The single DSAP-3 (Defense Satellite Application Program Block 3) was a modified DSAP-2 satellite to provide experimental tactical access to weather data. May 20, 1965 at 16:30 UTC · Launch Successful Thor Burner 1 — United States Air Force, to Sun-Synchronous Orbit Space Launch Complex 10W, Vandenberg SFB, CA, USA The world's 436th orbital launch attempt, and 43rd of 1965. Data: Launch Library 2, The Space Devs.