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Technical Paper

Technical Review: Comparison of IC and CE for Monitoring Ionic Water Contaminants on SSF

1991-07-01
911438
The measurement of ionic contaminants in samples from the potable water system on Space Station Freedom is one of the basic functions of the Crew Health Care System (CHeCS). The U. S. Environmental Protection Agency has identified ion chromatography as the analytical method of choice for measurement of anions and cations in water as described in USEPA method numbers 300.0 and 300.7, respectively. For this reason, ion chromatography was the technology initially identified to perform the ion contaminant monitoring function in the CHeCS Water Quality Subsystem. Subsequently, mass, size, and maintenance restrictions have led to a reevaluation of method options. Capillary electrophoresis (CE) has emerged as one of the more promising alternatives. CE is inherently microgravity compatible and uses an order of magnitude less reagent volume than ion chromatography. The major drawback to CE is its present state of development.
Technical Paper

Microbiological Characterization of the Biomass Production Chamber during Hydroponic Growth of Crops at the Controlled Ecological Life Support System (CELSS) Breadboard Facility

1991-07-01
911427
The initial goal of the Controlled Ecological Life Support System (CELSS) Breadboard Project is to develop and evaluate a ground-based bioregenerative system scaled to support the equivalent of one crew member. The Biomass Production Chamber (BPC) is the plant growing module of this project. We describe here the characterization of the microbial constituents of the BPC during production tests of hydroponically-grown crops of wheat and soybeans. Bacterial and fungal viable counts were determined for the hydroponic solution, dehumidifier condensate water, and atmosphere. Bacterial communities were characterized by taxonomic identification (Vitek AutoMicrobic System) of randomly selected isolates. For all crop tests, bacteria dominated the microflora of both the hydroponic solution (range--104 to 106 colony forming units [cfu] per mL), and dehumidifier condensate (103 to 106 cfu/mL).
Technical Paper

Regenerative Life Support Systems (RLSS) Test Bed Performance: Characterization of Plant Performance in a Controlled Atmosphere

1991-07-01
911426
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.
Technical Paper

Life Support Concept in Lunar Base

1991-07-01
911431
Abstract Lunar base construction study has been conducted under the sponsorship of many Japanese industries to amend the man tended lunar outpost study carried by NASDA. Permanent lunar base construction is to be constrained by the ability of the usable transportation system carrying the basic modules composing lunar base itself. Based upon the experiences of Antarctic Research Expedition and of designing International Space Station now going on it was assumed the initial permanent lunar base has to be composed of two habitats and one power module for letting possible to alive 8 crews, and has to be expanded by adding three or four modules in every year for improving the easiness of livingness. In early stage of construction, crew members have to live and work using only two habitat modules with getting the electric power from power module, therefore the minimum self support functions except the food and oxygen supplying have to be attached to the habitat modules.
Technical Paper

Development of the Process Control Water Quality Monitor for Space Station Freedom

1991-07-01
911432
On-line monitoring of the effluent from the Space Station Freedom (SSF) water reclamation process determines acceptable quality for delivery to tanks supplying the crew's potable and hygiene water needs. TOC, pH, conductivity and iodine (biocide) are continuously monitored by the integrated, computer-controlled Process Control Water Quality Monitor (PCWQM). This paper describes the development of the system with emphasis on membrane gas-liquid separation and reagentless oxidation necessary to adapt standard TOC analysis to the unique requirements of the space environment.
Technical Paper

Conceptual Design of Snail Breeder Aboard Space Vehicle

1991-07-01
911430
In the Closed Ecological Life Support System ( CELSS ) concepts which have been proposed up to now, most of the foods to be provided to the crew have been based on plant and vegetable produce. In this paper, a snail breeding module which will serve, as a subsystem of CELSS, to provide the space crew with animal nutrients has been studied. As a source of nutrition for the crew, snails have various advantages over other animal species. Snails can normally be bred in a limited space and they are insensitive to the lack of oxygen and feed. In this breeding module, a species of snail ( Helix pomatia ) will grow, mature, mate and reproduce. In order to minimize the crew's work, automated operations for feeding, cleaning wastes, handling snails and their spawn, as well as for the maintenace of the module, will be applied. A submodule which processes snails for food production is also studied.
Technical Paper

Regenerative Life Support Systems (RLSS) Test Bed Development at NASA-Johnson Space Center

1991-07-01
911425
Future manned habitats for a Lunar outpost or Martian base will require increased levels of self-sufficiency over Space Station Freedom to reduce the high costs and complexities of resupplying expendables, such as food for the crew. By growing food at these remote sites, not only will self-sufficiency be greatly increased, but significant benefits for crew life support will also be realized. Higher plants, such as those grown typically for food, are capable of consuming carbon dioxide (CO2), producing oxygen (O2), and reclaiming water (H2O) via transpiration. At NASA's Johnson Space Center (JSC) in Houston, Texas, the Regenerative Life Support Systems (RLSS) Test Bed project will use higher plants grown in a closed, controlled environment in conjunction with physicochemically-based life support systems to create an integrated biological/physicochemical RLSS.
Technical Paper

