Endurance Test of Microwave Discharge Ion Thruster System for Asteroid Sample Return Midon MUSES-C

Institute of Space and Astronautical Science has just initiated the space program MUSES-C in which a spacecraft about 360 kg will be launched in January 2003 and bring back rocks or sand from the asteroid Nereus to Earth in January 2006. For its round trip between Earth aad .Nereus the cathode-less microwave discharge ion thruster system will propel the spacecraft. The englneerlng model of the ion thruster has been devoted to the endurance test since February 1997. It achieved 3,000 hours in an accumulated operational time in the beginning of August 1997 and is still under test.