Transport and mitigation of lunar dust for lunar exploration utilizing travelling wave field

Transport and mitigation technology of lunar dust has been developed utilizing the electrostatic traveling wave applied to the electrostatic conveyer consisting of parallel electrodes. Four-phase rectangular voltage was applied to electrodes because it was most efficient compared to the sine or triangular wave. Traveling-wave propagation was achieved utilizing a set of positive and negative amplifiers controlled by a microcomputer. The power system was designed simple, small, and lightweight for the space application. The transport rate of more than 90% was realized in vacuum with this system under conditions of 700 V voltage and less than 100 Hz frequency. However, very small particles adhered mainly on the electrodes, probably due to the electrostatic image force, and they were not transported. The adhered dust was increased but saturated to the repeated operation. Because it is assumed that the lunar dust is charged by the irradiation of the solar wind and the cosmic ray, it was investigated whether initially charged particles can be transported efficiently with this system. The transport rates with positively charged particles (+0.6 μC/g) and negatively charged particles (-0.6 μC/g) were almost the same to the rate without charge. The power consumption of this system was measured and it was estimated that it takes only 0.08 Wh for once operation of a lm² conveyer. Numerical investigation was carried out with a three-dimensional hard-sphere model of the Distinct Element Method to clarify the mechanism of the transport. This technology is expected to be utilized for the transport and mitigation of lunar dust for the lunar exploration.