Carbon Dioxide Removal by Ionic Liquid System for Mobility (CDRILS-M) for Mars Exploration Extravehicular Mobility Unit (mxEMU)

Carbon dioxide (CO2) and humidity control are required functions for a spacesuit Portable Life Support Subsystem (PLSS) as the system operates in a closed loop mode removing bioproducts generated by the crew before supplementing with makeup oxygen. For suits such as the Apollo Extravehicular Mobility Unit (EMU), Shuttle EMU, and International Space Station (ISS) EMU single bed solid sorbents have been used for CO2 control with humidity control via a condensing heat exchanger. For new suit designs such as the Exploration EMU (xEMU) solid adsorbents have been used for both CO2 control and humidity control but in a swingbed implementation that loses O2 and CO2/H2O to the vacuum environment and requires vacuum access during Intra Vehicular Activity (IVA) operations. For the vehicle cabin life support application a new approach has been in development referred to as Carbon Dioxide Removal by Ionic Liquid System (CDRILS). This approach utilizes a continuously recirculated ionic liquid sorbent and hollow fiber membrane contactors for CO2 removal from spacecraft cabin air. CDRILS is working toward a flight demonstration on the International Space Station (ISS) in 2028. Honeywell and the NASA Space Suit & Crew Survival Systems Branch are exploring a variation of CDRILS tailored to the spacesuit application seeking to control the CO2 and humidity in the suit ventilation loop while minimizing losses to the environment and no longer requiring vacuum access to function. The CDRILS for Mobility (CDRILS-M) will be integrated into the NASA Mars Exploration EMU (mxEMU) PLSS concept. The benefits of continuous, liquid based CO2 and humidity control for Mars Exploration applications, the CDRILS-M mxEMU concept, and the exploration of alternative ionic liquids mixtures and operating configurations targeted to this application are discussed.