Atlas B

XB-65B SM-65B

Mission Profile

Atlas B was an early development variant of the Atlas ICBM and the second in a series of test models that progressively refined the design that would become America's first operational ICBM. Standing 24.9 meters tall with a liftoff mass of 117,000 kg and generating 1,630 kN of thrust, it was used primarily to validate Atlas propulsion and guidance systems through a series of test flights beginning in July 1958. Although not all flights were successful, the Atlas B program yielded critical engineering data that directly shaped the final operational Atlas and its remarkable family of space launch derivatives, including the rockets that carried America's first orbital astronauts and later the Mariner planetary probes.