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The Major Constituent Analyzer (MCA) is a mass spectrometer based system that measures the major components of the International Space Station (ISS) atmosphere, including water. The measurement of water vapor has been difficult due to adsorption on various surfaces in the sample path, and has thus far been discounted in MCA atmosphere monitoring. This paper summarizes the results in identifying the primary source of the problem, the modeling being used to further elucidate the water surface adsorption/desorption process, and the proposed means available to provide a stable calibration and accurate measure of the water abundance.

Determining the fundamental role of gravity in vital biological systems in space is one of six science and research areas that provides the philosophical underpinning for why NASA exists. The study of cells, tissues, and microorganisms in a spaceflight environment holds the promise of answering multiple intriguing questions about how gravity affects living systems. To enable these studies, specimens must be maintained in an environment similar to that used in a laboratory. Cell culture studies under normal laboratory conditions involve maintaining a highly specialized environment with the necessary temperature, humidity control, nutrient, and gas exchange conditions. These same cell life support conditions must be provided by the International Space Station (ISS) Cell Culture Unit (CCU) in the unique environment of space. The CCU is a perfusion-based system that must function in microgravity, at unit gravity (1g) on earth, and from 0.1g up to 2g aboard the ISS centrifuge rotor.

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.

Neutral buoyancy (NB) and parabolic flight (PF) are the only available human-scale three-dimensional spaceflight simulation environments. As such, both environments are used extensively for both research and mission operations purposes despite a lack of quantitative (or even qualitative) characterization of the fidelity of either environment to the spacelfight analog. The present study was undertaken as part of a larger research effort to begin to build such characterizations. Eight healthy adults (4 men and 4 women) were asked to adopt relaxed postures while ‘standing’ in space shuttle middeck standard-type foot restraints, in NB and during the 0g periods of PF. Subjects were tested in NB in 9 orientations, 3 trials each: Upright; tilted 45° Front, 45° Back, 45° Right, 45° Left; and tilted 90° Front, Back, Right, and Left. PF limitations prohibited 90° testing; consequently the PF test protocol included only Upright and 45° orientations.

In applications that require space-suited crewmembers to traverse rough terrain, boot fit and mobility are of critical importance to the crewmember's overall performance capabilities. Current extravehicular activity (EVA) boot designs were developed for micro-gravity applications, and as such, incorporate only minimal mobility features. Recently three advanced space suit boot designs were evaluated at the National Aeronautics and Space Administration Johnson Space Center (NASA/JSC). The three designs included: 1) a modified Space Shuttle suit (Extravehicular Mobility Unit or EMU) boot, 2) the Modified Experiment Boot designed and fabricated by RD & PE Zvezda JSC, and 3) a boot designed and fabricated by the David Clark Company. Descriptions of each configuration and rationale for each boot design are presented.

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.

An important, though often unstated, requirement to achieve NASA’s strategic goals will be an Extravehicular Activity (EVA) system that will let future astronauts work safely and effectively at the chosen destinations without imposing unacceptable burdens on the astronauts or the mission systems that support them. Past studies have shown that this may present an insurmountable challenge if pursued with current technologies and system design concepts. With funding from the NASA Institute for Advanced Concepts (NIAC), Hamilton Sundstrand has been studying a conceptual architecture for future EVA systems to meet this challenge. The Chameleon Suit concept shifts the EVA design paradigm from one in which the pressure garment and life support system are separate, largely independent subsystems to one in which the EVA system integrates distributed life support functions with the pressure suit.

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.