【Readingcomprehension：HaveyoueverdreamedofvisitingaplanetintheMilkyWay(银河系)?Whilethetripsoundsexcitingitwouldtakeyearsandyearstoreachyourdestination．Sointhefu】

　　Readingcomprehension：

　　HaveyoueverdreamedofvisitingaplanetintheMilkyWay(银河系)?Whilethetripsoundsexcitingitwouldtakeyearsandyearstoreachyourdestination．Sointhefuturebedtimeforastronautsmaybemorethanafewhoursofregularshuteye．Theywouldhavetosleepforyears．

　　Europeanresearchersarenowconductinghibernationexperiments．Thestudymayhelpthemunderstandwhetherhumanscouldeversleepthroughtheyearsitwouldtakeforaspaceflighttodistantplanets．"Iftherewasaneffectivetechnologyitcouldmakedeepspacetravelareality"saidMarkAyreoftheEuropeanSpaceAgencylastmonth．

　　Whatseemslikeasciencefictionisnotcompletelyunlikely．Researchershavebeenabletousechemicalstoputlivingcellsintoasleeplikestatewheretheydon’tage．Theyhavenowmovedontothesmallnonhibernatingmammals(哺乳动物)likerats．

　　Amajorchallengeisthefactthatcellscanbeverysimplesystemswhereasbodyorgansarefarmorecomplex(复杂的)．"It'slikemovingfromasimpleApplecomputertoasupercomputer"saidMarcoBiggiogeraahibernationresearcheratItaly'sUniversityofPavia．Justlikebearsandfrogsthehibernationofhumanbeingswouldcauseaperson'smetabolism(新陈代谢)tolowersotheywouldneedlessenergy．

　　Medicalresearchhoweverisjusthalfofaspaceflighthibernationsystem．Thereisachallengeofdesigningasuitableprotectiveshelter(栖身所)．Suchashelterwouldprovidetheproperenvironmentforhibernationsuchasthepropertemperature．Itwouldalsohavetomonitor(监控)lifefunctionsandservethephysiologicalneedsofthehibernator．

　　AccordingtoAyrethesixpersonHumanOuterPlanetsExplorationMission(使命)toJupiter'smoon(木星的卫星)Callistocouldbeanopportunitytousehumanhibernation．ThemissionaimstosendsixpersonsonafiveyearflighttoCallistowheretheywillspend30daysin2045．

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　　Accordingtothearticlethehibernationr