Development and Test of a Lunar Excavation and Size Separation System (LES³) for the LUVMI-X Rover Platform

Future sustained human presence on the Moon will require us to make use of lunar resources. This in-situ resource utilisation (ISRU) process will require suitable feedstock (i.e., lunar regolith) that has been both acquired and prepared (or beneficiated) to set standards. Acquisition of pre-processed regolith, is an often overlooked engineering challenge in the demanding and low-gravity environment of the lunar surface. Currently, regolith excavation and size separation are often developed independently of each other. Here, we present the Lunar Excavation and Size Separation System (LES³), which is an engineered one-system solution to combine the acquisition of lunar regolith as well as separate it into two distinct size fractions, and therefore, can assist to define the quality of the feedstock material for ISRU processes. Intended for use with a lightweight (40–60 kg) lunar rover (LUnar Volatiles Mobile Instrumentation-X; LUVMI-X) currently under development, the mechanism utilises vibrations to reduce excavation forces and facilitate size separation. Low excavation forces are crucial for lunar excavators to be deployable on lightweight robotic platforms as limited traction forces are available. The rationale behind the mechanism is explained, its capabilities in the support of science and ISRU are showcased, and results from several laboratory test campaigns, including tests of gravitational dry sieving of different regolith simulants, are presented. The LES³ can excavate up to 100 g in a single charge while maintaining excavation forces of less than 8 N and having a mass of less than 2 kg. Finally, areas of improvement for a second iteration of the design are presented and explained. The LES³ proof of concept shows that combining of regolith excavation and size-separation in a single mechanism is feasible.