Combined H2O/CO2 Solid Oxide Electrolysis for Mars In Situ Resource Utilization

Abstract

Mars sample return missions and eventual human missions will both benefit from using Martian resources to produce Earth-return propellant and life support consumables. A new architecture for an in situ propellant production plant is introduced that utilizes solid oxide electrolysis to perform the combined electrolysis of both water and carbon dioxide. The proposed system produces methane via a Sabatier reactor and oxygen via electrolysis in the optimal oxidizer-to-fuel mixture ratio with the capability to produce extra oxygen for life support needs. Each major component of the combined electrolysis/Sabatier architecture is modeled to assess the feasibility and size of such a propellant production plant. Sample return and human missions are analyzed with the models. Results demonstrate that combined electrolysis enables a competitive system for in situ resource utilization as well as an ease of scaling for sample return vs human missions. When compared to published data of other oxygen/methane-producing architectures, the proposed system is shown to be less massive while comparable in power. Other advantages of implementing combined electrolysis in a propellant production plant are discussed.