EntityQ6311356· pop 8· linked from 102 articlesJumpseatSign in to saveseries of reconnaissance satellitesConnectionssignals intelligenceEntityUnited StatesCountryphotographyEntityUnited States Air ForceEntityEdward Mills PurcellEntitylow Earth orbitEntityDijkstra's algorithmEntitygeosynchronous orbitEntityreconnaissance satelliteEntityInternational DesignatorEntityEdwin H. LandEntitysynthetic aperture radarEntityWilliam PerryEntitySatellite Catalog NumberEntityTitanEntityNational Reconnaissance OfficeEntityArs TechnicaEntityVelaEntityCoronaEntityUSA-193EntityCategories1971 in spaceflight1973 in spaceflightMilitary equipment introduced in the 1970sNational Reconnaissance Office satellitesSignals intelligence satellites