The KH-4A (Keyhole-4A) was the fifth optical reconnaissance satellite version in the Corona-program. April 27, 1964 at 23:23 UTC · Launch Successful Thor SLV-2A Agena D — United States Air Force, to Low Earth Orbit Space Launch Complex 1W, Vandenberg SFB, CA, USA The world's 321st orbital launch attempt, and 28th of 1964. Data: Launch Library 2, The Space Devs. Image via The Space Devs.