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At least 217 records · Page 12

Controlled Ecological Life Support System: Regenerative Life Support Systems in Space

A wide range of topics related to the extended support of humans in space are covered. Overviews of research conducted in Japan, Europe, and the U.S. are presented. The methods and technologies required to recycle materials, especially respiratory gases, within a closed system are examined. Also presented are issues related to plant and algal productivity, efficiency, and processing methods. Computer simulation of closed systems, discussions of radiation effects on systems stability, and modeling of a computer bioregenerative system are also covered.

Macelroy, Robert D.↗

Controlled Ecological Life Support Systems (CELSS) physiochemical waste management systems evaluation

Parametric data for six waste management subsystems considered for use on the Space Station are compared, i.e.: (1) dry incineration; (2) wet oxidation; (3) supercritical water oxidation; (4) vapor compression distillation; (5) thermoelectric integrated membrane evaporation system; and (6) vapor phase catalytic ammonia removal. The parameters selected for comparison are on-orbit weight and volume, resupply and return to Earth logistics, power consumption, and heat rejection. Trades studies are performed on subsystem parameters derived from the most recent literature. The Boeing Engineering Trade Study (BETS), an environmental control and life support system (ECLSS) trade study computer program developed by Boeing Aerospace Company, is used to properly size the subsystems under study. The six waste treatment subsystems modeled in this program are sized to process the wastes for a 90-day Space Station mission with an 8-person crew, and an emergency supply period of 28 days. The resulting subsystem parameters are compared not only on an individual subsystem level but also as part of an integrated ECLSS.

Oleson, M.↗

Growth of plant tissue cultures in simulated lunar soil: Implications for a lunar base CELSS (Controlled Ecological Life Support System)

Experiments were carried out on plant tissue cultures, seed germination, seedling development and plants grown on Simulated Lunar Soil to evaluate the potential of future development of lunar based agriculture. The studies done to determine the effect of the placement of SLS on tissue cultures showed no adverse effect of SLS on tissue cultures. Although statistically insignificant, SLS in suspension showed a comparatively higher growth rate. Observations indicate the SLS, itself cannot support calli growth but was able to show a positive effect on growth rate of calli when supplemented with MS salts. This positive effect related to nutritive value of the SLS was found to have improved at high pH levels, than at the recommended low pH levels for standard media. Results from seed germination indicated that there is neither inhibitory, toxicity nor stimulatory effect of SLS, even though SLS contains high amounts of aluminum compounds compared to earth soil. Analysis of seeding development and growth data showed significant reduction in growth rate indicating that, SLS was a poor growth medium for plant life. This was confirmed by the studies done with embryos and direct plant growth on SLS. Further observations attributed this poor quality of SLS is due to it's lack of essential mineral elements needed for plant growth. By changing the pH of the soil, to more basic conditions, the quality of SLS for plant growth could be improved up to a significant level. Also it was found that the quality of SLS could be improved by almost twice, by external supply of major mineral elements, directly to SLS.

Venketeswaran, S.↗

Carbon recycling in materially closed ecological life support systems

Results of studies are presented of materially closed energetically open microbial ecosystems or 'closed ecosystems'. These are natural marine ecosystems that have been sealed in glass containers to prevent material exchange with the environment but allow energy to pass freely through them. They represent model life support systems for the future human habitation of space. The results are discussed analytically and indicate that these ecosystems, when subjected to a constant energy flux, seem to be reliable and self-sufficient systems for recycling of biologically produced carbon compounds.

Obenhuber, D. C.↗

Controlled Ecological Life Support System

The NASA CELLS program is based upon the integration of biological and physiochemical processes in order to produce a system that will produce food, a breathable atmosphere, and potable water from metabolic and other wastes. The CELSS concept is described and a schematic system diagram is provided. Central to the CELSS concept is the Plant Growth Chamber, where green plant photosynthesis produces food, and aids in the production of oxygen and water. Progress to date at the Breadboard Facility at the Kennedy Space Center is summarized. The Breadboard Facility will implement the basic techniques and processes required for a CELSS based on photosynthetic plant growth in a ground-based system of practical size and results will be extrapolated to predict the performance of a full-sized system. Current available technology and near-future forecasts for plant growth techniques (focusing on maximum productivity), food sources (to select optimal CELSS plants), and waste management and contaminant control are discussed.

