The Vela (meaning "watchman" in Spanish) series of spacecraft were designed to monitor worldwide compliance with the 1963 nuclear test ban treaty. July 17, 1964 at 08:22 UTC · Launch Successful Atlas LV-3 Agena D — United States Air Force, to Elliptical Orbit Space Launch Complex 13, Cape Canaveral SFS, FL, USA The world's 342nd orbital launch attempt, and 49th of 1964. Data: Launch Library 2, The Space Devs. Image by NASA (NASA Image and Media Guidelines) via The Space Devs.