Study of Oxygen Generation System for Space Application

1991-07-01
911429
Non-regenerative carbon dioxide (CO2) removal system, oxygen (O2) gas storage system, and other consumables have been utilized for the past short-term environmental control system on orbit because of the advantages of system weight, electric power consumption, system reliability, and so forth. However, to sustain long-term manned activity, regenerative resource recycle systems should be essential to reduce the quantity and frequency of resupply from the Earth. O2 generation system (OGS) is indispensable to this resource recycle systems and water electrolysis technology is considered to be suitable for near future space applications. The authors have been studying OGS since 1985 concerning a new solid polymer electrolyte (SPE) and simplified cell structure. This paper describes OGS development status and results of preliminary experiments.
Technical Paper

Developing Real-Time Control Software for Space Station Freedom Carbon Dioxide Removal

1991-07-01
911418
Embedded control system design requires a cross-disciplinary development effort involving design, software, and test engineering staffs. Conventional embedded control system development involves the use of various tools, each of which is applicable only to a portion of the development life cycle. Cross-disciplinary development using various design tools is expensive and a disproportionate amount of effort is required to translate control law algorithms into executable code. A toolset to increase productivity and reduce life cycle cost by providing an integrated development environment, including automated generation of high-level code from control law block diagrams, is needed. This paper presents AiResearch experience to date in using the NASA/Boeing Application Generator (AG) to develop real-time control systems for the Carbon Dioxide Removal Assembly (CDRA) in Work Package 01.
Technical Paper

Waste Water Processing Technology for Space Station Freedom: Comparative Test Data Analysis

1991-07-01
911416
Comparative tests were performed by Boeing, Marshall Space Flight Center (MSFC) or Boeing subcontractors to select the optimum technology for waste water processing on Space Station Freedom (SSF). A Thermoelectric Integrated Membrane Evaporation Subsystem (TIMES) and a Vapor Compression Distillation Subsystem (VCDS) were built and tested to compare urine processing capability. A portion of the distillate recovered from pretreated urine; ie, the water which originates in the resupply food, is the basis for closed loop life support on SSF. Several other waste water “Challenge Solutions”, representing laboratory experiment waste water, were also comparatively processed with these two technologies. Performance, water quality and specific energy were compared for conceptual designs intended to function as part of the Water Recovery and Management (WRM) system.
Technical Paper

Small Life Support System for Free Flyer

1991-07-01
911428
Abstract With astronauts and cosmonauts spending longer periods in space, we must understand and anticipate the effects of the environment on those who live and work in space and on their progeny. Since current launch vehicles restrict payload to low volumes and low masses, we must work within these design restrictions. Two biological experiments, one involving female newts and the other involving the eggs of a small fresh-water fish called revulines, are to be carried aboard the Japanese space flyer unit (SFU) in 1994. The experiment system, named BIO, is implemented on Special Payload Unit (SPLU) of SFU. Experiment are conducted with a service provided for SPLU. BIO consists of two experiment units, a controller, and a power supply. Each experiments, contains an aqua chamber to hold the live specimens. The temperature and gas in the chamber are maintained by a thermo exchanger and gas exchanger.
Technical Paper

Space Station Freedom ECLSS Design Configuration: A Post Restructure Update

1991-07-01
911414
Abstract The Space Station Freedom Program (SSFP) has undergone major design changes within the last year due to reduced budget appropriations imposed by Congress. This paper outlines the impacts of the design changes on the Environmental Control and Life Support System (ECLSS), with emphasis on the system aspects of the ECLSS. Brief descriptions of design impacts to all six ECLSS subsystems are provided in addition to interactions with other distributed systems such as Data Management, Electrical Power, and Man Systems. The assembly sequence for SSF is addressed with emphasis on key flights with respect to the ECLSS.
Technical Paper

ECLSS Regenerative Systems Comparative Testing and Subsystem Selection

1991-07-01
911415
In support of Space Station Freedom Phase C/D Environmental Control and Life Support Systems (ECLSS) regenerative systems development, comparative testing was performed on predevelopment hardware of competing technologies for each regenerative function. This testing was conducted by The Boeing Aerospace and Electronics Company (BAE) at Marshall Space Flight Center (MSFC) from late 1989 through early 1990. The purpose of the test program was to collect data on latest generation hardware in order to make final technology selections for each subassembly in the oxygen recovery and water reclamation strings. This paper discusses the testing performed, test results, and evaluation of these results relative to subsystem selections for CO2 reduction, O2 generation, potable water processing, hygiene water processing, and urine processing.
Technical Paper

