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Advanced planning within NASA is currently being focused on a manned Space Station as the next major step in the U.S. space program. Capabilities such as evolutionary growth on-orbit, indefinite life through maintenance, and flexibility to accommodate a time-varying complement of users constitute requirements for the Space Station thermal management system that are radically different from those of previous or current missions. Anticipating the need to identify the technology required for long-life, high-power orbital platforms/stations, NASA began a multicenter thermal management system technology development program in 1979. This program, sponsored by the Office of Aeronautics and Space Technology, has continued to evolve in parallel with the increasingly detailed planning for a Space Station program.

The current design base of the Space Shuttle Orbiter employs hydraulic actuation for control of aerosurfaces, engine thrust, engine thrust vector, brakes, and landing gear functions. As early as 1972, electromechanical actuation (EMA) was considered as an alternative system. As a result of continued advances in technology development, studies now indicate that EMA is a more attractive alternative. Major advantages are weight reduction, striking improvement in energy efficiency, easier maintenance, and a cleaner vehicle. The results of a system study advocating EMA for the Orbiter are presented. Emphasis is placed on a clear understanding of the relationships between mission requirements and design parameters. EMA system energy requirements are compared with those of the existing hydraulic system. Detailed discussion of the synthesized EMA system is limited to the aerosurface actuators. The design is consistent with the Orbiter “fail operational,” “fail safe” redundancy requirement.

In 1985, the Man-Systems Division at the Johnson Space Center initiated a program for the development of a whole body shower suitable for operation in a microgravity environment. Supporting this development effort has been a systematic research program focused on four critical aspects of the design (i.e., human factors engineering, biomedical, mechanical, and electrical) and on the interfaces between the whole body shower system and the other systems to be aboard the Space Station (e.g., the water reclamation and air revitalization systems). A series of tests has been conducted to help define the design requirements for the whole body shower. Crew interface research has identified major design parameters related to enclosure configurations, consumable quantities, operation timelines, displays and controls, and shower and cleanup protocols.