This page no longer updated from 31 October 2001. Latest version can be found at www.astronautix.com
astronautix.com MR-502 IMPEHT
Other Designations: Improved Electrothermal Hydrazine Thruster. Designer: Rocket Research. Application: Communications satellite N-S stationkeeping, MMAS 5000. Propellants: Hydrazine Thrust(vac): 0 kgf. Thrust(vac): 0.00 kN. Isp: 304 sec. Burn time: 7,200 sec. Mass Engine: 1 kg. Diameter: 0.1 m. Length: 0.2 m. Chambers: 1. Chamber Pressure: 6.50 bar. Area Ratio: 100.00. Country: USA. Status: In Production.

First Flown: Astra 1B (March 1991). Flown: 16 (32 produced) planned to end-1995. Dry Mass: 848 gm. Length: 19.4 cm. Max Diameter: 8.84 cm. Mounting Method: bolted four places. Propellant: hydrazine at 0.119-0.167 gm/sec over Shell 405 catalyst and 610-839.6. W electric heater. Feed Method: GN2 or Ghe at 21.8-23.8 atm through Wright Components 9 W dual seat. solenoid valve. Thrust: 0.36-0.50 N. Isp: 280-304 sec vacuum. Expansion Ratio: 100:1. Nozzle Length: 0.879 cm. Nozzle Cooling Method: radiative. Combustion Chamber Pressure: 3.4-6.5 atm. Combustion Chamber Temperature: 800 Celsius. Combustion Chamber Cooling Method: radiative. Duty Cycle: 300 sec minimum to 2 hr maximum. 430,000 pulses. Itotal: 525 kNs.

Back to Index
Last update 12 March 2001.
Definitions of Technical Terms.
Contact Mark Wade with any corrections or comments.
Conditions for use of drawings, pictures, or other materials from this site..
© Mark Wade, 2001 .