinancingAgreementMember" xlink:label="fly_FinancingAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermALoansMember" xlink:label="fly_TermALoansMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SecuredOverFinancingRateMember" xlink:label="fly_SecuredOverFinancingRateMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember" xlink:label="srt_RangeMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember" xlink:label="srt_MaximumMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis" xlink:label="us-gaap_VariableRateAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis" xlink:label="srt_RangeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_WarrantsToPurchaseSeriesJPreferredStockMember" xlink:label="fly_WarrantsToPurchaseSeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermBLoansMember" xlink:label="fly_TermBLoansMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesDPreferredStockMember" xlink:label="us-gaap_SeriesDPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansHeldForSaleMaturityDate" xlink:label="us-gaap_LoansHeldForSaleMaturityDate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermLoanMember" xlink:label="fly_TermLoanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativePremiumPaid" xlink:label="us-gaap_DerivativePremiumPaid"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleNotesMember" xlink:label="fly_ConvertibleNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription" xlink:label="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="us-gaap_LettersOfCreditOutstandingAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ExitFeePercentage" xlink:label="fly_ExitFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SwinglineLoans" xlink:label="fly_SwinglineLoans"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeBasisSpreadOnVariableRate" xlink:label="us-gaap_DerivativeBasisSpreadOnVariableRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForFees" xlink:label="us-gaap_PaymentsForFees"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SelfInsuranceReserve" xlink:label="us-gaap_SelfInsuranceReserve"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_InterestExpenseContractual" xlink:label="fly_InterestExpenseContractual"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaintainMinimumInterestReserveAmount" xlink:label="fly_MaintainMinimumInterestReserveAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentRepaidPrincipal" xlink:label="us-gaap_DebtInstrumentRepaidPrincipal"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentIncreaseAccruedInterest" xlink:label="us-gaap_DebtInstrumentIncreaseAccruedInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SpecificAdditionalInterestRate" xlink:label="fly_SpecificAdditionalInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebt" xlink:label="us-gaap_InterestExpenseDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" xlink:label="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnamortizedDebtIssuanceExpense" xlink:label="us-gaap_UnamortizedDebtIssuanceExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts" xlink:label="us-gaap_AmortizationOfFinancingCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet" xlink:label="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" xlink:label="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentFaceAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="fly_FinancingAgreementMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_LongtermDebtTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_TermALoansMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_VariableRateDomain" xlink:to="fly_SecuredOverFinancingRateMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_RangeMember" xlink:to="srt_MaximumMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_VariableRateAxis" xlink:to="us-gaap_VariableRateDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_VariableRateAxis" xlink:to="us-gaap_VariableRateDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_RangeAxis" xlink:to="srt_RangeMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_WarrantsToPurchaseSeriesJPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="srt_RangeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_TermBLoansMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesDPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LoansHeldForSaleMaturityDate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_TypeOfArrangementAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_TermLoanMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DerivativePremiumPaid" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_ConvertibleNotesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityRevolvingCreditConversionToTermLoanDescription" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_CreditFacilityAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LettersOfCreditOutstandingAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_VariableRateAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_ExitFeePercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_SwinglineLoans" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DerivativeBasisSpreadOnVariableRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityCommitmentFeePercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_PaymentsForFees" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_AccountsPayableInterestBearingCurrentAndNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_SelfInsuranceReserve" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_InterestExpenseContractual" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtPercentageBearingFixedInterestRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="16" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_MaintainMinimumInterestReserveAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentRepaidPrincipal" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="19" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="20" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentIncreaseAccruedInterest" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="21" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="22" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_SpecificAdditionalInterestRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="23" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_InterestExpenseDebt" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="24" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="25" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="26" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_UnamortizedDebtIssuanceExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="27" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_AmortizationOfFinancingCosts" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="28" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityIncreaseDecreaseForPeriodNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="29" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtCurrent" xlink:label="us-gaap_DebtCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherNotesMember" xlink:label="fly_OtherNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LongTermDebtNet" xlink:label="fly_LongTermDebtNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember" xlink:label="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentCarryingAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_LongtermDebtTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DeferredFinanceCostsNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtCurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_OtherNotesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_LongTermDebtNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableNetCarryingAmountOfTheCompanysOutstandingDebtParentheticalDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" xlink:label="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" xlink:label="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" xlink:label="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" xlink:label="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_CreditFacilityAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayableAndWarrantsPrincipalPaymentsUnderTheTermLoansDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TermLoanMember" xlink:label="fly_TermLoanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="us-gaap_DebtInstrumentCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" xlink:label="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="fly_TermLoanMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentCarryingAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNotesPayablePrincipalPaymentsUnderTheTermLoansParentheticalDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_CreditFacilityAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureCommitmentsAndContingenciesDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsLineItems" xlink:label="us-gaap_OtherCommitmentsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsTable" xlink:label="us-gaap_OtherCommitmentsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsDomain" xlink:label="us-gaap_OtherCommitmentsDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCancelableServiceContractCommitmentsMember" xlink:label="fly_NonCancelableServiceContractCommitmentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsAxis" xlink:label="us-gaap_OtherCommitmentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCommitmentsDomain" xlink:label="us-gaap_OtherCommitmentsDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCancelableSubscriptionBasedServicesMember" xlink:label="fly_NonCancelableSubscriptionBasedServicesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossRelatedToLitigationSettlement" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FormerGainContingencyRecognizedInCurrentPeriod" xlink:label="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationNumberOfLaunches" xlink:label="fly_ContractualObligationNumberOfLaunches"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligation" xlink:label="us-gaap_ContractualObligation"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationCancellationFeePercentage" xlink:label="fly_ContractualObligationCancellationFeePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractualObligationAnnualInstallments" xlink:label="fly_ContractualObligationAnnualInstallments"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_OtherCommitmentsTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsDomain" xlink:to="fly_NonCancelableServiceContractCommitmentsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_OtherCommitmentsTable" xlink:to="us-gaap_OtherCommitmentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_OtherCommitmentsAxis" xlink:to="us-gaap_OtherCommitmentsDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_OtherCommitmentsAxis" xlink:to="us-gaap_OtherCommitmentsDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsDomain" xlink:to="fly_NonCancelableSubscriptionBasedServicesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_GainLossRelatedToLitigationSettlement" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_FormerGainContingencyRecognizedInCurrentPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