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Various topics related to closed ecological systems are discussed. Space habitats, vegetative growth, photosynthesis, recycling, culture techniques, waste utilization bioreactors and controlled atmospheres on space stations are among the topics covered.
Life support systems in space travel, in closed ecological systems were studied. Topics discussed include: (1) problems of life support and the fundamental concepts of bioregeneration; (2) technology associated with physical/chemical regenerative life support; (3) projection of the break even points for various life support techniques; (4) problems of controlling a bioregenerative life support system; (5) data on the operation of an experimental algal/mouse life support system; (6) industrial concepts of bioregenerative life support; and (7) Japanese concepts of bioregenerative life support and associated biological experiments to be conducted in the space station.
Biochemical fuel cell - an answer to waste management in closed ecological systems - electric energy source
Acceptable nonmetallic materials for closed ecological systems
Organization of closed ecological systems for prolonged manned space flight
Studies with algal cultures which relate to closed ecological life support systems (CELSS) are discussed. A description of a constant cell density apparatus for continuous culture of algae is included. Excretion of algal by-products, and nitrogen utilization and excretion are discussed.
Trace contaminants isolated during simulated manned spacecraft conditions, and testing of closed ecological system involving 5 men for 30 days
Spin inertia culture system in waste treatment in closed ecological system
Effects of ultraviolet radiation on photosynthesis of plants as related to closed ecological system
Assuming that crops grown in controlled ecological life-support systems (CELSS) should provide a basis for meals that are both nutritious and attractive (to taste and vision), and that CELSS diets on the moon or Mars or in space-craft during long voyages will have to be mostly vegetarian, a workshop was convened at the Johnson Space Center, Houston, Texas, U.S.A. on 19 to 21 January, 1994. Participants consisted of trained nutritionists and others; many of the approximately 18 presenters who discussed possible diets were practicing vegetarians, some for more than two decades. Considering all the presentations, seven conclusions (or points for discussion) could be formulated: nutritious vegetarian diets are relatively easily to formulate, vegetarian diets are healthy, variety is essential in vegetarian diets, some experiences (e.g., Bios-3 and Biosphere 2) are relevant to planning of CELSS diets, physical constraints will limit the choice of crops, a preliminary list of recommended crops can be formulated, and this line of research has some potential practical spinoffs. The list of crops and the reasons for including specific crops might be of interest to professionals in the field of health and nutrition as well as to those who are designing closed ecological systems.
A collection of technical reports on research conducted by the participants in this program is presented. The topics covered include: human-computer interface software, multimode fiber optic communication links, electrochemical impedance spectroscopy, rocket-triggered lightning, robotics, a flammability study of thin polymeric film materials, a vortex shedding flowmeter, modeling of flow systems, monomethyl hydrazine vapor detection, a rocket noise filter system using digital filters, computer programs, lower body negative pressure, closed ecological systems, and others. Several reports with respect to space shuttle orbiters are presented.
Planning in Controlled Ecological Life Support Systems (CELSS) requires special look ahead capabilities due to the complex and long-term dynamic behavior of biological systems. This project characterizes the behavior of CELSS, identifies the requirements of intelligent planning systems for CELSS, proposes the decomposition of the planning task into short-term and long-term planning, and studies the crop scheduling problem as an initial approach to long-term planning. CELSS is studied in the realm of Chaos. The amount of biomass in the system is modeled using a bounded quadratic iterator. The results suggests that closed ecological systems can exhibit periodic behavior when imposed external or artificial control. The main characteristics of CELSS from the planning and scheduling perspective are discussed and requirements for planning systems are given. Crop scheduling problem is identified as an important component of the required long-term lookahead capabilities of a CELSS planner. The main characteristics of crop scheduling are described and a model is proposed to represent the problem. A surrogate measure of the probability of survival is developed. The measure reflects the absolute deviation of the vital reservoir levels from their nominal values. The solution space is generated using a probability distribution which captures both knowledge about the system and the current state of affairs at each decision epoch. This probability distribution is used in the context of an evolution paradigm. The concepts developed serve as the basis for the development of a simple crop scheduling tool which is used to demonstrate its usefulness in the design and operation of CELSS.
