Psyche’s Payload Fault Protection Design and Strategy for Launch Readiness

NASA’s Psyche mission is a journey to the unique metal-rich (16) Psyche asteroid orbiting the Sun between Mars and Jupiter to get a better insight into the Earth’s core and the core of other terrestrial planets. The mission will offer a unique scientific value by mapping the asteroid and studying its properties with the help of a robust Spacecraft that carries a highly capable Payload suite onboard. Psyche’s Payload suite is a novel collection of heritage and technology demonstration instruments. Heritage instruments include a Multispectral Imager, a Magnetometer, and a Gamma Ray and Neutron Spectrometer. The Deep Space Optical Communications (DSOC) instrument is a Class D technology demonstration that will perform optical communications at AU-magnitude distances. The Spacecraft will need to survive in vaguely known environments and with a wide range of uncertainties from the time of Launch to the Psyche Science Orbital Operations period. Most of these instruments will be functioning at the same time in conjunction with the rest of the subsystems, and with limited contact with the ground operations team on Earth.To ensure that the Spacecraft and instruments are robust to possible anomalies and can remain healthy and functional to meet the science goals and overall mission success criteria, Psyche’s Fault Protection (FP) and Payload teams designed and implemented an autonomous onboard fault management architecture and engine. This Flight Software-based autonomy will execute fault detection, isolation and perform health recovery actions to prevent propagation of anomalous behavior between the instruments and the rest of the Spacecraft.This paper details the history of how Psyche’s Payload Fault Protection design evolved and was fine-tuned through a rigorous testing and analysis campaign to address the needs and challenges of the diverse set of instruments. It describes the key lessons learned, including the ones that emerged post launch-slip in the year 2022, and how a shift in the FP Verification and Validation (V&V) strategy helped the team gain increased confidence in the instruments for Launch readiness.