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A mathematical model was developed in order to predict quantities of CO2 and O2 gas exchange, transpiration, biomass production, food production and nutrient absorption by candidate crops in Closed Ecology Experiment Facilities (CEEF) in which material recycling in a controlled ecological life support system (CELSS) is to be made. This model includes effects of physical parameters such as light intensity, air temperature, humidity and atmospheric CO2 concentration on these processes and plant aging effect on these processes. Using results from experiments in which candidate crops were grown under controlled environment and data from literature, mathematical models for each crop was given physiological parameters. Then, changes in biomass and food accumulation, gas exchange and transpiration of each crop with time were calculated.

The catalytic Wet-Oxidation process is the most feasible candidate for the waste management process of CELSS in comparison with other applicable technologies such as dry incineration, vapor compression distillation, etc. In this report we try and discuss the design of a Wet-Oxidation Waste Management Process which supports 1 person's life in a closed system. The proposed Wet-Oxidation Waste Management process treats the waste by a two-step reaction. Planned capacity is approximately 2.5kg- dry/day. A design concept, schematic flow and basic configuration of Wet-Oxidation apparatus are considered and discussed in this paper.

Selected vegetables for life support are continuously produced in the lunar farming module. Inedible parts of the vegetables are decomposed and provided as the fertilizer elements for the next vegetables. In this report, contained elements in their inedible mass for recyclingare discussed for each of the four vegetables. Elements and concentration of cultural liquid which are required by each vegetable are surveyed as well. Adjustment of decomposition liquid is discussed in view of transforming inedible vegetable to cultural liquid. Authors are proposing wet oxidization as one of the decomposition methods for these inedible parts. Some adjusting sub-system is necessary here, since elements and their concentration in decomposition liquid is not enough to reproduce vegetables. This report aims to clarify the composition of a vegetable production system for an eight-member

A series of experiments to evaluate performance of catalysts for CELSS System Wet-oxidation process has been carried out. Data obtained from the experiments show that the noble metal selected for the catalyst gives a good performance in oxidizing Organic Carbon and Organic Nitrogen. The data also show that a catalyst with certain amount of the metal (wt%) shows maximum efficiency in the oxidation; in addition, a catalyst with a different amount of metal gives good performance in producing high quality fertilizer.

Developments of many subsystems, such as gas separater, water purifier, decomposition unit of waste materials and others, are necessary to construct the closed loop life support test facility for studying the material circulationin earth environment and for human habitation in space. On the other hand, in order to develop and integrate these subsystems infacility, the designing paramaters of each subsystem are to be determined based on the required material flows estimation. The required material flows are very complicated and difficult to be analyzed. Therefore the trade study method for determining the design paramaters of each subsystem is to be integrated based on the break down of system configulation Level as below. Level-0 is the material flow level between the total closed loop life support facility and outside. Level-1 is the material flow level between the plantation, habitat and animal breeding modules and their supporting systems.

The Closed Ecology Experimental Facilities (CEEF), is designed to simulate material circulation, and is an artificial closed agricultural ecosystem with plants, humans and animals. The first seven-day air circulated confinement experiments using the CEEF were conducted three times. The experiments included psychological monitoring of two crew members named “Eco-nauts”. Even though there was some trouble with the CEEF regarding the atmospheric gases (which one of the Eco-nauts discovered himself), all three experiments were completed without critical problems and both Eco-nauts maintained a stable psychological status. Through the experiments, it was found that the interior environment of the CEEF could fluctuate within short time periods, and that frequent monitoring by the instantaneous and sensitive Face Scale Test allowed scoring of the Eco-nauts' response to such fluctuations.

The plant system plays roles of edible biomass production, O2 production, CO2 removal, and so on, in bioregenerative life support systems. In order to simulate the edible and inedible biomass production and gas exchange of crops, it is necessary to construct reliable dynamic prediction models for each crop considering not only short-term environmental effects but also its long-term effects, because response of plant system is highly dependent on plant age, plant size, and environmental condition experienced by the plant. Closed Plantation Experiment Facility (CPEF) of Closed Ecology Experiment Facilities (CEEF) has three plantation chambers with artificial lighting system, which has maximum capability for providing PPFD of approximately 1900 μmol·m-2·s-1 for crops at canopy top level in these chambers. Each even-aged population of rice and soybean was grown in each plantation chamber.

