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Viewing 70801 to 70830 of 107566
1990-07-01
Technical Paper
901255
Brian L. Benson, Stuart A. Oerle, Melvin V. Kilgore
LiquidChromatogry/Mass Spectrometry (LC/MS) can improve Freedom water recovery systems testing by providing analytical information about non-volatile organic contaminants not amenable to conventional analytic techniques. A preliminary liquid chromatography method has been developed for organic acids in human urine. Using this method over twenty organic acids and related compounds can be resolved. Some of these compounds have not been reported previously from Environmental Control and Life Support System hardware testing.
1990-07-01
Technical Paper
901279
C.L. Straight, R.D. MacElroy
Under the NASA Space Biology Initiative (SBI), a CELSS Test Facility (CTF) is being planned for installation on Space Station Freedom. The CTF will be used to study the productivity of typical CELSS higher plant crops under the micro-gravity conditions of the Space Station Freedom (SSF). Such science studies will be supported under the CELSS Space Research Project (CSRP). The CTF will be used to evaluate fundamental issues of crop productivity, such as the production rates of O2, food and transpired water, and CO2 uptake. A series of precursor tests that are essential to the development of the CTF will be flown on Space Shuttle flights. The tests will be used to validate and qualify technology concepts, and to answer specific questions regarding seed germination, root/shoot orientation, water condensation and recycling, nutrient delivery and liquid/gas phase interactions.
1990-07-01
Technical Paper
901280
M. Kliss, R.D. MacElroy
Abstract Work completed to date within the NASA CELSS program suggests that the technologies needed for growing plants in the space environment are sufficiently well understood to allow an early application that would enhance the quality of life for the crew while they are in space. Specifically, the growth of salad vegetables on Space Station Freedom, and during other long duration missions, can provide psychological and dietary benefits to crewmembers. For this reason, a unit capable of producing 600 grams of edible salad vegetables, enough for one salad three times a week for a crew of four is being planned at the NASA Ames Research Center with the involvement of university scientists and engineers. Although the growth requirements for specific plants are well established, providing these requirements within the constraints of the space environment will demand preliminary space flight tests of selected technologies, and of some plant growth behaviors.
1990-07-01
Technical Paper
901269
H. A. Preisig, Tae-Yeong Lee, Frank Little
Abstract: Based on the canonical decomposition of Physical-Chemical-Biological (PCB)-systems, a prototype kernel has been developed to efficiently model alternative life-support systems. It supports (i) the work in an interdisciplinary group through an easy-to-use mostly graphical interface, (ii) modularized object-oriented model representation, (iii) reuse of models, (iv) inheritance of structures from model object to model object, (v) model data base.
1990-07-01
Technical Paper
901267
Robert C. DaLee, Allen S. Bacskay, James C. Knox
This paper presents an updated overview of the Computer Aided System Engineering and Analysis (CASE/A)-ECLSS series modeling package. CASE/A is an Environmental Control and Life Support System (ECLSS) and Active Thermal Control System (ATCS) analysis and trade study tool developed primarily for VAX mainframe usage. The program was developed under NASA MSFC contract NAS8-36407 and is currently being used by MSFC and selected support contractors to support their Space Station Freedom WP-01 ECLSS preliminary design modeling activities. Many new additions and enhancements to the program have been incorporated since the first paper was presented on the topic three years ago. An extensive components verification program was completed to assure component modeling validity based on actual test data from the Phase II comparative test program recently completed at MSFC.
1990-07-01
Technical Paper
901265
R. S. Barker, R. G. Von Jouanne
This paper contains a review of the requirements and design of the Environmental Control and Life Support System (ECLSS) for Space Station Freedom; a review of an ECLSS computer program model developed at Boeing for the complete configuration of pressurized elements or volumes; and some significant computed results from this model showing transient performance for subsystems responsible for Temperature and Humidity Control, Atmosphere Control and Supply, Air Revitalization, and Water Recovery and Management. The model referred to is a comprehensive ECLSS Model which has been developed using the G189A Environmental Control System simulation tool.(1)*. The development and potential application of the Model was presented at the 1989 ICES Conference (2). The Model has since been slightly revised and extensively operated, to obtain information regarding nominal and off-nominal ECLSS conditions onboard Space Station Freedom.
