SM-65 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.

The development of the Atlas begun in 1946, but over the next few years the project underwent several cancellations and re-starts. The deepening of the Cold War and intelligence showing the Soviet Union was working on an ICBM design led to it becoming a crash project in late 1952, along with the creation of several other missile projects to ensure one would enter service as soon as possible. The first test launch was carried out in June 1957, which failed. The first success of the Soviet R-7 Semyorka in August gave the program new urgency, leading to the first successful Atlas A launch in December. Of the eight flights of the A model, only three were successful, but the later models demonstrated increasing reliability and the D model was cleared for use.

Atlas C was declared operational in September 1959. Even at that time it was considered less than ideal as it had to be fuelled immediately before launch and thus had very slow reaction times. The Air Force still saw its strategic bombers as its primary force and considered Atlas as a last-ditch weapon that would ensure a counterattack in the case the Soviets attempted a sneak attack on the US bomber bases. The initial versions were stored at ground level and thus subject to attack by Soviet bombers, which greatly reduced their suitability for this role. Starting with the F models they were stored in underground silos that offered some protection from air attack. New designs, especially the Minuteman, rendered Atlas obsolete and it was retired from the ICBM role by 1965.

These disadvantages had no bearing on its use for space launches, and Atlas-derived launch vehicles served as launchers for NASA for four decades. 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. Mergers led to the acquisition of the Atlas Centaur line by the United Launch Alliance. Today ULA supports the larger Atlas V, which combines the Centaur upper stage with a new booster. Until 1995, many retired Atlas ICBMs were refurbished and combined with upper stages to launch satellites.