KH-5 (Keyhole 5, codenamed Argon) was the area survey component of the Corona program. June 8, 1961 at 21:16 UTC · Launch Failure Why: Power 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 110th orbital launch attempt, and 17th of 1961. Data: Launch Library 2, The Space Devs. Image by USAF via The Space Devs.