The Atlas I was a US expendable launch system manufactured by General Dynamics in the 1990s to launch a variety of satellites. It was largely a commercial rebrand of the Atlas G, but did feature several electrical and guidance improvements. Atlas I did not feature any major payload capacity improvements over its predecessor but did offer a larger payload fairing option. Eleven launches took place, with three failures.

Atlas II was a member of the Atlas family of launch vehicles, which evolved from the successful Atlas missile program of the 1950s. The Atlas II was a direct evolution of the Atlas I, featuring longer first stage tanks, higher-performing engines, and the option for strap-on solid rocket boosters. It was designed to launch payloads into low Earth orbit, geosynchronous transfer orbit or geosynchronous orbit. Sixty-three launches of the Atlas II, IIA and IIAS models were carried out between 1991 and 2004; all sixty-three launches were successes, making the Atlas II a highly reliable space launch system. The Atlas line was continued by the Atlas III, used between 2000 and 2005, and the Atlas V which is still in use.