UPREB: Universal Predictors of Regolith Behaviour – Concept and Overview

To develop successful missions involving In-situ Resource Utilisation (ISRU), such as extraction of oxygen or metals from regolith or use of regolith in a lunar construction, fundamental knowledge gaps regarding the rheology of regolith on the Moon must be closed. The complex mechanical behaviour of the irregularly shaped and sharp-edged regolith particles, which is particularly influenced by the extreme lunar conditions, is currently not well understood. To harness the full potential of lunar regolith, it is essential to understand how it behaves during handling, transportation, and processing. With this in mind, we report on a new approach we have developed to understand and predict the flow behaviour of regolith on the Moon. Earth-based tests on regolith simulants and initial numerical models predicting its behaviour in different settings represent the starting point, allowing us to identify flow-relevant characteristics of regolith in Earth’s environment. In parallel, a digital twin of lunar regolith will be generated from 3D tomograms, chemical composition data and observed physical interactions, with the intention to perform virtual materials testing on this digital twin using the developed numerical models. These activities lead to flow and material tests using regolith simulants in a parabolic flight campaign, where the harsh lunar conditions are recreated with a dedicated testing facility, i.e., a vacuum and plasma chamber operating at appropriate temperatures and 1/6 g. Regolith rheology data collected in this setting will be used to validate and improve the numerical models and the digital twin. The validated numerical models and digital twins are key to generalise the methodologies developed on the ground and in the parabolic flight to the behaviour of lunar regolith on the Moon. Future lunar missions will provide more experimental data and allow further refinement and validation of the predictive models.