Two Steps Forward: Evolving Psyche’s Fault Protection Validation Post-Launch Slip

On October 5th, 2023, the Psyche Mission is targeted to launch to the large metallic asteroid (16) Psyche that will be exploring the exposed core material of a differentiated planetesimal-class asteroid. This unique NASA Discovery-class Mission combines a Solar Electric Propulsion (SEP) Chassis from Maxar Technologies with JPL’s contribution of avionics, flight software, and fault protection design. The Psyche Fault Protection (FP), implemented as autonomous algorithms, can detect, isolate, respond to, and recover from off-nominal conditions that may prevent mission success.The FP Verification and Validation (V&V) campaign involved numerous types of testing including FP infrastructure, monitor & response end-to-end (E2E) functionality, scenario testing, and stress and robustness testing across both high and low-fidelity venues. Due to delays in system level software testing, Psyche had to reschedule its original launch window from July 2022 to October 2023. This paper focuses on how the V&V campaign was scoped and executed prior to the launch slip and then improved after the launch slip. Adaptations included testing a comprehensive E2E regression test suite by targeting updates made to the GNC FP design, a streamlined data execution that employed variance of initial conditions and a consistent test procedure, and a robust and efficient data review strategy including tooling to automate checks. By capitalizing on the additional time, resources, and insights gained from Psyche’s launch slip, the Fault Protection V&V campaign benefited from a more comprehensive and rigorous validation process. This paper captures the knowledge and processes employed to validating Psyche’s Fault Protection design such that future FP V&V campaigns can benefit from more robust testing.