The effects of cultivating conditions, was specifically gas composition and illumination period, on the growth rate and gas exchange efficiency of the algae Spirulina platensis was investigated. The growth temperature was 30°C, the pH was maintained at approximately 10, and 450 ml culture bottles were used and shaked reciprocally. The culture bottles were flushed with a mixture of CO₂, O₂ and N₂ once per day. Before that time the gas composition and the mass of algae were measured.
The following results were obtained: (1) The volume of oxygen generated was in proportion to the illumination period, (2) The rate of photosynthesis and the growth rate of algae were retarded when the concentration of oxygen in the supply gas mixture was increased from 2 vol% to 20 vol%, (3) The carbon source exploited fo the photosynthesis was the carbonate contained in the medium.
We conclude that algae S. platensis is useful for CO₂-O₂ gas exchange, which makes it a potential candidate for a gas-exchange subsystem in a life suport system.

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It is certain that in future space missions such as long-term stationing in a lunar base, the need for comfortable living Quarters, qualityaried meals, as well as exercise or sports, will become critically important for the crew's mental and physical well-being. Future lunar crews with clearly defined functions and tasks to performed as part of a daily routine will have many hours of leisure time to spend reading, listening to music, watching TV or engaging in artistic activities including painting and playing musical instruments.
This paper reports on the crew's needs for lunar base life in terms of food, clothing, housing, communication, and mental and physical requirements. We have divided each of these items, or sectors, into three parts; namely, basal life, passive pursuits, and active pursuits. It is our belief that human needs develop to a higher degree of freedom and options as the requirements expand from basal life to passive pursuits, and to active pursuits.

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Several programs to construct the lunar base are in progress to develop the lunar resources such as helium3.
In order to remove heat from the lunar base, the radiative heat exchangers can be used, however they have been estimated at both large and heavy.
To miniaturize the area of radiative heat exchangers, we studied two subjects, one is the increase of the operating temperature of the radiative heat exchanger, the other is the improvement of the radiative heat exchanger configuration.
The efficiencies of the three cycles are compared, and a Rankine cycle booster heat pump using high temperature refrigerant is added to conventional cycle to attain higher temperature level.
A radiative heat exchanger composed of vertical radiating panels, horizontal reflectors, and heat reservoirs is selected, to maximize the capacity on the lunar surface.
The surface area of this radiative heat exchanger is estimated about a 50% smaller than that of the conventional cycle.

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The preliminary design of the Japanese Experiment Module (JEM) started in January 1990, and the first and second interim design reviews were held in July 1990 and February 1991 respectively. As a result of the JEM configuration review activity and the technical interface coordination with NASA through the Environmental Control and Life Support System (ECLSS) working group meetings, a part of the JEM ECLSS function was changed. This paper presents the JEM ECLSS baseline and the subsystem configuration at the second interim design review. Also the outline of the preliminary cabin air ventilation testing which was conducted from 1989 to 1990 is described.

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Many research activities relating the environment control and life support systems to be used in space have been conducted and continued in Japan since 1982 in order to obtain his own manned flight technologies for future Japanese missions.
Research and development activities are able to be divided in two phases according mission scheduling such as JEM development to be used in International Space Station now going on and the future Japanese space infrastructures, for examples, Japanese Space Station and Lunar Base.
Temperature, humidity, total atmospheric pressure and partial pressure of oxygen and carbon dioxide, necessary for all living things, are to be controlled by the environment control function. This function can be performed by technologies already developed and used as the Environment Control Life Support System (ECLSS) of Space Shuttle, and the new oxygen recovering technology from carbon dioxide in now going to be developed for more long duration stay in International Space Station.
All life support functions such as oxygen and purified water supplies and heat, carbon dioxide and used water eliminations in JEM are to be fullfilled in the American module outside of JEM in normal operation phase, however if emergency case occured, least self sufficient life support function should be performed inside of JEM. Therefore air conditioning and carbon dioxide elimination systems are now going to be developed in NASDA as shown in Fig. 1.
On the other hand, more advanced life support system technologies such as closed ecological life support system have now investigated in various organizations under the guide line of CELSS Research Society, Japan.
The status of the over all activities are discussed in this paper.

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