ThisphototakenbysatellitebracketcameraofLongMarch8carrierrocketonMarch20,2024showstheQueqiao2relaysatellite(C)successfullyseparatingfromthecarrierrocketwithitssolarwingandantennasuccessfullyunfolded.China'srelaysatelliteQueqiao2,orMagpieBridge2,isreadytoprovidecommunicationservicetomissionsoperatingonthemoon'sfarside,accordingtotheChinaNationalSpaceAdministration.TheadministrationsaidinanewsreleaseonFridaymorningthatthespacecrafthasfinishedin-orbitcommunicationtests.Groundcontrollersassessedtheresultsanddeterminedthatthesatellite'sframeworkandmissionpayloadshadbeenrunningnormally.ItscapabilityandperformancehaveprovedtobegoodenoughforsignalrelaytasksforChineseandforeignlunarexpeditions,thereleasesaid.Queqiao2wasliftedatopaLongMarch8carrierrocketfromacoastallaunchpadattheWenchangSpaceLaunchCenterinthesouthernmostislandprovinceofHainan.Thespacecraftcarriedoutaseriesofmaneuvers,suchasamidcoursetrajectorycorrectionandabrakingoperation,beforeitenteredafrozenellipticalorbitonApril2tobecometheworld'ssecondrelaysatelliteabovethemoon.Afterarrivinginitspredeterminedorbitalposition,Queqiao2conductedtwo-waycommunicationtestswiththeChang'e4probe,whichisonthelunarfarside,andChang'e6,whichiswaitingtobelaunchedattheWenchangcenter,toexamineitsperformance.AllofthetestswerecompletedbeforeWednesday,accordingtotheadministration.Currently,thesatelliterevolvesaroundthemoonaboutevery24hoursandwillsoonstartrelayingsignalsforChang'e4andthecomingChang'e6,itnoted.TheChang'e4probe,whichlandedintheSouthPole-AitkenBasininJanuary2019,istheworld'sfirstspacecrafttolandonthemoon'sfarside,whichneverfacesEarth.ItssignalshavebeentransmittedthroughQueqiao1,whichwaslaunchedinMay2018.Chang'e6,ifeverythinggoesaccordingtoplan,willembarkonitsjourneyinthecomingweeksandtouchdownintheSouthPole-AitkenBasin.ItistaskedwithcollectingdustandrocksamplesandsendingthembacktoEarth.Thatwillbeagroundbreakingendeavorthatischallenging,sophisticatedandhasneverbeendonebefore.CommunicationservicesbetweentheChang'e4and6probesandEarthrequirerelaysatellitesduetotheirspeciallocationss.PangZhihao,anexpertonspaceexplorationtechnologyandarenownedwriteronspaceflight,saidthesuccessfuldeploymentofQueqiao2haspavedthewayforChang'e6'sarrivalonthelunarfarside."IfQueqiao2failedtoreachitspresetposition,consideringthefactthatQueqiao1isnotfarfromitsretirement,itwouldbeimpossibletosendprobestothefarsidebecausetherewouldbenorelayservice,"heexplained.TheexpertsaidthatcomparedwithQueqiao1,theworld'sfirstlunarrelaysatellite,Queqiao2incorporatesnewtechnologies,morefunctionsandstrongertransmissioncapacity.DevelopedbytheChinaAcademyofSpaceTechnology,Queqiao2weighsabout1.2metrictonsandhastwomajorpayloads—a4.2-meterparabolicantennaforcommunicationswithlunarprobesanda0.6-meterparabolicantennatotransmitdatatogroundcontrol.BeyondChang'e4and6,thesatellitewillalsoservetheChang'e7and8missionsinthenearfuture,whichwillbethebasisforanambitiousmultinationalplaninitiatedbyChinaandknownastheInternationalLunarResearchStation,whichisexpectedtobebuiltinthe2030s.Inanotherdevelopment,thetwoexperimentalsatelliteslaunchedwithQueqiao2,theTiandu1and2,havebeguntoverifynewcommunicationandnavigationtechnologiesinlunarorbit,accordingtothespaceadministration.zhaolei@chinadaily.com.cnEditor:DisclaimerTheviewsandopinionsexpressedinthisarticlearethoseoftheauthor's,GMW.cnmakesnorepresentationsastoaccuracy,suitability,orvalidityofanyinformationonthissiteandwillnotbeliableforanyerrors,omissions,ordelaysinthisinformation.