Biology

Problems of space medicine. How space medicine saves people on earth

GOU Lyceum No. 000

Kalininsky district of St. Petersburg

Research

Biomedical research in space

Gurshev Oleg

Head: biology teacher

St. Petersburg, 2011

Introduction 2

The beginning of biomedical research in the middle of the 20th century. 3

Impact space flight on the human body. 6

Exobiology. 10

Prospects for the development of research. 14

List of used sources. 17

Application (presentation, experiments) 18

Introduction

space biology and medicine- complex science, which studies the features of the life of a person and other organisms in space flight. The main task of research in the field of space biology and medicine is the development of means and methods for life support, maintaining the health and performance of crew members of spacecraft and stations during flights of various durations and degrees of complexity. Space biology and medicine is inextricably linked with astronautics, astronomy, astrophysics, geophysics, biology, aviation medicine, and many other sciences.

The relevance of the topic is quite large in our modern and fast-paced XXI century.

The topic "Medical and biological research" interested me recent years two, ever since I decided on my choice of profession, so I decided to do research work on this topic.

2011 is an anniversary year - 50 years since the first human flight into space.

Beginning of Biomedical Research in the middleXXcentury

The following milestones are considered the starting points in the development of space biology and medicine: 1949 - for the first time, the possibility of conducting biological research during rocket flights appeared; 1957 - for the first time Living being(the dog Laika) was sent on a near-Earth orbital flight on the second artificial Earth satellite; 1961 - the first manned flight into space, perfect. With the aim of scientific justification the possibilities of a medically safe flight of a person into space, the tolerance of impacts characteristic of the launch, orbital flight, descent and landing of spacecraft (SCV) to Earth was studied, and the operation of biotelemetric equipment and systems for supporting the life of astronauts was tested. The main attention was paid to studying the effect of weightlessness and cosmic radiation on the body.

Laika (dog astronaut) 1957

R results obtained during biological experiments on rockets, the second artificial satellite (1957), rotated spaceships satellites (1960-1961), together with data from ground-based clinical, physiological, psychological, hygienic and other studies, actually opened the way for man into space. In addition, biological experiments in space at the stage of preparation for the first human space flight made it possible to identify a number of functional changes that occur in the body under the influence of flight factors, which was the basis for planning subsequent experiments on animal and plant organisms during flights of manned spacecraft, orbital stations and biosatellites. . The world's first biological satellite with an experimental animal - the dog "Laika". Launched into orbit on 11/03/1957 and stayed there for 5 months. The satellite existed in orbit until April 14, 1958. The satellite had two radio transmitters, a telemetry system, a programming device, scientific instruments for studying solar radiation and cosmic rays, regeneration and thermal control systems to maintain conditions in the cabin necessary for the existence of the animal. First scientific information on the state of a living organism under conditions of space flight.

Achievements in the field of space biology and medicine largely predetermined success in the development of manned astronautics. Along with flight , committed on April 12, 1961, it should be noted such epoch-making events in the history of astronautics as the landing of astronauts on July 21, 1969 Armstrong(N. Armstrong) and Aldrin(E. Aldrin) to the surface of the Moon and multi-month (up to a year) crew flights to orbital stations"Salute" and "Mir". This became possible thanks to the development of the theoretical foundations of space biology and medicine, the methodology for conducting biomedical research in space flights, substantiation and implementation of methods for the selection and pre-flight training of cosmonauts, as well as the development of life support means, medical control, preservation of the health and working capacity of crew members in flight.

Apollo 11 team (left to right): Neil. A. Armstrong, Command Module Pilot Michael Collins, Commander Edwin (Buzz) E. Aldrin.

The impact of space flight on the human body

In space flight, the human body is affected by a complex of factors related to flight dynamics (acceleration, vibration, noise, weightlessness), stay in a sealed room of a limited volume (altered gas environment, hypokinesia, neuro-emotional stress, etc.), as well as factors outer space as habitats (cosmic radiation, ultraviolet radiation, etc.).

At the beginning and end of a space flight, the body is affected by linear accelerations . Their magnitude, rise gradient, time and direction of action during the period of launching and launching the spacecraft into near-Earth orbit depend on the characteristics of the rocket and space complex, and during the return to Earth, on the ballistic characteristics of the flight and the type of spacecraft. Performing maneuvers in orbit is also accompanied by the impact of accelerations on the body, however, their magnitudes during flights of modern spacecraft are insignificant.

