Electric Propulsion for the Psyche Mission

NASA’s Psyche mission will launch in 2022 and begin a 3.5-year cruise to the metallic asteroid Psyche, where it will orbit and examine this unique body. All primary propulsion for the mission will be done with the Maxar SPT-140 system; this will be the first use of Hall thrusters for a NASA mission and the first time they will be used beyond cis-lunar space. The electric propulsion system architecture and its usage for the Psyche mission are described here, along with the modifications to the commercial Earth-orbiting system that are required for deep-space operation. Recent efforts for system development have included thruster plasma diagnostics in support of modeling activities, component development testing, system integrated testing, thruster in-flight performance model development, and thruster life validation. The status of all of these activities is discussed here. Of particular note are the challenges to throttle curve development caused by facility effects on thruster performance as well as the effects of thruster aging, and life validation activities aimed at bridging the gap between the as-performed thruster life test and the Psyche-mission-specific environments and thruster operating conditions.