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Research into increased capacity solid amine sorbents has found a candidate (SA9T) that will provide enough increase in cyclic carbon dioxide removal capacity to produce a fully redundant Regenerative Carbon Dioxide Removal System (RCRS). This system will eliminate the need for large quantities of backup LiOH, thus gaining critical storage space on board the shuttle orbiter. This new sorbent has shown an ability to package two fully redundant (four) sorbent beds together with their respective valves, fans and plumbing to create two operationally independent systems. The increase in CO2 removal capacity of the new sorbent will allow these two systems to fit within the envelope presently used by the RCRS. This paper reports on the sub-scale amine testing performed in support of the development effort. In addition, this paper will provide a preliminary design schematic of a fully redundant RCRS.

Computer simulation of extravehicular activity (EVA) is increasingly being used in planning and training for EVA. A space suit model is an important, but often overlooked, component of an EVA simulation. Because of the inherent difficulties in collecting angle and torque data for space suit joints in realistic conditions, little data exists on the torques that a space suit’s wearer must provide in order to move in the space suit. A joint angle and torque database was compiled on the Extravehicular Maneuvering Unit (EMU), with a novel measurement technique that used both human test subjects and an instrumented robot. Using data collected in the experiment, a hysteresis modeling technique was used to predict EMU joint torques from joint angular positions. The hysteresis model was then applied to EVA operations by mapping out the reach and work envelopes for the EMU.

Hamilton Sundstrand Space Systems International (HSSSI) participated with the National Aeronautics and Space Administration (NASA), the Search for Extraterrestrial Intelligence (SETI) Institute and Simon Fraser University in the 2001 field season of NASA's Haughton-Mars Project (HMP) to study information technologies concepts and hardware systems for advanced Extravehicular Activity (EVA). The research was focused on developing an improved understanding of the uses of the interface in an exploration / field science context. Interface integration with communication, navigation and scientific data systems, and the special challenges posed by the expeditionary environment were investigated. This paper presents a discussion of the field test systems, test activities and results. Recommendations for future, higher fidelity research are included.

The cost of delivering the payloads to space increases dramatically with distance and therefore missions to deep space place a strong emphasis on reducing launch weight and eliminating resupply requirements. The Vapor Phase Catalytic Ammonia Removal (VPCAR) system, which is being developed for water purification, is an example of this focus because it has no resupply requirements. A key step in the VPCAR system is the catalytic oxidation of ammonia and volatile hydrocarbons to benign compounds such as carbon dioxide, water, and nitrogen. Currently, platinum-based commercial oxidation catalysts are being used for these reactions. However, conventional platinum catalysts can convert ammonia (NH3) to NO and NO2 (collectively referred to as NOX), which are more hazardous than ammonia.

As manned spacecraft travel farther from Earth, the cost of delivering the payloads to space increases dramatically. For example the cost of delivering a payload to low Earth orbit currently is about $10,000/lb. On the other hand the cost of delivering a payload to Mars may be up to 40 times greater and therefore missions to deep space place a strong emphasis on reducing launch weight and eliminating resupply requirements. The Vapor Phase Catalytic Ammonia Removal (VPCAR) system, which is being developed to purify water, is an example of this focus. In addition to having a lower launch weight than the Water Recycle System (WRS) currently used on the International Space Station, it also has no resupply requirements. A key step in the VPCAR system is the catalytic oxidation of ammonia and volatile hydrocarbons to benign compounds such as carbon dioxide, water, and nitrogen. Currently platinum-based commercial oxidation catalysts are being used for these reactions.

The Thermoelectric Integrated Membrane Evaporative Subsystem (TIMES) was evaluated to determine its ability to process reverse osmosis brine as one of the Advanced Water Processor steps. As the baselined membrane (Nafion 117) was unable to retain ammonia, a NASA-sponsored project was conducted to find an alternate membrane capable of retaining ammonia while maintaining reasonable water production rates. A long term test was performed with up to 90% water recovery using a hydrophilic membrane and a hydrophobic membrane. The ammonia rejection for the hydrophilic membrane was 80%. The average water production rates for both membranes were greater than for the pretreated baselined Nafion membrane.

Closed-loop inhabited spacecraft, including a space suit, require removal of carbon dioxide from the breathing atmosphere. A membrane device that separates CO2 from breathing air can effectively control CO2 levels in the breathing loop by venting the carbon dioxide directly to the vacuum of space. Such a membrane device requires no regeneration and, therefore, imposes no limitations on mission length. Systematic studies have expanded our knowledge of the parameters most critical to the successful development of a membrane carbon dioxide removal system. The membrane type disclosed in this paper is an immobilized liquid membrane (ILM) in which the liquid is engineered to facilitate the transport of carbon dioxide while inhibiting the progress of oxygen. Selectivity superior to that achieved in previously published studies has been demonstrated and has approached values desired for an Extravehicular Mobility Unit (EMU) system.