In order to prolong the duration of manned missions around the earth and to expand the human existing region from the earth to other planets such as a Lunar Base or a manned Mars flight mission, the CELSS becomes an essential factor of the future technology to be developed through utilization of Space Station. The preliminary SE&I (System Engineering and Integration) efforts regarding CELSS have been carried out by the Japanese CELSS concept study group for clarifying the feasibility of hardware development for Space Station Experiments and for getting the time phased mission sets after Fy 1992. The results of these studies are breifly summarized and thereafter, the design and utilization methods of a Gas Recycle System for CELSS experiments are discussed.

Recycling human and animal excreta is an important part of the proposed Closed Ecology Experiment Facility (CEEF) in Japan. This paper introduces a conceptual design for the waste collection and transfer system. Mineral-rich wastes such as urine and wool grease must be separated from other wastes to recover the minerals. Solids and liquids also require separate handling methods. Our design uses inclined conveyer belts to separate feces and urine. A fluorocarbon polymer coating prevents wastes from sticking to the belt. In-line freezers are used to solidify liquid wastes and retard premature decomposition. A summary of available data on animal excreta is included, but there is a distinct shortage of useful information. This data is insignificant for usual biology or animal husbandry, but is essential for designing the self-contained environment.

In the Closed Ecology Experiment Facilities (CEEF), with integrating the Closed Plantation Experiment Facilities (CPEF) and the Closed Animal Breading & Habitation Facilities (CABHF), closed habitation experiments without material exchange with the outside will be conducted after the 2005 fiscal year. Cultivation experiments of about 30 crops and the integrating test of the material circulation system required for the closed habitation experiments have been performed since 2000 fiscal year. Using data reported in these experiments, material circulation in CEEF is simulated based on the recent operation strategy, and the storage capacity needed for the buffer of an air processing subsystem was estimated. In order for two humans to dwell over 120 days, the storage capacities of the carbon dioxide tank, the oxygen tank, and the waste gas tank in CPEF, and the carbon dioxide tank and the oxygen tank in CABHF are 820 g, 2830 g, 4425 g, 1780 g, and 1792 g, respectively.

Construction of Closed Ecology Experiment Facilities (CEEF) is started in Rokkasho village of Aomori prefecture, the northern part of Honshu island in Japan. CEEF consist of Closed Plant Experiment Facility (CPEF) and Closed Geo-Hydrosphere Experiment Facility (CGEF) with capability to simulate ecological systems containing plants, animals, human, trees and sea living things. These biospecies are selected according to experimental plans and are maintained their lives in controlled environments. Recyclings of materials circulating in the closed system of CEEF are made mainly utilizing physical chemical treatments. The construction of CEEF will be completed by 1998. This paper mainly describes design of CPEF.

In the closed environments, removal of trace contaminants generated from persons, animals, and plants is important function to keep the environment below the allowable level. We conducted the fundamental tests in order to confirm design of TCCA (Trace Contaminants Control Assembly) for Closed Ecology Experiment Facilities (CEEF), and obtained the following results; 1) The palladium-on-alumina catalyst is suitable for CO, CH4, C2H4 conversion at temperature lower than 400°C. 2) The alkali impregnated AC (activated charcoal) is effective for NO2, SO2 removal and prevents catalyst poisoning from SO2. 3) The active-desorbing conducted by hot air blow-throw an AC is effective for C2H5OH, CH2Cl2 desorbing. We discuss the fundamental test and design conditions for TCCA.

The front half of the nitrogen fixation system, which is one of the subsystems of Controlled Ecological Life Support System (CELSS), or NH3 synthesis loop at atmospheric pressure, was studied. The NH3 separation essential in the loop is discussed. The NH3-PSA method was newly developed, since the NH3-PSA was evaluated best among separation methods from the viewpoints of CELSS criteria. It is essential to retain the H2/N2 ratio in the outlet gas the same as that of the inlet gas to the PSA. From the experimental result of PSA a material balance of the NH3 synthesis loop was calculated. Additionally a material balance of the overall process was calculated by assuming some performances in the down stream sections of the NH3 synthesis loop.