1990-07-01
Technical Paper
901262
L. A. Cioletti, S. K. Mishra, E. Richard, R. Taylor, D. L. Pierson
Abstract A comprehensive microbiological facility is being designed for use on board Space Station Freedom (SSF). Its purpose will be to conduct microbial surveillance of the SSF environment and to examine clinical specimens. Air, water, and internal surfaces will be periodically monitored to satisfy requirements for a safe environment. Crew health will remain a principle objective for every mission. This paper will review the Microbiology Subsystem capabilities planned for SSF application.
1990-07-01
Technical Paper
901263
Bruce A. McKinley
Analogous to Earth-based medical care facilities, space-based facilities must provide capability for laboratory diagnosis. A clinical laboratory system, based on commercially available devices or technologies, is being designed for space station Freedom that can be used by the crew medical officer to provide analysis of discrete samples of blood and other biological fluids. Clinical chemistry, blood gas analysis, hematology, and microbiology are planned to be available at the space station as components of the Crew Health Care System. As with many space systems, ease of use, compact size and reliability are primary guidelines. Due to the many types of blood and urine analyses that are available, clinical chemistry may be the most frequently used analytical procedure for space medicine.
1990-07-01
Technical Paper
901296
H.V. Venkatasetty
Electrochemical amperometric sensors are widely used in environmental monitoring and in biomedical applications. These sensors have selectivity, fast response time, are small in size, use very low power, are easy to use and are potentially low cost. However, the conventional aqueous electrolyte based amperometric sensors have many drawbacks: they have limited operating life because of the high vapor pressure of aqueous based electrolytes, have poor baseline stability due to the build up of reaction products, and are expensive. To overcome these limitations, Honeywell has developed a new class of electrochemical gas and vapor sensors based on nonaqueous electrolytes. These sensors have a wide operating voltage, a wide operating temperature and have the potential for a long operating life. These sensors also have multigas sensing capability.
1990-07-01
Technical Paper
901297
John R. Palmer, William P. Lloyd, Candace Campbell
Abstract This paper addresses the constraints concerning the allocation of equipment to volume within two of the pressurized, habitable modules of Space Station Freedom. This problem of topology optimization must address multiple competing constraints at various stages of the design evolution. Consistent and logical balance of conflicting location constraints is the objective in design optimization. This study defines the physical, functional, and operational constraints affecting the optimization of the Space Station Freedom Habitation and U.S. Laboratory module configurations, and discusses the evolution of their current baseline.
1990-07-01
Technical Paper
901294
Larry D. Noble, Franz H. Schubert, Rick J. Pudoka, Janie H. Miernik
Vapor Compression Distillation technology for phase change recovery of water from wastewater has evolved as a technically mature and energy efficient approach for meeting the National Aeronautics and Space Administration mission needs/goals for the near-term Space Station Freedom Program and future advanced missions such as a Lunar Base and Mars exploration. Water is essential not only for the survival of humans in space, but also for efficient and economical operation for various space stations. Life Systems, Inc., in conjunction with the National Aeronautics and Space Administration, has been developing the Vapor Compression Distillation Phase Change Concept. During the development of this technology over the past 17 years an extensive engineering and scientific database has been assembled.
1990-07-01
Technical Paper
901295
Scott B. McCray, Randi Wright Wytcherley, Dwayne T. Friesen, Rod J. Ray
Processes to remove and/or recover C02 from air are essential to the long-term success of the U.S. space program. In this paper, the results of a preliminary investigation of the use of a novel membrane-based system for removal of C02 from air are presented. Features of this technology that make it attractive include the following: 1) it is lightweight, 2) it requires no consumables or expendables, 3) it is relatively simple, and 4) it does not rely directly on other subsystems. Preliminary designs of systems for removing C02 from spacecraft cabin atmospheres and from the extravehicular mobility unit (EMU) are presented.
