KH-5 (Keyhole 5, codenamed Argon) was the area survey component of the Corona program. April 8, 1961 at 19:21 UTC · Launch Successful Thor DM-21 Agena-B — United States Air Force, to Low Earth Orbit Space Launch Complex 1E, Vandenberg SFB, CA, USA The world's 106th orbital launch attempt, and 13th of 1961. Data: Launch Library 2, The Space Devs. Image by USAF via The Space Devs.