Refuge Sphere Lunar Village — Life Support Systems and Advanced Construction: In-Situ Resource Utilization, Thermal Energy Storage, 3D-Printed Regolith Structures, and Elimination of Large-Structure Launch Constraints

Complete technical design document for the life support systems and advanced construction architecture of the Refuge Sphere Lunar Village (DOI: 10.5281/zenodo.19920193). Energy architecture: Stirling engines exploiting the surface/subsurface thermal gradient (−25 °C at 1–2 m depth) providing 4–6 kW continuously H24; liquid sodium thermal energy storage system heated to 500–700 °C by solar concentrators during the 14-day lunar day and discharged through Stirling engines during the 14-day lunar night (ΔT up to 870 °C, estimated output 10–13 kW); photovoltaic panels at South Pole; ISRU hydrogen fuel cells as backup. Vanadium dioxide photochromic coating and piezoelectric self-cleaning on collector surfaces. Closed-loop life support: hydroponic food production; Sansevieria trifasciata (CAM metabolism, nocturnal O₂ production); Epipremnum aureum (VOC removal); Spirulina algae bioreactors on transparent wall panels; composting; passive water recovery from air condensation on geothermal heat exchanger; LED circadian lighting; virtual window display panels for crew psychological wellbeing. ISRU processing chain: hydrogen reduction of ilmenite (FeTiO₃ + H₂ → Fe + TiO₂ + H₂O, 800–1000 °C) + water electrolysis for O₂ and H₂ recovery. Iron oxide and regolith sintered into curved interlocking blocks by autonomous rover — enabling in-situ construction of the Ø10m Phase 2 hub without launching pre-assembled structural panels. Launch mass saving vs CFRP panel approach: ~48,500 kg. Regolith blocks also provide additional radiation shielding for inter-module corridors. Full system integration table and mass budget included.