The launch of the Soyuz TMA-18 spacecraft to the International space station from Baikonur Cosmodrome

Basic information about the effect of accelerations on the human body and ways to protect against their adverse effects were obtained during research in the field of aviation medicine, space biology and medicine only supplemented this information. It was found that staying in weightlessness, especially for a long time, leads to a decrease in the body's resistance to the action of accelerations. In this regard, a few days before the descent from orbit, the cosmonauts switch to a special regime of physical training, and immediately before the descent they receive water-salt supplements to increase the degree of hydration of the body and the volume of circulating blood. Special chairs have been developed - lodgments and anti-g suits, which provide an increase in the tolerance of accelerations during the return of astronauts to Earth.

Among all factors of space flight, constant and practically unreproducible in laboratory conditions is weightlessness. Its influence on the body is diverse. There are both non-specific adaptive reactions characteristic of chronic stress, and a variety of specific changes caused by a violation of the interaction of the sensory systems of the body, redistribution of blood in the upper half of the body, a decrease in dynamic and almost complete removal of static loads on the musculoskeletal system.

ISS summer 2008

Examinations of cosmonauts and numerous experiments on animals during the flights of the Kosmos biosatellites made it possible to establish that the leading role in the occurrence of specific reactions combined in the symptom complex of the space form of motion sickness (motion sickness) belongs to the vestibular apparatus. This is due to an increase in the excitability of otolith and semicircular canal receptors under weightless conditions and a disruption in the interaction of the vestibular analyzer and other sensory systems of the body. Under conditions of weightlessness, humans and animals show signs of detraining of the cardiovascular system, an increase in blood volume in the vessels of the chest, congestion in the liver and kidneys, changes in cerebral circulation, and a decrease in plasma volume. Due to the fact that under conditions of weightlessness the secretion of antidiuretic hormone, aldosterone and the functional state of the kidneys change, hypohydration of the body develops. At the same time, the content of extracellular fluid decreases and the excretion of calcium, phosphorus, nitrogen, sodium, potassium and magnesium salts from the body increases. Changes in the musculoskeletal system occur mainly in those departments that, under normal conditions of life on Earth, carry the greatest static load, that is, the muscles of the back and lower extremities, in the bones of the lower extremities and vertebrae. There is a decrease in their functionality, a slowdown in the rate of periosteal bone formation, osteoporosis of the spongy substance, decalcification and other changes that lead to a decrease in the mechanical strength of the bones.

In the initial period of adaptation to weightlessness (takes on average about 7 days), approximately every second cosmonaut experiences dizziness, nausea, movement incoordination, impaired perception of the position of the body in space, sensation of a rush of blood to the head, difficulty in nasal breathing, loss of appetite. In some cases, this leads to a decrease in overall performance, which makes it difficult to perform professional duties. Already at the initial stage of the flight, initial signs of changes in the muscles and bones of the limbs appear.

As the duration of stay in weightlessness increases, many unpleasant sensations disappear or smooth out. At the same time, practically in all astronauts, if proper measures are not taken, changes in the state of the cardiovascular system, metabolism, muscle and bone tissue progress. To prevent adverse shifts, a wide range of preventive measures and means is used: a vacuum tank, a bicycle ergometer, a treadmill, training load suits, an electrical muscle stimulator, training expanders, taking salt supplements, etc. This allows you to maintain good health and high level efficiency of crew members in long-term space flights.

An inevitable concomitant factor of any space flight is hypokinesia - restriction of motor activity, which, despite intense physical training during the flight, leads to general detraining and asthenia of the body under weightless conditions. Numerous studies have shown that prolonged hypokinesia created by staying in bed with the head end tilted (-6°) has almost the same effect on the human body as prolonged weightlessness. This method of modeling some physiological effects of weightlessness in laboratory conditions was widely used in the USSR and the USA. The maximum duration of such a model experiment, conducted at the Institute of Biomedical Problems of the Ministry of Health of the USSR, was one year.

A specific problem is the study of the effects of cosmic radiation on the body. Dosimetric and radiobiological experiments made it possible to create and put into practice a system for ensuring the radiation safety of space flights, which includes means of dosimetric control and local protection, radioprotective preparations (radioprotectors).

Orbital station "MIR"

The tasks of space biology and medicine include the study of biological principles and methods for creating an artificial habitat on spacecraft and stations. For this, living organisms are selected that are promising for inclusion as links in a closed ecological system, the productivity and stability of populations of these organisms are studied, experimental unified systems of living and non-living components - biogeocenoses are modeled, their functional characteristics and possibilities of practical use in space flights are determined.

