High Temperature Mechanically Pumped Fluid Loop for Space Applications – Working Fluid Selection

Mechanically pumped single-phase fluid loops are well suited for transporting and rejecting large amounts of waste heat from spacecraft electronics and power supplies. While past implementations of such loops on spacecraft have used moderate operating temperatures (less than 60oC), higher operating temperatures would allow equivalent heat loads to be rejected by smaller and less massive radiators. A high temperature (100 to 150oC) mechanically pumped fluid loop is currently being investigated at the Jet Propulsion Laboratory (JPL) for use on future Mars missions. This paper details the trade study used to select the high temperature working fluid for the system and the initial development testing of loop components.