Averner, Maurice M.↗

Closed Ecological Life Support Systems (CELSS) Test Facility

The CELSS Test Facility (CTF) is being developed for installation on Space Station Freedom (SSF) in August 1999. It is designed to conduct experiments that will determine the effects of microgravity on the productivity of higher (crop) plants. The CTF will occupy two standard SSF racks and will accommodate approximately one square meter of growing area and a canopy height of 80 cm. The growth volume will be isolated from the external environment, allowing stringent control of environmental conditions. Temperature, humidity, oxygen, carbon dioxide, and light levels will all be closely controlled to prescribed set points and monitored. This level of environmental control is needed to prevent stress and allow accurate assessment of microgravity effect (10-3 to 10-6 x g). Photosynthetic rates and respiration rates, calculated through continuous recording of gas concentrations, transpiration, and total and edible biomass produced will be measured. Toxic byproducts will be monitored and scrubbed. Transpiration water will be collected within the chamber and recycled into the nutrient solution. A wide variety of crop plants, e.g., wheat, soy beans, lettuce, potatoes, can be accommodated and various nutrient delivery systems and light delivery systems will be available. In the course of its development, the CTF will exploit fully, and contribute importantly, to the state-of-art in closed system technology and plant physiology.

Macelroy, Robert D.↗

Controlled Ecological Life Support System (CELSS) modeling

Attention is given to CELSS, a critical technology for the Space Exploration Initiative. OCAM (object-oriented CELSS analysis and modeling) models carbon, hydrogen, and oxygen recycling. Multiple crops and plant types can be simulated. Resource recovery options from inedible biomass include leaching, enzyme treatment, aerobic digestion, and mushroom and fish growth. The benefit of using many small crops overlapping in time, instead of a single large crop, is demonstrated. Unanticipated results include startup transients which reduce the benefit of multiple small crops. The relative contributions of mass, energy, and manpower to system cost are analyzed in order to determine appropriate research directions.

Drysdale, Alan↗

Lunar base Controlled Ecological Life Support System (LCELSS): Preliminary conceptual design study

The objective of this study was to develop a conceptual design for a self-sufficient LCELSS. The mission need is for a CELSS with a capacity to supply the life support needs for a nominal crew of 30, and a capability for accommodating a range of crew sizes from 4 to 100 people. The work performed in this study was nominally divided into two parts. In the first part, relevant literature was assembled and reviewed. This review identified LCELSS performance requirements and the constraints and advantages confronting the design. It also collected information on the environment of the lunar surface and identified candidate technologies for the life support subsystems and the systems with which the LCELSS interfaced. Information on the operation and performance of these technologies was collected, along with concepts of how they might be incorporated into the LCELSS conceptual design. The data collected on these technologies was stored for incorporation into the study database. Also during part one, the study database structure was formulated and implemented, and an overall systems engineering methodology was developed for carrying out the study.

Schwartzkopf, Steven H.↗

Resource recovery and epidemiology of anaerobic wastewater treatment process in a controlled ecological life support system

The results of work accomplished under two different areas: (1) Resource Recovery of an Anaerobic Wastewater Treatment process, and (2) Epidemiological Study of an Anaerobic Wastewater Treatment Process are documented. The first part of the work was to set up and test three anaerobic digesters and then run these three digesters with a NASA-simulated wastewater. The second part of the work was to use a multi-drug resistant strain of Salmonella choleraesuis as the indicator bacteria for the epidemiological study. Details of these two parts can be found in two master's theses and are described in Sections 3 and 4 of this report. Several important results condensed from these two parts are summarized in Section 2.

Li, Ku-Yen↗

Controlled ecological life support systems (CELSS) flight experimentation

The NASA CELSS program has the goal of developing life support systems for humans in space based on the use of higher plants. The program has supported research at universities with a primary focus of increasing the productivity of candidate crops plants. To understand the effects of the space environment on plant productivity, the CELSS Test Facility (CTF) has been conceived as an instrument that will permit the evaluation of plant productivity on Space Station Freedom. The CTF will maintain specific environmental conditions and collect data on gas exchange rates and biomass accumulation over the growth period of several crop plants grown sequentially from seed to harvest. The science requirements for the CTF will be described, as will current design concepts and specific technology requirements for operation in micro-gravity.

