From Big Medical Encyclopedia

BIOASTRONAUTICS — a complex of the sciences studying features of life activity biol, objects in the conditions of space and during the flights in spacecrafts (space physiology, ecobiology), the principles of creation of life support systems of members of crews of spaceships; in a task To. also search of extraterrestrial life forms enters (exobiology). Being a complex preferential biol, sciences, To. it is inseparably linked with air and space medicine (see. Air medicine , Meditsina space ). V K. apply methods and achievements of astronomy, astrophysics, geology, geochemistry, geophysics, physics, radio electronics, mathematics and many other sciences.

The space represents Wednesday, sharply excellent according to the characteristics from that, in a cut live organisms within the biosphere of Earth live (see. Biology , Life ). The insignificant density of substance, lack of oxygen, existence of intensive space radiation, an originality of a thermal conditions — all this excludes a possibility of life activity of the unprotected terrestrial life forms in free space. Also conditions of flights on spacecrafts as they are connected with influence are peculiar accelerations (see), vibrations (see), noise (see) and dynamic zero gravity (see).

Clarification of features of reactions of live organisms at influence of extreme factors of space, limits of stability and portability of these factors allow to solve practical problems of ensuring flights of the person (see. Life support ).

Researches in the area K. were begun in the USSR in 1935 originally in balloons, and since 1949 by means of rockets. At the first stages the geophysical missiles adapted for biol, experiences launched on height from 100 to 450 km were used. Researches were conducted on various biol, objects (mice, rats, rabbits, dogs, etc.). The extensive experimental material characterizing reactions various fiziol, systems of animals in response to influence of factors of suborbital flight was received (duration of dynamic zero gravity at these flights made from 4 to 8 min.).

Orbital flight of a dog of the Laika (on November 3, 1957) laid the foundation biol, for researches on artificial Earth satellites that became the dominating direction of researches in the area K. Biol, satellites were equipped with the equipment necessary for ensuring life activity of various live organisms, and also measuring devices for carrying out scientific research and a transmitting system of information during flight to Earth (see. Biotelemetry ). According to implementation of the program of researches and development of space biol, researches were conducted practically in all piloted flights, including space «Salute» stations and «Skayleb», on specialized biol, satellites of the Space series (USSR) and Bios (USA), and also at the joint international flights which are carried out within the Intercosmos program. A row biol, experiences was carried out on automatic spacecrafts, napr, the Probe type, etc.

In addition to expansion of researches in actual practice of space flight, researches in land laboratories with modeling of impact on live organisms of various factors of space flight were conducted. Use of centrifuges allowed to study with the broad range impact of accelerations, cameras lowered and supertension (pressures chamber) — value and a role of a barometric factor and the changed gas composition of the atmosphere; the installations creating different types of ionizing radiation — influence of a radiation factor, etc.

In experiences on various a lab. animals (a mouse, a rat, Guinea pigs, rabbits, dogs, monkeys, etc.) it is shown that are most sensitive to action of zero gravity a musculoskeletal system, system of a hemopoiesis and endocrine organs providing adaptive reactions of an organism. Larger animals (dogs, monkeys) have clear shifts from cardiovascular system and some indicators of a metabolism (e.g., exchange of calcium). The shifts arising under the influence of zero gravity, as a rule, are reversible and disappear after return of animals to Earth. It is supposed that creation in the spaceship of artificial gravity can exclude adverse effects of long action of zero gravity on a human body in space flight.

Specific problem K. impact on an organism of space radiation of high intensity is (see. Space radiation ), a cut, according to the assumption of a number of scientists, can be the cause of radiation injury of an organism (see. Radial illness ). However data on this question are not enough, and estimates of a risk degree are contradictory.

The problem of the ionizing radiation having the expressed mutagen effect is important; possible genetic effects are especially carefully investigated ionizing radiation (see), to-rogo astronauts can be affected during the flights on Earth orbits. Appropriate means of protection and prevention are developed.

