Atlas Missile Versions

Project MX-774
      Project MX-774 inaugurated by AAF with Consolidated-Vultee to study rocket capabilities with an ICBM as a final objective. Limited funds permitted a few test launches. These rockets demonstrated technologies that would later be applied to the Atlas.
Atlas A  First test model of Atlas ICBM. Two booster engines, no sustainer, dummy warhead. 50% reliability
in 8 flight tests.
Atlas B  First all-up version of Atlas ICBM, with jettisonable booster engines and single engine sustainer on core. '1 1/2' stage launch vehicle.
Atlas C  Last development version of Atlas. Never deployed operationally or used for space launches.
Launch Vehicle: Atlas D . First operational version of Atlas ICBM and used as launch vehicle for Project Mercury.
Launch Vehicle: Atlas-Vega
Atlas-Vega consisted of an Atlas booster with a storable propellant upper stage. It was planned by NASA at its inception for deep space and planetary missions before the Atlas Centaur was available. Work had already begun when NASA discovered that the CIA and the US Air Force had an essentially identical launch vehicle (Atlas-Hustler, later called Atlas-Agena) in development for the highly classified Corona reconnaisance satellite program. Atlas-Vega was accordingly cancelled.
Launch Vehicle: Atlas E . Initial fully operational version of Atlas ICBM. Differed in guidance system from Atlas F. Deployed as missiles from 1960 to 1966. After retirement, the ICBM's were refurbished and used over twenty years as space launch vehicles.
Launch Vehicle: Atlas F . Final operational version of Atlas ICBM. Differed in guidance systems. Deployed as missiles from 1961 to 1966. After retirement, the ICBM's were refurbished and used over twenty years as space launch vehicles.
Launch Vehicle: Atlas Able . Atlas with upper stage based on Vanguard second stage.
Launch Vehicle: Atlas LV-3A / Agena A . Agena originally called 'Hustler', based on engine for cancelled rocket-propelled nuclear warhead pod for B-58 Hustler bomber.
Launch Vehicle: Atlas LV-3A / Agena B . Improved, enlarged Agena upper stage.
Launch Vehicle: Atlas LV-3B / Mercury . Atlas D modified for use in Project Mercury.