Lunar Organic Output Neutralization and Advanced Recovery (LOO-NAR): A conceptual framework and feasibility review for human waste pyrolysis

Long-duration lunar habitation will require technologies that convert crew-generated wastes into recoverable resources while operating within strict limits on mass, power, volume, reliability, and resupply. Human fecal waste and associated sanitation materials remain a major unresolved stream because current spacecraft systems emphasize collection and containment rather than downstream conversion. This review assesses the potential applicability of pyrolysis to lunar human-waste management by synthesizing evidence from human feces, simulated fecal material, fecal sludge, biosolids, sanitation-related materials, and relevant terrestrial analogs. The analysis examines torrefaction, intermediate-temperature pyrolysis, and high-temperature conversion with emphasis on product yields, gas composition, biochar properties, aqueous pyrolysis liquid treatment, contaminant fate, reactor design, and habitat integration. Across the literature, pyrolysis shows potential to support waste stabilization, moisture recovery, solid-waste reduction, biochar production, and non-condensable gas generation, but performance varies with feedstock composition and operating conditions. Based on this evidence, the review introduces Lunar Organic Output Neutralization and Advanced Recovery, or LOO-NAR, as a mission-adaptive conceptual framework linking sealed collection, pre-drying, staged thermal conversion, product separation, gas cleanup, heat recovery, water treatment, and selective resource use. The framework is designed to allow treatment intensity and product recovery to increase as mission duration and resource demands increase. Human fecal waste and sanitation materials form the baseline feedstock, with future potential for compatible organic outputs. Key gaps include reduced-gravity and vacuum validation, mixed-feedstock variability, contaminant control, product quality, long-duration reliability, and integrated systems and equivalent system mass evaluation. These findings identify a focused validation pathway for assessing the potential future lunar application of LOO-NAR.