Abstract: CCSDSfiledeliveryprotocol（CFDP）wasimprovedbydoubleretransmissionmechanismorsettingtheretransmittedtimesinviewofbiterrorrate（BER）.However，withoutconsideringtheimpactofthenumberofprotocoldataunits（PDUs），packeterrorrate（PER）andtheratiooflinkpropagationdelaytoPDUtransmissiondelay，theseschemesarenotthemostappropriateinspecificspacemissionsunderdifferentchannelconditions.  BasedonCFDP，anewfiledeliveryprotocoladjustingtheretransmittedtimesoflostPDUsadaptively（AR-FDP）wasproposedinspacecommunication.ThetheoreticalmodelsoffiledeliverytimeandextratransmissioneffortofAR-FDPwereestablished.Also，theeffectsofretransmittedtimesonthenumberofretransmissionroundsandthenumberofretransmittedpacketswereanalyzedandtheschemeoftheadaptivecontrolmodulewaspresented.ThetheoreticalanalysisandsimulationresultsindicatethattheAR-FDPshortensthefiledeliverytimeby55.69%and74.28%comparedtothedoubleretransmissionschemeandCFDPrespectivelyinMars-to-EarthcommunicationwithPDUnumberof1kandPERof0.79.InMoon-to-Earthcommunication，theAR-FDPshortensthefiledeliverytimeby28.05%comparedtotheschemeadjustingtheretransmittedtimesinviewofBERwithPDUnumberof100kandPERof0.79.

Key words: filedeliveryprotocol, adaptive, spacecommunications, filedeliverytime, extratransmissioneffort, theoreticalmodel