CO2 Removal from Mars EMU

CO2 control for during ExtraVehicular Activity (EVA) on mars is challenging. Lithium hydroxide (LiOH) canisters have impractical logistics penalties, and regenerable metal oxide canisters weigh too much. Cycling bed systems and permeable membranes that are regenerable in space vacuum cannot vent on Mars due to the high partial pressure of CO2 in the atmosphere. Although sweep gas regeneration is under investigation, the feasibility, logistics penalties, and failure modes associated with this technique have not been fully determined. TDA Research, Inc. proposes to develop a durable, high-capacity regenerable sorbent that can remove CO2 from the breathing loop. The system design allows sorbent regeneration at or above 6 torr, eliminating the potential for Martian atmosphere to leak into the regeneration bed and into the breathing loop. In the proposed work, we will synthesize sorbent formulations to remove CO2 from the breathing loop of the PLSS and evaluate the performance of these sorbents under representative conditions (adsorption and regeneration under sub-atmospheric pressures across the desired temperature differential). We will explore the methods to prepare these sorbents on engineered structures to increase durability and promote better heat transfer during the thermal regeneration process. We will perform a minimum of 1,000 adsorption/regeneration cycles to demonstrate the life of these sorbents. Finally, we will carry out a detailed engineering analysis and design to assess the technical viability of the concept. More »