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TDA Research, Inc (TDA) is developing a compact lightweight emergency system that provides 30–minute life–support in the case of system or component failure in the Portable Life Support System (PLSS). This emergency system is based on a regenerable sorbent technology developed at TDA, which removes carbon dioxide (CO2) and moisture (H2O). The emergency Extravehicular Activity (EVA) system must control CO2 levels as well as humidity and temperature. Two thermal sources that must be managed are the metabolic heat from the astronaut, mostly in the form of water vapor and the heat released from the exothermic reaction of CO2 and H2O with the sorbent. Consideration of the thermal management is critical in the design of this system because it affects sorbent performance. Additionally, it is important in maintaining astronaut comfort.

During extravehicular activities (EVAs) it is crucial to keep the astronaut comfortable. Currently, a sublimator rejects to space both the astronaut's metabolic heat and that produced by the Portable Life Support System. In doing so, it consumes up to 3.6 kg (8 lbm) of water; the single largest expendable during an eight-hour EVA. While acceptable for low earth orbit, resupply for moon and interplanetary missions will be too costly. Fortunately, the amount of water consumed can be greatly reduced if most of the heat load is radiated to space. However, the radiator must reject heat at the same rate that it is generated to prevent heat stroke or frostbite. Herein, we report on a freezable radiator and heat exchanger to proportionally control the heat rejection rate.

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.