Development of the Psyche Mission for NASA ’ s Discovery Program

In January 2017, the proposed mission Psyche: Journey to a Metal World, led by principal investigator Dr. Lindy Elkins-Tanton of Arizona State University (ASU), was selected for implementation as part of NASA’s Discovery Program. The planned Psyche mission is enabled by electric propulsion and would use SPT-140 Hall thrusters to rendezvous and orbit the largest metal asteroid in the solar system. The spacecraft requires no chemical propulsion and, when launched in 2022, would be the first mission to use Hall thrusters beyond lunar orbit. This paper describes the ongoing development of the Psyche mission concept and describes how Psyche would use commercially provided solar power and electric propulsion to meet its mission’s science requirements. It describes the mission’s scientific objectives and low thrust mission trajectory, the spacecraft architecture, including its power and propulsion systems, and the all-electric attitude control strategy that allows Psyche to fly without the use of chemical propulsion. Together, these elements provide a robust baseline design that maximizes heritage, leverages the strongest experience bases within the partner organizations, and minimizes risk across the design; providing a firm basis for implementation of the Psyche mission.