="fly_ContractualObligationNumberOfLaunches" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_ContractualObligation" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="fly_ContractualObligationCancellationFeePercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="us-gaap_LossContingencyEstimateOfPossibleLoss" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OtherCommitmentsLineItems" xlink:to="fly_ContractualObligationAnnualInstallments" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="us-gaap_ScheduleOfStockByClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ShareRepurchaseProgramAxis" xlink:label="srt_ShareRepurchaseProgramAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ShareRepurchaseProgramDomain" xlink:label="srt_ShareRepurchaseProgramDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ShareRepurchaseProgramDomain" xlink:label="srt_ShareRepurchaseProgramDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedeemableConvertiblePreferredStocksMember" xlink:label="fly_RedeemableConvertiblePreferredStocksMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="us-gaap_TemporaryEquityParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeedPreferredStockMember" xlink:label="fly_SeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesAuthorized" xlink:label="us-gaap_TemporaryEquitySharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeed-1PreferredStockMember" xlink:label="fly_SeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="us-gaap_TemporaryEquitySharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="us-gaap_SeriesAPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="us-gaap_TemporaryEquitySharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockMember" xlink:label="fly_SeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-2PreferredStockMember" xlink:label="fly_SeriesD-2PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableConvertiblePreferredStockMember" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ScheduleOfStockByClassTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_ShareRepurchaseProgramAxis" xlink:to="srt_ShareRepurchaseProgramDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_ShareRepurchaseProgramAxis" xlink:to="srt_ShareRepurchaseProgramDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ShareRepurchaseProgramDomain" xlink:to="fly_RedeemableConvertiblePreferredStocksMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquityParOrStatedValuePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeedPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquitySharesAuthorized" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeed-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="srt_ShareRepurchaseProgramAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquitySharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquitySharesOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquityCarryingAmountAttributableToParent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-2PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_RedeemableConvertiblePreferredStockMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockholdersEquityDeficitAndRedeemableConvertiblePreferredStockAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems" xlink:label="us-gaap_ClassOfStockLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="us-gaap_ScheduleOfStockByClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesCPurchaseAgreementMember" xlink:label="fly_SeriesCPurchaseAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain" xlink:label="us-gaap_EquityComponentDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="us-gaap_SaleOfStockPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfShareSold" xlink:label="fly_NumberOfShareSold"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeedPreferredStockMember" xlink:label="fly_SeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IPOMember" xlink:label="us-gaap_IPOMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-2PreferredStockMember" xlink:label="fly_SeriesD-2PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CashProceeds" xlink:label="fly_CashProceeds"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="us-gaap_SeriesAPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IPOClosingPreferredStockDividendMember" xlink:label="fly_IPOClosingPreferredStockDividendMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConvertiblePreferredStockMember" xlink:label="us-gaap_ConvertiblePreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice" xlink:label="us-gaap_SharePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesSeed-1PreferredStockMember" xlink:label="fly_SeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockMember" xlink:label="fly_SeriesJPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PreferredStockIssuedAtAPurchasePrice" xlink:label="fly_PreferredStockIssuedAtAPurchasePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes" xlink:label="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesDPreferredStockMember" xlink:label="us-gaap_SeriesDPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_DeemedSharesIssuedPricePerShare" xlink:label="fly_DeemedSharesIssuedPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPreferredStockCash" xlink:label="us-gaap_DividendsPreferredStockCash"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonCompoundingRate" xlink:label="fly_PercentageOfNonCompoundingRate"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MajoritySponsorMember" xlink:label="fly_MajoritySponsorMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedeemableConvertiblePreferredStocksMember" xlink:label="fly_RedeemableConvertiblePreferredStocksMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare" xlink:label="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PercentageOfNonAccruingOrignalIssuePricePerShare" xlink:label="fly_PercentageOfNonAccruingOrignalIssuePricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="us-gaap_SharesIssuedPricePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TemporaryEquityLiquidationPreference" xlink:label="us-gaap_TemporaryEquityLiquidationPreference"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccretionExpense" xlink:label="us-gaap_AccretionExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockVotingRights" xlink:label="us-gaap_PreferredStockVotingRights"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsPerShareDeclared" xlink:label="us-gaap_PreferredStockDividendsPerShareDeclared"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantExercisePriceDecrease" xlink:label="us-gaap_WarrantExercisePriceDecrease"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="us-gaap_PreferredStockSharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OptionIndexedToIssuersEquityShares" xlink:label="us-gaap_OptionIndexedToIssuersEquityShares"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PrepaidPurchaseCredit" xlink:label="fly_PrepaidPurchaseCredit"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ScheduleOfStockByClassTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="fly_SeriesCPurchaseAgreementMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_WarrantMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_NumberOfShareSold" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeedPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementEquityComponentsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockSharesAuthorized" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_IPOMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_TypeOfArrangementAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-2PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_CashProceeds" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_IPOClosingPreferredStockDividendMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ConvertiblePreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SharePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesSeed-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesJPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PreferredStockIssuedAtAPurchasePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesMPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesDPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_DeemedSharesIssuedPricePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DividendsPreferredStockCash" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PercentageOfNonCompoundingRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_MajoritySponsorMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CommonStockSharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_RedeemableConvertiblePreferredStocksMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="16" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PercentageOfNonAccruingOrignalIssuePricePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_SharesIssuedPricePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="19" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_TemporaryEquityLiquidationPreference" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="20" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_AccretionExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="21" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockVotingRights" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="22" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockDividendsPerShareDeclared" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="23" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalWarrantIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="24" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_WarrantExercisePriceDecrease" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="25" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_CommonStockValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="26" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockSharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="27" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="28" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_PreferredStockValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="29" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_OptionIndexedToIssuersEquityShares" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="30" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="fly_PrepaidPurchaseCredit" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandSeventeenEquityIncentivePlanMember" xlink:label="fly_TwoThousandSeventeenEquityIncentivePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockOptionMember" xlink:label="us-gaap_StockOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember" xlink:label="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" xlink:label="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfReservedSharesIncrease" xlink:label="fly_NumberOfReservedSharesIncrease"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_OtherArrangementsMember" xlink:label="fly_OtherArrangementsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NumberOfReservedSharesIncreaseApproximately" xlink:label="fly_NumberOfReservedSharesIncreaseApproximately"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_VotingPowerPercentage" xlink:label="fly_VotingPowerPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SharesOutstandingPercentage" xlink:label="fly_SharesOutstandingPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FairMarketValueOfSharePercentage" xlink:label="fly_FairMarketValueOfSharePercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableAllowance" xlink:label="us-gaap_LoansAndLeasesReceivableAllowance"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonRecourseEmployeeLoans" xlink:label="fly_NonRecourseEmployeeLoans"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PrepaidAsset" xlink:label="fly_PrepaidAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableOtherCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableOtherCurrentAndNoncurrent"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_PlanNameAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_TwoThousandSeventeenEquityIncentivePlanMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_StockOptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharesIssued" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_NumberOfReservedSharesIncrease" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PlanNameDomain" xlink:to="fly_OtherArrangementsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_NumberOfReservedSharesIncreaseApproximately" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_VotingPowerPercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_SharesOutstandingPercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_FairMarketValueOfSharePercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedWeightedAverageGrantDateFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="16" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="19" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ProceedsFromStockOptionsExercised" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="20" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_LoansAndLeasesReceivableAllowance" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="21" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_NonRecourseEmployeeLoans" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="22" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_PrepaidAsset" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="23" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="24" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AccountsPayableOtherCurrentAndNoncurrent" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfRestrictedStockActivityDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember" xlink:label="us-gaap_RestrictedStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationSummaryOfStockOptionActivityDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="us-gaap_DerivativeInstrumentRiskAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="us-gaap_DerivativeContractTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockOptionMember" xlink:label="us-gaap_StockOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" xlink:label="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" xlink:label="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" xlink:label="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Weighted-AverageRemainingContractualTermUnvested" xlink:label="fly_Weighted-AverageRemainingContractualTermUnvested"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeContractTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_StockOptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_DerivativeInstrumentRiskAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="19" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="20" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="fly_Weighted-AverageRemainingContractualTermUnvested" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="21" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="23" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfWeightedAverageAssumptionsUsedInTheEstimatedGrantDateFairValueCalculationsDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureStockbasedCompensationScheduleOfStockbasedCompensationExpenseRelatedToOptionsAndRsusDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="us-gaap_IncomeStatementLocationAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="us-gaap_IncomeStatementLocationDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="us-gaap_IncomeStatementLocationDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="us-gaap_ResearchAndDevelopmentExpenseMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_IncomeStatementLocationAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_IncomeStatementLocationAxis" xlink:to="us-gaap_IncomeStatementLocationDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_IncomeStatementLocationAxis" xlink:to="us-gaap_IncomeStatementLocationDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementLocationDomain" xlink:to="us-gaap_ResearchAndDevelopmentExpenseMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeStatementLocationDomain" xlink:to="us-gaap_GeneralAndAdministrativeExpenseMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwardsLineItems" xlink:label="us-gaap_OperatingLossCarryforwardsLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwardsTable" xlink:label="us-gaap_OperatingLossCarryforwardsTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="us-gaap_IncomeTaxAuthorityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="us-gaap_IncomeTaxAuthorityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="us-gaap_IncomeTaxAuthorityDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CurrencyAxis" xlink:label="srt_CurrencyAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2025/currency-2025.xsd#currency_AllCurrenciesDomain" xlink:label="currency_AllCurrenciesDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2025/currency-2025.xsd#currency_AllCurrenciesDomain" xlink:label="currency_AllCurrenciesDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain" xlink:label="us-gaap_AssetAcquisitionDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PurchaseAccountingMember" xlink:label="fly_PurchaseAccountingMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/currency/2025/currency-2025.xsd#currency_USD" xlink:label="currency_USD"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionAxis" xlink:label="us-gaap_AssetAcquisitionAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionDomain" xlink:label="us-gaap_AssetAcquisitionDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DomesticCountryMember" xlink:label="us-gaap_DomesticCountryMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="us-gaap_StateAndLocalJurisdictionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" xlink:label="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="us-gaap_OperatingLossCarryforwards"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardAmount" xlink:label="us-gaap_TaxCreditCarryforwardAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CumulativeOwnershipPercentage" xlink:label="fly_CumulativeOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CumulativeOwnershipPeriod" xlink:label="fly_CumulativeOwnershipPeriod"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_OperatingLossCarryforwardsTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_IncomeTaxAuthorityAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_IncomeTaxAuthorityAxis" xlink:to="us-gaap_IncomeTaxAuthorityDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_IncomeTaxAuthorityAxis" xlink:to="us-gaap_IncomeTaxAuthorityDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_CurrencyAxis" xlink:to="currency_AllCurrenciesDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_CurrencyAxis" xlink:to="currency_AllCurrenciesDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AssetAcquisitionDomain" xlink:to="fly_PurchaseAccountingMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="currency_AllCurrenciesDomain" xlink:to="currency_USD" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AssetAcquisitionAxis" xlink:to="us-gaap_AssetAcquisitionDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AssetAcquisitionAxis" xlink:to="us-gaap_AssetAcquisitionDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeTaxAuthorityDomain" xlink:to="us-gaap_DomesticCountryMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeTaxAuthorityDomain" xlink:to="us-gaap_StateAndLocalJurisdictionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="us-gaap_AssetAcquisitionAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_OperatingLossCarryforwardsTable" xlink:to="srt_CurrencyAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_OperatingLossCarryforwards" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_TaxCreditCarryforwardAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="fly_CumulativeOwnershipPercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="fly_CumulativeOwnershipPeriod" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_UnrecognizedTaxBenefits" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_OperatingLossCarryforwardsLineItems" xlink:to="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfEffectiveIncomeTaxReconciliationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTable" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" xlink:label="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxReconciliationNondeductibleExpenseOther" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_IncomeTaxExpenseBenefit" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationLineItems" xlink:to="us-gaap_EffectiveIncomeTaxRateContinuingOperations" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesSummaryOfIncomeTaxPaidByJurisdicationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" xlink:label="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="us-gaap_TypeOfAdoptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidFederalAfterRefundReceived" xlink:label="us-gaap_IncomeTaxPaidFederalAfterRefundReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountingStandardsUpdate202309ProspectiveMember" xlink:label="us-gaap_AccountingStandardsUpdate202309ProspectiveMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived" xlink:label="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="us-gaap_IncomeTaxesPaidNet"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_TypeOfAdoptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxPaidFederalAfterRefundReceived" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_AccountingStandardsUpdate202309ProspectiveMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionTable" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxPaidStateAndLocalAfterRefundReceived" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems" xlink:to="us-gaap_IncomeTaxesPaidNet" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="srt_EquityMethodInvesteeNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EquityMethodInvesteeNameDomain" xlink:label="srt_EquityMethodInvesteeNameDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TypeOfArrangementAxis" xlink:label="us-gaap_TypeOfArrangementAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConsultingAgreementMember" xlink:label="fly_ConsultingAgreementMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EquityMethodInvestmentMember" xlink:label="fly_EquityMethodInvestmