scope:

Abstract:

This lesson learned addresses the development and evolution of a test technique for revalidating the Space Shuttle Orbiter Main Propulsion System (MPS) during ground turnaround operations between flights. This test technique, the Helium Signature Test, is an end-to-end leak check of the entire MPS and serves as a final validation of flightworthiness. A test such as the Helium Signature Test can be used for any enclosed hazardous system with a control volume to ensure overall system integrity before the hazardous medium is introduced.