KH-4BRocket launchby USALaunch time20 May 197021:35 UTCsuccessOrbit: LEOSerial number: Thor 555MissionRocketPayloadsRocket Thorad SLV-2H Agena-Dlaunched from Vandenberg AFB, SLC-3WUSAPayloadsNamePurposeMassCommentKH-4B (S/N 1110)Reconnaissance--