1990-07-01
Technical Paper
901289
Wolfram Knorr, Helmut Funke, Helmut Preiss, Gijsbert Tan
In support of the Columbus ECLSS, a technology development program has been performed on four items: Regenerative CO2 removal Trace Gas Contamination Control Trace Gas Contamination Monitoring Low Noise Variable Speed Fan This paper describes the contents and results of the concluding Subsystem Level Tests and consecutive programme extensions which concentrated on: performance of the Contamination Monitoring Unit noise generation of the Variable Speed Fan lifetime tests of the CO2 removal solid amine closed water loop operation of a solid amine CO2 removal unit
1990-07-01
Technical Paper
901293
David J. Grigger, B-j Chang, Andrew J. Kovach
The Static Feed Electrolyzer is one of the key technologies that are needed for meeting the National Aeronautics and Space Administration mission needs/goals for the near-term Space Station Freedom Program and future advanced missions such as Lunar Bases and Mars explorations. Oxygen and hydrogen are essential not only for the survival of humans in space but also for efficient and economical operation of various space systems. The Static Feed Electrolyzer technology is a very efficient tool for generating oxygen and hydrogen for various applications including propulsion, energy storage, life support and oxygen recharge for Extravehicular Activity. Life Systems, Inc., in conjunction with the National Aeronautics and Space Administration, has been developing an alkaline-based Static Feed Electrolyzer. During the development of the water electrolysis technology over the past 20 years, an extensive engineering and scientific data base has been assembled.
1990-07-01
Technical Paper
901285
Rainer Sonnenschein, Hienerwadel Karl-Otto
Methods of fire detection for space application are reviewed and compared. Arguments are given in favour of a decentralized, combined particulate and gas measurement system with highly sensitive, selective and miniaturized sensor elements. For the COLUMBUS pressurized modules this leads to a new baseline concept which now includes ionization chamber and light scattering smoke detectors in the return ducts as well as CO sensors on rack level.
1990-07-01
Technical Paper
901288
Hermann Abele, Klaus Ammann, Jochen Franzen
The COLUMBUS pressurized modules APM and PM2 are designed for a useful lifetime of 30 years. The APM, which forms part of the International Space Station, will be permanently manned with a 3-men-crew. The PM2, which is the pressurized module of the Men-Tended-Free-Flyer (MTFF) will be manned for the servicing period of 10 days followed by a 180-day unmanned period. In order to protect the crew from contamination by hazardous substances, which may be present in the cabin air, effective contamination management is required. This consists of a contamination monitoring system to detect and measure trace gases in the cabin atmosphere, and a contamination control system to be able to maintain the concentration of each potential contaminant below the maximum allowable concentration.
1990-07-01
Technical Paper
901352
Daniel J. Ehntholt, Itamar Bodek, James R. Valentine, Rudy Trabanino, Johanna Vincze, Richard L. Sauer
Abstract The process used to identify, select and design an approach to the isolation and concentration of volatile organic compounds from a water sample prior to chemical analysis in a microgravity environment is described. The Volatile Organics Concentrator (VOC) system described in this paper has been designed for attachment to a gas chromatograph/mass spectrometer (GC/MS) for analysis of volatile organics in water on Space Station. In this work, in order to rank the many identified approaches, the system was broken into three critical areas. These were gases, volatile separation from water and water removal/GC/MS interface. Five options involving different gases (or combinations) for potential use in the VOC and GC/MS system were identified and ranked. Nine options for separation of volatiles from the water phase were identified and ranked. Seven options for use in the water removal/GC column and MS interface were also identified and included in overall considerations.
1990-07-01
Technical Paper
901351
Johanna E. Vincze, Richard L. Sauer
One of the unique aspects of the Space Station is that it will be a totally encapsulated environment and the air and water supplies will be reclaimed for reuse. The Environmental Health System, a subsystem of CHeCS (Crew Health Care System), must monitor the air and water on board the Space Station Freedom to verify that the quality is adequate for crew safety. Specifically, the Water Quality Subsystem will analyze the potable and hygiene water supplies regularly for organic, inorganic, particulate, and microbial contamination. The equipment selected to perform these analyses will be commercially available instruments which will be converted for use on board the Space Station Freedom. Therefore, the commercial hardware will be analyzed to identify the gravity dependent functions and modified to eliminate them.
