17-07-2017, 10:12 AM
NASA's Integrated Vehicle Health Management (IVHM) experiment for X-37 was intended to run IVHM software aboard the X-37 spacecraft. The X-37 is an unmanned vehicle designed to orbit the Earth for up to 21 days before landing on a runway. The objectives of the experiment were to demonstrate the benefits of IVHM in flight to the operation of a reusable launch vehicle to advance the level of technological preparation of this IVHM technology in a flight environment and demonstrate that the IVHM software could operate Computer Management Vehicles. The objective of the experiment was to perform real-time fault detection and isolation for the X-37 electric power system and electromechanical actuators. The experiment used Livingstone, a software system that performs the diagnosis using a reasoning approach based on the qualitative model that looks for system-wide interactions to detect and isolate faults. Two of the challenges we faced were making this research software more efficient to fit within the limited computing resources available to us on the X-37 spacecraft and to modify it to meet the software security of the X-37. X-37 Requirements. Although the experiment is not funded, the development effort resulted in significant improvements in Livingstone's efficiency and safety. This paper reviews some of the details of modeling and integration efforts and some of the lessons learned.