Preprint Calculates Local Manufacturing Cuts Mars Settlement Freight by 58% for 1000 Residents

The analysis compares Earth resupply, robotic predeployment, and in-situ resource utilization under fixed constraints of 1% annual population growth and specific equipment retention times. It derives a requirement of 1.8 tonnes of replacement and expansion hardware per resident-year and shows that localized manufacture increases mean electricity needs from 11.8 MW to 19.5 MW. Radiation shielding mass of 63,000 tonnes per hectare and 224-m radius habitats for 2 rpm artificial gravity further favor modular, locally shielded rotating structures. Wastewater storage must be sized to 1.4 times inflow to survive repeated 10-day outages. Health data gaps on lifelong partial gravity, mixed radiation fields, gestation, and fertility remain unresolved, limiting claims of demographic self-sufficiency. The work is a modeling study without new empirical data; a real 100-ton pilot demonstration within the next decade would test the freight-reduction projection.