Utilization of Lunar Resources for Human Mars Missions

Abstract

Proposed human missions to Mars require a large initial mass in low Earth orbit (IMLEO). Delivering this mass to orbit requires several launches of a heavy lift launch vehicle, such as the previously proposed Ares V, or many launches of a smaller vehicle and significant on-orbit assembly. A significant fraction of the launch mass is propellant for the in-space propulsion system. Removing the propellant mass from the launch manifest has the potential to significantly reduce the number of launches required for a Mars mission. One proposed method for replacing the launched propellant is to utilize propellant manufactured from lunar resources. If it is possible to produce the oxygen required from lunar regolith, and deliver it to the Mars transfer vehicles (MTV) in an economical manner, dramatic cost savings for the overall architecture could be realized. This study examined the requirements for the manufacture and transport of oxygen from lunar regolith for the fueling of a hydrogen-oxygen MTV. The goal of the study was to determine what combination of architectural elements best facilitates the use of lunar derived resources for production of propellant for the MTV. The relevant surface and transportation systems were modeled, with several different architectures considered under a variety of assumptions. These various architectures were compared to two baselines: the nuclear thermal rocket driven MTVs from the Mars Design References Architecture 5.0, and a chemical propulsion baseline modeled using this study’s tools, with all of the propellant launched from the Earth’s surface. The bases for comparison included the estimated cost of the architectures, the reliability of the architectural elements, and the total launch manifest required for a multi-mission campaign. It was found that under an optimistic set of assumptions, one architecture outperformed both baselines, while three In-Situ Resource Utilization (ISRU) architectures outperformed the nuclear baseline.