Analyzing the Economic and Environmental Trade-offs of In-Situ Resource Utilization (ISRU)

As lunar surface missions evolve from short-term missions to sustained habitation, optimizing resource logistics becomes critical. This paper presents a simulation-based analysis comparing Earth-based resupply and In-Situ Resource Utilization (ISRU) for supporting a 4-person lunar crew over three years. A custom, modular simulation environment was developed to capture costs, CO₂ emissions, system failure risks, terrain-aware mining operations, and policy levers such as carbon taxes and maintenance subsidies. Earth resupply costs grow linearly, reaching $500 million by year three and emitting 57 million kg of CO₂. ISRU, while requiring an $800 million setup and $10,000/day in maintenance, maintains stable emissions ( 42 million kg) and cost profiles, albeit with higher technical risk due to lower TRL. Modeling indicates that ISRU does not yield a return on investment until 30 years after deployment, far beyond typical mission timelines, and policy levers like a 15% carbon tax or 30% maintenance subsidy are insufficient to offset the initial costs of setting up ISRU operations. Notably, simulations reveal that ISRU operations are highly spatially compact, extracting all necessary ice within a 0.761 km² permanently shadowed region, minimizing lunar environmental disruption and potential territorial disputes. These findings indicate that, unless crew sizes increase, mission timelines lengthen, or lunar water ice is used for more than daily crew needs, ISRU cannot be economically justified in near-term missions. This work provides a repeatable framework for assessing lunar resource strategies under both engineering and economic constraints.