life support in the spaceship

From Big Medical Encyclopedia

LIFE SUPPORT in the spaceship — a complex of the actions directed to creation and maintenance in cabins of spaceships of the conditions necessary for preservation of life, health and efficiency of astronauts at all stages of space flight. Enter this complex: means of maintenance of the set level of barometric pressure, temperature, humidity and chemical structure of a prepared atmosphere (see. prepared atmosphere ); water supply and food of crew; collecting and waste disposal; carrying out gigabyte. the procedures combined in a so-called life support system (SZhO). Such systems, irrespective of type, consist of the following functional links, or subsystems: regenerations and air conditionings, food, water supply, dignity. - tekhn, devices, personal hygiene means.

SZhO shall have high reliability, have the minimum starting weight, small dimensions and convenient configuration, automatically support the set parameters of the habitat of astronauts, smoothing the indignations created by unexpected situations (jump of gas exchange and energy costs, a gas leak from the ship etc.).

Need of strict restriction of weight creates dependence of the general scheme and a design of links of SZhO on the planned duration of flight. At short-term flights (to 30 days) it is reasonable to use not regenerative SZhO based on reserves of the substances (the oxygen, water, food, sorbents absorbing carbonic acid and harmful impurity, etc.) spent by the person. At increase in duration of flight use of regenerative SZhO in which the spent substances are partially or completely recovered is reasonable.

By the Soviet «East» spaceships, «Rising», «Union» and American — «Mercury», Dzhemini, Apollo, intended for short-term flights, were used not regenerative SZhO. As a source of oxygen by the Soviet ships superoxide of potassium was applied (KO 2 ), edges at the same time served as an absorber of carbon dioxide gas and water vapor. On an amer. spaceships reserves of oxygen contained in special vessels in which oxygen was stored in a gaseous or liquid look. Carbonic acid was absorbed by hydrate of lithium oxide. A cache and waters as in Soviet, and an amer. the ships undertook for all the time of flight. In certain cases on an amer. the ships for drink the water which is emitted from fuel cells was used.

At the space piloted stations with a duration of flight from several months to one year apply SZhO with partial recovery of consumable materials. So, at the Soviet space «Salute» stations the revitalization system of water based on purification of condensate of moisture of a gaseous fluid of cabins by means of refrigerating and drying units of system of thermal regulation is used.

On an amer. Skayleb stations the revitalization system of a prepared atmosphere of cabins based on use of reversible sorbents of carbon dioxide gas — so-called zeolites was applied. The absorber of carbon dioxide gas consists of two cartridges filled with grains of zeolite. Through one of cartridges previously dehydrated air is passed; carbon dioxide gas communicates grains of zeolite, and oxygen and nitrogen freely pass through it. The second boss which is earlier saturated with carbon dioxide gas is desorbed at this time. Then cartridges are interchanged the position. For a desorption vacuum of space and heating can be used.

Long space flights require creation of revitalization systems of water from condensate of atmospheric moisture, urine and other moisture containing waste, and also revitalization systems of oxygen from carbon dioxide gas and the water which is formed in an organism at oxidation of feedstuffs (water of combustion). Use various physical is for this purpose supposed. - chemical processes of decomposition of carbon dioxide gas and water in the spark category, a thermolysis, a photolysis, electrolysis etc.

Food of astronauts onboard spaceships will be organized by the principle of creation of stocks of the preserved and lyophilized products in an extra packing (see. Food ). The lyophilized products are exposed as required to processing in the special device hot water then they are ready for the use (they are exposed to culinary processing in advance, before lyophilizing). Such food is expected limited time of flight.

At increase in duration of flights up to several years it is rational to carry out food on the basis of regeneration of food from waste. The solution of the problem of regeneration of foodstuff is possible in two ways. The first is physical. - chemical synthesis of feedstuffs from end products of metabolism, the second — biol, synthesis of necessary components of food. One of possible ways physical. - chemical synthesis of feedstuffs receiving formaldehyde from carbon monoxide and hydrogen is (2CO + H 2 —> CH 2 O) with the subsequent its polymerization to monosugars, and also synthesis fat to - t, amino acids, alcohol, glycerin and other substances which can be used as foodstuff. Solution physical. - chemical synthesis of food meets, however, big tekhnol. and technical difficulties.

The most real possibility of providing astronauts with foodstuff at long flights is biosynthesis of foodstuff. At the same time the problem of receiving oxygen and removal of carbonic acid and other end products of life activity of the person is at the same time solved. Implementation of biosynthesis can go on the way of creation closed ekol, the system onboard the spaceship (people, a plant, animal) expected full satisfaction of needs of the person for oxygen, water and food due to regeneration of these substances from end products of metabolism.

Creation closed ekol, systems is one of the main conditions of ensuring long and autonomous existence of people out of the biosphere of Earth.

Gigabyte. needs are provided with special napkins and towels, and also a deposit of moisture and lotions. At space stations and the interplanetary ships shower installations and other devices can be applied. Providing with water for a gigabyte. is more whole in long space flight is one of links of a uniform life support system.

Collecting and isolation of urine and a calla is carried out by special cesspool devices. In not regenerative SZhO urine and kcal gather in hermetic tanks and can be removed from the ship. In regenerative SZhO urine is used for regeneration of water, and in closed ekol, systems urine and kcal can be the power supply of the plants used during creation closed ekol, systems of the spaceship.

See also Cabins of aircraft .

Bibliography: Voronin G. I. Air conditioning systems on aircraft, M., 1973; Bioastronautics and medicine, under the editorship of V. I. Yaz-dovsky, M., 1966, bibliogr.; Lapnikov A. A. Fundamentals of air and space medicine, M., 1975; Fundamentals of bioastronautics and medicine, under the editorship of O. G. Gazenko and M. Calvin, t. 1 — 3, M., 1975, bibliogr.

A. M. Genin.