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-4PreferredStockMember" xlink:label="fly_SeriesD-4PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction" xlink:label="us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAnnualPrincipalPayment" xlink:label="us-gaap_DebtInstrumentAnnualPrincipalPayment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfRelatedPartyDebt" xlink:label="us-gaap_RepaymentsOfRelatedPartyDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExtinguishmentOfDebtAmount" xlink:label="us-gaap_ExtinguishmentOfDebtAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestExpenseInvestmentAdvisoryFees" xlink:label="us-gaap_NoninterestExpenseInvestmentAdvisoryFees"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="srt_EquityMethodInvesteeNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:to="srt_EquityMethodInvesteeNameDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="fly_ConsultingAgreementMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_EquityMethodInvesteeNameDomain" xlink:to="fly_EquityMethodInvestmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-4PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SaleOfStockConsiderationReceivedOnTransaction" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_TypeOfArrangementAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DebtInstrumentAnnualPrincipalPayment" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RepaymentsOfRelatedPartyDebt" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ExtinguishmentOfDebtAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NoninterestExpenseInvestmentAdvisoryFees" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NonoperatingIncomeExpense" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureRelatedPartyTransactionsScheduleOfRelatedPartyTransactionsDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="us-gaap_RelatedPartyTransactionLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain" xlink:label="us-gaap_RelatedPartyDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AEIndustrialMember" xlink:label="fly_AEIndustrialMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent" xlink:label="us-gaap_AccountsPayableCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_GSPrecisionMember" xlink:label="fly_GSPrecisionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingCostsAndExpenses" xlink:label="us-gaap_OperatingCostsAndExpenses"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_RedwireCorporationMember" xlink:label="fly_RedwireCorporationMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_BelcanLLCMember" xlink:label="fly_BelcanLLCMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyMember" xlink:label="us-gaap_RelatedPartyMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_AEIndustrialMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_AccountsPayableCurrentAndNoncurrent" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_GSPrecisionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_OperatingCostsAndExpenses" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_RedwireCorporationMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="fly_BelcanLLCMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfComputationOfBasicAndDilutedNetLossPerShareDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasicLineItems" xlink:label="us-gaap_EarningsPerShareBasicLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="us-gaap_StatementClassOfStockAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain" xlink:label="us-gaap_ClassOfStockDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ClassA1PreferredStockMember" xlink:label="fly_ClassA1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareBasic" xlink:label="us-gaap_EarningsPerShareBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="us-gaap_EarningsPerShareDiluted"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_EarningsPerShareBasicLineItems" xlink:to="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicLineItems" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_ClassA1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_NetIncomeLoss" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_EarningsPerShareBasicLineItems" xlink:to="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_EarningsPerShareBasic" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract" xlink:to="us-gaap_EarningsPerShareDiluted" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersDilutedAbstract" xlink:to="us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="fly_SeriesD-3PreferredStockMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureNetLossPerShareScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesSeedPreferredStockMember" xlink:label="fly_ConvertibleSeriesSeedPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesSeed-1PreferredStockMember" xlink:label="fly_ConvertibleSeriesSeed-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesAPreferredStockMember" xlink:label="us-gaap_SeriesAPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesBPreferredStockMember" xlink:label="us-gaap_SeriesBPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeriesCPreferredStockMember" xlink:label="us-gaap_SeriesCPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-1PreferredStockMember" xlink:label="fly_SeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesD-3PreferredStockMember" xlink:label="fly_SeriesD-3PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesMPreferredStockMember" xlink:label="fly_SeriesMPreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJPreferredStockWarrantsMember" xlink:label="fly_SeriesJPreferredStockWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SeriesJWarrantsMember" xlink:label="fly_SeriesJWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_CommonStockWarrantsMember" xlink:label="fly_CommonStockWarrantsMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleSeriesD-1PreferredStockMember" xlink:label="fly_ConvertibleSeriesD-1PreferredStockMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="us-gaap_EmployeeStockOptionMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="us-gaap_RestrictedStockUnitsRSUMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SubordinatedConvertiblePromissoryNoteMember" xlink:label="fly_SubordinatedConvertiblePromissoryNoteMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ConvertibleNotesMember" xlink:label="fly_ConvertibleNotesMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantMember" xlink:label="us-gaap_WarrantMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SMINoteMember" xlink:label="fly_SMINoteMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PreferredStockConvertedToCommonSharesMember" xlink:label="fly_PreferredStockConvertedToCommonSharesMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleSeriesSeedPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleSeriesSeed-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_SeriesBPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesD-3PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesMPreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesJPreferredStockWarrantsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SeriesJWarrantsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_CommonStockWarrantsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleSeriesD-1PreferredStockMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_EmployeeStockOptionMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="13" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="14" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SubordinatedConvertiblePromissoryNoteMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="15" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_ConvertibleNotesMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="16" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_WarrantMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="17" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_SMINoteMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="18" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="fly_PreferredStockConvertedToCommonSharesMember" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentMember" xlink:label="us-gaap_PropertyPlantAndEquipmentMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaterialMember" xlink:label="fly_MaterialMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis" xlink:label="us-gaap_FairValueByAssetClassAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="us-gaap_NumberOfOperatingSegments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="fly_MaterialMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_NumberOfOperatingSegments" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_FairValueByAssetClassAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSegmentAndGeographicalInformationScheduleOfSegmentReportingInformationBySegmentDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="us-gaap_SegmentReportingInformationLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain" xlink:label="srt_ConsolidationItemsDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember" xlink:label="us-gaap_OperatingSegmentsMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis" xlink:label="srt_ConsolidationItemsAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain" xlink:label="srt_ConsolidationItemsDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues" xlink:label="us-gaap_Revenues"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold" xlink:label="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_MaterialsAndConsumables" xlink:label="fly_MaterialsAndConsumables"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ContractorsAndOutsideServices" xlink:label="fly_ContractorsAndOutsideServices"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAndAmortization" xlink:label="us-gaap_DepreciationAndAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeOperating" xlink:label="us-gaap_InterestIncomeOperating"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating" xlink:label="us-gaap_InterestExpenseNonoperating"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_GainOnSettlementOfContingentLiabilities" xlink:label="fly_GainOnSettlementOfContingentLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingOtherItemAmount" xlink:label="us-gaap_SegmentReportingOtherItemAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="srt_ConsolidationItemsDomain" xlink:to="us-gaap_OperatingSegmentsMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="srt_ConsolidationItemsAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="srt_ConsolidationItemsAxis" xlink:to="srt_ConsolidationItemsDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="srt_ConsolidationItemsAxis" xlink:to="srt_ConsolidationItemsDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_Revenues" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_CostOfGoodsAndServicesSold" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="3" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="fly_MaterialsAndConsumables" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="4" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="fly_ContractorsAndOutsideServices" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="5" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