pale blue dot -carl sagan- 第51节

These　remendations　add　up　to　a　fraction　of　the　full　cost　of　a　human　mission　to　Mars　and—spread　out　over　a　decade　or　so　and　done　jointly　with　other　nations—a　fraction　of　current　space　budgets。　But；　if　implemented；　they　would　help　us　to　make　accurate　cost　estimates　and　better　assessment　of　the　dangers　and　benefits。　They　would　permit　us　to　maintain　vigorous　progress　toward　human　expeditions　to　Mars　without　premature　mitment　to　any　specific　mission　hardware。　Most；　perhaps　all；　of　these　remendations　have　other　justifications；　even　if　We　were　sure　wed　be　unable　to　send　humans　to　any　other　world　in　the　next　few　decades。　And　a　steady　drumbeat　of　acplishments　increasing　the　feasibility　of　human　voyages　to　Mars　would—in　the　minds　of　many　at　least—bat　widespread　pessimism　about　the　future。



THERE'S　SOMETHING　MORE。　There's　a　set　of　less　tangible　arguments；　many　of　which；　I　freely　admit；　I　find　attractive　and　resonant。　Spaceflight　speaks　to　something　deep　inside　us—many　of　us；　if　not　all。　An　emerging　cosmic　perspective；　an　improved　understanding　of　our　place　in　the　Universe；　a　highly　visible　program　affecting　our　view　of　ourselves　might　clarify　the　fragility　of　our　planetary　environment　and　the　mon　peril　and　responsibility　of　all　the　nations　and　peoples　of　Earth。　And　human　missions　to　Mars　would　provide　hopeful　prospects；　rich　in　adventure；　for　the　wanderers　among　us；　especially　the　young。　Even　vicarious　exploration　has　social　utility。

I　repeatedly　find　that　when　I　give　talks　on　the　future　of　the　space　program—to　universities；　business　and　military　groups；　professional　organizations—the　audiences　are　much　less　patient　with　practical；　real…world　political　and　economic　obstacles　than　1。　They　long　to　sweep　away　the　impediments；　to　recapture　the　glory　days　of　Vostok　and　Apollo；　to　get　on　with　it　and　once　more　tread　other　worlds。　We　did　it　before；　we　can　do　it　again；　they　say。　But；　I　caution　myself；　those　who　attend　such　talks　are　self…selected　space　enthusiasts。

In　1969；　less　than　half　the　American　people　thought　the　Apollo　program　was　worth　the　cost。　But　on　the　twenty…fifth　anniversary　of　the　Moon　landing；　the　number　had　risen　to　two　thirds。　Despite　its　problems；　NASA　was　rated　as　doing　a　good…to…excellent　job　by　63　percent　of　Americans。　With　no　reference　to　cost；　75　percent　of　Americans　（according　to　a　CBS　News　poll）　favored　〃the　United　States　sending　astronauts　to　explore　Mars。'　For　young　adults；　the　figure　was　68　percent。　I　think　〃explore〃　is　the　operative　word。

It　is　no　accident　that；　whatever　their　human　flaws；　and　how　ever　moribund　the　human　space　program　has　bee　（a　trend　that　the　Hubble　Space　Telescope　repair　mission　may　have　helped　to　reverse）；　astronauts　and　cosmonauts　are　still　widely　regarded　as　heroes　of　our　species。　A　scientific　colleague　tells　me　about　a　recent　trip　to　the　New　Guinea　highlands　where　she　visited　a　stone　age　culture　hardly　contacted　by　Western　civilization。　They　were　ignorant　of　wristwatches；　soft　drinks；　and　frozen　food。　But　they　knew　about　Apollo　11。　They　knew　that　humans　had　walked　on　the　Moon。　They　knew　the　names　of　Armstrong　and　Aldrin　and　Collins。　They　wanted　to　know　who　was　visiting　the　Moon　these　days。

Projects　that　are　future…oriented；　that；　despite　their　political　difficulties；　can　be　pleted　only　in　some　distant　decade　are　continuing　reminders　that　there　will　be　a　future。　Winning　a　foothold　on　other　worlds　whispers　in　our　ears　that　we're　more　than　Picts　or　Serbs　or　Tongans：　We're　humans。

Exploratory　spaceflight　puts　scientific　ideas；　scientific　thinking；　and　scientific　vocabulary　in　the　public　eye。　It　elevates　the　general　level　of　intellectual　inquiry。　The　idea　that　we've　now　understood　something　never　grasped　by　anyone　who　ever　lived　before—that　exhilaration；　especially　intense　for　the　scientists　involved；　but　perceptible　to　nearly　everyone—propagates　through　the　society；　bounces　off　walls；　and　es　back　at　us。　It　encourages　us　to　address　problems　in　other　fields　that　have　also　never　before　been　solved。　It　increases　the　general　sense　of　optimism　in　the　society。　It　gives　currency　to　critical　thinking　of　the　sort　urgently　needed　if　we　are　to　solve　hitherto　intractable　social　issues。　It　helps　stimulate　a　new　generation　of　scientists。　The　more　science　in　the　media…especially　if　methods　are　described；　as　well　as　conclusions　and　implications…the　healthier；　I　believe；　the　society　is。　People　everywhere　hunger　to　understand。



