Pressure Sintered icy lunar regolith Simulant (PSS): A novel icy regolith simulant production method

Abstract

Due to the lack of in-situ geotechnical data from lunar Permanently Shadowed Regions (PSRs), it is important that a versatile icy regolith simulant be used in terrestrial development of rovers, excavators, and water extractors intended for operating in lunar PSRs. Fine tuning of existing icy regolith simulant properties is not possible; for a given water percentage they either exhibit strength similar to high strength concrete or to sand, but nothing in between. In this work we present a novel method for creating icy lunar regolith simulant, called Pressure Sintered icy lunar regolith Simulant. PSS is notable for being created from solid phase water, and for being tailorable to a wide range of mechanical properties through the sintering of ice and regolith grains, induced by applied uniaxial pressure. Samples were produced at 0%, 2%, 5%, and 10% ice content as measured by weight, and were pressed at four different pressure levels. Penetration resistance was measured for each of these samples, and it was observed that a continuous distribution of penetration resistance levels could be achieved by varying the applied pressure and ice content. Significant relaxation of samples during the pressing process was also observed. The production method for PSS is included, and is followed by the penetration resistance and density results along with some qualitative observations. Finally, we make recommendations for the use of PSS in terrestrial testing activities.