Silverstein Committee

The Saturn Vehicle Evaluation Committee, better known as the Silverstein Committee, was a US government commission assembled in 1959 to recommend specific directions that NASA could take with the Saturn rocket program. The committee was chaired by Abe Silverstein, a long-time NASA engineer, with the express intent of selecting upper stages for the Saturn after a disagreement broke out between the Air Force and Army over its development. During the meetings the Committee members outlined a number of different potential designs, including the low-risk solution von Braun was developing with existing ICBM airframes, as well as versions using entirely new upper stages developed to take full advantage of the booster stage. The advantages of using new uppers were so great that the committee won over an initially skeptical von Braun, and the future of the Saturn program changed forever.

In 1957 the Department of Defense (DoD) released a set of requirements for a new heavy-lift booster for missions starting in the early 1960s. At the time, all three branches of the US military were in the process of developing their own rockets, which led to considerable in-fighting between them on the priority of future developments. In 1956 the US Air Force won the concession that long range rocketry was its domain, including all ground-to-ground missiles over 200 miles (320 km) range. The agreement did not cover "other roles" however, and existing projects at the Navy and Army continued as before.

The Air Force was in the midst of their Dyna-Soar project, and were designing a new booster to launch it under their "SLV-4" requirement. Their primary answer to this requirement was a Titan II missile equipped with a new hydrogen-burning upper stage, the Titan C. The resulting design had a somewhat bulbous appearance; as the hydrogen fuel required large tanks, the upper stage was 160 inches (4,100 mm) in diameter, compared to the 120 inches (3,000 mm) of the Titan II. Other teams within the Air Force were also developing the Space Launcher System concept, which combined the same Titan II with a number of solid fuel rockets as a "zeroth stage". By combining different numbers and sizes of these rockets, the launch stack could be tuned to different payloads. The SLS team also outlined a development path for a manned lunar mission under their Lunex Project proposal, using the Titan with four solids to test the re-entry vehicle from Earth orbit, and entirely new solids and liquid stages for flights to the moon.

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