Such a direction of space biology and medicine as exobiology, which studies the presence, distribution, features and evolution of living matter in the Universe, is also successfully developing. On the basis of ground-based model experiments and studies in space, data were obtained indicating the theoretical possibility of the existence of organic matter outside the biosphere. There is also a search program extraterrestrial civilizations by registering and analyzing radio signals coming from space.

Soyuz TMA-6

Exobiology

One of the areas of space biology; searches for living matter and organic matter in space and on other planets. The main goal of exobiology is to obtain direct or indirect data on the existence of life in space. The basis for this is the findings of precursors of complex organic molecules ( hydrocyanic acid, formaldehyde, etc.), which are detected in outer space by spectroscopic methods (in total, up to 20 organic compounds). Methods of exobiology are different and are designed not only to detect alien manifestations of life, but also to obtain some characteristics of possible extraterrestrial organisms. To suggest the existence of life in extraterrestrial conditions, for example, on other planets of the solar system, it is important to find out the ability of organisms to survive under experimental reproduction of these conditions. Many microorganisms can exist at temperatures close to absolute zero and high (up to 80-95 °C) temperatures; their spores withstand deep vacuum and long drying times. They endure much large doses ionizing radiation than in outer space. Extraterrestrial organisms should probably have a higher adaptability to life in an environment containing a small amount of water. Anaerobic conditions do not serve as an obstacle to the development of life, therefore, it is theoretically possible to assume the existence in space of the most diverse microorganisms in terms of their properties, which could adapt to unusual conditions by developing various protective devices. The experiments carried out in the USSR and the USA did not give evidence of the existence of life on Mars, there is no life on Venus and Mercury, it is also unlikely on the giant planets, as well as their satellites. IN solar system life is probably only on Earth. According to some ideas, life outside the Earth is possible only on a water-carbon basis, which is characteristic of our planet. Another point of view does not exclude the silicon-ammonia base, however, mankind does not yet possess methods for detecting extraterrestrial life forms.

"Viking"

Viking Program

Viking program- NASA's space program to study Mars, in particular, for the presence of life on this planet. The program included the launch of two identical spacecraft - "Viking-1" and "Viking-2", which were supposed to conduct research in orbit and on the surface of Mars. The Viking program was the culmination of a series of missions to explore Mars that began in 1964 with Mariner 4, followed by Mariner 6 and Mariner 7 in 1969, and the Mariner 9 orbital missions in 1971 and 1972 The Vikings took their place in the history of the exploration of Mars as the first American spacecraft to land safely on the surface. It was one of the most informative and successful missions to the red planet, although it failed to detect life on Mars.

Both vehicles were launched in 1975 from Cape Canaveral, Florida. Before the flight, the descent vehicles were carefully sterilized to prevent contamination of Mars. earthly forms life. Flight time took a little less than a year and arrived at Mars in 1976. The duration of the Viking missions was planned to be 90 days after landing, but each device worked much more than this period. The Viking-1 orbiter operated until August 7, 1980, the descent vehicle - until November 11, 1982. The Viking-2 orbiter operated until July 25, 1978, the descent vehicle - until April 11, 1980.

Snow-covered desert on Mars. Snapshot of Viking-2

BION program

BION program includes complex research on animal and plant organisms in flights of specialized satellites (bio-satellites) in the interests of space biology, medicine and biotechnology. From 1973 to 1996, 11 biosatellites were launched into space.

Leading scientific institution: State Scientific Center of the Russian Federation - Institute of Biomedical Problems of the Russian Academy of Sciences (Moscow)
Design department: SNP RCC "TsSKB-Progress" (Samara)
Flight duration: from 5 to 22.5 days.
Launch location: Plesetsk Cosmodrome
Landing area: Kazakhstan
Participating countries: USSR, Russia, Bulgaria, Hungary, Germany, Canada, China, Netherlands, Poland, Romania, USA, France, Czechoslovakia

Studies on rats and monkeys in biosatellite flights have shown that exposure to weightlessness leads to significant but reversible functional, structural and metabolic changes in the muscles, bones, myocardium and neurosensory system of mammals. The phenomenology is described and the mechanism of development of these changes is studied.

