The lunar soil contains approximately 43% oxygen as oxides, which could be extracted to provide oxygen for future Lunar bases. One method of extracting the oxygen is hydrogen reduction: the lunar regolith is heated using a solar concentrator to approximately 1050°C and exposed to hydrogen gas. Water is formed from the reaction and the oxygen is recovered by electrolysis of the water. To minimize mass, it is desirable for the solar concentrator to supply heat to more than one reactor. ACT is developing a thermal management system using Constant Conductance Heat Pipes (CCHPs) and Pressure Controlled Heat Pipes (PCHPs) solar receiver for this process. A PCHP is similar to a Variable Conductance Heat Pipe and permits control over heat pipe operation by varying the gas quantity or the volume of the gas reservoir. The PCHP solar receiver is designed to accept, isothermalize and transfer the solar thermal energy through CCHP’s to multiple reactors for oxygen production. The final system will use sodium as the working fluid, with a Haynes 230 envelope material. This paper will report on the transient modeling and design and fabrication of a lower temperature system that was used to verify performance of the overall design.