Vertical Transport of Lunar Regolith and Ice Particles Using Electrodynamic Traveling Wave

The existence of water (ice) has been discovered in the polar regions of the Moon, and it is expected to be used to support life for astronauts and to provide the raw material of hydrogen and oxygen. Because the exact location of ice, including the depth from the lunar surface, chemical and physical forms, and the amount of water, is unclear, the Japan Aerospace Exploration Agency (JAXA) is planning to search for ice directly by operating an uncrewed rover on the Moon. A long drill, approximately 1.5 m long, will be screwed in the regolith layer, and regolith mixed with ice will be captured and transported from the lower deep portion of the regolith layer to chemical and physical analyzers mounted on the rover. A long-range technology for vertical ice transport is indispensable for ice exploration. To this end an electrodynamic sampling system that can transport crushed ice particles vertically up to the 1.5-m height is developed. Parallel ring electrodes were attached to a collection tube, and four-phase rectangular wave high voltage was applied to the electrodes to form an electrodynamic traveling wave. Ice particles were transported upward synchronized to the traveling wave. It was demonstrated that this system could be used to capture and transport crushed ice particles, as well as regolith particles. Performance in the lunar environment (1/6-G and absence of air drag) was evaluated by the numerical calculation based on the modified discrete-element method.