Microwave extraction of water from lunar regolith simulant

Nearly a decade ago the DOD Clementine lunar orbital mission obtained data indicating that the permanently shaded regions at the lunar poles may have permanently frozen water in the lunar soil or 'permafrost'. Currently a Lunar Lander Exploration Program is expected to land at the lunar pole to determine if water is present. The detection of water from the permafrost is an important goal for NASA. Extraction of water from lunar permafrost would be a valuable In-Situ Resource for Utilization (ISRU) in human life support and as a fuel. The use of microwave processing could permit the extraction of water without the need to dig, drill, or excavate the lunar surface. Microwave heating of regolith is potentially faster and more efficient than any other heating methods due to the very low thermal conductivity of the lunar regolith. Also, microwaves can penetrate into the soil permitting water removal from deep below the lunar surface. A cryogenic vacuum test facility was developed for evaluating the use of microwave heating and water extraction from a lunar regolith simulant. Water was collected in a cryogenic cold trap even with soil temperature well below 0 degrees C. The results of microwave extraction of water experiments will be presented.