Bioregenerative life support systems will be an essential part of long duration manned space flight. Studies have been made of various components of these closed ecological systems. these studies have included those spaceborne experiments on Spacelab and Mir, as well as ground-based simulations. The effects of reduced gravity include alterations in food crop and other plant growth and vigor. Systems have also been designed and tested to provide a balanced regenerative system that recycles airborne and other wastes while providing nutrients and other input for future cycles. Hydroponic cultivation must include control of pathogens. All closed systems require sensing and automatic control.
Sweet potatoes were grown hydroponically using the nutrient film technique (NFT) in support of the Closed Ecological Life Support System (CELSS) program. Experiments in the greenhouse with the TI-155 sweet potato cultivar produced up to 1790 g/plant of fresh storage roots. Studies with both TI-155 and Georgia Jet cultivars resulted in an edible biomass index of approximately 60 percent, with edible biomass linear growth rates of 12.1 to 66.0 g m(exp -2)d(exp -1) in 0.05 to 0.13 sq meters in 105 to 130 days. Additional experimental results are given. All studies indicate good potential for sweet potatoes in CELSS.
Studies were conducted to scope the principal areas of technology that can contribute to the development of closed-ecology life support systems (CELSS). Such systems may be required for future space activities, such as space stations, manufacturing facilities, or colonies. A major feature of CELSS is the regeneration of food from carbon in waste materials. Several processes, using biological and/or physico-chemical components, have been postulated for closing the recycle loop. At the present time, limits of available technical information preclude the specification of an optimum scheme. Nevertheless, the most significant technical requirements can be determined by way of an iterative procedure of formulating, evaluating and comparing various closed-system scenario. The functions features and applications of this systems engineering procedure are discussed.
A total of nine chlorinated ethanes and ethenes were circulated over lithium hydroxide in a laboratory scale closed system simulator. System volume and lithium hydroxide temperature were varied from that intended to maximize possible reactions to conditions approximating those of a space cabin environment. Of the nine compounds tested, seven were found to be dehydrohalogenated (viz., loss of hydrogen chloride) in the course of one or more experimental treatments. Of particular significance was the conversion of 1,2-dichloroethane to chloroethene, a known carcinogen, and of trichloroethene to dichloroethyne, a highly toxic substance. It is therefore concluded that a potentially hazardous situation exists for the inhabitants of closed ecological systems such as spacecraft, one for which precautions must continue to be taken.
While this third volume of the bibliography was in preparation, a number of changes and new developments took place which, it is hoped, will be instrumental in furthering the bibliography's main objective: to provide as rapidly as possible comprehensive coverage of the aerospace-medical and bio-astronautical literature. To begin with, it will be noted that the title of the compilation has been changed from Aviation Medicine to Aerospace Medicine and Biology. This will bring into relief the fact that the general subject scope of the bibliography has been expanded to include new areas of interest in space-medical and space-biological research. Thus, to the subject fields heretofore covered by the bibliography (a full listing of which may be found in the Preface to Volume 2) new ones have been added, such as Biological Rhythms, Biological Orientation, Closed Ecological Systems, Physiological and Psychological Effects of Heat, Cold, Isolation, Restraint, and many others. Another important change was administrative in nature. Sponsorship of the bibliography for the fiscal year 1959/60 was taken over by the U. S. Advanced Research Project Agency (ARPA), the U. S. Aeronautics and Space Administration (NASA), and the Defense Research Board of Canada. Under a substantially increased budget, the Library of Congress was enabled to produce two volumes during the fiscal year. The Library also agreed to prepare selected abstracts from the current aerospace and bio-astronautic literature, which are published monthly in Aerospace Medicine, the official organ of the Aerospace Medical Association.*) If the present rate of production can be maintained, it will be possible to bring the bibliography up to date within about three years. In format, style, and arrangement, this volume follows closely the preceding ones. References are arranged alphabetically by author; abstracts are informative; and full bibliographic information is provided, including foreign and translated titles, volume and issue numbers, place of publication (if foreign), inclusive paging, full dates, and library call numbers or other location symbols. While the bulk of the publication is devoted to journal articles, reports, and monographs published during the year 1954, items published in 1952 or 1953 not included in the preceding volumes have been incorporated in this volume. For quick identification, the publication years of these off-year references have been printed next to the first author's name. As before, cumulated corporate and secondary author and subject indexes are included, the latter being revised and enlarged considerably, in keeping with the over-all expansion of subject scope.
Waste stabilization in closed ecological systems of manned space environments