This is a 25-pound thrust RCS (Reentry Control System) rocket motor, or thruster, for the Gemini spacecraft and was fired in tests. RCS thrusters controlled the spacecraft's attitude (roll, pitch, and yaw). They were fixed thrust, self-contained propulsion systems using hypergolic (self-igniting) propellants and therefore did not need an ignition system.
Developed beginning in early 1962 by the Rocketdyne Division of North American Aviation, RCS thrusters were very similar in appearance and power to the spacecraft's 25-pound thrust OAMS (Orbital Attitude Maneuvering System) units and were located forward of the crew compartment in an independent module. The RCS consisted of a pair of independent systems, each having eight 25-pound thrusters fired in groups. The RCS performed up to expectations in all the Gemini flights from March 1965 to November 1966.
This RCS thruster was donated by the McDonnell Douglas Corporation to the Smithsonian Institution in 1974.
Gift of the McDonnell Douglas Corporation