Development of a 6-kW-class Hall thruster for geostationary missions

摘要

To meet the growing demand for all-electric propulsion satellite, a 6-kW-class Hall thruster was newly fabricated and tested in laboratory. A Hall thruster that has an annular ceramic channel in 150-mm effective diameter and a centered hollow cathode was designed to optimize thrust performance with an appropriate channel-geometry and magnetic-field-topology combination. At an input power of 6 kW, both high thrust (392 mN) and high specific impulse (1940s) was demonstrated for 300 V discharge voltage with xenon propellant. In this case a thrust efficiency of 62.7% was obtained. The thruster also worked in a low power mode at 1.8 kW, in which 92.7 mN and 1870s were available for 400 V operation. In comparison with existing thrusters, this thruster enables lower-power and higher-Isp operation for station keeping with satisfactory discharge stability, which will improve the all-electric propulsion satellite not only by reducing the propellant mass during station keeping but also by increasing the electric power available for mission payloads. Analysis in this study showed that the 6kW operation is suitable for orbit raising maneuvers of geostationary satellites from a launch orbit to a geostationary orbit because a satellite from 3-ton to 10-ton can be transferred with two- or up to four-6kW-thrusters with a high payload ratio and a relatively short transfer time of 4- to 6-months. After transferred to a geostationary orbit, station keeping operation will be executed by the lower power mode. The Hall thruster will hence play an important role in the field of geostationary satellites.