Deep Space Probes

TheVoyagerspaceprogram,launchedbytheNationalAeronauticsandSpaceAdministrationinthelatenineteenseventies,standsasoneofhumanity'smostambitiousandenduringlysuccessfulscientificendeavors.Thetwinroboticprobes,VoyagerOneandVoyagerTwo,wereinitiallydesignedtotakeadvantageofahighlyuniqueplanetaryalignmentthatoccursonlyonceeveryonehundredandseventy-fiveyears.Thisraregeometricconfigurationallowedthespacecrafttoutilizeacomplextechniqueknownasagravitationalslingshot.Bycarefullyflyingclosetoamassiveplanet,theprobescouldstealatinyfractionofitsorbitalmomentum,dramaticallyincreasingtheirownvelocityandallowingthemtosequentiallyvisitJupiter,Saturn,Uranus,andNeptunewithoutrequiringmassiveamountsofonboardrocketfuel.Theincrediblydetailed,close-upphotographsbeamedbacktoEarthfundamentallytransformedourunderstandingoftheoutersolarsystem.TheyrevealedactivevolcaniceruptionsonJupiter'smoonIo,discoveredintricatenewringsaroundSaturn,anddocumentedthebrutal,supersonicwindstearingacrossthefrozen,blueatmosphereofNeptune.Beyondtheirprimaryscientificmission,theVoyagerprobescarryaprofoundculturalartifact:theGoldenRecord.Thisheavilyshielded,gold-platedcopperphonographrecordwasdesignedasatimecapsuleandagreetingtoanypotentialextraterrestrialintelligencethatmightencountertheprobesinthedistantfuture.ItcontainsaneclecticmixofsoundsfromEarth,includingthecrashofoceanwaves,thesongsofhumpbackwhales,spokengreetingsinfifty-fivedifferenthumanlanguages,andadiverseselectionofmusicalmasterpiecesrangingfromclassicalBachcompositionstotraditionalfolksongs.Havingsuccessfullycompletedtheirgrandplanetarytour,bothVoyagerprobesarenowtravelingatstaggeringspeedsexceedingthirty-fivethousandmilesperhour,headingoutintothedark,unchartedexpanseofinterstellarspace.Theyarethefurthestartificialobjectsevercreatedbyhumanhands,servingassilent,lonelyambassadorsofourtinyblueplanettothewidergalaxy.