For the first time in the flights of the BION biosatellites, the idea of creating an artificial gravity force (IGF) was put into practice. In experiments on rats, it was found that IST, created by the rotation of animals in a centrifuge, prevents the development of adverse changes in muscles, bones, and myocardium.

Within the framework of the Federal Space Program of Russia for the period 2006-2015. in the "Space tools for fundamental space research" section, the continuation of the BION program is planned, the launches of the BION-M spacecraft are scheduled for 2010, 2013 and 2016.

"BION"

Prospects for the development of research

The current stage of exploration and study of outer space is characterized by a gradual transition from long-term orbital flights to interplanetary flights, the closest of which is seen expedition to Mars. In this case, the situation changes radically. It changes not only objectively, which is associated with a significant increase in the duration of stay in space, landing on another planet and returning to Earth, but also, which is very important, subjectively, since, having left the Earth orbit that has already become habitual, astronauts will remain (in a very small time). the size of a group of their colleagues) "lonely" in the vast expanses of the universe.

At the same time, fundamentally new problems arise associated with a sharp increase in the intensity cosmic radiation, the need to use renewable sources of oxygen, water and food, and most importantly, the solution of psychological and medical problems.

Mercury" href="/text/category/mercury/" rel="bookmark">Mercury -Redstone 3" with Alan Shepard.

The difficulty of controlling such a system in a limited hermetically closed volume is so great that one cannot hope for its early introduction into practice. In all likelihood, the transition to a biological life support system will occur gradually as its individual links are ready. At the first stage of development of the BSJO, obviously, there will be a replacement physical and chemical method obtaining oxygen and utilizing carbon dioxide - for biological. As you know, the main "suppliers" of oxygen are higher plants and photosynthetic unicellular organisms. A more difficult task is to replenish water and food supplies.

Drinking water will obviously have a very long time to " earthly origin”, and the technical one (used for household needs) is already being replenished due to the regeneration of atmospheric moisture condensate (CDA), urine and other sources.

Undoubtedly, the main component of the future closed ecological system is plants. Studies on higher plants and photosynthetic unicellular organisms on board spacecraft showed that under conditions of space flight, plants go through all stages of development, from seed germination to the formation of primary organs, flowering, fertilization and maturation of a new generation of seeds. Thus, the fundamental possibility of realizing the full cycle of plant development (from seed to seed) under microgravity conditions was experimentally proven. The results of space experiments were so encouraging that already in the early 80s they made it possible to conclude that the development of biological life support systems and the creation on this basis of ecologically closed system in a limited hermetic volume is not such a difficult task. However, over time, it became obvious that the problem cannot be solved completely, at least until the main parameters are determined (calculated or experimentally) that make it possible to balance the mass and energy flows of this system.

To renew food supplies, it is also necessary to introduce animals into the system. Of course, at the first stages, these should be "small-sized" representatives of the animal world - mollusks, fish, birds, and later, perhaps rabbits and other mammals.

Thus, during interplanetary flights, astronauts need not only to learn how to grow plants, keep animals and cultivate microorganisms, but also develop a reliable way to control the “space ark”. And for this, you first need to find out how a single organism grows and develops in a space flight, and then what requirements each individual element of a closed ecological system imposes on the community.

My main task in research work it was to find out how interesting and exciting space exploration has been and how long it still has to go!

If you only imagine what a variety of all life is on our planet, then what can be assumed then about the cosmos ...

The universe is so big and unknown that this kind of research is vital for us who live on planet Earth. But we are only at the very beginning of the journey and we have so much to know and see!

During the whole time when I was doing this work, I learned so many interesting things that I never suspected, I learned about excellent researchers like Carl Sagan, I learned about the most interesting space programs conducted in the 20th century, both in the USA and in the USSR, I learned a lot about modern programs, like "BION", and much more.

Research continues...

List of sources used

Big Children's Encyclopedia Universe: Popular science edition. - Russian Encyclopedic Association, 1999. Site http://spacembi. *****/ Big Encyclopedia Universe. - M.: Publishing house "Astrel", 1999.

4. Encyclopedia Universe (“ROSMEN”)

5. Wikipedia site (pictures)

6.Space at the turn of the millennium. Documents and materials. M., International relationships(2000)

Application.

"Mars Transfer"

"Mars transfer" Development of one of the links of the future biological and technical life support system for astronauts.

