Blueshift, LLC doing business as Outward Technologies proposes to develop a Discrete Element Method (DEM) modeling framework using open-source software to simulate the combined thermal and mechanical interactions between rovers and regolith in Permanently Shadowed Regions (PSRs) at the lunar poles. This proposed set of numerical tools innovates on the current state of the art by explicitly solving for both thermal and mechanical interactions between rover components and regolith, and by the inclusion of volatiles such as water ice of multiple forms (e.g. vapor deposited “frost”, blocky deposits, and icy regolith mixtures) in a grain-based DEM model. Rover components including probes, drills, wheels, and soil sampling equipment will be simulated using coupled FEM software to reduce computation time. A coupled thermo-hydro-mechanical model will further be explored for its suitability in simulating volatile phase change and gas transport through cryogenic regolith as represented by a bonded-particle DEM. These numerical modeling capabilities will be integrated within a single, easy to use simulation framework for approximating thermal and mechanical interactions between rovers and regolith across ranges of possible conditions which may be encountered in and near PSRs on the Moon. These combined numerical tools will enable NASA and its partners to inexpensively evaluate hardware designs for lunar ISRU missions aimed at exploration and prospecting for volatiles. These improved modeling capabilities will further de-risk planned missions to the lunar south pole by identifying successful control strategies and hardware designs for ISRU sampling, material handling, increased rover operability, and surviving the lunar night, leading to more rugged and capable rovers for lunar polar missions while reducing their costs related to development and testing.
This project leads to many potential NASA applications including the design and evaluation of rovers and sampling equipment for use in lunar polar regions for ISRU prospecting and exploration missions. The proposed DEM-FEM coupled software and its associated advancements will bring additional knowledge to the challenges faced in lunar polar missions while presenting a low-cost evaluation tool for hardware design, rover control strategies, and volatile sampling. These improvements will lead to lower cost lunar ISRU missions with reduced risk.
By increasing the sampling of the high-dimensional design space of DEM microscale input selection, Outward Technologies will be able to gain a competitive advantage in thermo-mechanical DEM models related to granular mechanics and will be able to incrementally increase our customer base, tailoring services to companies in the field of powder handling, pharmaceuticals, oil and gas, and mining.