The scale of lunar base and the construction methods to be adopted are to be determined by the scenario of lunar utilization program but to be constrained by the availability of the established space transportation technologies. As indicated in the scenarios described in many papers regarding lunar base construction, the first steps of lunar missions are to be the investigation of lunar itself for conducting scientific researches and for surveying the lunar base construction sites, the second steps are to be the outpost construction for conducting the man tended missions regarding more precise scientific researches and for studying the lunar base construction methods, and third steps are to be the construction of permanent base and to be the expansion of this lunar base for exploiting the lunar resources.
The missions within the first and second steps, mentioned above, are all possible to be executed using the ferry (OTV) similar to the service and command modules of Apollo Spacecraft because all necessary weights to be landed on the lunar surface for these missions seem to be under the equivalent weight of Apollo Lunar Lander. On the other hand, the permanent facilities to be constructed on lunar surface in third steps require larger quantities of construction materials to be transported from earth, and new ferry (advanced OTV) having higher transportation ability, at least, above 6 times, compared with Apollo Service and Command Modules, are to be developed. The largest problems in the permanent lunar base construction are just related with the food production facilities in it, 30-40 square meters of plant cultivation area per person are required at present art of technology for providing the nutrition requirement of human beings and the necessary electric power per person for producing high energy foods such as wheat, rice and potato is now estimated ranging from 30 to 40kw.
The extension program of crew numbers under the limitation of usable transportation capability to be anticipated at present stage and the construction scenarios including the numbers of facilities to be constructed every year are to be determined based upon the requirements of plant cultivation area and of electric power for producing the necessary and sufficient foods in order to accelerate the feasibility studies of each subsystem to be installed in the permanent lunar base in future.

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A plan of the health care system for the crew on the lunar base is described in this study. The health care system is consisted of two subsystems. The first is the daily health care system. The system contains most health care menu same as on the earth and some biochemical and ordinary medical examinations. The second system is a periodic medical inspection for the crew's bone and the determination of natural radioisotopes in the body. These care systems are automatically treated with the whole examinations and data filings. Usually these examinations are carried out without any medical doctor. Examinations and files of the whole results are controlled by a computer. The daily results of examinations are compared with data in his file. If any abnormal value are found in his results, a necessary message is sent through him whether he must be receive close examination by medical doctor soon or be reexamined same submenu.
The automatic health care systems also keep on their movement all day by contacting with the life support monitoring system.

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With the aim of developing the lunar resources, helium-3, the scheme to build a lunar base has been advanced. In the oxygen separation methods, several methods such as the membrane separation method, the adosorption method, the complex synthesis method, the magnetic separation method and the absorption liquid method have been developed.
In the membrane separatpn method, oxygen separation is performed by the use of a high polymer membrane which has higher permeability for oxygen than for nitrogen.
DAIKIN has developed the membrane materials for oxygen separation, the technique of thin film coating, the manufacturing technique for separasion modules units and for the enriched oxygen air generator. The developed membrane material is novel fluoro plastic. Its oxygen permeability coefficient (Po₂) [pmol m/m² hr Pa] has a value of a 150. This value becomes to be 2.6 times that of nitrogen.
The oxygen separation by PSA methed is performed by the use of molecular sieve which is a nitrogen absolvent.
An oxygen separation method available for the lunar base has been evaluated based on indexes of reliability, the effect of gravitation and oxygen concentration recovery ability. As a result, the membrane separation method with the PSA method was selected as the oxygen separation method from the practical stand points. In this method, one compressor can be used in both the membrane separation system and the PSA method, so that the present method can bring about the reductions in the weight and power.
The specifications to meet the requirement of the oxygen supply volume for the residential and the plants space at the lunar base were determined.

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The paper proposes the optimal process for the nitrogen fixation system for 8 crews in a lunar base. Evaluation was carried out by the MUF method from the overall viewpoints of safety, compactness, efficiency, realizability, operability and maintainablity. Through the evaluation an unit process which had better be improved by establishment of preventive measures for safety was also made clear.

