Atlas

The SM-65 Atlas was the first operational intercontinental ballistic missile (ICBM) developed by the United States and the first member of the Atlas rocket family. It was built for the U.S. Air Force by the Convair Division of General Dynamics at an assembly plant located in Kearny Mesa, San Diego. Atlas became operational in October 1959, but was soon made obsolete as an ICBM by new development, and was retired from this role by 1965.

Atlas required long preparation times which made it unsuitable for a quick launch ICBM. However, this was not a requirement for planned space launches, and so Atlas-derived launch vehicles served a long history as space launchers. Even before its ICBM use ended in 1965, Atlas had placed four Project Mercury astronauts in orbit and was becoming the foundation for a family of successful space launch vehicles, most notably Atlas Agena and Atlas Centaur.