Diet Expert Subsystem for CELSS

1991-07-01
911424
Abstract A major problem of control in a Controlled Ecological Life Support System (CELSS) is to maintain and manage a stable diet for its human crew. In this paper, the development and mathematical basis of a “diet” control subsystem, functioning as a well characterized expert program, is described. The general formulation of the expert program, which is named Ceres, is presented. The method can provide both steady-state and dynamic solutions for the problem of diet in a CELSS. The distinction between Ceres and the nutritional modeling methods is demonstrated for the case of a three-component, potato-wheat-soybean food system. The significance of food processing in providing added flexibility in the management and planning of diet is discussed. It is shown that diet solutions, obtained by simple optimizations, are not necessarily best suitable for the optimum operation of the CELSS.
Technical Paper

Options for Transpiration Water Removal in a Crop Growth System Under Zero Gravity Conditions

1991-07-01
911423
Abstract The operation of a crop growth system in micro-gravity is an important part of the National Aeronautics and Space Administration's Closed Ecological Life Support System development program. Maintaining densely arrayed plants in a closed environment imposed to induce high growth rates must be expected to result in substantial levels of water transpiration rate. Since the environmental air is recirculated, the transpiration water must be removed. In an operating CELSS, it is expected that this water will provide potable water for use of the crew. There is already considerable knowledge about water removal from crew environmental air during orbital and transfer activities, and the difference between the conditions of the described requirement and the conditions for which experience has been gained is the quantities involved and the reliability implications due to the required periods of operation.
Technical Paper

Bioregenerative Life Support: The Initial CELSS Reference Configuration

1991-07-01
911420
As extended manned space missions and permanent bases become integral components of future space exploration, a Controlled Ecological Life Support System (CELSS) could provide numerous advantages, including reduced launch mass over the life of a long-term mission, fewer and less time-critical logistic revisits, and a better crew environment (e.g., cleaner air, water, and fresh food). Because of the enabling nature of this technology it is important that it be proven and available to mission planners as soon as practicable, consistent with the requirements of the overall exploration strategy. The next major step in developing an operational CELSS is the development of a human-rated CELSS ground-based demonstrator that will supply the proof-of-concept for the use of a CELSS on a mission.
Technical Paper

SAX: A Thermal Control Design for a Scientific Satellite

1991-07-01
911407
SAX (Satellite Astronomia Raggi-X) is the Italian Satellite devoted to study in the X-Ray wavelengths. X-rays in the range 300 keV to 0.1 keV will be observed over a wide field by means of 8 Scientific Instruments. The SAX orbit is circular with an altitude of 600 km and a maximum inclination of 5°. A life of 26 months is foreseen. The Thermal Control Design, which will make use of Passive Thermal Control elements ( Heaters, MLI, Paints), shall guarantee the best thermal environment for the Scientific Instruments. This includes not only control of the temperature level, but also of the magnitude of temperature gradients between different sides of the same Instrument. Naturally, the thermal control features must not obstruct the Instrument Field of View (FoV). The TCS shall also control the temperature of all the other Satellite equipment such as the Battery, Propulsion (Hydrazine) elements (Tank, Thrusters and Lines), and AOCS sensors.
Technical Paper

Evolutionary Development of a Lunar CELSS

1991-07-01
911422
This paper describes an evolutionary method of technology integration for the development of a Lunar base life support system. The baseline is a partially-closed Regenerative Life Support System (RLSS) based upon Space Station Freedom physicochemical technology. The paper describes the stepwise evolution of this baseline system into a closed-loop, Lunar base Controlled Ecological Life Support System (LCELSS), a hybrid design which incorporates both physicochemical and bioregenerative technologies. The steps taken in the evolutionary process are derived from a rationale which addresses: 1) the incorporation of specific bioregenerative functions into the life support system, 2) the supplementation of specific physicochemical functions with bioregenerative systems, 3) the replacement of initial physicochemical technologies with more advanced technologies, and 4) the addition of new physicochemical technologies.
Technical Paper

A Feed-Back Thermal Regulation System for the Columbus Free Flyer Battery Section

1991-07-01
911409
Abstract The BSTCA (Battery Section Thermal Control Assembly) is a module of the Columbus MTFF (Man Tended Free Flyer). Electrical power required during eclipse periods, is made available from six nickel hydrogen batteries. A sophisticated multi-radiator configuration, with a hybrid heat pipe network, has evolved. Autonomous control of the assembly heat rejection capability has been achieved by a integrated network of LTHP's (Liquid Trap Heat Pipes) and CCHP's (Constant Conductance Heat Pipes) under the control of a conventional HCU (Heater Control Unit). The process of design selection and verification is discussed, for the BSTCA, with a detailed LTHP component presentation.
Technical Paper

Bioburden Control for Space Station Freedom's Ultrapure Water System

1991-07-01
911405
Bioburden Control is one of the challenges for the Ultrapure Water System on Space Station Freedom. Bioburden Control must enable the system to deliver water with a low bacterial count (≤ 1 CFU/100 ml), as well as maintain biological contamination at a manageable level, to permit continued production of quality water. Ozone has been chosen as the primary means of Bioburden Control. Planned tests to determine the effectiveness of ozone on free-floating microbes and biofilms are described.
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