_DepreciationAndAmortization" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="6" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_InterestIncomeOperating" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="7" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_InterestExpenseNonoperating" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="8" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_FairValueAdjustmentOfWarrants" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="9" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="10" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="fly_GainOnSettlementOfContingentLiabilities" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="11" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingOtherItemAmount" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="12" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_NetIncomeLoss" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems" xlink:label="us-gaap_SubsequentEventLineItems"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable" xlink:label="us-gaap_SubsequentEventTable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationPriceOfAcquisitionExpected" xlink:label="us-gaap_BusinessCombinationPriceOfAcquisitionExpected"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateDomain" xlink:label="us-gaap_VariableRateDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BaseRateMember" xlink:label="us-gaap_BaseRateMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis" xlink:label="us-gaap_CreditFacilityAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain" xlink:label="us-gaap_CreditFacilityDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="us-gaap_RevolvingCreditFacilityMember"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableRateAxis" xlink:label="us-gaap_VariableRateAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain_default"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_SecuredOverFinancingRateMember" xlink:label="fly_SecuredOverFinancingRateMember"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FireflyMember" xlink:label="fly_FireflyMember"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="us-gaap_SubsequentEventLineItems" xlink:to="us-gaap_SubsequentEventTable" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsequentEventLineItems" xlink:to="us-gaap_BusinessCombinationPriceOfAcquisitionExpected" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_VariableRateDomain" xlink:to="us-gaap_BaseRateMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_RevolvingCreditFacilityMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_VariableRateAxis" xlink:to="us-gaap_VariableRateDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_SubsequentEventTypeAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeDomain" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeDomain_default" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_VariableRateDomain" xlink:to="fly_SecuredOverFinancingRateMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="fly_FireflyMember" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="1" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_VariableRateAxis" priority="2" use="optional"/>
          <link:definitionArc xlink:type="arc" order="2" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_CreditFacilityAxis" priority="2" use="optional"/>
        </link:definitionLink>
        <link:definitionLink xlink:type="extended" xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists">
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UsefulLifeDescriptionOfTermDomain" xlink:label="us-gaap_UsefulLifeDescriptionOfTermDomain"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:definitionArc xlink:type="arc" order="0" xbrldt:closed="false" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="us-gaap_UsefulLifeDescriptionOfTermDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" priority="2" use="optional"/>
        </link:definitionLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedBalanceSheets">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_Liabilities" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_AccountsPayableCurrent" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_LiabilitiesCurrent" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_CommonStockValue" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_AssetsCurrent" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_CommitmentsAndContingencies" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="fly_AccountsPayableCurrentRelatedParties" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_ShortTermInvestments" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_AdditionalPaidInCapital" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_PrepaidExpenseNoncurrent" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_RestrictedCashCurrent" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_OperatingLeaseLiabilityCurrent" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_DeferredRevenueNoncurrent" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_RestrictedCashNoncurrent" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_FinanceLeaseLiabilityCurrent" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_PrepaidExpenseCurrent" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="fly_NotesPayableNoncurrent-RelatedParties" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_OperatingLeaseRightOfUseAsset" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_DeferredRevenueCurrent" order="5" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_OtherAssetsCurrent" order="5" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_LongTermNotesPayable" order="5" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_FinanceLeaseRightOfUseAsset" order="5" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_NotesPayableCurrent" order="6" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_WarrantsAndRightsOutstanding" order="6" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill" order="6" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent" order="7" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_OtherLiabilitiesNoncurrent" order="7" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Goodwill" order="7" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_OtherAssetsNoncurrent" order="8" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccountsPayableCurrentRelatedParties" xlink:label="fly_AccountsPayableCurrentRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermInvestments" xlink:label="us-gaap_ShortTermInvestments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseNoncurrent" xlink:label="us-gaap_PrepaidExpenseNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashCurrent" xlink:label="us-gaap_RestrictedCashCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount" xlink:label="us-gaap_RedeemableNoncontrollingInterestEquityPreferredCarryingAmount"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:label="us-gaap_DeferredRevenueNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashNoncurrent" xlink:label="us-gaap_RestrictedCashNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NotesPayableNoncurrent-RelatedParties" xlink:label="fly_NotesPayableNoncurrent-RelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="us-gaap_DeferredRevenueCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermNotesPayable" xlink:label="us-gaap_LongTermNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NotesPayableCurrent" xlink:label="us-gaap_NotesPayableCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstanding" xlink:label="us-gaap_WarrantsAndRightsOutstanding"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfNetLossAndComprehensiveLoss">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_OperatingIncomeLoss" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_ResearchAndDevelopmentExpense" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="0" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="us-gaap_NetIncomeLoss" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="fly_ChangeInFairValueOfWarrantLiability" order="0" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_GrossProfit" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_CostOfGoodsAndServicesSold" order="1" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_NonoperatingIncomeExpense" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_SellingGeneralAndAdministrativeExpense" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="us-gaap_PreferredStockDividendsIncomeStatementImpact" order="1" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingExpenses" order="1" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" order="2" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_InterestIncomeOperating" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_InterestIncomeExpenseNonoperatingNet" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_GainLossRelatedToLitigationSettlement" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense" order="5" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit" xlink:label="us-gaap_GrossProfit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeInFairValueOfWarrantLiability" xlink:label="fly_ChangeInFairValueOfWarrantLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="us-gaap_CostOfGoodsAndServicesSold"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeOperating" xlink:label="us-gaap_InterestIncomeOperating"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet" xlink:label="us-gaap_InterestIncomeExpenseNonoperatingNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossRelatedToLitigationSettlement" xlink:label="us-gaap_GainLossRelatedToLitigationSettlement"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/StatementConsolidatedStatementsOfCashFlows">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_ProfitLoss" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_DepreciationDepletionAndAmortization" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleOfShortTermInvestments" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts" order="1" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_GainLossOnDispositionOfAssets1" order="2" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" order="2" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_ShareBasedCompensation" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="fly_PaymentsToAcquireTimeDeposits" order="3" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_FinanceLeasePrincipalPayments" order="3" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" order="4" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="fly_PaymentsOnNotesPayable" order="4" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_FairValueAdjustmentOfWarrants" order="5" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_PaymentsForMortgageDeposits" order="5" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_GainsLossesOnExtinguishmentOfDebt" order="6" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_ProceedsFromNotesPayable" order="6" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="fly_Non-CashInterestExpense" order="7" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" order="7" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