This emerging technology is an effort by the Air Force Research Laboratory's propulsion directorate to demonstrate its use in space and evaluate its performance and interactions with other experiments and spacecraft systems on board an Air Force scientific satellite.

AFRL's project manager, Daron Bromaghin, notified lab personnel of the first successful test in space March 15. Barely able to contain his excitement, he stated that, "The arcjet ran perfectly. We fired for 141 seconds and quit only because we were running out of contact time with the satellite on its pass over Vandenberg AFB (Calif.). We were firing at full power, more than 27 kilowatts, and everything worked great."

The lab's electric propulsion researchers are gathering data at three different Air Force ground station sites while controlling the arcjet's space demonstration from the Air Force's Space and Missile Systems Center's space experiment control facility at Kirtland AFB, N.M.

The team examined data during and after the firing using a variety of onboard sensors. They were able to determine that everything worked as predicted. The firing changed the orbit of the ARGOS spacecraft by 215 meters while generating about a third of a pound of thrust. The ammonia propellant consumed was four times less than the best performing chemical rocket engine in use today. For the team, the best information gathered was the validation that firing the highest powered electric propulsion system in space did not interrupt telemetry or affect other equipment on the spacecraft.

Arcjet propulsion is based on creating a directed plasma in space. The simple system uses an anode/cathode design with 26 kilowatts of electrical power sparking between the electrodes. Ammonia gas is released through the "spark" and the resulting ignited gas becomes a plasma which superexpands and creates thrust.

The experimental propulsion system is part of the payload of an Air Force scientific satellite called Advanced Research and Global Observation Satellite, or ARGOS, built by Boeing. A Delta II rocket launched the new space satellite propulsion experiment Feb. 23 from Vandenberg.