The Vela (meaning "watchman" in Spanish) series of spacecraft were designed to monitor worldwide compliance with the 1963 nuclear test ban treaty. October 17, 1963 at 02:37 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 274th orbital launch attempt, and 50th of 1963. Data: Launch Library 2, The Space Devs. Image by NASA (NASA Image and Media Guidelines) via The Space Devs.