Air Revitalization for Vacuum Environments

The NASA life support system uses a regenerable vacuum swing adsorption process, known as Sorbent-Based Air Revitalization (SBAR), to separate water and carbon dioxide for disposal. The SBAR system is an adsorbent-based swing bed system that has been optimized to provide both humidity and carbon dioxide control for a spacecraft cabin atmosphere. The system comprises composite silica gel and zeolite-packed beds for adsorption and a bypass system for flow control. Under normal operating conditions, the disposal system would require a high-quality vacuum environment to operate. Improvements to the SBAR system include an enhanced inherent capacitance that extends the operation time within a non-vacuum environment for up to 4.5 hours. Flight time can be further expanded with multiple SBAR systems to allow for system regeneration. By scheduling periodic thermal regenerations&#151nominally during sleep periods&#151the SBAR technology may be suitable for missions of unlimited duration. NASA has developed a lightweight atmosphere revitalization system to support short-duration human space flights. Air revitalization is a critical component of manned space flights since passenger-carrying vehicles require a way to control humidity and process metabolic carbon dioxide to sustain an environment that can support human life. For long-duration flights, metabolic water from respiration and evaporated sweat are typically treated and reclaimed, requiring extra equipment such as gas/liquid separators and condensing heat exchangers. To minimize equipment and reduce excess loads, NASA developed an adsorption-based carbon dioxide scrubber and water removal system for disposal in vacuum environments, ultimately reducing mass, power, and volume requirements. The lightweight, low-mass system is also regenerable, flexible, and can be arranged into different spatial configurations.