NASA’s Project Prometheus is developing nuclear power and propulsion technology that are enabling for NASA’s mission to explore the universe and search for life. In addition to the proposed Jupiter Icy Moons Orbiter (JIMO) mission, which would be the first space science mission to utilize these technologies, Project Prometheus is sponsoring broad-based research and development efforts for future exploration applications. One such activity is the investigation of high-power, high specific impulse Hall thrusters.

During FY03, NASA GRC began investigating two approaches to achieve Hall thruster specific impulses greater than 4000 s at a 50 kW power level: 1) Utilizing lower molecular weight propellants and 2) Increasing the applied discharge voltage of xenon Hall thrusters. The feasibility of using krypton propellant to achieve the performance goals was demonstrated using the existing NASA-457M V1 Hall thruster. A discharge specific impulse of 4500 seconds was demonstrated at a discharge voltage of 1000 Volts and discharge efficiencies up to 64% were measured. During FY04, a new high-power Hall thruster, designated the NASA-400M was designed to investigate high-specific impulse operation. A brief description of the thruster and the experiments conducted with the device are presented below.