Encyclopedia Astronautica
ESEX Arcjet

Esex Arcjet
Redmond electric/ammonia rocket engine. 2 N. In Production. Isp=800s. Electric Propulsion Space Experiment) program begun 1989 under the then Air Force Astronautics Lab. Flew once in 1999 on board the ARGOS satellite.

The ESEX (Electric Propulsion Space Experiment) program began in 1989 under the then Air Force Astronautics Lab, Edwards AFB, CA. The prime contractor was TRW, Space Park, Redondo Beach, CA. The Arcject was build by Rocket Reseach (now Aerojet), Redmond, WA. The ESEX experiment flew once in 1999 on board the ARGOS satellite. The ARGOS satellite was built by Space & Missile system Center (SMC), Los Angeles AFB, CA under the program P-91-1. ARGOS carried 8 other DoD space experiments to orbit.

ESEX was the first High Power Electric Propulsion flight. The system operated on 30 kW with about 26 kW to the thruster. The experiment was powered by 205 kg of silver zinc batteries built by Eagle Pitcher Company of Joplin, Mo. At the time this was the highest power subsystem ever flown in space.

The objective was to verify Arcjet performance in space and determine if any spacecraft compatibility or contamination issues existed. AGROS operated with no detectable impact when the thruster operating. Sensors detected no RF interference, no increase in contamination, and measurements of specific impulse and thrust were within ground measurement uncertainty.

This truly pioneering flight program gave the satellite community great confidence in using High Power Electric propulsion. The ammonia fuel was fed at 0.25mg/sec steady state. Design life of the engine was 1500 hours and 400 on/off cycles.

Status: In Production.
Thrust: 2.00 N (0.40 lbf).
Specific impulse: 800 s.

More... - Chronology...

Associated Countries
Associated Spacecraft
  • ARGOS American ion engine technology satellite. One launch, 1999.02.23. ARGOS was the USAF Space Test Program P91-1 technology satellite by Boeing/Seal Beach. More...

See also
Associated Manufacturers and Agencies
  • Redmond American manufacturer of rocket engines. Redmond, USA. More...

Associated Propellants
  • Electric/Ammonia The many versions of electric engines use electric or magnetic fields to accelerate ionized elements to high velocity, creating thrust. The power source can be a nuclear reactor or thermal-electric generator, or solar panels. Ammonia (NH3) is a colourless gas and liquid with a strong irritating characteristic odour. More...

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