Using telemetry to measure equipment usable life on the NASA Orion spacecraft

The NASA Orion manned spacecraft will replace the NASA Space Shuttle for getting astronauts to low earth orbit, moon and Mars and returned to the earth safely. It also serves as a crew escape vehicle at the ISS to increase astronaut safety The NASA integrated, vehicle health management (IVHM) program has been adopted by many segments of the aerospace industry. The IVHM is the tool to prevent catastrophic failures by identifying the equipment that will fail prematurely for replacement, thus preventing/eliminating surprise equipment failures from threatening both safety and mission success. Due to the extreme environments experienced by both the launch vehicle and its payload (s) during launch and while operating in space the space industry often rejects most advancements made in other aerospace industries in technology related to and improving reliability. Personnel on the ground responsible for launch vehicle and spacecraft receive limited technical information from an on-board telemetry system that generates routes engineering data, whose accuracy is suspect, available from spacecraft when both planned and unplanned events occur. Included in this paper are examples of spacecraft equipment failures that have been accurately predicted to occur or prevented from occurring. We provide many examples of equipment telemetry measurements used to measure spacecraft equipment usable life. The equipment with a measured usable will fail prematurely with certainty. The equipment that will fail prematurely should be replaced at the factory or if the spacecraft is in space, the failure can be managed to a positive conclusion. This paper summarizes the use of a prognostic and health management program including using predictive algorithms to measure equipment life and predict remaining usable life with certainty on the many NASA space missions as specified in the NASA IVHM technical plan published in 2009. The non-Markov reliability paradigm for measuring equipment usable life was specifically developed for preventing surprise catastrophic equipment failures. It is already in use on the Air Force F-35 Joint Strike Fighter. The decision to use a PHM is in part, based on the results from our prognostic analysis we completed on the NASA GSFC Extreme Ultra Violet Explorer LEO space science satellite and the NASA Space Shuttle Challenger and Columbia accidents. Our results identified the information that was present but was ignored for a variety of reasons that would have prevented both Space Shuttle accidents if the information had been properly interpreted.