="fly_NonCashInterestIncome" order="8" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="fly_ProceedsFromNotesPayableRelatedParties" order="8" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="fly_Non-CashInventoryWrite-Off" order="9" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_RepaymentsOfNotesPayable" order="9" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccountsReceivable" order="10" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts" order="10" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="fly_IncreaseDecreaseInAdvancedPayments" order="11" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="fly_PaymentsOfDebtIssuanceCostsRelatedParties" order="11" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets" order="12" weight="-1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="fly_ProceedsFromRepaymentOfEmployeeNote" order="12" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" order="13" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_ProceedsFromLinesOfCredit" order="13" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="fly_IncreaseDecreaseAccountsPayableRelatedParties" order="14" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_ProceedsFromStockOptionsExercised" order="14" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities" order="15" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" order="16" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="fly_ChangeInRight-Of-UseAssets" order="17" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInOperatingLeaseLiability" order="18" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInDeferredRevenue" order="19" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfShortTermInvestments" xlink:label="us-gaap_ProceedsFromSaleOfShortTermInvestments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="us-gaap_GainLossOnDispositionOfAssets1"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsToAcquireTimeDeposits" xlink:label="fly_PaymentsToAcquireTimeDeposits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeasePrincipalPayments" xlink:label="us-gaap_FinanceLeasePrincipalPayments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsOnNotesPayable" xlink:label="fly_PaymentsOnNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="us-gaap_FairValueAdjustmentOfWarrants"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForMortgageDeposits" xlink:label="us-gaap_PaymentsForMortgageDeposits"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromNotesPayable" xlink:label="us-gaap_ProceedsFromNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInterestExpense" xlink:label="fly_Non-CashInterestExpense"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_NonCashInterestIncome" xlink:label="fly_NonCashInterestIncome"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsFromNotesPayableRelatedParties" xlink:label="fly_ProceedsFromNotesPayableRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_Non-CashInventoryWrite-Off" xlink:label="fly_Non-CashInventoryWrite-Off"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfNotesPayable" xlink:label="us-gaap_RepaymentsOfNotesPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IncreaseDecreaseInAdvancedPayments" xlink:label="fly_IncreaseDecreaseInAdvancedPayments"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_PaymentsOfDebtIssuanceCostsRelatedParties" xlink:label="fly_PaymentsOfDebtIssuanceCostsRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ProceedsFromRepaymentOfEmployeeNote" xlink:label="fly_ProceedsFromRepaymentOfEmployeeNote"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="us-gaap_ProceedsFromLinesOfCredit"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_IncreaseDecreaseAccountsPayableRelatedParties" xlink:label="fly_IncreaseDecreaseAccountsPayableRelatedParties"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="us-gaap_ProceedsFromStockOptionsExercised"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_ChangeInRight-Of-UseAssets" xlink:label="fly_ChangeInRight-Of-UseAssets"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosurePropertyAndEquipmentNetScheduleOfPropertyAndEquipmentNetDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentGross" order="0" weight="1.0" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" order="1" weight="-1.0" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureAccruedExpensesDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedProfessionalFeesCurrent" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="fly_AccruedPayrollCurrent" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_OtherAccruedLiabilitiesCurrent" order="4" weight="1.0" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPayableCurrentAndNoncurrent" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="us-gaap_AccruedProfessionalFeesCurrent"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_AccruedPayrollCurrent" xlink:label="fly_AccruedPayrollCurrent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="us-gaap_OtherAccruedLiabilitiesCurrent"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIntangibleAssetsNetScheduleOfFutureAmortizationExpenseOnIntangibleAssetsDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive" order="5" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureLeasesScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentsDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_LesseeOperatingTotalLeaseLiability" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_FinanceLeaseLiabilityTotalPayments" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_LesseeOperatingTotalLeaseLiability" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_FinanceLeaseLiabilityTotalPayments" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_LesseeOperatingTotalLeaseLiability" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_FinanceLeaseLiabilityTotalPayments" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_LesseeOperatingTotalLeaseLiability" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_FinanceLeaseLiabilityTotalPayments" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_LesseeOperatingTotalLeaseLiability" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_FinanceLeaseLiabilityTotalPayments" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_LesseeOperatingTotalLeaseLiability" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" order="5" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="fly_FinanceLeaseLiabilityTotalPayments" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" order="5" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_LesseeOperatingTotalLeaseLiability" xlink:label="fly_LesseeOperatingTotalLeaseLiability"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_FinanceLeaseLiabilityTotalPayments" xlink:label="fly_FinanceLeaseLiabilityTotalPayments"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeBeforeIncomeTaxDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" order="1" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfIncomeTaxExpenseDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_CurrentIncomeTaxExpenseBenefit" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_IncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:to="us-gaap_CurrentForeignTaxExpenseBenefit" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredForeignIncomeTaxExpenseBenefit" order="2" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit"/>
        </link:calculationLink>
        <link:calculationLink xlink:type="extended" xlink:role="http://fireflyspace.com/20251231/taxonomy/role/DisclosureIncomeTaxesScheduleOfProvisionForEffectiveIncomeTaxReconciliationDetails">
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" order="0" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" order="1" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" order="2" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" order="3" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes" order="4" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" order="5" weight="1" use="optional"/>
          <link:calculationArc xlink:type="arc" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" order="6" weight="1" use="optional"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes"/>
          <link:loc xlink:type="locator" xlink:href="fly-20251231.xsd#fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" xlink:label="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent"/>
          <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
        </link:calculationLink>
      </link:linkbase>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:element id="fly_MaterialsAndConsumables" name="MaterialsAndConsumables" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_FireflyMember" name="FireflyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_WeightedAverageFairValuePerWarrant" name="WeightedAverageFairValuePerWarrant" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_DiscountsOnUnderwriting" name="DiscountsOnUnderwriting" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_PercentageOfNonCompoundingRate" name="PercentageOfNonCompoundingRate" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_ContractorsAndOutsideServices" name="ContractorsAndOutsideServices" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_ProceedsFromNotesPayableRelatedParties" name="ProceedsFromNotesPayableRelatedParties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_FinancingAgreementMember" name="FinancingAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ContractualObligationAnnualInstallments" name="ContractualObligationAnnualInstallments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_SecuredOverFinancingRateMember" name="SecuredOverFinancingRateMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" name="ThirteenPointEightHundredSeventyFivePercentDueTwoThousandTwentyEightMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementMaximumValueRecognized" name="ShareBasedCompensationArrangementMaximumValueRecognized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" name="ShareBasedCompensationArrangementByShare-BasedPaymentAwardEquityInstrumentsOtherThanOptionsCancelledInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_SeriesMPreferredStockMember" name="SeriesMPreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ProceedsFromRepaymentOfEmployeeNote" name="ProceedsFromRepaymentOfEmployeeNote" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_ContractWithCustomerLossProvisionPeriodIncreaseDecrease" name="ContractWithCustomerLossProvisionPeriodIncreaseDecrease" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_PurchaseAccountingMember" name="PurchaseAccountingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_FairValueInputsDiscountRate" name="FairValueInputsDiscountRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_WarrantsToPurchaseAnAggregate" name="WarrantsToPurchaseAnAggregate" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_DebtInstrumentCarryingAmountNetOfIssuanceCosts" name="DebtInstrumentCarryingAmountNetOfIssuanceCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_ExitFeePercentage" name="ExitFeePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_SpacecraftSolutionsRevenueMember" name="SpacecraftSolutionsRevenueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