MR-103

Redmond hydrazine monopropellant rocket engine. Attitude control thruster for Voyager, GPS, Intelsat 5, MMAS 3000, 4000,. 5000, and 7000, Mars Observer, ACTS, and Magellan. In Production. First flight 1974.

First Flown: ATS 6 comsat( May 1974 ). Flown: 1014 (1744 produced) planned to end-1997. Dry Mass: 332 gm. Length: 14.7 cm. Max Diameter: 3.43 cm. Mounting Method: bolted three places. Propellant: hydrazine at 0.091-0.499 gm/sec (Shell 405 catalytic decomposition). Feed Method: GN2 at 4.8-28.6 atm through 9 W solenoid dual seat valve. Thrust: 0.19-1.12 (0.89 nominal). Isp: 206-227 sec vacuum. Time to Full Thrust (millisec): 150 to 90%. Nozzle Area Ratio: 100:1. Nozzle Length: 0.98 cm. Nozzle Cooling Method: radiative. Combustion Chamber Pressure: 4.35-23.9 atm. Combustion Chamber Temperature: 800 Celsius. Combustion Chamber Cooling Method: radiative. Duty Cycle: 0.008 sec minimum to unlimited maximum burn. 750,000 pulses. Itotal: 158.46 kNs.

Engine: 0.33 kg (0.73 lb). Chamber Pressure: 23.90 bar. Area Ratio: 100. Thrust to Weight Ratio: .34.