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Incineration is a promising method for converting biomass and human waste into CO2 and H2O during extended planetary exploration. During incineration, however, small amounts of NOx and SO2 are produced and must be removed. TDA Research, Inc. (TDA) has developed a safe and effective process to remove NOx and SO2 from waste incinerator product gas streams. In our process, NO is oxidized into NO2 with high selectivity. The NO2 is then removed by wet scrubbing with a weak base to form an innocuous water solution of nitrates and nitrites. SO2 will be removed by a packed bed containing a basic sorbent developed at TDA. As part of an SBIR Phase II project, TDA is to design and construct a pilot-scale effluent cleaning system to be coupled with an existing waste incinerator at NASA Ames Research Center. The effluent from this incinerator may contain fly ash, SO2, unburned hydrocarbons, CO, and NOx.

Incineration is a promising method for converting biomass and human waste into CO2 and H2O during extended planetary exploration. During incineration, small amounts NOX and SO2 are produced and must be removed. TDA has developed a NOX control process that is safe and effective and does not require addition of NH3, which is commonly used in selective catalytic reduction of NOx. In our process, NO is catalytically oxidized to NO2 which is then removed by wet scrubbing with a weak base to form an innocuous water solution of nitrates and nitrites. We plan to integrate our catalytic NO oxidation process into a complete gas cleaning system that will remove NOX, SO2, particulate material, CO and unburned organic compounds.

The development of a portable diode laser based gas sensor and its application to sensitive, selective, on-line monitoring of formaldehyde concentrations present in a catalytic Trace Contaminant Control System (TCCS) in a 5-day period in August 1999 is reported. The TCCS was originally developed for the Lunar-Mars Life Support Test program in 1996-1997 at NASA-JSC. The motivation for monitoring H2CO levels in a sealed human rated environment is that its presence can cause headaches, throat and ear irritation at low concentrations (>100 ppb), and more serious adverse effects at higher concentration levels. Consequently, NASA has established a spacecraft maximum allowable H2CO concentration of 40 ppb for crew exposure for a 7 to 180 days period [1].

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.

Incineration is a promising method for converting biomass and human waste into CO2 and H2O during extended planetary exploration. However, incineration produces small amounts of NOX and SO2 in the effluent, which must be removed. TDA Research has developed a safe and effective process to remove NOX and SO2 from waste incinerator product gas streams. In our process, NO is catalytically oxidized to NO2, using a low temperature oxidation catalyst developed at TDA. Wet scrubbers then remove the NO2, with most of the NO2 converted into an aqueous solution that can be used as a plant nutrient. A packed bed containing a basic sorbent, also developed at TDA, removes SO2 from the effluent. As part of an SBIR Phase II project, TDA designed and constructed a pilot scale effluent cleaning system, which will be used with the incinerator at NASA Ames Research Center.

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.

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.