Marquardt R-4D RCS rocket engine combustion chamber, 3.75 x 6, labeled on the side in white stenciling, “S28TC3214.” Side of upper rim engraved, “VN, 228128, J” and “S/N 242,” with the underside of the lower rim engraved, “VN 221774–501” and “H S/N 012 (64).” In fine condition. The combustion chamber was intended for application on a R-4D hypergolic liquid rocket engine found on an Apollo Command Service Module (CSM) and Lunar Module (LM). Manufactured by Marquardt Corporation, the 100-pound thrust rocket engines were used in groups of four—configured as a ‘quad’—to provide attitude control of the CSM and LM, as a means to include roll, yaw and pitch maneuvers. An incredible piece of hardware related to the control of Apollo command and lunar modules.
