Exploiting the Reliability-Maintenance Relationship for Manned Missions of Extended Duration 640314
Traditional reliability design concepts, and even extensive redundancy, fail to achieve the necessary reliability potential required for long term orbital and space missions. A design and operational approach allowing system restoration through maintenance can significantly arrest reliability degradation for missions extending up to several years This paper discusses some facets of the reliability-maintenance relationship, including accessibility, spares, crew duty cycle, and design standardization. An example application demonstrates the effectiveness of the maintenance approach while utilizing conservative state-of-the-art failure rates. Although the concepts described are somewhat theoretical, analogies in past experience substantiate them.