Cryogenic-Based Environmental Control for the Extra-Vehicular Mobility Unit

The present NASA extravehicular mobility unit employs several complex systems to provide metabolic cooling, breathing oxygen and CO2 and water vapor removal. We propose here to develop a cryogen- based environmental control system that will perform all these functions in a simple and reliable fashion with less weight and volume. The key component is a cryogen cooling garment (CCG) that is constructed from liquid crystal polymer (LCP) film. Liquid air, the cooling fluid, flows to the CCG from storage tank and is vaporized and then heated to approximately 60@F while providing cooling to the wearer. The gas venting from the garment can be used to provide breathing air, while the gas leaving the suit removes CO2 and water vapor from the EMU. If necessary, further CO2 and water removal could be achieved by vaporizing the air prior to entry to CCG, causing the CO2 and water to freeze. Initial estimates suggest that the cryogen-based environmental control system would weigh less than 60 lbs (with cryogen) and occupy a volume of less than 2 ft3.