This is the rocket engine for the Ranger Mid-Course Propulsion System of the Ranger spacecraft. The function of the engine was to make mid-course corrections for the spacecraft while it was enroute to the Moon. This amounted to turning the spacecraft so that it was correctly aimed at the Moon. Another propulsion system was used to make fine attitude adjustments. The Mid-Course engine used the monopropellant of hydrazine and produced 224 Newtons (50 lbs) of thrust. The Ranger spacecraft was the U.S.'s first series designed to take close-up images of the Moon just prior to their impact upon the lunar surface. Nine of the spacecraft were sent to the Moon during 1961 to 1965. The engine was transferred to the Smithsonian from the NASA Jet Propulsion Laboratory in 1996.
Transferred from NASA, Jet Propulsion Lab, Pasadena, Calif.