阅读理解

Throughouthistorysoldiershavefoughtbloodybattlesinordertocontrolthehighground．Thereisnodoubtthatthisisatactical(战术的)necessity．Standingaboveyourenemyisanadvantagethatoftenleadstovictory．

Nowadayshighgrounddoesnotjustmeanhill-tops．Italsomeansspacewhichhasbecomeanincreasinglyimportantpartofmilitarystrategy(军事战略)．

WithitsmoreadvancedsatellitetechnologiesAmericaisthemajorpowerinspace．AndnowtheUSAirForcehasputintoserviceanewweapondesignedtojamenemysatellitecommunications．ItisanimportantsteptowardUScontrolofspace．

Theso-calledCounterCommunicationsSystem(反卫星通信系统)wasdeclaredoperationalonNovember1．Theground-basedsystemuseselectromagneticradiofrequencies(无线电磁波)tostopenemysatellitesworkingonashort-termbasis．

“Ashort-termeffectensuresthatduringthetimeofneedtheenemy’sspace-basedcapability(能力)isreduced"saidaUSmilitaryofficial．“Followingthetimeofneedtheircapabilitiescanreturntoitsoriginalstate．”

Thesystemismadeupofanantenna(天线)transmitters(发射机)andreceiversandcanbeeasilytransportedaroundinavehicle．

TocontrolspacewasoneoffouraimsofanationalspacepolicystartedbyformerpresidentBillClintonin1996．ThegoalistomakesureUSforcescanrelyonspace-basedservicesandtodenyanenemyanysimilarbenefits．

TheUSmilitaryhasexperimentedwithseveral"anti-satellite"weaponsincludinglaserstodestroyordamageenemyunits．

TheresaHitchensvicepresidentoftheCenterforDefenceInformationinWashingtonwelcomedthenewsystemaslongasitdoesnotcreaterubbishthatcouldthreatenglobaluseofspace．Shebelieveditshouldnotdestroysatellitesonlystopthemworkingforawhile．

Unfortunatelyitseemsthatwearenotgoingtolimitourgoalfor'spacecontrol'tonon-violentsystems"shesaidraisingthedangerofaspacearmsrace．

TochangethebalanceofpowerinspacetheEUandChinaareworkingtogetherontheGalileoproject．By20