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Human beings will start permanent scientific and technological endeavours in the moon in the first decade of te next century.
This paper reports the results of the study for developing the design method of plant culturing systems of the closed ecological life support system, or CELSS, in lunar base.
From among conceivable plants, wheat, rice, potato, soy bean, butter head lettuce and spinach have been selected as plants to be cultivated.
A cylindrical configuration of the culturing module, which is 4 m in diameter and 14.5 m long, has been selected.
Conveniences to transportation in space and to installation in lunar base, and superior pressure proofness and air tightness are major advantages of the configuration.
The hydroponical culturing system is provided with multistack culturing segments each of which has sand beds, artificial lightings, and irrigation lines. Double deckers are for cereal culturing and three deckers for the other crops. An overhead travelling robot serves to all the culturing segments for necessary culturing operations.
Auxilliary equipments are located in the spaces at above and below the segments. A computerized processing system facilitates the realization of suitable ambients.
The shape and the arrangements thus described with the total culturing area of 65.3 af per module should grow sufficient amounts of crops to sustain 1.63 inhabitants in lunar base.

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The paper discusses a plan for nutrient supply and plant farming for the 8 crews lunar base (to be lxpanded to 16 crews as the base grows).
If the plant produces crop according to our estimation, our study shows that rice, soybean, lettuce and strawberry in less than 40 m² of farming area per crew is able to supply enough food for the crews from the nutritious point of view.
Among the essential nutrient elements required, however, vitamin B₂, calcium and sodium are not satisfied. We hope supply of the unsatisfied nutrients will be realized by the following ways.
For example, they are mushroom cultivation for supply of vitamin B₂, transportation of lime from the earth for calcium and recovery of sodium from human urine for sodiumchloride.
Under the isolated and closed environment like in a luna base, not only nutritious sufficiency but also pleasure of eating is very important. Also we think it is necessary to generate as many kinds of foods as possible out of limited number of plant species.
The plant module is equipped with such accommodations as ventilation, dew defending devices for the ceiling, wall showers, entrance air-showers, hazard protection structures for the linkage to the pathway section which leads to the habitat modules, etc..
The module also is furnished with monitors for its environment and they control CO₂, O₂, temperature, humidity and illumination. In addition, plant diagnostic monitors are equipped and are capable of predicting the outbreak of diseases or taking necessary measures such as sprinkling antibiotic agricultural chemicals etc.. And for the emergency case, steam sterilization or ultraviolet sterilization etc. is to be activated.

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We looked at the basic specifications of a plant cultural system as a subsystem, in a closed ecological life support system (CELSS).
In order to confirm the possibility of plant culture under microgravity in space, the growth rates and morphological characteristics of lettuce and turnips cultivated upside down were investigated on Earth. Rooting beds were arranged above and below an array of fluorescent lamps. Plants were grown normally on the lower bed and upside down on the upper bed.
The results were as follows: the top fresh weight of lettuce in the lower and upper beds was 42 and 46 g /plant, respectively, 30 days after the treatment. For turnips, the fresh weight of leaves and the swollen root, in the lower and upper beds, was 60 and 66 g /plant, and the weight of the swollen root was 30 and 42 g /plant, respectively, 25 days after the treatment. The growth rate for both species grown in the upper beds tended to be slightly higher than those in the lower beds. In addition, there were no remarkable morphological differences between the lower and upper plots for either plants. The above facts show that phototropism can overcome geotropism. A PPFD of about 300 μE /m² /s at the plant canopy is sufficient to ensure that vegetable crops such as lettuce and turnips grow normally, in the direction of a light source regardless of gravity direction.
A method of growing more plants in a small space is proposed. Our system is composed of small units and each unit is constructed of vertical panels supporting rooting beds arranged on two sides of an array of fluorescent lamps. Plants in these beds grow horizontally toward the lamps. Assuming that vegetable crops such as lettuce and turnips are cultivated at a planting density of 25 plants /m², 200 plants can grow in each unit and 100 plants per 1m² of the floor area.
In order to obtain basic data for the gas balance in the CELSS, the rates of CO₂ absorption and O₂ release for lettuce and turnips growing in this system were also estimated in this study.

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