Timeline of American rockets

Viking 1 was launched by a Titan/Centaur rocket from Complex 41 at Cape Canaveral Air Force Station at on Aug. 20, 1975, to begin a half-billion mile, 11-month journey through space to explore Mars. The 4-ton spacecraft went into orbit around the red planet in mid-1976.

PHOTO: NASA/Sipa Press/Newscom/File