Nanofibrillated Cellulose–Regolith Composite Aerogels for Lunar Thermal Insulation

Life support systems in extraterrestrial settings face severe material constraints, demanding innovative in situ resource utilization (ISRU) strategies. One material that merits attention is cellulose, which can be procured in relative abundance from locally generated waste. Here, we present an ISRU approach toward thermally insulating composite aerogels based on nanofibrillated cellulose (NFC) and a lunar regolith simulant. Cellulose fibers are ground by planetary ball milling with lunar highland simulant (LHS-1) into NFC-regolith slurries with subsequent conversion into aerogels by supercritical drying. Comminution of cellulose fibers and LHS-1 particles enable the production of composite aerogels with thermal conductivities as low as 30 mW/m·K. Multiparametric optimization of aerogel properties can be guided by design of experiments (DOE) based on the mass ratios of NFC in water, LHS-1 in aerogel, and amount of milling media. The study illustrates how composite aerogels made of regolith and fibrillated cellulose can provide sustainable routes toward functional materials for lunar habitats and other extraterrestrial resource-limited environments.