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Future National Aeronautics and Space Administration (NASA)-planned missions set stringent demands on the design of the Portable Life Support Systems (PLSS), requiring dramatic reductions in weight, decreased reliance on supplies and greater flexibility on the types of missions. Use of regenerable systems that reduce weight and volume of the Extravehicular Mobility Unit (EMU) is of critical importance to NASA, both for low orbit operations and for long duration manned missions. TDA Research, Inc. (TDA) is developing a high capacity, rapid cycling sorbent to control CO2 and humidity in the space suit ventilation loop. The sorbent can be regenerated using space vacuum during the EVA, eliminating all duration-limiting elements in the life support system. This paper summarizes the results of the sorbent development and testing, and evaluation efforts.

TDA Research, Inc. (TDA) is developing a simple system that provides an effective way of interfacing the carbondioxide (CO2) removal and reduction functions. The system uses a chemical absorbent and a Sabatier catalyst combination to remove the CO2 and water vapor (H2O) produced by metabolic processes from cabin air and subsequently reduce the CO2 to methane and water. The system has the potential to weigh less than the Four Bed Molecular Sieve and CO2 Reduction Assembly combination, which is connected with a CO2 pump/compressor and storage tank due to the high CO2 absorption capacity of the sorbent and its ability to simultaneously absorb both CO2 and H2O (which eliminates the need for desiccant beds in the Four Bed Molecular Sieve System). The system does not require a CO2 pump/compressor or storage tank offering energy savings that come from effective utilization of the heat released by the Sabatier reaction to drive sorbent regeneration.

With an increased rate and length of extravehicular activities (EVAs), a low, but statistically significant possibility exists for system and component failures. In that potential event, it is critical to provide oxygen support, carbon dioxide and moisture removal and thermal control to sustain life. The existing EVA emergency system in the Portable Life Support Unit (PLSS) is reliable, and works well, however, it is heavy because of the high oxygen consumption inherent in its open-loop mode of operation. TDA Research, Inc. (TDA) is developing a low-venting emergency system that provides 30-minute life-support in the case of system or component failures in the Portable Life Support System (PLSS). The approach is to minimize the quantity of the gas vented from the suit and thereby to reduce the weight of the stored oxygen. The operation of the system however, requires an effective sorbent that would remove carbon dioxide from the suit. TDA has developed such a sorbent.

The recovery of oxygen from a concentrated stream of carbon dioxide (CO2) offers significant advantage to long duration manned space missions by reducing the requirement for consumables. TDA Research, Inc. (TDA) has developed a chemical absorbent-based system to carry out CO2 removal and CO2 reduction for the Environmental Control and Life Support System (ECLSS) at the International Space Station (ISS). The system eliminates interfacing problems associated with the currently operational CO2 Removal Assembly (CDRA) and planned CO2 Reduction Assembly (CRA). This paper discusses the plans for TDA’s CO2 removal and CO2 reduction system. A high capacity, long-life CO2 sorbent was developed and tested under representative conditions. In addition, the performance of a state-of-the-art catalyst for CO2 reduction to water and methane at the conditions of interest was tested.

TDA Research, Inc. (TDA) is developing a compact, lightweight ExtraVehicular activity (EVA) emergency system that provides 30-minute life-support in the case of system or component failures in the Portable Life Support System (PLSS). The system uses a low ventilation rate to reduce the amount of stored oxygen, reducing the associated weight and volume penalty. Operation of the system requires an effective sorbent that would remove carbon dioxide and moisture from the suit. We are developing a regenerable sorbent that is suitable for the conceptual system. Recently, we tested the sorbent performance in an adiabatic reactor setup simulating representative EVA emergency conditions. This paper summarizes results of these adiabatic tests.

The recovery of oxygen from a concentrated stream of carbon dioxide (CO2) offers significant advantage to long duration manned space missions by reducing the requirement for consumables. TDA Research, Inc. (TDA) is developing a chemical absorbent-based system to carry out CO2 removal and CO2 reduction for the Environmental Control and Life Support System (ECLSS) at the International Space Station (ISS). The system eliminates the interfacing problems associated with the currently operational CO2 Removal Assembly (CDRA) and planned CO2 Reduction Assembly (CRA). This paper discusses the development efforts of a regenerable absorbent that is suitable for our conceptual system recommended for future missions. We also tested the performance of a state-of-the-art catalyst for CO2 reduction to water and methane at the conditions of interest. We demonstrate the technical feasibility of carrying out CO2 removal and reduction.