This is the vernier rocket motor for the Surveyor unmanned lunar landing probe, America's first spacecraft to soft-land on the Moon. It was never flown but was test fired and probably therefore served as a developmental model. The vernier was small but of critical importance in providing propulsion for mid-course correction maneuvers and attitude and velocity control before and during the landing. It had to be absolutely reliable with restart capability. The vernier produced 30-104 pounds of thrust and was only fired for short bursts as required. The engine was used successfuly on all of the Surveyor missions from 1966 to 1968. This motor was transferred to the Smithsonian in 1979 from the NASA Jet Propulsion Laboratory.
Gift of Reaction Motors Division, Thiokol Chemical Corp.