Risk-value optimization of performance and cost for propellant production on Mars

Abstract

The nominal two-and-a-half year round-trip Mars mission requires extensive infrastructure to transport and safeguard its human crew, thus requiring large amounts of Initial Mass in Low Earth Orbit (IMLEO). Any technologies that can reduce this load may have the potential to realize dramatic savings in overall architecture cost. One such technology is the in-situ production of propellant for the Mars ascent vehicle utilizing Martian resources, such as the atmosphere, rather than transporting the propellant from the Earth's surface to the Martian surface. This topic has previously been studied on the basis of the reduction of the IMLEO, because of the assumption that the reduction in IMLEO would lower Earth-to-orbit launch and space transportation costs more than the increase in in-situ propellant production system production and operations cost. However, with low-cost commercial launch now being considered by NASA, the costs of propellant production on Mars may not be a positive trade for these lower launch costs. The objective of this research is to evaluate, under uncertainty, an optimal ISPP system for a human-to-Mars mission. To do this, the necessary ISPP approaches and corresponding Mars transportation system architecture (consisting of the Earth-to-orbit, in-space, Mars descent, and ascent transportation systems) must be modeled in such a way that the effects of uncertainty in their performance and mass can be evaluated. With this framework, the sensitivity of the mass, power, volume, and cost of each ISPP approach and transportation architecture includes the uncertainty of its modeling, and the most relevant system architecture dependent parameters for each technology are identified for future research. Additionally, technologies will be compared using this framework to determine which has the greatest chance of success at having the least cost; this design approach will yield a ranked list of preferred ISPP approaches as compared to a non-ISPP baseline approach. The final product of this research is an evaluation of each technology, including the uncertainty in its modeling parameters, as well as a ranked comparison of multiple ISPP approaches. From this, recommendations for an overall approach to Mars ISPP, as well as the most important technologies to be further researched, will be presented. This research serves as a guide to future mission planners, decision makers, and technology investors in planning the best path for the eventual human exploration of Mars.