Target: Obtaining new data on the processes of gas-liquid supply in root-inhabited media during space flight

Tasks: Experimental determination of the coefficients of capillary diffusion of moisture and gases

Expected results: Creation of an installation with a rooted environment for growing plants in relation to microgravity conditions

· Set "Experimental cuvette" for determining the characteristics of moisture transfer (velocity of the impregnation front and moisture content in separate zones)

Video complex LIV for video recording of the movement of the impregnation front

Target: The use of new computer technologies to improve the comfort of an astronaut's stay during a long-term space flight.

Tasks: Activation of specific areas of the brain responsible for the astronaut's visual associations associated with his native places and family on Earth with a further increase in his performance. Analysis of the state of the astronaut in orbit by testing according to special methods.

Used scientific equipment:

Block EGE2 (individual astronaut hard disk with photo album and questionnaire)

"vest" Obtaining data to develop measures to prevent the adverse effects of flight conditions on the health and performance of the ISS crew.

Target: Evaluation of the new integrated clothing system from various types materials for use in space flight.

Tasks:

wearing clothes "VEST", specially designed for the flight of the Italian cosmonaut R. Vittori on the ISS RS; receiving feedback from the astronaut regarding the psychological and physiological well-being, that is, the comfort (convenience), wearability of clothing; her aesthetics; the effectiveness of heat resistance and physical hygiene on board the station.

Expected results: Confirmation of the functionality of the new integrated clothing system "VEST", including its ergonomic performance in space flight, which will reduce the weight and volume of clothing planned for use in long-term space flights to the ISS.

A Western medical study and observation of 12 astronauts showed that with prolonged exposure to microgravity, the human heart becomes 9.4 percent more spherical, which in turn can cause a variety of problems with its work. This problem can become especially urgent during long-term space travel, for example, to Mars.

"The heart in space works very differently from how it works in Earth's gravity, which in turn can lead to the loss of its muscle mass," says Dr. James Thomas from NASA.

“All of this will have serious consequences once we return to Earth, so we are currently looking at possible ways to avoid or at least reduce this loss of muscle mass.”

Experts note that after returning to Earth, the heart takes on its original form, but no one knows how one of the most important organs of our body will behave after long flights. Doctors are already aware of cases when returning astronauts experienced dizziness and disorientation. In some cases, there is a sharp change in blood pressure (there is a sharp decrease in it), especially when a person tries to stand up. In addition, some astronauts experience arrhythmia during missions (disturbance heart rate).

The researchers note the need to develop methods and rules that will allow deep space travelers to avoid these types of problems. As noted, such methods and rules could be useful not only to astronauts, but also ordinary people on Earth — those experiencing problems with the work of the heart, as well as those who are prescribed bed rest.

A five-year research program has now begun to determine the level of space impact on accelerating the development of atherosclerosis (blood vessel disease) in astronauts.

Drunkenness and mental disorders

Although NASA's anonymous survey cleared up suspicions of astronauts' frequent drinking of alcoholic beverages, there were two cases in 2007 when actually drunk NASA astronauts were allowed to fly inside the Russian Soyuz spacecraft. At the same time, people were allowed to fly even after the doctors who prepared these astronauts for the flight, as well as other participants in the mission, told the authorities about the very hot condition of their colleagues.

According to the safety policy of the time, NASA spoke of officially banning astronauts from drinking alcohol 12 hours before training flights. The operation of this rule was also implicitly assumed for the duration of space flights. However, after the incident described above, NASA was outraged by the carelessness of the astronauts that the agency decided to make this rule regarding space flight official.

Former astronaut Mike Mullane once said that astronauts drank alcohol before a flight to dehydrate the body (alcohol dehydrates), in order to ultimately reduce the load on the bladder and suddenly not want to go to the toilet at the time of launch.

Your place among the dangers within space missions also had a psychological aspect. During the Skylab 4 space mission, the astronauts were so “tired” of communicating with the space flight control center that they turned off radio communications for almost a day and ignored messages from NASA. After this incident, scientists are trying to identify and address potential negative psychological effects, which may arise as part of more stressful and lengthy missions to Mars.

Sleep deprivation and use of sleeping pills

A ten year study showed that recent weeks before launch and during the start of space missions, astronauts clearly lack sleep. Among those interviewed, three out of four admitted to using medications that helped them sleep, even though the use of such medications could be dangerous while flying the spacecraft and when working with other equipment. The most dangerous situation in this case could be when the astronauts took the same medicine and at the same time. In this case, at the time of an emergency that requires an emergency solution, they could simply oversleep it.

