EntityQ906162· pop 6· linked from 62 articlesDiscoverer 4Sign in to saveAmerican military reconnaissance satelliteConnectionsCoronaEntityUnited States Air ForceEntityInternational Standard Book NumberEntityOCLC, Inc.EntityGeneral ElectricCompanyLuna 1EntityUnited States Department of DefenseConceptLuna 2EntityLockheed U-2EntityDefense Advanced Research Projects AgencyEntityLuna 3Entityreconnaissance satelliteEntityLockheed CorporationEntitySatellite Catalog NumberEntityPioneer 4EntityNational Reconnaissance OfficeEntityspacecraft busEntityRM-81 AgenaEntityVanguard 2EntityExplorer 6EntityCategoriesSpacecraft launched in 1959Spacecraft which reentered in 1959