Systematic formulation of spacecraft health management decisions

New paradigms in space missions require radical changes in spacecraft operations. In the past, operations were insulated from competitive pressures of cost, quality and time by system infrastructures, technological limitations and historical precedent. However, modern demands require operations to meet competitive performance goals. In order to develop rational, demonstrable methods for improving operations, it is necessary to develop systematic definitions for operations. This is because conventional operations are based on operator experience and intuition rather than 'first-principles' decomposition. The first step in developing systematic methods for improving the performance of spacecraft operations is the creation of a formal definition of health management tasks. Next, metrics must be assigned to each task in order to rationally compare the performance of different concepts. This paper presents a candidate health management method, defining six generalized health management decisions. A model-based format for describing spacecraft is proposed, including cost, quality and timeliness performance metrics. These models and definitions were implemented in the Pandora application, automatically creating all decisions. Pandora was applied to a subsystem of the Sapphire satellite; the output compared favorably to the existing operations plan. The. implications of this work are discussed, especially the new operations concept of decision scheduling, and suggestions are given for future work.