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Pentagon Preps Nuclear Moon Rocket
日期:2020-02-26 00:29 作者: 来源:美国新闻周刊网 相似文章:0条
           ThePentagonwantstoextendthereachofitssatellitestensofthousandsmilestowardthemoon.Andit’sworkingonahigh-tech,atomic-powered“nuclearthermalpropulsion”enginetomakeitpossible.Themilitary’sgoalistodeploymaneuverablesatellitesintothevastspacebetweentheEarthandthemoon—“cislunar”space,it’scalled—beforeChinagetstherewithitsownspacecraft.Butthisisn’tthefirsttimetheU.S.governmenthastriedtodevelopanatomicrocket.Andthere’snoguaranteethesameproblemsthatendedpreviouseffortswon’talsoscuttlethisone.“Thecapabilityaffordedby[nuclearthermalpropulsion]willexpandtheoperatingpresenceoftheU.S.inspacetothecislunarvolumeandenhancedomesticoperationstoanewhigh-ground,whichisindangerofbeingdefinedbytheadversary,”theDefenseAdvancedResearchProjectsAgency,whichoverseestheatomicrocketeffort,explainedinitsbudgetproposal.TheU.S.andChinesespaceagenciesandevenprivatecorporationsareeagertominethemoonformineralsthatcouldsupportdeep-spacemissions,potentiallyincludinghumanity’sfirsttriptoMars.“Anagilenuclearthermalpropulsionvehicleenablesthe[DefenseDepartment]tomaintainspacedomainawarenessoftheburgeoningactivitywithinthisvastvolume,”JaredAdams,aDARPAspokesperson,toldTheDailyBeast.DARPA’sbudgetrequestfor2021,whichtheagencyreleasedinearlyFebruary,asksfor$21millionforthe“DemonstrationRocketforAgileCislunarOperations”program,orDRACO.CongressgaveDARPA$10millionin2020tostartstudyingtheDRACOengine.The2021budgetwouldallowtheagencytostartbuildingcomponents.TheplanisforDARPAtotestDRACObeforehandingitovertotheU.S.AirForceforroutineoperations.Themilitary’snuclearthermalpropulsionprojectisavirtualtwinofasimilarNASAprogramthat’sacoupleofyearsolder.DRACOiswhatexpertscalla“high-assaylow-enricheduraniumnuclear-thermalpropulsionsystem.”Basically,it’sasmallnuclearreactoratopaspacerocket.Thereactorheatsupapropellant—hydrogen,forexample—thatacceleratesthroughanozzle,pushingthesatelliteintheoppositedirection.Nuclear-thermalenginesaren’tforlaunchingfromEarth’ssurface.They’reforcruisinglongdistancesthroughspaceormaneuveringalotwhilekeepingclosertoEarth.Themoonis240,000milesfromEarth.Mostman-madesatellitesorbitnomorethanafewthousandmilesfromEarth’ssurface.TheUnitedStatesandChinaarebothinascrambletofillthatgap.Beijingin2019landedhumanity’sfirst-everprobeonthemoon’sdifficult-to-reachfarside,whichalwaysfacesawayfromEarth.NowtheChinesespaceagencyisworkingonfollow-onmoonmissionsandcouldevensendhumanexplorerstothelunarsurfaceasearlyasthemid-2020s.NASA,meanwhile,hasattheurgingofPresidentDonaldTrumptriedtoaccelerateapotentially$30billionplantobuildanewmannedstationincislunarspace.ThatwouldfunctionasastagingbaseforU.S.astronautstoreturntothemoonby2024,thetheoreticalfinalfullyearofapossiblesecondtermforTrump.AtomicrocketscouldsupportAmerica’snewmoonpush.YoulaunchthepiecesofthereactorintoEarthorbitontopoftraditionalchemicalrocketsandthenassemblethemwhilethey’rezoomingthousandsofmilesperhouraroundtheplanet.Attachthenuclearmotortoaspacecapsule,spysatelliteororbitalweapon,anditcouldtravelhugedistancesoveraspanofyearsorevendecades.Itwasthelong-distancepotentialthatmotivatedearlyAmericaneffortstobuildanuclearthermalpropulsionsystembackinthe1960sand’70s.NASAwasmakingprogresswhenPresidentRichardNixonabruptlycanceledabunchofrocketprogramsinordertofocusthespaceagencyonarguablylessambitiousmissions.Nowtheideaofareactoronarocketisbackinvogue.“Comparedtochemicalpropulsionsystems,theperformanceadvantagesofNTPcanenableshortertotalmissiontimesandenhancedflexibilityforcrewedMarsmissions,”ClareSkelly,aNASAspokesperson,toldTheDailyBeast.Forthearmedforces,nuclearthermalpropulsionis“awaytogetmoremaneuverabilityintheirsatellites—repositioningsatelliteschewsthroughtheonboardpropellantofasatellite,”DaleThomas,aspaceexpertattheUniversityofAlabamainHuntsville,toldTheDailyBeast.Ofcourse,civilianandmilitaryspacefundingarebothsubjecttopoliticalwhims.JustbecausethePentagonandNASAwantnuclearthermalpropulsionsystemstodaydoesn’tmeanthepresidentandCongresswillbeequallyenamoredoftheidealongenoughtoactuallybuildthem.CongresshasalreadybeguntocoolonTrump’smoonplan.Trumpwanted$1.6billionforthemoonmissioninthe2020budget.Lawmakersapproved$1.3billion.Plusthere’stheissueofallthatradiation.Inthe’60s,NASAcouldtestanatomicrocketinthedesert,ventingradioactivegasstraightintotheair,withouttoomanypeopleprotesting.“Thatisnotacceptabletoday,”Thomaspointedout.Thegovernmentcouldreplacelivetestingwithsophisticatedcomputersimulations,Thomasexplained.Thelasttimeahumanexplorersetfootonthemoonwasin1972duringthefinalU.S.Apollomission.NASAhopesthecurrentmoonraceresultsina“sustainable”long-termhumanpresenceonorabovethelunarsurface.ThePentagonwantstogettherefirstwithspacecraftthatcankeepaneyeon…whateverarrivesnext.ToDARPA,thatmeansbuildinganatomicrocket.Theagencysurelyhopesthat,thistime,itactuallyfinishesbuildingthething.