One of tasks To. studying biol, the principles and methods of creation of artificial environment of dwelling in spaceships and stations is. Private questions at the solution of this problem are: search of live organisms, perspective for their inclusion as links (subsystems) in closed ekol, system; a research of a complex of factors of the habitat and the methods providing optimum productivity and stability of populations of these organisms; modeling of experimental biocenoses and their research funkts, characteristics and opportunities of practical use in space flights. Most intensively these researches develop in the USSR. Long experiments in sealed chambers during which needs of the person were satisfied due to complete regeneration of the atmosphere, water and partially food are conducted. At the same time in quality biol, links the higher plants (wheat, rice, a garden radish, etc.), seaweed (a chlorella, a spirulina, etc.), various mollusks, poultry, etc. were used. Creation artificial closed ekol, systems — habitats of the person in a space object — gives the chance of the analysis and review obshchebiol. values and acceptability of traditional terrestrial living conditions and ways of satisfaction of basic needs of the person. As a result there can be new criteria of formation of gas structure of the air environment and its physical. properties, food, level and nature of physical and mental activity of the person etc.

A component To. the exobiology studying existence, distribution, features and evolution of living matter in the Universe is. Researches in this area are conducted in two main directions: modeling of conditions of space environment or any planets and the researches conducted by means of automatic spacecrafts. It is established that at least some terrestrial microorganisms can keep life activity and develop in the conditions of space environment. As for existence of extraterrestrial life forms (e.g., on Venus, Mars), the researches conducted by means of spacecrafts for the present did not yield positive takes. Problems of an exobiology are closely connected with a problem chemical and biol, evolutions of matter in the Universe, with a problem of an origin of life on Earth (see. Life ).

Questions, important for medical practice, are studying of influence of factors of space (in particular the Sun) on biol, the processes proceeding in the biosphere of Earth.

In process of formation and development To. the AN and USSR Academy of Medical Sciences various institutions was involved in the solution of various tasks, separate problem laboratories, and since 1964 were created by studying of problems K. Ying t of medicobiological problems M3 of the USSR began to be engaged.

Abroad researches in the area K. the greatest development was gained in France, Germany, Japan and other countries. These problems develop in the USA in scientific centers of National administration on aeronautics and a research of space (NASA), at some universities, industrial firms, etc.

Remarkable line of development of researches in the area K. the expansion of the international cooperation which is carried out by Council «Intercosmos» of Academy of Sciences of the USSR is.

The first experience of multilateral international cooperation in implementation biol, an experiment in space was start of the Space-782 biosatellite in 1975, in work on Krom, in addition to scientists of the USSR, specialists from Bulgaria, Hungary, Poland, Czechoslovakia, Romania, France and the USA took part.

Training of specialists on To. it is carried out in system of a postgraduate study. In some higher educational institutions the course K is taught. (MSU, medico-biol. faculty of the 2nd MMI, TsIU in Moscow, etc.).

Specialists in the area K. hl are integrated. obr. in Section of bioastronautics and aerospace medicine of All-Union physiological society of I. P. Pavlov of Academy of Sciences of the USSR.

Abroad the largest association of specialists of this profile is the American aerospace medical association.

On problems K. are published: the «Bioastronautics and Aerospace Medicine» magazine (it is founded in 1967) and a series of the editions «Problems of Bioastronautics» (it is founded in 1962). From foreign editions the largest and widespread is the Aviation Space and Environmental Medicine magazine (the USA, it is founded in 1930).

In the organization of the international exchange of scientific information on To. take active part the Working group of Committee on Space Research (To SMALLPOX ARE), Committee of bioastronautics of the International Astronautical Federation (IAF), and also the International academy of air and space medicine (MAAKM).

See also Space radiobiology .

Bibliography: History of biology since the most ancient times up to now, under the editorship of L. Ya. Blyakher, page 560, M., 1975; Kovalyov E. E. Radiation risk on the earth and in space, M., 1976, bibliogr.; Astronautics (the small encyclopedia), under the editorship of V. P. Glushko, M., 1970; Odum Yu. Fundamentals of ecology, the lane with English, page 629, M., 1975; Fundamentals of bioastronautics and medicine, under the editorship of O. G. Gazenko and M. Calvin, t. 1 — 3, M., 1975; Development of biology in the USSR, under the editorship of B. E. Bykhovsky, page 613, M., 1967; Progress of the USSR in a research of space, under the editorship of A. A. Blagonravov, page 321, M., 1968; Bioastronautics data book, ed. by J. F. Parker, Washington, 1973.

O. G. Gazenko.