Concept Evaluation of Four Thermal Utility Systems for Low Orbit Spacecraft

Future long term missions in space require the development of a thermal management system capable of collecting, transporting and rejecting waste heat from various components in the nominal temperature range of 0-100°C. A summary of four, two-phase heat transport systems currently under consideration at NASA-JSC is presented. The comparative merits of four systems, which include a mechanically pumped two-phase loop, a capillary pumped loop, an osmotic pumped loop and a loop using a biomorph pump, are presented based on a comprehensive literature review and contractor reports supplied by NASA-JSC.

A recommended conceptual design for a thermal utility using a capillary pumped loop is proposed along with an evaluation of its strengths and weaknesses. System start up and control are discussed and areas of continued investigation are identified.