Discoverer 16 was an American optical reconnaissance satellite. The launch failed when the Agena stage failed to seperate from Thor. October 26, 1960 at 20:26 UTC · Launch Failure Thor DM-21 Agena-B — United States Air Force, to Low Earth Orbit Space Launch Complex 1W, Vandenberg SFB, CA, USA The world's 83rd orbital launch attempt, and 29th of 1960. Data: Launch Library 2, The Space Devs. Image by USAF via The Space Devs.