Kliss, M.↗

Monitoring ethylene emissions from plants cultured for a controlled ecological life support system

Emission of hydrocarbons and other volatile compounds by materials and organisms in closed environments will be a major concern in the design and management of advanced life support systems with a bioregenerative component. Ethylene, a simple hydrocarbon synthesized by plants, is involved in the elicitation of a wide range of physiological responses. In closed environments, ethylene may build up to levels which become physiologically active. In several growouts of 'Yecora Rojo' wheat in Kennedy Space Center's Biomass Production Chamber (BPC), it was observed that leaf flecking and rolling occurred in the sealed environment and was virtually eliminated when potassium permanganate was used to scrub the atmospheric environment. It was suggested that ethylene, which accumulated to about 60 ppb in the chamber and which was effectively absorbed by potassium permanganate, was responsible for the symptoms. The objectives of this work were to: (1) determine rates of ethylene evolution from lettuce (Lactuca sativa cultivar Waldemann's Green) and wheat (Triticum aestivum cultivar Yecora Rojo) plants during growth and development; (2) determine the effects of exposure of whole, vegetative stage plants to exogenous ethylene concentrations in the range of what would develop in closed environment growth chambers; and (3) develop predictive functions for changes in ethylene concentration that would develop under different cropping and closed environment configurations. Results will lead to the development of management strategies for ethylene in bioregenerative life support systems.

Corey, Kenneth A.↗

A data acquisition system for marine and ecological research.

Description of a self-contained portable data acquisition system for use in marine and ecological research. The compact lightweight data acquisition system is capable of recording 14 variables in its present configuration and is suitable for use in either a boat, pickup truck, or light aircraft. This system will provide the acquisition of reliable data on the structure of the environment and the effect of man-made and natural activities on the observed phenomenon. Utilizing both self-contained analog recording and a telemetry transmitter for real-time digital readout and recording, the prototype system has undergone extensive testing. Currently undergoing component performance upgrading, the prototype system has been utilized in several environmental science investigations associated with air pollution investigations and weather modification and is currently being used for marine data acquisition.

Johnson, R. A.↗

Long Term Ecological Research Main Cropping System Experiment

We leverage the Kellogg Biological Station Long Term Ecological Research Main Cropping System Experiment (KBS MCSE) field experiment to test trade-offs among high growth yield (Y), resource acquisition (A), and stress tolerance (S) traits using metagenomic data from plots with different land use, drought manipulation, and C addition.

Jones, Jennifer M.↗

Controlled Ecological Life-Support Systems

Document contains proceedings of February, 1989 meeting of Scientists of NASA's Controlled Ecological Life Support Systems (CELSS) program. Includes 25 scientific papers and bibliography of CELSS documents published as NASA reports.

Macelroy, Robert D.↗

Microgravity particle reduction system

The Controlled Ecological Life Support System (CELSS) project, sponsored by NASA, is assembling the knowledge required to design, construct, and operate a system which will grow and process higher plants in space for the consumption by crew members of a space station on a long term space mission. The problem of processing dry granular organic materials in microgravity is discussed. For the purpose of research and testing, wheat was chosen as the granular material to be ground into flour. Possible systems which were devised to transport wheat grains into the food processor, mill the wheat into flour, and transport the flour to the food preparation system are described. The systems were analyzed and compared and two satisfactory systems were chosen. Prototypes of the two preferred systems are to be fabricated next semester. They will be tested under simulated microgravity conditions and revised for maximum effectiveness.

Brandon, Vanessa↗

Bioregenerative technologies for waste processing and resource recovery in advanced space life support system

The Controlled Ecological Life Support System (CELSS) for producing oxygen, water, and food in space will require an interactive facility to process and return wastes as resources to the system. This paper examines the bioregenerative techologies for waste processing and resource recovery considered for a CELSS Resource Recovery system. The components of this system consist of a series of biological reactors to treat the liquid and solid material fractions, in which the aerobic and anaerobic reactors are combined in a block called the Combined Reactor Equipment (CORE) block. The CORE block accepts the human wastes, kitchen wastes, inedible refractory plant materials, grey waters from the CELLS system, and aquaculture solids and processes these materials in either aerobic or anaerobic reactors depending on the desired product and the rates required by the integrated system.

Chamberland, Dennis↗