Abstract: A terrestrial thermal vacuum system that tests spacecraft by developing a thermal balance having a margin of error of less then 5% and preheats spacecraft prior to terrestrial thermal vacuum testing are disclosed. In operation, working fluid is pumped through a cooling plate that receives heat from the spacecraft and then passes through a heat exchanger where the heat is discarded. The temperature of the working fluid is measured at both the supply and return portions of the cooling plate and the flow rate determined for the fluid. From these measurements an initial heat flow from the spacecraft is determined and an equivalent amount of heat is added back to the spacecraft at the appropriate location. The process is repeated until thermal balance is achieved. Also disclosed is a method for designing the cooling plate used by the above described system.

Abstract: A mechanically pumped heat pipe having an evaporator section and a condenser section disposed at a location below the evaporator section. A solenoid actuated cavitation-free mechanical pump returns a working fluid from the condenser section to the evaporator section. An armature connected to the piston head of the mechanical pump is disposed inside the condenser section and the solenoid coil is disposed outside of the condenser section in the vicinity of the armature permits the piston head to be periodically reciprocated without any electrical or mechanical feedthroughs.