1990-07-01
Technical Paper
901331
Robert L. Heath, Rachel M. S. Hurd, Monica A. Madore
Abstract As mankind explores the planets, human needs for air, clean water, and food suggest that plants be carried to and exist on his colonies. The complexities of even a simple ecosystem of humans and a single plant crop require a sophisticated understanding of the interactions between atmosphere, nutrients and lifeforms. While many experiments could be done to find the relationships between mass flows and chemical/energy transformations, it would be simpler to develop a generalized model of plant growth, to validate it, and to use it to test the variations possible within a closed environment. Such a model specifically designed for a closed space system should focus on gas mass transfers through the photosynthetic processes, leaf radiation/heat balances, and the production/distribution of carbohydrates.
1990-07-01
Technical Paper
901329
Stephen R. Gustavino, Melanie M. Mankamyer, Andrea M. Gardner
Under a presidential directive, the United States has begun preparations to return to the moon. The purpose of this new initiative is not to repeat what the Apollo missions accomplished earlier, but to build on these accomplishments. President Bush has called for a long range continuing commitment to expand human presence beyond Earth orbit. This is a program that will span decades. It will establish a permanent station on the Moon and send a manned mission to Mars. The challenge is to develop the systems and technologies necessary to travel to the Moon and Mars and to provide an environment in which the crew can safely live and work in both of these new worlds. Perhaps the most critical technology to the success of these advanced missions is that related to the basic environmental control and life support system.
1990-07-01
Technical Paper
901319
John L. Wilson, B. Michael Lawson
During the continuing effort to design the Space Station Freedom extravehicular activity (EVA) life support system, NASA has extensively researched and evaluated venting and non-venting technologies. In conducting this study, NASA has concentrated on a system-level approach that emphasizes on-orbit regeneration capabilities, minimization of expendables, minimal on-orbit maintenance requirements, a four to eight hour EVA capacity, and a system weight and volume close to the Space Shuttle unit. This paper will describe various venting and non-venting technologies and review the estimated weights and volumes for the options on a component and system level. At this time, a final design concept for the Space Station extravehicular mobility unit has not been chosen.
1990-07-01
Technical Paper
901311
M. Gene Lee, Mariann F. Brown
For future extended duration, manned missions, development of life support systems that require minimum expendables, power, weight and volume are essential. The ability to produce useful materials with minimum processing by using metabolic and life support byproducts is also of great importance. Life Systems, working with the National Aeronautics and Space Administration - Johnson Space Center, has been investigating various combinations of physical, chemical, electrochemical and biological methods for this purpose. (I)* This paper describes a closed ecosystem air revitalization concept, called a Hybrid Air Revitalization System, that uses higher plants in a plant habitat for removing metabolic carbon dioxide and moisture for their photosynthesis while producing oxygen and supplemental food for crew consumption.
1990-07-01
Technical Paper
901315
C.E. George, H.S. Cullingford
A study was made to investigate the potential of microwave pretreatment as a means of enhancing enzymatic hydrolysis of waste paper and other cellulosic wastes generated in the Controlled Ecological Life Support Systems (CELSS) of long-term space missions. The experimental data obtained with high-cellulose paper showed that pretreatment at 383 K for 5 minutes with microwave irradiation resulted in 92 percent cellulose conversion to glucose compared to only 37 percent conversion without the microwave pretreatment. The microwave irradiation appears to collapse the highly crystaline structure of the cellulose matrix as exhibited in photomicrographs. Addition of acetic acid during the same process reduced significantly the enzymatic action.
1990-07-01
Technical Paper
901299
Martin Agrella, Al Kwan, Jon Zelon
This paper describes the current Space Station Freedom (SSF) Galley and Wardroom system designs which enhance crew productivity and comfort, ensure crew safety, minimize technical impacts on the SSF Environmental Control and Life Support System (ECLSS) and allow for future SSF growth/modification. The discussion presented encompasses the design definition of the Galley and Wardroom integrated systems, identification of heat loads and contaminants that affect the SSF ECLSS, and the design approach taken to incorporate localized water and air treatment to minimize the impact on the SSF ECLSS.
1990-07-01
Technical Paper
901383
Dennis M. Casserly, Dane M. Russo
The monitoring needs for Space Station Freedom were identified by examining: the experiences of past missions; ground based tests of proposed life support systems; a contaminant load model; metabolic production from an 8-person crew; and a fire scenario. Continuous monitoring is recommended for components critical for life support, and that intermittent analysis be provided for all agents that may exceed one-half the Spacecraft Maximum Allowable Concentration (SMAC). The minimum monitoring effort recommended includes continuous monitoring for: nitrogen (N2), oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO), water (H2O), hydrogen (H2), methane (CH4), non-methane hydrocarbons, aromatic hydrocarbons, refrigerants, and halons. Information on over 70 compounds is presented on the rationale for monitoring, the frequency of analysis, and concentration ranges.
