Discoverer 10 was an American optical reconnaissance satellite, the seventh of ten operational flights of the Corona KH-1 spy satellite series. February 19, 1960 at 20:15 UTC · Launch Failure Thor Agena A — United States Air Force, to Low Earth Orbit Space Launch Complex 1E, Vandenberg SFB, CA, USA The world's 56th orbital launch attempt, and 2nd of 1960. Data: Launch Library 2, The Space Devs.