Concept and preliminary structural analysis of a crater-covering dome for future lunar habitats

The prospect of establishing a human presence on the Moon has transitioned from the realm of science fiction to an achievable goal. The long-term objective of the Artemis program is to establish a habitat on the Moon that would enable crews to remain on the lunar surface for extended periods. The developmental pathway for such facilities culminates in structures that are manufactured and constructed predominantly from materials sourced on the lunar surface, in alignment with the In-Situ Resource Utilization (ISRU) concept. This paper presents a conceptual lunar habitat that was created by covering 17 m diameter crater in the Mare Tranquillitatis with a structure made from a lunar regolith-based geopolymer. Five shapes of the covering lid were analysed, including: two concave domes with rises of 0.5 m and 1 m; a flat circular slab; and two convex domes with rises of 0.5 m and 1 m. Structural analysis was performed using the Finite Element Method, employing material data from existing literature as well as original strength tests of alkali-activated material based on lunar regolith simulants conducted by the authors. Each model of structure was subjected to dead loads and varying levels of internal air pressure. The numerical analysis revealed the advantages of concave-shaped structures, where internal pressure induced compressive stress within the cross-section, thereby mitigating the risks of air leakage and decompression of the habitat and taking advantage of material in which compressive strength is higher than tensile strength.