Measurement of force to excavate extraterrestrial regolith with a small bucket-wheel device

The plans for NASA missions to the moon and mars require excavation of regolith (soil) especially to realize the benefits of in situ resource utilization. Micro-scale excavators might be good candidates for these missions since they will significantly reduce launch mass. Even though the excavator might be small, it still has to be capable, reliable, and power efficient. This paper reports on research to measure the amount of force such a small excavator must generate to be effective. Previous research indicates a bucket-wheel excavator is a good candidate excavator tool; so, we developed a laboratory-scale apparatus to measure the horizontal and vertical forces and power required to excavate simulated regolith with a micro-scale bucket wheel. This paper describes the apparatus and presents the results of measurements along with a comparison with modeled forces, concluding that micro-excavators are feasible candidates for ISRU work. (C) 2009 ISTVS. Published by Elsevier Ltd. All rights reserved.