Despite the fact that NASA assigned every astronaut to sleep at least eight and a half hours a day, most of them only got about six hours of rest every day while on missions. The seriousness of such a load on the body was aggravated by the fact that during the last three months of training before the flight, people slept less than six and a half hours a day.

"Future missions to the Moon, Mars and beyond will require the development of more effective measures to address sleep deprivation and optimize human performance during spaceflight," said senior researcher on the subject, Dr. Charles Kseiler.

“These measures may include changes in the schedule of work that will be carried out taking into account human exposure to certain light waves, as well as changes in the behavioral strategy of the crew for a more comfortable entry into the state of sleep, which is essential for restoring health, strength and good mood the next day. ".

hearing loss

have shown that since the time of space shuttle missions, some astronauts have experienced cases of temporary significant and less significant hearing loss. They were noted most often when people were exposed to high sound frequencies. Crew members of the Soviet space station Salyut 7 and the Russian Mir also experienced mild to severe hearing loss after returning to Earth. Again, in all these cases, the cause of partial or complete temporary hearing loss was exposure to high sound frequencies.

The crew of the International Space Station are required to wear earplugs every day. To reduce noise on board the ISS, among other measures, it was proposed to use special soundproof pads inside the walls of the station, as well as the installation of quieter fans.

However, in addition to the noisy background, other factors can also influence hearing loss: for example, the state of the atmosphere inside the station, increased intracranial pressure, as well as increased levels of carbon dioxide inside the station.

In 2015, NASA plans with the help of the ISS crew to start studying possible ways avoiding the effects of hearing loss during year-long missions. The scientists want to see how long these effects can be avoided and the acceptable risk associated with hearing loss. Key task The experiment will determine how to minimize hearing loss entirely, and not just during a particular space mission.

Stones in the kidneys

Every tenth person on Earth sooner or later develops the problem of kidney stones. However this question becomes much sharper when it comes to astronauts, because in space the bones of the body begin to lose useful substances even faster than on Earth. Inside the body, salts (calcium phosphate) are released, which penetrate through the blood and accumulate in the kidneys. These salts can be compacted and take the form of stones. At the same time, the size of these stones can vary from microscopic to quite serious - up to the size of a walnut. The problem is that these stones can block the vessels and other flows that feed the organ or remove excess substances from the kidneys.

For astronauts, the risk of developing kidney stones is more dangerous because in microgravity conditions, the volume of blood inside the body can decrease. In addition, many astronauts do not drink 2 liters of liquids a day, which, in turn, could ensure their body is completely hydrated and do not allow stones to stagnate in the kidneys, removing their particles with urine.

It is noted that at least 14 American astronauts developed a problem with kidney stones almost immediately after the completion of their space missions. In 1982, a case of acute pain was recorded in a crew member aboard the Soviet Salyut-7 station. The cosmonaut suffered from severe pain for two days, while his comrade had no choice but to helplessly watch the suffering of his colleague. At first, everyone thought it was acute appendicitis, but after a while, along with the urine, the astronaut got a small kidney stone.

Scientists have been developing a special desktop-sized ultrasound machine for a very long time, which allows you to detect kidney stones and remove them using pulses. sound waves. It seems that on board a ship heading to Mars, such a thing could definitely come in handy.

lung diseases

Although we don't yet know exactly what negative health effects dust from other planets or asteroids can cause, scientists do know some very unpleasant effects that can occur as a result of exposure to lunar dust.

The most serious effect of dust inhalation is most likely to be in the lungs. However, incredibly sharp particles of moon dust can cause serious damage not only to the lungs, but also to the heart, at the same time causing a whole bunch of various ailments, ranging from severe inflammation of the organs to cancer. Similar effects can be caused, for example, by asbestos.

Sharp dust particles can harm not only internal organs, but also cause inflammation and abrasions on the skin. For protection, it is necessary to use special multilayer Kevlar-like materials. Moon dust can easily damage the corneas of the eyes, which in turn may be the most serious emergency for a person in space.

Scientists note with regret that they are unable to simulate the lunar soil and conduct the full set of tests necessary to determine the effects of lunar dust on the body. One of the difficulties in solving this problem is that on Earth, dust particles are not in a vacuum and are not constantly exposed to radiation. Only additional studies of dust directly on the surface of the Moon itself, and not in the laboratory, will be able to provide scientists with the necessary data for the development effective methods protection from these tiny toxic killers.

