[20p-KD-2~9] Plasma Processing in Space Science and Engineering

[20p-KD-5] High-power Electric Propulsion

〇Hirokazu Tahara¹ (1.Dept. Mechanical Eng., Osaka Inst. Tech.)

Keywords:electric propulsion,high-power propulsion,manned Mars exploration

High-power electric thruster is a promising one in space for future missions, such as construction of Moon base and 1GW solar power generation satellite, and manned Mars exploration. In this presentation, high-power electric propulsion will be reviewed. Research and development of Hall-effect ion thruster, direct-current (DC) arcjet thruster and magneto-plasma-dynamic (MPD) thruster will be introduced. Hall thruster is classified into Magnetic-Layer type (SPT type) and Anode-Layer type (TAL type). 5-25kW class SPT-type Hall thrusters have been developed for large-satellite attitude control and in-space propulsion all over the world. In Japan, RAIJIN (Robust Anode-layer Intelligent thruster for Japan IN-space propulsion) project was started in 2012 for development of high-efficiency 5kW TAL-type Hall thruster system. The RAIJIN and OIT (Osaka Institute of Technology) TALT2 TAL-type thrusters achieved a thrust of 47.3-102.0 mN, a specific impulse of 1,608-3,468 s and a thrust efficiency of 48.9-63.4% with an input power of 3-5 kW. 5-10 kW DC arcjet thrusters have been developed for orbital transfer or in-space propulsion. Hydrogen and ammonia are used for high-performance and long-time operation. In Japan, a radiation-cooled arcjet thruster system was developed at OIT. 5-10 kW steady-state MPD thrusters have been investigated for manned Mars exploration. At OIT, a radiation-cooled MPD thruster system with simple structure has been designed. For an application of axial magnetic field, permanent magnets are used. Also, cathode erosion is one of important problems for practical use. One of the solutions may to use a hollow cathode. Accordingly, an MPD thruster system with permanent magnets and a multi-hollow cathode achieved a thrust of 21.4 mN, a specific impulse of 2,907 s and a thrust efficiency of 4.92 % at 5.18 kW with hydrogen and a performance of 151 mN, 768 s and 5.73 % at 6.71 kW with ammonia.