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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.

This novel technology builds upon a previously (NASA-developed) store-and-forward overlay architecture using COTS RFID protocols for BAP devices. It enables the range-extension and priority forwarding of critical sensor-collected data, even when an RFID interrogator is not in range. With this method, an RFID sensor maintains data queues of varying priority, maintaining at least one high priority queue. When high priority data is collected, the RFID sensor activates a BAP mode that enhances the effective range of the RFID link to the interrogator. After high priority queues are cleared, BAP mode is deactivated to preserve onboard battery life and passive RFID operations resume for proximity-based data delivery. This technology may deliver the most value in applications where long battery lifetime and remote sensing/data collection are essential and when regularly scheduled data transfer may not be available or possible if the target is out of the normal coverage area. The RFID sensor tags described here can operate in a low to no power mode and collect data until a trigger or threshold value is measured. At this time, the critical data can be transmitted from outside passive RFID coverage areas to the nearest interrogator. Although this technology was developed to enhance the effective range of CO2 sensors worn by astronauts aboard the International Space Station, it could find additional applications in food, pharmaceutical, and other industries whose perishable and/or fragile goods rely on a stable climate throughout the transport and storage lifecycle.

The technology is a solid state, Carbon Dioxide (CO2) sensor configured for sensitive detection of CO2 having a concentration within the range of about 100 Parts per Million (ppm) and 10,000 ppm in both dry conditions and high humidity conditions (e.g., > 80% relative humidity). The solid state CO2 sensor achieves detection of high concentrations of CO2 without saturation and in both dynamic flow mode and static diffusion mode conditions. The composite sensing material comprises Oxidized Multi-Walled Carbon Nanotubes (O-MWCNT) and a metal oxide, for example O-MWCNT and iron oxide (Fe2O3) nanoparticles. The composite sensing material has an inherent resistance and corresponding conductivity that is chemically modulated as the level of CO2 increases. The CO2 gas molecules absorbed into the carbon nanotube composites cause charge-transfer and changes in the conductive pathway such that the conductivity of the composite sensing material is changed. This change in conductivity provides a sensor response for the CO2 detection. The solid state CO2 sensor is well suited for automated manufacturing using robotics and software controlled operations. The solid state CO2 sensor does not utilize consumable components or materials and does not require calibration as often as conventional CO2 sensors. Since the technology can be easily integrated into existing programmable electronic systems or hardware systems, the calibration of the CO2 sensor can be automated.