Assessing the economics of asteroid-derived water for propellant

Abstract

This paper assesses the economic viability of using asteroid-based resources to support government and commercial space missions between 2031 and 2050. The economic viability of asteroid resources for space missions is driven by three major factors: the cost of the asteroid mining and in-space processing infrastructure; the total demand for the in-space resources over which the infrastructure cost is spread; and the competing cost of launching those same resources from Earth. We assess that water for on-orbit propellant is the only asteroid-derived resource that may become economical in our period of interest. We estimate demand for asteroid resources by investigating the exploration plans of NASA and other space agencies, as well as potential sources of demand from the private space sector. To estimate a total cost for delivery of asteroid-based propellant, we posit an asteroid mining architecture that can service the demand we identified and provide cost estimates for the elements within the architecture. Finally, we estimate the costs of delivering equivalent amounts of the demanded resources from Earth instead of from an asteroid. We estimate that demand for LOX/LH2 propellant in space over this 20-year period is about 6000–10,000 metric tons. We estimate that the cost of delivering this propellant from an asteroid to low-Earth orbit (LEO), $2–3000 per kilogram, could be comparable to the estimated costs of delivering propellant to LEO using a Falcon Heavy. Deprived of the market in LEO, we estimate the cost of delivering asteroid-derived propellant to lunar orbit is at least $3600 per kilogram.