_CommonStockWarrantsMember" name="CommonStockWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_BusinessCombinationIncurredCost" name="BusinessCombinationIncurredCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_UnauditedProFormaInformationMember" name="UnauditedProFormaInformationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_CustomerMember" name="CustomerMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_CostOfSalePolicyTextBlock" name="CostOfSalePolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingLeaseLiabilitiesNonCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_DavidWheelerMember" name="DavidWheelerMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_NonCancelableSubscriptionBasedServicesMember" name="NonCancelableSubscriptionBasedServicesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_CustomerThreeMember" name="CustomerThreeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_MinimumCashBalanceForPurchaseAndLeasebackAgreements" name="MinimumCashBalanceForPurchaseAndLeasebackAgreements" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_FairValuePerShareMarketableSecurity" name="FairValuePerShareMarketableSecurity" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_DiscountForLackOfMarketability" name="DiscountForLackOfMarketability" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_BusinessCombinationEquityConsiderationPaid" name="BusinessCombinationEquityConsiderationPaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_LaunchRevenueMember" name="LaunchRevenueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_OtherNotesMember" name="OtherNotesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_CumulativeOwnershipPeriod" name="CumulativeOwnershipPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_AccountsPayableCurrentRelatedParties" name="AccountsPayableCurrentRelatedParties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_ContractualObligationCancellationFeePercentage" name="ContractualObligationCancellationFeePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_PropertyAndEquipmentAdditionsInAccountsPayable" name="PropertyAndEquipmentAdditionsInAccountsPayable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_MajoritySponsorMember" name="MajoritySponsorMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ConvertibleSeriesSeedPreferredStockMember" name="ConvertibleSeriesSeedPreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SeriesJPreferredStockWarrantsMember" name="SeriesJPreferredStockWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_DepositoryRiskMember" name="DepositoryRiskMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock" name="ScheduleOfPresentsTheKeyInputsAppliedInTheValuationTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_DeferredRevenuePolicyTextBlock" name="DeferredRevenuePolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_NumberOfReservedSharesIncrease" name="NumberOfReservedSharesIncrease" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_ScheduleOfRedeemableConvertiblePreferredStock" name="ScheduleOfRedeemableConvertiblePreferredStock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_Weighted-AverageRemainingContractualTermUnvested" name="Weighted-AverageRemainingContractualTermUnvested" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_PaymentForPurchaseAndLeasebackAgreements" name="PaymentForPurchaseAndLeasebackAgreements" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_SaleAndLeasebackPolicyTextBlock" name="SaleAndLeasebackPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_SeriesD-1PreferredStockMember" name="SeriesD-1PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_PaymentsToAcquireTimeDeposits" name="PaymentsToAcquireTimeDeposits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_ExerciseOfCommonWarrantsIntoCommonStockShares" name="ExerciseOfCommonWarrantsIntoCommonStockShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" name="IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_AverageFairValuePerWarrant" name="AverageFairValuePerWarrant" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_CustomerFourMember" name="CustomerFourMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_AccuredInterestFromSubordinatedConvertiblePromissoryNotes" name="AccuredInterestFromSubordinatedConvertiblePromissoryNotes" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_SharesOutstandingPercentage" name="SharesOutstandingPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_OperatingLeaseRight-Of-UseAssetDecreased" name="OperatingLeaseRight-Of-UseAssetDecreased" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_SeriesSeed-1PreferredStockMember" name="SeriesSeed-1PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_PercentageOfNonAccruingOrignalIssuePricePerShare" name="PercentageOfNonAccruingOrignalIssuePricePerShare" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_WeightedAveragePricePerShare" name="WeightedAveragePricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" name="AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationStockOptionsRequisiteServicePeriodRecognitionShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_AccruedPayrollCurrent" name="AccruedPayrollCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_Rule10B51ArrModifiedFlag" name="Rule10B51ArrModifiedFlag" type="xbrli:booleanItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_PaymentsOfDebtIssuanceCostsRelatedParties" name="PaymentsOfDebtIssuanceCostsRelatedParties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_TestStandsMember" name="TestStandsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_TimeDepositsMember" name="TimeDepositsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ConvertibleSeriesD-1PreferredStockMember" name="ConvertibleSeriesD-1PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_DeemedSharesIssuedPricePerShare" name="DeemedSharesIssuedPricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_RPMCallOptionMember" name="RPMCallOptionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SpaceflightMember" name="SpaceflightMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_FairValuePerShareNonMarketableSecurity" name="FairValuePerShareNonMarketableSecurity" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_GainOnSettlementOfContingentLiabilities" name="GainOnSettlementOfContingentLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_FairMarketValueOfSharePercentage" name="FairMarketValueOfSharePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_RedwireCorporationMember" name="RedwireCorporationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" name="NetExerciseOfCommonStockWarrantsToCommonStockInConnectionWithInitialPublicOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" name="Share-BasedCompensationArrangementsByShare-BasedPaymentAwardOptionsCanceledInPeriodWeightedAverageExercisePrice" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_CustomerOneMember" name="CustomerOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_BusinessCombinationTotalConsiderationPaid" name="BusinessCombinationTotalConsiderationPaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_RightOfUseAssetObtainedInForLeaseLiability" name="RightOfUseAssetObtainedInForLeaseLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_CashProceeds" name="CashProceeds" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_CommonWarrantsMember" name="CommonWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SwinglineLoans" name="SwinglineLoans" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_LeasesTextBlock" name="LeasesTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_TermBLoansMember" name="TermBLoansMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ContractualObligationNumberOfLaunches" name="ContractualObligationNumberOfLaunches" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_Non-CashInventoryWrite-Off" name="Non-CashInventoryWrite-Off" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_SeriesCPurchaseAgreementMember" name="SeriesCPurchaseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_TermALoansMember" name="TermALoansMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ProceedsOfUnderwritngDiscounts" name="ProceedsOfUnderwritngDiscounts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_PricePerSquareFoot" name="PricePerSquareFoot" type="dtr-types:areaItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_BelcanLLCMember" name="BelcanLLCMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_InterestExpenseOnPurchaseAndLeasebackAgreement" name="InterestExpenseOnPurchaseAndLeasebackAgreement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" name="ShareBasedCompensationArrangementOptionOutstandingFairValueMajoritySponsor" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_SeriesD-3PreferredStockMember" name="SeriesD-3PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementOptionFairValueAssumption" name="ShareBasedCompensationArrangementOptionFairValueAssumption" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination" name="Non-CashInvestingAndFinancingActivitiesEquityIssuedForBusinessCombination" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_OutstandingBorrowingsOnRevolvingCreditFacilityMember" name="OutstandingBorrowingsOnRevolvingCreditFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_RestrictedCashMember" name="RestrictedCashMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_WarrantLiabilitiesPolicyTextBlock" name="WarrantLiabilitiesPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_PrepaidPurchaseCredit" name="PrepaidPurchaseCredit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_SpecificAdditionalInterestRate" name="SpecificAdditionalInterestRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_RentIncraeseAnuallyInPercent" name="RentIncraeseAnuallyInPercent" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsWeightedAverage" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_DevelopedTechnologyMember" name="DevelopedTechnologyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_AverageValuePerUnitAsPerMonteCarloSimulations" name="AverageValuePerUnitAsPerMonteCarloSimulations" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_GSPrecisionMember" name="GSPrecisionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_CustomerTwoMember" name="CustomerTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" name="EightPointThirtyOnePercentDueTwoThousandThirtyOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SciTecMember" name="SciTecMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_TermLoanMember" name="TermLoanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_TwoThousandSeventeenEquityIncentivePlanMember" name="TwoThousandSeventeenEquityIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SaleAndLeasebackTransactionsMember" name="SaleAndLeasebackTransactionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ExerciseOfCommonWarrantsIntoCommonStock" name="ExerciseOfCommonWarrantsIntoCommonStock" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_FollowOnOpportunitiesMember" name="FollowOnOpportunitiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_IssuanceOfPreferredStockDividend" name="IssuanceOfPreferredStockDividend" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_OtherRevenueMember