In order to collect basic data about CO₂and O₂ budgets of a plant cultural system in the CELSS, the variation of the CO₂ absorption rates of lettuce and turnips were observed during the growing period, under different conditions. The O₂ release rates were deduced from the CO₂ absorption rates. As a result, when the light intensity, the photoperiod and the atmospheric CO₂concentration increased, the rates also increased. The effects on the turnips were more significant than those on the lettuce. Turnips at 310μmol/m²/s of PPFD, 24 hours of photoperiod and 1100 ppm of CO₂ concentration grew most actively in the present experimental conditions. One turnip absorbed 33g CO₂ and released 24g O₂ for one week between 21 days and 28 days after sowing.

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Most important problem to create CELSS system to be used in space, such as Lunar Base or Manned Mars Spacecraft seems how to design and operate various material recycling subsystems in order to avoid material accumulation in the closed space constituting Lunar Base and Mars Spacecraft themselves.
Living creatures such as human beings and plants in the closed space become main parts of CELSS system, and metabolic functions of these creatures are to be fully supported by various material recycling subsystems.
Through recent studies about Lunar Base, one example of preferable CELSS configuration to be appled in Habitat Module and Plant Cultivation Module have been elucidated.
Material recycling subsystems to be installed in Plant Cultivation Module are to be composed of various systems such as dehumidifier, oxygen separation system, catalytic wet oxidation system, nitrogen fixation system including water electrolysis, ammonia and nitrate synthetic reactors and nutrient adjusting system including tanks and so on.
The required performances of such various material recycling subsystems are to be determined using precise metabolic data of various species of plants to be selected and experimented and using the transplanting sequence plan.
The plant metabolic data except for wheat and potato has not fully accumulated in the pesent stage, Therefore much of plant cultivation experiments are required to obtain such data for determining the performances of each material recycling subsystems introduced in Plant Cultivation Module.
In this papper, detailed explanations about preferable system configuration to be applied in Plant Cultivation Module and about the experimental chamber recently installed in National Aerospace Laboratory for obtaining basic metabolic data of plants are given.

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A wet oxidation is considered to be one of the most effective methods of waste processing and recycling in CELSS (Closed Ecological Life Support System). The first test using rabbit waste as raw material was conducted under a decomposition temperature of 280°C for 30minutes and an initial pure oxygen pressure of 4. 9MPa (50kgf/cm²) before heating, and the following results were obtained. The value of COD (Cr) (Chemical Oxygen Demand) was reduced 82. 5% by the wet oxidation. And also the Kjeldahl nitrogen concentration was decreased 98.8%. However, the organic carbon compound in the residual solution was almost acetic acid and ammonia was produced.
In order to activate the oxidation more strongly, the second tests using catalysts such ua Pd, Bu and Ru+Rh were conducted. As the results of these tests, the effectiveness of catalysts for oxidizing raw material was shown as follows:
COD and the Kjeldahl nitrogen values were drastically decreased 99. 65% and 99. 88%, respectively. Furthermore, the quantity of acetic acid and ammonia were reduced considerably. On the other hand, nitrate was showed a value 30 times as much as without catalytic oxidatiou.

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An increasing number of lunar base construction programs are in the process of developing lunar resources such as helium 3. The objective of the present work is to evaluate the temperature and humidity control system which will allow man to live and work on the moon while developing lunar resources.
The results of thermal load calculation show that the load of electric lighting is 80 to 90% of the cooling load in the habitat module and that only the cooling function is required for temperature control.
Due to this, a fluorocarbon refrigerant heat pump system was selected to satisfy reliability, energy consumption, weight and size requirements for the lunar base equipment.
According to the load calculation, occupants will feel discomfort due to radiant heat from lighting fixtures. To resolve this problem, an air conditioning system used in combination with forced convective cooling and panel cooling on the ceiling was adopted in the living space.
Moreover, the experiment on the ground was carried out to evaluate the effects of panel cooling.

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For the Closed Ecological Life Support System (CELSS) of a manned lunar base which is planned to be built on the moon early in the 21st century, a program exists to grow vegetables inside a farming module. Table 1 shows other proposed farming modules. At the 40th IAF (Malaga, 1989) the author et al presented a proposal for supplying food and nutrients to a crew of eight members, a basic concept which is based on growing four kinds of vegetables. This paper describes measures for biohazard protection in farming modules. In this study, biohazard protection means prevention of the dispersion of plant diseases to other plant species or other portions of farming beds.

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The wet-oxidation catalysis of a Ru-Rh catalyst carried on a ceramic honeycomb was studied at 290°C or 300°C. The filtrate of non-catalytically wet-oxidized sewage sludge was used as a raw material. In each temperature, 16 times' repeated batch tests were carried out. Both oxidation and denitrification efficiency of organic matter in a raw material were studied.
As a result, at 300°C, high and stable oxidation occurred. 98.0% of organic carbon in a raw material was oxidized and 98.3% of organic nitrogen was denitrified. In contrast, at 290°C, though high and stable denitrification occurred, oxidation did not occur highly and stably. A catalytic wet-oxidation system using this catalyst at 300°C will be useful as a waste management subsystem for a human life support system for space use where all food is resupplied from the earth and both air and water is regenerated within it, because this subsystem can prevent the accumulation of organic waste in the system.

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Fuzzy algorithm is applied to a CELSS which consists of the habitat and plant modules having necessary artificial processing means for each material recycling. Tentative application of the fuzzy reasoning is made to control the gas contents and the plant cultivation. Brief discussions are given to the emergency management. Useful effect by application of the fuzzy algorithm to the CELSS is expected.

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Carbon dioxide can be decomposed into carbon almost completely (-100%) with the activated magnetite at 300°C. The activated magnetite is obtained by treating magnetite powder with H₂ gas at 300°C. Chemical analysis and the X-ray diffractometry showed that the activated magnetite is the oxygen-deficient magnetite (Fe₃₊ δO₄: δ=0.122). The CO₂ decomposition reaction is considered to proceed associated with the incorporation of the O^2- ion of CO₂ into the oxygen-deficient site in the magnetite. We discussed the application of this new method to the closed ecological life support systems (CELSS) in space craft. A higher efficiency of the gas recycling system using this method is expected compared to that where the BOSCH reaction is adopted.

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In considering extended manned space missions, it is important to establish CELSS in space station. Of many areas in CELSS, the author gave attendants a lecture on some methods of environmental control in plants as food crops.
At frist, we have to understand the kinds of plant responses to environment. Especially, developmental events such as photoperiodism, thermoperiodism, and vernalization require disparate quantities of the different elements and environmental parameters with age or growth stage.
Further, author detailed his own experiences of plant culture under controlled conditions regarding habitat construction.

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