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Conceptual designs for initial, intermediate, and advanced lunar base life support systems (LSS) are under development at JSC. The initial air revitalization, water recovery, and waste management subsystems are based on space station technologies. The intermediate system expands on the initial capabilities; for example, the initial waste management subsystem allows only for compacting and storing solid waste, while the intermediate waste management subsystem includes measures for recovering useful substances from the waste. The advanced system includes biological waste treatment and higher plants to be used for air revitalization and water processing. This paper describes the three systems and discusses the basis for selecting individual processes. System-level mass balances are used to illustrate the interaction of the air, water, and waste loops. The effect of introducing different waste treatment processes into the initial LSS is examined.

Future manned habitats such as a Lunar or Martian outpost will require a high degree of self-sufficiency to minimize cost and dependency on resupply from Earth. Food and other life support expendables are major resupply items required for long-term habitation of planetary surfaces. By growing higher plants for food, resupply can be reduced and self-sufficiency increased. Additionally, higher plants provide carbon dioxide (CO2) removal and reduction, oxygen (O2) production, and water reclamation for human life support. Plants have been grown in the controlled environment of the Regenerative Life Support Systems (RLSS) Test Bed at Johnson Space Center. The systems performance in terms of supporting human life was determined for plant CO2 assimilation, O2 generation, and evapotranspiration rates, trace contaminant generation, and biomass production. In addition, test conditions and anomalies are described.

Over the last three years, the University of Utah (UofU), NASA Ames Research Center (ARC), and Reaction Engineering International (REI) have been developing an incineration system for the regeneration of components in waste materials for long-term life support systems. The system includes a fluidized bed combustor and a catalytic flue gas clean up system. An experimental version of the incinerator was built at the UofU. The incinerator was tested and modified at ARC and then operated during the Phase III human testing at NASA Johnson Space Center (JSC) during 1997. This paper presents the results of the work at the three locations: the design and testing at UofU, the testing and modification at ARC, and the integration and operation during the Phase III tests at JSC.

The Waste and Hygiene Compartment will serve as the primary facility for metabolic waste management and personal hygiene on the United States segment of the International Space Station. The Compartment encloses the volume of two standard ISS racks and will be installed into Node 3 after launch inside a Multipurpose Logistics Module on the Space Shuttle. Long duration space flight requires a departure from the established hygiene and waste disposal practices employed on the Space Shuttle. This paper describes requirements and a conceptual design for the Waste and Hygiene Compartment that are both logistically practical and acceptable to the crew.

The Major Constituent Analyzer (MCA) was activated on-orbit on 2/13/01 and provided essentially continuous readings of partial pressures for oxygen, nitrogen, carbon dioxide, methane, hydrogen and water in the ISS atmosphere. The MCA plays a crucial role in the operation of the Laboratory ECLSS and EVA operations from the airlock. This paper discusses the performance of the MCA as compared to specified accuracy requirements. The MCA has an on-board self-calibration capability and the frequency of this calibration could be relaxed with the level of instrument stability observed on-orbit. This paper also discusses anomalies the MCA experienced during the first year of on-orbit operation. Extensive Built In Test (BIT) and fault isolation capabilities proved to be invaluable in isolating the causes of anomalies. The process of fault isolation is discussed along with development of workaround solutions and implementation of permanent on-orbit corrections.

This paper describes the approach and results of an effort to characterize plant growth under various environmental conditions at the Johnson Space Center variable pressure growth chamber. Using a field of applied mathematics and statistics known as design of experiments (DOE), we developed a test plan for varying environmental parameters during a lettuce growth experiment. The test plan was developed using a Box-Behnken approach to DOE. As a result of the experimental runs, we have developed empirical models of both the transpiration process and carbon dioxide assimilation for Waldman's Green lettuce over specified ranges of environmental parameters including carbon dioxide concentration, light intensity, dew-point temperature, and air velocity. This model also predicts transpiration and carbon dioxide assimilation for different ages of the plant canopy.

Orbiter radiator performance provides the most variance in determining the amount of Shuttle Transportation System (STS) Orbiter water available for transfer to the International Space Station (ISS). As radiator performance decreases, dependence upon the Flash Evaporator System (FES), which requires Fuel Cell (FC) water to reject the Orbiter's waste heat, increases. Generally, radiator performance decreases as the ISS assembly size increases (especially as solar arrays are added), and also as beta angle increases. A parametric study has been accomplished that provides a quick-reference table for determining the amount of Orbiter water available for transfer during ISS missions 2A.2 through 7A.1. An hourly Orbiter net water generation rate is reported according to variations in ISS assembly configuration, beta angle, ISS attitude, Orbiter radiator configuration, and Orbiter heat load. Those permutations of higher probability of occurrence than others have been identified.

Crewmember ingress of the International Space Station (ISS) before that time accorded by the original ISS assembly sequence, and thus before the ISS capability to adequately control the levels of temperature, humidity, and carbon dioxide, poses significant impacts to ISS Environmental Control and Life Support (ECLS). Among the most significant considerations necessitated by early ingress are those associated with the capability of the Shuttle Transportation System (STS) Orbiter to control the aforementioned levels, the capability of the ISS to deliver the conditioned air among the ISS elements, and the definition and distribution of crewmember metabolic heat, carbon dioxide, and water vapor. Even under the assumption that all Orbiter and ISS elements would be operating as designed, condensation control and crewmember comfort were paramount issues preceding each of the ISS Missions 2A and 2A.1.