Overview of NASA's Electric Propulsion Development Activities for Robotic Science Missions

Abstract

The In-Space Propulsion Technology Program (ISPT) is responsible for the development of electric propulsion technologies for NASA robotic scientific missions. The ISPT Program is managed at the NASA Glenn Research Center on behalf of the Science Mission Directorate. The objective of the Electric Propulsion project area is to develop near- term electric propulsion technology to enhance or enable science missions while minimizing risk and cost to the end user. Major hardware tasks include developing NASA's Evolutionary Xenon Thruster (NEXT), developing a long-life High Voltage Hall Accelerator (HIVHAC), and developing an advanced feed system. The objective of the NEXT task is to advance next generation ion propulsion technology readiness. The baseline NEXT system consists of a high-performance, 7-kW ion thruster; a high-efficiency, 7-kW power processor unit (PPU); a highly flexible advanced xenon propellant management system (PMS); a lightweight engine gimbal; and key elements of a digital control interface unit (DCIU) including software algorithms. This design approach was selected to provide future NASA science missions with the greatest value in mission performance benefit. The objective of the HIVHAC task is to advance the Hall thruster technology readiness for science mission applications. The task seeks to increase Hall thruster specific impulse, throttle-ability and operational life and thus broaden Hall propulsion system applicability to low-cost, deep space science missions. The primary application focus for the resulting Hall propulsion system would be cost-capped missions, such as competitively-selected, Discovery-class missions. The objective of the advanced xenon feed system task is to demonstrate novel manufacturing techniques that will significantly reduce mass, volume, and footprint size of xenon feed systems over conventional feed systems. This task has focused on the development of combined flow control and pressure control module, which regulates pressure from the propellant tank and provides two-channel flow control for Hall propulsion systems. Progress on current hardware development, recent test activities and future plans are discussed.