On-orbit demonstration of a pulsed self-field magnetoplasmadynamic thruster system

A repetitively pulsed self-field magnetoplasmadynamic arcjet thruster was i ntegrated into a propulsion system, which was tested on-orbit using liquid hydrazine propellant. This space test was designated as Electric Propulsion Experiment (EPEX) onboard Space Flyer Unit that was a Japanese unmanned re usable space platform launched by an H-H rocket in March 1995, and retrieve d by a U,S. Space Shuttle in January 1996, The EPEX. successfully verified the propulsive function of the pulsed magnetoplasmadynamic arcjet thruster system by repetitively firing over 40,000 shots during a few days of alloca ted experiment period, and confirmed that the on-orbit thrust performance w as in good agreement with that obtained in the ground test. The residual hy drazine was successfully dumped into space according to NASA safety require ments. The postflight inspection exhibited no signature of abnormal are dis charge and no hydrazine concentration in the EPEX system.