KH-4BRocket launchby USALaunch time24 Mar 197121:05 UTCsuccessOrbit: LEOSerial number: Thor 538MissionRocketPayloadsRocket Thorad SLV-2H Agena-Dlaunched from Vandenberg AFB, SLC-3WUSAPayloadsNamePurposeMassCommentKH-4B (S/N 1114)Reconnaissance--