WHEN　I　WAS　A　CHILD；　my　most　exultant　dreams　were　about　flying—not　in　some　machine；　but　all　by　myself。　I　would　be　skipping　or　hopping；　and　slowly　I　could　pull　my　trajectory　higher。　It　would　take　longer　to　fall　back　to　the　ground。　Soon　I　would　be　on　such　a　high　arc　that　I　wouldn't　e　down　at　all。　I　would　alight　like　a　gargoyle　in　a　niche　near　the　pinnacle　of　a　skyscraper；　or　gently　settle　down　on　a　cloud。　In　the　dream—which　I　must　have　had　in　its　many　variations　at　least　a　hundred　times—achieving　flight　required　a　certain　cast　of　mind。　It's　impossible　to　describe　it　in　words；　but　I　can　remember　what　it　was　like　to　this　day。　You　did　something　inside　your　head　and　at　the　pit　of　your　stomach；　and　then　you　could　lift　yourself　up　by　an　effort　of　will　alone；　your　limbs　hanging　limply。　Off　you'd　soar。

I　know　many　people　have　had　similar　dreams。　Maybe　most　people。　Maybe　everyone。　Perhaps　it　goes　back　10　million　years　or　more；　when　our　ancestors　were　gracefully　flinging　themselves　from　branch　to　branch　in　the　primeval　forest。　A　wish　to　soar　like　the　birds　motivated　many　of　the　pioneers　of　flight；　including　Leonardo　da　Vinci　and　the　Wright　brothers。　Maybe　that's　part　of　the　appeal　of　spaceflight；　too。

In　orbit　about　any　world；　or　in　interplanetary　flight；　you　are　literally　weightless。　You　can　propel　yourself　to　the　spacecraft　ceiling　with　a　slight　push　off　the　floor。　You　can　go　tumbling　through　the　air　down　the　long　axis　of　the　spacecraft。　Humans　experience　weightlessness　as　joy；　this　has　been　reported　by　almost　every　astronaut　and　cosmonaut。　But　because　spacecraft　are　still　so　small；　and　because　space　〃walks〃　have　been　done　with　extreme　caution；　no　human　has　yet　enjoyed　this　wonder　and　glory：　propelling　yourself　by　an　almost　imperceptible　push；　with　no　machinery　driving　you；　untethered；　high　up　into　the　sky；　into　the　blackness　of　interplanetary　space。　You　bee　a　living　satellite　of　the　Earth；　or　a　human　planet　of　the　Sun。

Planetary　exploration　satisfies　our　inclination　for　great　enterprises　and　wanderings　and　quests　that　has　been　with　us　since　our　days　as　hunters　and　gatherers　on　the　East　African　savannahs　a　million　years　ago。　By　chance—it　is　possible；　I　say；　to　imagine　many　skeins　of　historical　causality　in　which　this　would　not　have　transpired—in　our　age　we　are　able　to　begin　again。

Exploring　other　worlds　employs　precisely　the　same　qualities　of　daring；　planning；　cooperative　enterprise；　and　valor　that　mark　the　finest　in　the　military　tradition。　Never　mind　the　night　launch　of　an　Apollo　spacecraft　bound　for　another　world。　That　makes　the　conclusion　foregone。　Witness　mere　F…14s　taking　off　from　adjacent　flight　decks；　gracefully　canting　left　and　right；　afterburners　flaming；　and　there's　something　that　sweeps　you　away—or　at　least　it　does　me。　And　no　amount　of　knowledge　of　the　potential　abuses　of　carrier　task　forces　can　affect　the　depth　of　that　feeling。　It　simply　speaks　to　another　part　of　me。　It　doesn't　want　recriminations　or　politics。　It　just　wants　to　fly。

〃I　。　。　。　had　ambition　not　only　to　go　farther　than　anyone　had　done　before；〃　wrote　Captain　James　Cook；　the　eighteenth…century　explorer　of　the　Pacific；　〃but　as　far　as　it　was　possible　for　man　to　go。〃　Two　centuries　later；　Yuri　Romanenko；　on　returning　to　Earth　after　what　was　then　the　longest　space　flight　in　history；　said　〃The　Cosmos　is　a　magnet　。　。　。　Once　you've　been　there；　all　you　can　think　of　is　how　to　get　back。〃

Even　Jean…Jacques　Rousseau；　no　enthusiast　of　technology；　felt　it：

The　stars　are　far　above　us；　we　need　preliminary　instruction；　instruments　and　machines；　which　are　like　so　many　immense　ladders　enabling　us　to　approach　them　and　bring　them　within　our　grasp。

〃The　future　possibilities　of　space…travel；〃　wrote　the　philosopher　Bertrand　Russell　in　1959；　which　are　now　left　mainly　to　unfounded　fantasy；　could　be