In Search of a Carbon Dioxide Removal Assembly for Crew Exploration Vehicle

This preliminary review was prepared for the selection of a CO₂ removal assembly for the Crew Exploration Vehicle (CEV). The CEV has a dual role in transporting crewmembers to ISS and as the Moon-bound spaceship. The LiOH-containing assembly is considered a reliable device for short missions, but unfavorable for longer missions due to weight and economic factors. Zoelite-based regenerative assemblies have been flight-ready and are good candidates when issues in valve and pump seal design are resolved. Solid-amine based CO₂ removal assemblies have showed promises and redundancy. There are three integrated subsystems to be considered for oxygen recovery if needed. In addition, five emerging technologies have been rated at low-to-middle of TRLs, but they are only potential candidates for Advanced Life Support (ALS) applications and for the second-generation CEV. Major mission requirements have been identified for CEV design and operations.