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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 selection of technologies for an evolutionary Space Station Freedom or a planetary (lunar or Martian) extravehicular mobility unit (EMU) are strongly driven by the system volume and weight as well as life cycle costs, reliability and safety. TDA Research, Inc. (TDA) is developing a compact, lightweight 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 developed a regenerable sorbent that is suitable for the conceptual system. We also carried out a preliminary system analysis to show that the design saves significant weight.

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) 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.

A safe, effective means to control solid waste is a critical need on long-term space missions. With current waste models, 1300 kg of waste occupying a volume 20 m3 will be generated in a 180-day mission to Mars. Unprocessed waste poses a biological hazard to crew health and morale. The waste processing methods currently under consideration include incineration, microbial oxidation, pyrolysis and compaction. Although each has advantages, no single method has yet been developed that is safe, recovers valuable resources including oxygen and water, and has low energy and space requirements. Thus, the objective of this project was to develop a low temperature oxidation process to convert waste cleanly and rapidly to carbon dioxide and water. In this Small Business Innovative Research (SBIR) Phase I project, TDA Research Inc. (TDA) conducted tests to measure the rates of oxidation using ozone with five model waste components.

In February 2004 NASA released “The Vision for Space Exploration.” The goals outlined in this document include extending the human presence in the solar system, culminating in the exploration of Mars. A key requirement for this effort is to identify a safe and effective method to process waste. Methods currently under consideration include incineration, microbial oxidation, pyrolysis, drying, and compaction. Although each has advantages, no single method has yet been developed that is safe, recovers valuable resources including oxygen and water, and has low energy and space requirements. Thus, the objective of this work is to develop a low temperature oxidation process to convert waste cleanly and rapidly to carbon dioxide and water. Previously, TDA Research, Inc. demonstrated the potential of a low temperature dry oxidation process using ozone in a small laboratory reactor.

In February 2004 NASA released “The Vision for Space Exploration.” The important goals outlined in this document include extending human presence in the solar system culminating in the exploration of Mars. Unprocessed waste poses a biological hazard to crew health and morale. The waste processing methods currently under consideration include incineration, microbial oxidation, pyrolysis and compaction. Although each has advantages, no single method has yet been developed that is safe, recovers valuable resources including oxygen and water, and has low energy and space requirements. Thus, the objective of this project is to develop a low temperature oxidation process to convert waste cleanly and rapidly to carbon dioxide and water. In the Phase I project, TDA Research, Inc. demonstrated the potential of a low temperature oxidation process using ozone. In the current Phase II project, TDA and NASA Ames Research Center are developing a pilot scale low temperature ozone oxidation system.

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 National Aeronautics and Space Administration's (NASA) planned future missions set stringent demands on the design of the Portable Life Support System (PLSS), requiring dramatic reductions in weight, decreased reliance on supplies and greater flexibility for Extravehicular Activity (EVA) duration and objectives. Use of regenerable systems that reduce weight and volume of the space suit life support system is of critical importance to NASA, both for low orbit operations and for long duration manned missions. The carbon dioxide and humidity control unit in the existing PLSS design is relatively large, since it has to remove and store eight hours worth of carbon dioxide (CO2). If the sorbent regeneration can be carried out during the EVA with a relatively high regeneration frequency, the size of the sorbent canister and weight can be significantly reduced.

The possibility and consequences of a fire on board a spacecraft and the subsequent effects of the resultant toxic gases and smoke on the crew, equipment and mission is an ever-present hazard for the National Aeronautics and Space Administration (NASA). The necessity to remove these contaminants in the presence of high levels of humidity and carbon dioxide has prompted the development of a new prototype atmospheric filter (smoke eater) that can scrub acid gases, basic gases, and carbon monoxide from a spacecraft atmosphere in a post-fire event to a concentration below one half the Spacecraft Maximum Allowable Concentration (SMAC) levels. TDA Research, Inc. (TDA) is developing an advanced smoke eater to remove combustion byproducts. The material makeup of the smoke eater will also be applicable to spacecraft evacuation masks and the shipboard atmospheric revitalization system.