Characterization and Discrete Element Modeling of LHS-1 Lunar Highlands Simulant

NASA's Artemis program aims to land the first woman and next men on the Moon while simultaneously working toward sustainable lunar exploration. A comprehensive understanding of the engineering properties and behavior of the lunar regolith is required for this program. As the amount of lunar regolith brought back to the earth is quite small, various lunar regolith simulants have been developed to simulate lunar regolith. In this work, LHS-1 Lunar Highlands Simulant, a high-fidelity, mineral-based simulant, is characterized for its physical and mechanical properties using conventional techniques such as sieve analysis, hydrometer analysis, and direct shear test. A discrete element method (DEM) model is then developed to simulate the grading-dependent behavior of LHS-1 in direct shear testing conditions. The DEM model is developed using the open-source software LIGGGHTS-INL and is calibrated and validated using characterization data of LHS-1. To the best of the knowledge of the authors, this is the first effort to develop DEM model for LHS-1. The validated DEM model can be used to simulate and predict the behavior of LHS-1 in complex systems such as the regolith-drill systems for more advanced applications.