Skip to content
79,433 pages · 13,741 images · since 1994 Browse A–Z Today in space history
Encyclopedia Astronautica The full story of spaceflight
Encyclopedia entry

MR-104

Engine · USA

Original archive entry. The text, images and links below are kept as they were written.

MR-104AC
MR-104AC
Credit: Aerojet Redmond

Redmond hydrazine monopropellant rocket engine. Attitude control and velocity corrections, Voyager, Magellan, DMSP, Tiros N, Landsat. In Production. First flight 1977.

First Flown: Voyager (August 1977). Flown: 48 (97 produced) planned to end-1995. Dry Mass: 1860 gm. Length: 46.0 cm. Max Diameter: 15.2 cm. Mounting Method: bolted three places. Propellant: hydrazine at 91-290 gm/sec (Shell 405/LCH-202 catalytic decomposition). Feed Method: GN2 or GHe at 6.8-28.6 atm through Wright Components 30 W single seat solenoid valve. Thrust: 205-572 N (445 nominal). Isp: 228-239 sec vacuum. Time to Full Thrust (millisec): 50 to 90% PC. Expansion Ratio: 53:1 (diameter 15.2 cm). Nozzle Length: 17.8 cm. Nozzle Cooling Method: radiative. Combustion Chamber Pressure: 3.8-19.0 atm. Combustion Chamber Temperature: 800 Celsius. Combustion Chamber Cooling Method: radiative. Duty Cycle: 0.022-2000 sec single firing. 2654 cumulative. 1742 pulses. Itotal: 693.9 kNs.

Engine: 1.86 kg (4.10 lb). Chamber Pressure: 19.30 bar. Area Ratio: 53. Thrust to Weight Ratio: 24.19.

Country
USA
Agency
Redmond