CPHTS Hardware Development for the EOS AM Spacecraft Instruments

NASA's Earth Observing System (EOS) Program will place a series of unmanned polar-orbiting spacecraft in low-earth orbit to support a variety of scientific and Earth-observing missions. The EOS AM spacecraft has a requirement for an advanced heat transportation system for thermal energy. A Capillary Pumped Heat Transportation System (CPHTS) using Capillary Pumped Loop (CPL) technology was selected to accommodate the instruments requiring advanced heat transport. The CPHTS is comprised of several major subassemblies: CPL Coldplate for instrument heat transfer interface; Heat Pipe Heat Exchanger (HPHX) used to exchange energy from the CPL loop vapor and the radiator mounted heat pipes; Constant Conductance Heat Pipes (CCHP) used to interface with the HPHX and distribute the over the radiator area; Non-Condensible Gas Trap (NCG Trap) used to remove non-condensible gases from the subcooled CPL liquid returning from the HPHX; and Reservoir used to control liquid inventory and system temperature setpoint. This paper describes the hardware design and development for the Coldplate's, HPHX's, CCHP's, and NCG Traps.