The closed ecology experiment facility (CEEF) has a small positive pressure control system consisting of rubber buffers and a mechanical subsystem. In the present study, effects of small temperature disturbances caused by changes of surrounding conditions on the pressure control system are investigated experimentally and in numerical simulations. Though solar radiation causes a pressure disturbance in the facility, choosing the proper diameter of ducts which connect the rubber buffers to the modules, the rubber buffers can follow fluctuations of low frequency, like daily atmospheric fluctuations and pressure changes caused by temperature control of the facility’s air conditioners, and can cut off those of high frequency due to changes of environmental conditions.

Preliminary seven-day habitation experiments without complete closure of the habitation module were performed in the Closed Ecology Experiment Facilities (CEEF) to obtain information for the closed habitation and to prepare for the actual closed habitation experiments to be launched in September 2005. Energy requirements have been estimated for habitant candidates in closed habitation experiments (to be called Eco-nauts). This paper presents the calculations of Eco-nauts' energy requirements using records of life activities during the preliminary experiments and compares them with the expected energy supply from the CEEF.

Closed habitation experiments are to be carried out using Closed Ecology Experiment Facilities (CEEF) from FY2005 to FY2009. The last target of duration of closed habitation is four months. Preliminary study and testing have been conducted in order to carry out the closed habitation experiments. The CEEF has three closed plantation chambers (PC-A, B and C) with artificial lighting solely having each cultivation area of 30 m2 and a closed plantation chamber (PC-F) with both natural lighting and supplemental artificial lighting having a 60-m2 cultivation area. A ‘stable’ period of sequential crop cultivation was maintained for four weeks in a trial experiment conducted in FY2003 using the Plantation Module (PM), in which rice, soybean and crops including rice sapling, soybean sapling, soybean, peanuts and safflower were cultivated in PC-A, PC-B, PC-C and PC-F, respectively. Amount of total clean water input to PM was 741 L day−1 on the average for the period.

As a CO2 removing and recovering technology, the solid amine utilized as a vacuum desorbing type was developed. The evaluation experiments to measure fundamental characteristics of this material was conducted using the dry air and as the results, the high adsorbing rate, 10 wt% for short period and 7 wt% for long period was obtained and also 7 wt% of adsorbing rate can be expected for the operation of desorption temperature of 80 °C. High accuracy thermobalance device so called thermogravimetric analyzer was utilized to measure adsorption and desorption values of CO2.

Nitrogen Fixation Systems(NFS) suitable for plant cultivation in a closed environment have been studied through experimental verification. The system is composed of physico-chemical processes only. Nitrogen gas and water are fed into the system as raw materials,and ammonia and ammonium nitrate solution are produced as final products, which are utilized as main fertilizers in plant cultivation. Each elemental chemical process in NFS is selected with regard to unique design criteria concerning safety, energy effectiveness, compactness and reliability. An experimental apparatus for important unit processes has been made for the purpose of verifying process data. A detail design for nitrogen fixation facilities, planned for construction as the first Japanese CELSS laboratory, was carried out.

In CEEF(Closed Ecological Experiment Facility) which is the first Japanese CELSS experiment facility, the ammonia and ammonium nitrate production system is a nitrogen fixation system as a part of nitrogen circulation system. Nitrogen and water which are input materials to the system are processed to produce ammonia water and ammonium nitrate solution as raw materials of fertilizer for plant cultivation. The design basis of the system is to convert 125g/day of nitrogen to ammonia and ammonium nitrate based on the amount of one person's metabolism. Experiment of the system has been carried out and we have studied characteristics of the system.

As a part of CEEF, a hydro-sphere experiment system has been installed in the air-tight hydro-sphere chamber built in fiscal 1997. Environmental factors in the chamber such as air composition, temperature and humidity could be fully controlled from 360 to 2000ppmCO2, from 20 to 30°C and 70%RH respectively using air composite adjusting system and air-conditioner. In this chamber having 640m3, three aquariums having 20m3 volume each have been installed. One of those aquarium will be used for the sea water buffer, the other two will be used for breeding living organisms such as small animals and macro-algae. A water reclamation system also has been installed in addition to those aquariums, and sea water is to be circulated at the rate of 20m3/3days between those aquariums and this reclamation system in order to realize the simulated sea water eco-system. The water reclamation system is composed of a membrane filter and bio-filter.