Inflight maintenance - Design for the future.

Extensive studies in the field of in-flight maintenance are reviewed. The progress made in this technology, and the design considerations essential for meeting the constraints imposed by a manned space mission lasting several years are outlined. Concepts for the design and packaging of maintainable systems are described. The requirement of full redundancy, with capability to perform in-flight maintenance, to provide reliability in long-duration missions is demonstrated from a reliability analysis.