Improving the Recovery of Oxygen from Carbon Dioxide

Long duration human exploration missions far from Earth will need to recycle life support consumables for missions to be affordable. The state-of-the-art for atmosphere revitalization is not closed. Although the Sabatier Carbon Dioxide Reduction Assembly (CRA) on the International Space Station has the capability for full closure, there is insufficient metabolic hydrogen available from the Oxygen Generation System to recover more than about 47% of oxygen from carbon dioxide. Methane is produced as a byproduct, which consumes hydrogen that would otherwise be available to reduce additional carbon dioxide. Several strategies are available to increase the fraction of oxygen recovered. One is to pyrolyze methane to recover the lost hydrogen. Others are to replace the Sabatier with a new processor that is more efficient. Candidates include Bosch, Carbon Dioxide Electrolysis and Co-Electrolysis, and electrochemical reactors. The National Aeronautics and Space Administration (NASA) has recently made investments in several of these technologies which will be described in this presentation.