" name="OtherRevenueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" name="Share-BasedCompensationArrangementByShare-BasedPaymentAwardOptionsAvailableForGrantGrantsInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_SubordinatedConvertiblePromissoryNoteMember" name="SubordinatedConvertiblePromissoryNoteMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ConvertibleNotesMember" name="ConvertibleNotesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ProbabilityWeightedFairValuePerCommonWarrant" name="ProbabilityWeightedFairValuePerCommonWarrant" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_ChangeInFairValueOfWarrantLiability" name="ChangeInFairValueOfWarrantLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_CommonStockOutstandingCommonWarrantsExercised" name="CommonStockOutstandingCommonWarrantsExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_DeferredTaxLiabilitiesRightOfUseAssets" name="DeferredTaxLiabilitiesRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_PaymentsOnNotesPayable" name="PaymentsOnNotesPayable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_IPOClosingPreferredStockDividendMember" name="IPOClosingPreferredStockDividendMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ChangeInRight-Of-UseAssets" name="ChangeInRight-Of-UseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementOptionFairValue" name="ShareBasedCompensationArrangementOptionFairValue" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_TaxReconciliationNotRequired" name="TaxReconciliationNotRequired" type="xbrli:booleanItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementOptionOutstandingFairValue" name="ShareBasedCompensationArrangementOptionOutstandingFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_CommonStockWarrantMember" name="CommonStockWarrantMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" name="IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsSharesDuringPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_AEIndustrialMember" name="AEIndustrialMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_FinanceLeaseLiabilityTotalPayments" name="FinanceLeaseLiabilityTotalPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_EquityMethodInvestmentMember" name="EquityMethodInvestmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_TrancheObligationsMember" name="TrancheObligationsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_BacklogMember" name="BacklogMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ConvertibleSeriesSeed-1PreferredStockMember" name="ConvertibleSeriesSeed-1PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_AssetsAndLiabilitiesLesseeTableTextBlock" name="AssetsAndLiabilitiesLesseeTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" name="IssuanceOfCommonStockUponSettlementOfPreferredStockDividendsValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_SeriesJWarrantMember" name="SeriesJWarrantMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_StockIssuedDuringPeriodSharesStockDividend" name="StockIssuedDuringPeriodSharesStockDividend" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_SeriesD-4PreferredStockMember" name="SeriesD-4PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_LesseeOperatingTotalLeaseLiability" name="LesseeOperatingTotalLeaseLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_ChangeOfControlScenarioMember" name="ChangeOfControlScenarioMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_PrepaidAsset" name="PrepaidAsset" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantExercisedInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_NotesPayableNoncurrent-RelatedParties" name="NotesPayableNoncurrent-RelatedParties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" name="SevenPointSeventyOnePercentDueTwoThousandTwentyNineMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_AggregateOfNumberOfWarrantsToPurchase" name="AggregateOfNumberOfWarrantsToPurchase" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_CustomerFiveMember" name="CustomerFiveMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" name="IssuanceOfUnderwritingDiscountsAndCommissionsAndOtherOfferingCostsValueDuringPeriod" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_LeaseRemainingLeaseTerm" name="LeaseRemainingLeaseTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccruedExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_ConsultingAgreementMember" name="ConsultingAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_FourPointFiveZeroPercentDueTwoThousandTwentySixMember" name="FourPointFiveZeroPercentDueTwoThousandTwentySixMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_IncreaseDecreaseInAdvancedPayments" name="IncreaseDecreaseInAdvancedPayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_DefaultScenarioMember" name="DefaultScenarioMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" name="WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_PropertyAndEquipmentUsefulLivesTableTextBlock" name="PropertyAndEquipmentUsefulLivesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_EventProbabilityPercentage" name="EventProbabilityPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_Weighted-AverageRemainingLeaseTermYears" name="Weighted-AverageRemainingLeaseTermYears" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_RedeemableConvertiblePreferredStocksMember" name="RedeemableConvertiblePreferredStocksMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementOptionOutstandingNumber" name="ShareBasedCompensationArrangementOptionOutstandingNumber" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_AllowanceForCreditLossesPolicyTextBlock" name="AllowanceForCreditLossesPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_SponsorTypeAxis" name="SponsorTypeAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_TwoThousandTwentyFiveOmnibusIncentivePlanMember" name="TwoThousandTwentyFiveOmnibusIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_DeferredTaxAssetsInterestLimitationCarryforwards" name="DeferredTaxAssetsInterestLimitationCarryforwards" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_SponsorTypeDomain" name="SponsorTypeDomain" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_AdvancedPaymentsPolicyTextBlock" name="AdvancedPaymentsPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_InterestExpenseContractual" name="InterestExpenseContractual" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_LongTermDebtNet" name="LongTermDebtNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_NonCancelableServiceContractCommitmentsMember" name="NonCancelableServiceContractCommitmentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SeriesSeedPreferredStockMember" name="SeriesSeedPreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_IssuanceOfDebtInExchangeOfSoftwareLicenses" name="IssuanceOfDebtInExchangeOfSoftwareLicenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_PreferredStockConvertedToCommonSharesMember" name="PreferredStockConvertedToCommonSharesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_OtherArrangementsMember" name="OtherArrangementsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_NonRecourseEmployeeLoans" name="NonRecourseEmployeeLoans" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_WarrantsToPurchaseSeriesJPreferredStockMember" name="WarrantsToPurchaseSeriesJPreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_NumberOfReservedSharesIncreaseApproximately" name="NumberOfReservedSharesIncreaseApproximately" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_NumberOfShareSold" name="NumberOfShareSold" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_ClassA1PreferredStockMember" name="ClassA1PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" name="ShareBasedCompensationArrangementOptionFairValueOutstandingNumber" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock" name="ScheduleOfReconcilesTheUndiscountedFutureMinimumLeasePaymentTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_IPOScenarioMember" name="IPOScenarioMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_MaterialMember" name="MaterialMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_DeferredTaxAssetsCapitalizedResearchCosts" name="DeferredTaxAssetsCapitalizedResearchCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" name="SummaryOfIncomeTaxPaidByJurisdicationTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedUncertainTaxPositionLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_InternalUseSoftwareMember" name="InternalUseSoftwareMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SMINoteMember" name="SMINoteMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_SeriesJPreferredStockMember" name="SeriesJPreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_Weighted-AverageDiscountRate" name="Weighted-AverageDiscountRate" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_VotingPowerPercentage" name="VotingPowerPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAvailableForGrantCanceledInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_WeightedAverageFairValuePerShare" name="WeightedAverageFairValuePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_NonCashInterestIncome" name="NonCashInterestIncome" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="fly_ITRelatedEquipmentMember" name="ITRelatedEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_PercentageOfNonAccruingDividendDeemedIssuePricePerShare" name="PercentageOfNonAccruingDividendDeemedIssuePricePerShare" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_PreferredStockIssuedAtAPurchasePrice" name="PreferredStockIssuedAtAPurchasePrice" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" name="Share-BasedPaymentArrangementOptionIncreaseForCostRecognitionShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_NonRule10B51ArrModifiedFlag" name="NonRule10B51ArrModifiedFlag" type="xbrli:booleanItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_IncreaseDecreaseAccountsPayableRelatedParties" name="IncreaseDecreaseAccountsPayableRelatedParties" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_ContractWithCustomerLossProvision" name="ContractWithCustomerLossProvision" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_Non-CashInterestExpense" name="Non-CashInterestExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="fly_SeriesJWarrantsMember" name="SeriesJWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" name="TwoThousandTwentyFiveEmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_MaintainMinimumInterestReserveAmount" name="MaintainMinimumInterestReserveAmount" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_CumulativeOwnershipPercentage" name="CumulativeOwnershipPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="fly_NotesPayablePolicyTextBlock" name="NotesPayablePolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_SeriesD-2PreferredStockMember" name="SeriesD-2PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="fly_EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" name="EffectiveIncomeTaxRateReconciliationPermanentItemsPercent" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="fly_BusinessCombinationCashConsiderationPaid" name="BusinessCombinationCashConsiderationPaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
</xsd:schema>
