Overview of the Development of a Low Cost High Voltage Hall Accelerator Propulsion System for NASA Science Missions

NASA’s Science Mission Directorate In-Space Propulsion Technology Program is funding NASA Glenn Research Center (GRC) to develop a high specific impulse, long-life, low-cost high voltage Hall accelerator (HiVHAc) engineering model (EM) Hall effect thruster. NASA GRC and Aerojet have completed the fabrication and extensive testing of a HiVHAc EM thruster that incorporates a discharge channel replacement mechanism as a means of achieving long-life. HiVHAc EM performance characterization indicated that the design met and exceeded desired performance levels. A new throttle table that includes high thrust-to-power operation has improved the thruster’s performance for some NASA science missions. However, testing also revealed that thermal, magnetic circuit saturation, and channel replacement mechanism issues and challenges exist. As a result, NASA GRC and Aerojet initiated and completed design changes to the EM thruster to alleviate encountered issues and challenges. In addition, the HiVHAc project is leveraging power processing unit (PPU) developments by Aerojet and by NASA’s Small Business Initiative Research Program. This includes evaluating performance of a wide-output range brassboard PPU that can process input voltages between 80 and 160 volts and is capable of output voltages between 200 and 700 V. Finally, the HiVHAc project has leveraged xenon feed system development by the Science Mission Directorate’s In Space Propulsion Technology Program. The HiVHAc project and Air Force Research Laboratory are funding the development of the next generation of light-weight, low-power consumption, and small-footprint xenon feed system. The unit, designated xenon flow control module, is manufactured by VACCO and will be delivered to NASA GRC in September 2011.