Enabling Inexpensive Robotic Precursors with the MIU-10 Microwave Discharge Ion Engine System

摘要

A visit to a Near Earth Asteroid is a compelling mission for human spaceflight and is baselined as a destination on the way to Mars. T h e number of candidate targets and information about their properties must be increased prior to attempting such a mission. Small spacecraft launched from an EELV Secondary Payload Adapter with propulsion provided by an MIU-10 microwave ion engine system can serve as inexpensive robotic precursors. The Japanese Hayabusa mission has demonstrated the ability to carry out such a mission with this technology. Microwave discharge ion engines have a long life and high reliability because of electorodeless plasma generation. The first model, “μ10”, was installed on Hayabusa asteroid explorer as main propulsion and contributed to its successful return to Earth. The Hayabusa mission and its use of the μ10 Ion Engine System is reviewed. Based upon the flight heritage of Hayabusa, a versatile, upgraded microwave ion engine system, “MIU-10”, using an upgraded “μ10HP” thruster, is under development. The MIU-10 has improved reliability, operability and design flexibility to adapt to various kinds of missions and satellite buses. The characteristics of the MIU-10 system is given. It is an enabling technology for robotic precursors that essentially requires high specific impulse, long life, high technological maturity and low cost. The development of MIU-10 has been almost finished and flight models are under manufacture for Hayabusa-2, which is scheduled to launch in 2014. F i n a l l y , a n o t i o n a l s p acecraft design using the MIU-10 system to explore near Earth asteroids is proposed.