Extravehicular Activity (EVA) Maintenance Scenarios for External Distributed Utilities Aboard Space Station Freedom

Innovative on-orbit extravehicular activity (EVA) maintenance techniques are currently being developed to effectively maintain external fluid and electrical functions on board Space Station Freedom. The fluid and electrical distribution system, spread over a distance never before experienced in a space environment, presents some unique challenges to the EVA crewmember during routine and contingency maintenance operations. This paper describes EVA maintenance techniques for the utility distribution system (UDS) developed by flight crew systems engineers in conjunction with system design engineers at McDonnell Douglas Space Systems Company. The paper includes photographs illustrating the high-lights of suited-subject underwater testing at McDonnell Douglas' Huntington Beach facility, which demonstrated the feasibility of using cut and swage techniques for on-orbit fluid line repair. This paper briefly summarizes the status of man-working-in-space concepts as they apply to the UDS.