KH-4BRocket launchby USALaunch time19 Mar 196921:38 UTCsuccessOrbit: LEOSerial number: Thor 541Satellite later failed.MissionRocketPayloadsRocket Thorad SLV-2G Agena-Dlaunched from Vandenberg AFB, SLC-3WUSAPayloadsNamePurposeMassCommentKH-4B (S/N 1150)/SRV S/N 737Reconnaissance--