1990-07-01
Technical Paper
901382
Thomas F. Limero, Robert D. Taylor, Duane L. Pierson, John T. James
The Space Station Freedom (SSF), with a 30-year projected lifetime and a completely closed-loop Environmental Control and Life Support System (ECLSS), is perhaps the ultimate “Tight Building.” Recognizing the potential for the development of “Tight Building Syndrome” (TBS), and initiating actions to minimize possible TBS occurrences on SSF, requires a multidisciplinary approach that begins with appropriate design concerns and ends with detection and control measures on board SSF. This paper will present a brief summary of current experience with TBS on Earth. While many of the circumstances and methodologies garnered from investigating tight buildings on Earth are similar to those that might be encountered aboard SSF, the Station also presents a unique environment and a special set of constraints which will require an adaptation of previous protocols. Air contamination, including volatile organic compounds and microorganisms, will be the focus of the discussion.
1990-07-01
Technical Paper
901381
Michael Boyle, Tim Ford, Ralph Mitchell, James Maki
The purpose of this research is to determine the survival of human pathogens within a water distribution system proposed for the orbiting space station. Initially we investigated the survival of opportunistic pathogenic microorganisms in water under nutrient limiting conditions. A strain of Pseudomonas aeruginosa and two strains of Staphylococcus aureus were grown to mid-log phase then transferred to a starvation regime of sterile deionized water. Cultures were incubated at 10°, 25° or 37° C and were sampled at 24 hr, 1 week, 4 weeks and 6 weeks. The viable cell density was determined by enumerating colony forming units and by directly counting cells stained with acridine orange. Neither of the Staphylococcus strains tested were detected after 1 week of starvation. Our data indicate that Pseudomonas aeruginosa can survive in deionized water at all three temperatures tested at levels exceeding 104 cells per ml.
1990-07-01
Technical Paper
901379
Anne H. Johnson, B. Keith Bounds
The emphasis is to characterize the mechanisms of bioregenerative revitalization of air and water as well as to assess the possible risks associated with such a system in a closed environment. Marsh and aquatic plants are utilized for purposes of wastewater treatment as well as possible desalinization and demineralization. Foliage plants are also being screened for their ability to remove toxic organics from ambient air. Preliminary test results indicate that treated wastewater is typically of potable quality with numbers of pathogens such as Salmonella and Shigella significantly reduced by the artificial marsh system. Microbiological analyses of ambient air indicate the presence of bacilli as well as thermophilic actinomycetes.
1990-07-01
Technical Paper
901360
C. C. Johnson, A. R. Hargens
The evolutionary history of life on Earth has occurred under the omnipresent influence of a gravitational force. The exposure to the microgravity environment of space produces an array of biochemical and physiological changes in plants and animals. These changes extend from the cellular to the whole organism level. In order to manipulate gravity as an experimental variable and to separate the effects of weightlessness from the other variables in spaceflight, it is essential to provide a source of gravity in space. The scientific user community was consulted on the potential need and science requirements for a centrifuge to be designed for and flown on Space Station Freedom.
1990-07-01
Technical Paper
901355
James M. Symons, Susan V. Muckle
Several compounds in the ersatz humidity condensate do react with iodine to form iodine-substituted organic compounds (TOI), most notably phenol, acetaldehyde, ethanol, and sodium formate. Iodination of the ersatz humidity condensate produced 3.0 to 3.5 mg/L of TOI within 24 hours. The TOI that was produced by the passage of the ersatz humidity condensate through the first iodinated resin (IR) in the adsorption system was removed by the granular activated carbon that followed. TOI detected in the final effluent was formed by the reaction of the non-adsorbable condensate compounds with the final IR in the treatment series. The activated carbon bed series in the adsorption system performed poorly in its removal of TOC. The rapid breakthrough of TOC was not surprising, as the ersatz humidity condensate contained several highly soluble organic compounds, alcohols and organic acids.