There are many open science questions in space resource utilisation due to the novelty and relative immaturity of the field. While many potential technologies have been proposed to produce usable resources in space, high confidence, large-scale design is limited by gaps in the knowledge of the local environmental conditions, geology, mineralogy, and regolith characteristics, as well as specific science questions intrinsic to each process. Further, the engineering constraints (e.g. energy, throughput, efficiency etc.) must be incorporated into the design. This work aims to summarise briefly recent activities in the field of space resource utilisation, as well as to identify key knowledge gaps, and to present open science questions. Finally, future exploration priorities to enable the use of space resources are highlighted.
Spacecraft using combustion engines require substantial amounts of oxygen for their propellant. The Moon could be a source of oxygen for rocket propellant, since the material composing the lunar surface can be processed to extract oxygen. However, little is known about overall energy requirements of the processes described in the literature for oxygen extraction from lunar regolith. This knowledge gap constrains the planning of lunar missions, since the scale of energy infrastructure required for oxygen production facilities is not well characterized. This study presents an energy consumption model for oxygen production via hydrogen reduction of the mineral ilmenite (FeTiO 3 ). We consider an end-to-end production chain starting from dry regolith as the feedstock. The production includes the following process steps: excavation, transportation, beneficiation, hydrogen reduction, water electrolysis, liquefaction, and zero boil-off storage. The model predicts the energy demand per kilogram oxygen produced based on adjustable parameters for each process step. As expected, the model indicates a strong dependence on feedstock composition. For regolith composed of 10 wt% ilmenite, the model predicts that a total of 24.3 (± 5.8) kWh is needed per kg of liquid oxygen produced. This study confirms that the hydrogen reduction and electrolysis steps have the highest energy requirements in the production chain. Sensitivity analysis reveals that the enrichment factor of the beneficiation process is the most critical parameter for optimizing energy utilization. Overall, this study provides a parameterized end-to-end model of energy consumption that can serve as a foundation for various production systems on the Moon.
Effective beneficiation of lunar regolith for in situ resource utilisation (ISRU) requires size classification methods compatible with vacuum environments, where fluid-based systems are impractical. This study evaluates vibrational segregation as a dry alternative, using sealed-vial excitation under Earth gravity. We test Apollo sample 15601 alongside three lunar simulants (JSC-1, LMS-1, TUBS-M) across multiple vibrational conditions. Micro-CT imaging, Rosin–Rammler modelling, and Jensen–Shannon Divergence analysis quantify internal structure and simulant similarity. Mechanistic models of aerodynamic drag and bulk mobilisation clarify the roles of fines, cohesion, and confinement. A15601 develops a stable three-layer structure driven by fines immobilisation and coarse particle lofting. LMS-1 exhibits similar layering but weaker compaction. TUBS-M provides the closest statistical match, while JSC-1 segregates efficiently but less representatively. Particle size distribution breadth emerges as the primary driver of compaction and stratification. Though tested under terrestrial conditions, the findings offer a framework for evaluating simulants and designing passive ISRU separation systems.