Space Environment Facility for Electric Propulsion Systems Research

A facility containing 15- and 25-foot-diameter space-environment tanks and support equipment is described. The facility is designed for testing ion and plasma thrustors, 10 sub -7 spacecraft, and related components at pressures in the 10 torr range. Total pumping capacity in the 10 sub -5 torr range for air has been measured at 250 000 liters per second and for hydrogen at 660 000 liters per second. The pumping systems and 28 000- square- foot liquid-nitrogen- cooled condenser are described. Data are presented on an auxiliary fast pumpdown tank that simulates ambient pressures encountered during a booster launch to 10 sub -6 torr range in approximately 2 minutes. Pertinent information concerning a spin test apparatus and thrustor installation method is also included. An electrical and instrumentation system is described consisting of 2 megawatts of 20-kilovolt direct- current power, a 2000-cable patch board network, a 600-channel thermocouple system, and a 400-channel digital data recorder. An annunciator system is provided to indicate status of operating equipment. Some aspects of safety are considered, including interlocking, personnel protection, and procedures.