The NASA application for this technology will be as Flight Hardware for deployment in support of future, long duration exploration missions to Mars or other Near Earth Objects (NEOs) where reclamation of in situ resources and reduction of the logistics burden will be highly valued. The Microchannel Sabatier Reactor System will efficiently reclaim oxygen (as water) and produce a propellant (methane) from atmospheric or frozen deposits of carbon dioxide on Mars or other NEOs using only hydrogen. The Microchannel Sabatier Reactor System (MSRS)provides a fundamental starting point for planetary habitats where precursor robotic staging can prepare the road for subsequent human missions by reducing the logistics burden. The MSRS technology can be used in the mitigation of carbon dioxide released into the atmosphere as a greenhouse gas. In a broader sense, in any situation where reaction kinetics and the thermodynamic driving force of a reaction are in thermal conflict, a graded temperature reactor or reactor array can be utilized to efficiently drive composition closer to the desired products. Additionally, a fully developed microchannel reactor technology will enable greater thermal control over highly exothermic/endothermic chemical reactions, which will improve selectivity and catalyst stability. A monolithic microchannel reactor with two parallel paths can also be used to mate exothermic and endothermic reactions eliminating costly and wasteful external heat transfer components.