Development of Fluid Power Techniques for Lunar Environments 650307

Power-amplified actuation systems for space vehicles are becoming a necessity with the advent of manned, lunar-mission space vehicles. Various actuation system types must be evaluated to appraise their ability to withstand the severe low-temperature and hard-vacuum environments that will be encountered. Problems must be solved through extensive analysis and breadboard test programs to ensure optimum subsystem selection and prove reliability before detailed design of space vehicles.

This paper reviews a lunar-vehicle hydraulic system analysis and development program. The actuation tasks of many types of advanced space vehicles are determined. Subsystem trade studies presented for some of these tasks include evaluation of hydraulic, pneumatic, and electromechanical approaches to control requirements determined. The problems of developing hydraulic systems for long stay times in severe lunar environments are discussed. New fluids and elastomeric seals for servo-actuation systems operating in the fluid temperature range of -150 to +275°F are discussed, as are thermal protection techniques to provide adequate performance in -240 to +275°F environments. Development of a breadboard test system, designed to solve some of the problems, is presented with the plans for an extreme-low-temperature hard-vacuum system performance test program. Recommendations concerning the role that fluid power systems will play on future space vehicles are presented in the conclusions.

Much of the work summarized is based on that accomplished under NASA (MSFC) Contract NAS8-11722.