Membrane for CO2 and H2O Control in Space Suits

CO2 Membrane Project

 

The development of new, robust, lightweight life support systems is currently a crucial need for NASA in order to continue making advances in space exploration, particularly in the development of Lunar outposts and the eventual exploration of Mars. Two functions that are critical to life support systems are the control of carbon dioxide (CO2) and moisture (H2O) during extra vehicular activities (EVA). The current system relies on a sorbent bed to control CO2. Thus in order to increase mission times, the bed must be enlarged or regenerated during the EVA. Both of these choices results in increased size and weight of the portable life support system and also increased chance of failure.

 

A much simpler approach would be to use a membrane system to separate CO2 from the O2 environment in the space suit. An effective membrane separation process would have several advantages over competing technologies: first it would be a continuous system with no theoretical limit on the quantity of CO2 removed, second it would require no consumables or hardware for switching beds and regeneration, third, it is a simple system with low potential for failure and low energy requirements, and fourth, it will not intentionally vent O2 to space. An even better solution would be the development of a single membrane system that controlled both CO2 and H2O, thereby eliminating the hardware required to condense moisture. Thus, Reaction Systems is developing a liquid membrane that utilizes a low vapor pressure liquid which also contains reagents to facilitate the selectivity separation of CO2 and H2O from O2.