KH-12

“锁眼”12（1）采用大型CCD多光谱线阵器件和凝视成像技术，使卫星在取得高几何分辨率的同时还有多光谱成像能力。其先进的红外相机可提供优秀的夜间侦察能力。（2）采用镜面曲率计算机控制技术，因而当卫星在高轨道普查或在低轨道详查时，能快速改变镜头焦距，在低轨道有优越的分辨率，而在高轨道则可获得宽的幅宽。（3）机动能力强，可满足现代战争的需要。（4）可进行电子侦察。“锁眼”12可把高清晰度图片传至五角大楼的美国侦察办公室，由电脑进行处理后可用来识别物体运动，且能清楚地显示地面上行驶汽车的车牌号码。瞬时观测幅度：40km~50km地面重复周期：2天（一对）轨道：太阳同步轨道IMPROVEDCRYSTAL-KH12TheIMPROVEDCRYSTALcanbeimaginedasaHubbleSpaceTelescope,withalargerocketengineattachedtoprovidemaneuverability.LiketheSpaceTelescope,theIMPROVEDCRYSTALisabout4.5meters(15feet)indiameter,andwithadditionofitsmaneuveringmodule,isover15meters(50feet)long(comparedtothe13meterSpaceTelescope).ContractorsontheIMPROVEDCRYSTALincludeTRWandLockheed.Thedryweight(minusfuel)oftheIMPROVEDCRYSTALisabout10metrictons,aboutthesameasthetotalweight,includingfuel,oftheKH-11.ThetotalweightoftheIMPROVEDCRYSTALhasgrownsignificantly,fromtheoriginal14tons,tothecurrent18tons.Theadditionalfuel-carryingcapacityaccountsformostoftheincrease,andtheIMPROVEDCRYSTALnowcancarryupto7tonsoffuel.Theprimarydifferencebetweenthe28,000poundKH-11andtheheavierKH-12isthattheadditionalamountofmaneuveringpropellantcarriedontheIMPROVEDCRYSTAL.ThisadditionalpropellantcanbeusedtoprolongtheoperatinglifeoftheIMPROVEDCRYSTAL,tomaneuvertoimprovecoverageofareasontheEarthofparticularinterest,andtomaneuvertoevadeSovietanti-satelliteinterceptors.AlthoughtheKH-12wasoriginallydesignedtobeplaceintoorbit(andperhapsservicedandrefueledinorbit)bytheShuttle,theTitan4isnowtheprimarylaunchvehiclefortheIMPROVEDCRYSTAL.TheopticalsensorsontheIMPROVEDCRYSTALaresimilartothethoseoftheKH-11.Theseelectroniccamerasprovidereal-timetransmissionofimagestogroundstationsviaMilstarrelaysatellites.TheIMPROVEDCRYSTALsensorsoperateinvisibleandnearinfraredlight,aswellasthermalinfraredtodetectheatsources.Thesesensorsprobablyincorporatelow-light-levelimageintensifierstoprovidenight-timeimages.TheKH-12'shaveaninfraredcapabilitysuperiortothatoftheIMPROVEDCRYSTAL,withtheadvantageininfraredprimarilyforcamouflagedetection,forlookingatburiedstructures,forlookingatdifferentialthermalinertiainthetargetarea,fortryingtodeterminewhichfactoriesareoperatingandwhichfactoriesarenot.TheIMPROVEDCRYSTAL'ssophisticatedelectronicsprovidessharperimagesthantheKH-11,comparableinqualitytothebestofthefilmreturnsatellites,witharesolutionapproachingtencentimeters.Aperiscope-likerotatingmirrorreflectsimagesontotheprimarymirror,enablingtheKH-12totakepicturesatveryhighanglesofobliquity,imagingobjectshundredsofkilometersawayfromitsflightpath.AssemblingtheInternationalSpaceStation[ISS]requirescooperationamongtheUnitedStatesanditsfourinternationalpartnersduring44SpaceShuttleflightscommencinginlate1998.ARussianServiceModuleisrequiredtosupporttheISS'sinitialassemblyprocessandon-orbitdevelopment.ContinueddelaysinRussianfundingoftheRSM,requiredforthethirdassemblyphaseoftheISS,raisedconsiderableconcernthroughouttheISScommunity.NASAfundedfeasibilitystudiestoprovidealternatesolutionsandthesestudiesidentifiedarelativelylow-costandlow-riskapproachforanInterimControlModule(ICM),referredtoastheNavalResearchLaboratory(NRL)Bus.Thisconceptoffersaflight-provendesign,initiallydevelopedastheBusfortheIMPROVEDCRYSTAL,capableofdeliverywithinthetimeframeneededtomaintainISSschedules.TheICMwillprovidereboostandattitudecontrolfortheISSfromassemblyphase2A-7A,andpossibly8A.TheICMisdeployedfromtheSpaceShuttleandmatedwiththeISSattheRussianNode(calledtheFGB).TheICMprovidesatleastoneyearofpropellantoperationwithagoalofthreeyearsofoperation.KH-12/1waslaunchedon28November1992byaTitan-4fromVandenberg.KH-12/2waslaunchedon05December1995byaTitan-4fromVandenberg.KH-12/3waslaunchedon20December1996byaTitan-4fromVandenberg.Thespacecraft'smirrorisbelievedtobeaslargeasorlargerthanthatoftheKH-11,believedtohavea2.3meterdiameter.Itmaybeaslargeas4meters.Asapointofcomparison,theHST'smirroris2.4minsize.Jane'sDefenceWeeklyindicatesthatthesecondarymirrorintheCassegrainreflectingtelescopeAreflectingtelescopereflectorisanopticaltelescopewhichusesmirrors,ratherthanlenses,toreflectlight.TheBritishscientistSirIsaacNewtondesignedthefirstreflectorcirca1670.Hedesignedthereflectorinordertosolvetheproblemofcsystemcanbemovedsignificantly,allowingimagestobetakenfromanglesunusualforasatellite.Also,thereareindicationsthatthesatellitecantakeimagesevery5secondThisarticleisabouttheunitoftime.Seesecond(disambiguation)forotherusesThesecond(symbolsisaunitfortime,andoneofsevenSIbaseunits.Itisdefinedasthedurationof9,192,631,770periodsoftheradiationcorrespondingtothetransis.SourcesvaryonhowtheKH-12communicateswithgroundstations.Severaldifferentclustersofrelaysatellitesareavailable,sothebirdsmayusetheSatelliteDataSystemTheSatelliteDataSystemSDSisasystemofUnitedStatesmilitarycommunicationssatellites.Atleasttwogenerationshavebeenused:SDS-1fromJuly1976toNovember1995,andSDS-2from1989tothepresent.SDSsatelliteshaveahighlyellipticalorbi(SDS),MILSTAR,orTrackingandDataRelaySatelliteSystem(TDRSS)networks.KH-11：Then,in1977,thefifthgenerationdawnedwiththelaunchoftheKH-11.Thiswasamajorbreakthrough,ascanisterswereno