Immune system failure

Our immune system changes and responds to any, even the most the slightest change in our body. Lack of sleep, inadequate nutrient intake, or even ordinary stress all weaken our immune systems. But this is on Earth. Change the same immune system in space can eventually turn into a common cold or carry a potential danger in the development of much more serious diseases.
In space, the distribution of immune cells in the body does not change much. A far greater threat to health can be caused by changes in the functioning of these cells. When the functioning of the cell is reduced, already suppressed viruses in the human body can re-awaken. And to do this in fact secretly, without the manifestation of symptoms of the disease. When immune cells become overactive, the immune system overreacts to irritants, causing allergic reactions and other side effects such as skin rashes.

“Things like radiation, microbes, stress, microgravity, sleep disruption, and even isolation can all change how the immune system of crew members works,” says NASA immunologist Brian Krushin.

"Long-term space missions will increase the risk of infections, hypersensitivity, and autoimmune problems in astronauts."

To solve problems with the immune system, NASA plans to use new methods of anti-radiation protection, a new approach to balanced nutrition and drugs.

Radiation Threats

The current very unusual and very long absence solar activity can contribute to dangerous changes in the level of radiation in space. Nothing like this has happened for nearly 100 years.

“Although such events are not necessarily a stopping factor for long missions to the Moon, asteroids and even Mars, galactic cosmic radiation itself is one factor that can limit the planned time for these missions,” says Nathan Schwadron of the Institute terrestrial, oceanic and space research.

The consequences of this kind of exposure can be very different, ranging from radiation sickness and ending with the development of cancer or injury. internal organs. In addition, dangerous levels of background radiation reduce the effectiveness of the spacecraft's anti-radiation protection by about 20 percent.

On just one mission to Mars, an astronaut could be exposed to 2/3 of the safe dose of radiation that a person could be exposed to in the worst case during their entire lifetime. This radiation can cause changes in DNA and increase the risk of cancer.

“If we talk about the cumulative dose, then this is the same as doing a full CT scan of the body every 5-6 days,” says scientist Cary Zeitlin.

cognitive problems

When simulating the state of being in space, scientists have found that exposure to highly charged particles, even in small doses, causes laboratory rats to react to their environment much more slowly, and at the same time the rodents become more irritable. Observation of rats also showed a change in the composition of the protein in their brains.

However, scientists are quick to point out that not all rats showed the same effects. If this rule holds true for astronauts as well, then the researchers think they could identify a biological marker that indicates and predicts that astronauts will soon develop these effects. Perhaps this marker would even allow us to find a way to reduce the negative effects of exposure to radiation.

Alzheimer's disease is a more serious problem.

“Exposure to levels of radiation equivalent to that experienced by a human on a mission to Mars can contribute to cognitive problems and accelerate the brain changes most commonly associated with Alzheimer’s disease,” says neuroscientist Kerry O’Banion.

“The longer you are in space, the greater the risk of developing the disease.”

One of the comforting facts is that scientists have already managed to investigate one of the most unfortunate scenarios for exposure to radiation. They exposed laboratory mice to a level of radiation at one time that would be typical for the entire time of the mission to Mars. In turn, when flying to Mars, people will be exposed to radiation in a dosed manner, during the three years of the flight. Scientists believe that the human body can adapt to such small doses.

In addition, it is noted that plastic and lightweight materials can provide people with more effective protection against radiation than aluminum currently used.

vision loss

Some astronauts have developed serious vision problems after being in space. The longer the space mission lasts, the more likely the chance of such unfortunate consequences.

Of at least 300 US astronauts who have been medically screened since 1989, 29 percent of people who have been in space on two-week space missions and 60 percent of people who have been on board the International Space Station for several months have had vision problems. .

Doctors from the University of Texas performed brain scans on 27 astronauts who had been in space for more than a month. In 25 percent of them, a decrease in the volume of the anterior-posterior axis of one or two eyeballs was observed. This change leads to farsightedness. Again, it was noted that the longer a person is in space, the more likely this change is.

Scientists believe that this negative effect can be explained by the rise of fluid to the head in conditions of migravitation. IN this case cerebrospinal fluid begins to accumulate in the cranium, intracranial pressure rises. Liquid cannot seep through the bone, so it begins to create pressure on the inside of the eyes. Researchers are not yet sure if this effect will decrease in astronauts who stay in space for more than six months. However, it is quite obvious that it will be necessary to find out before sending people to Mars.

If the problem is caused solely by intracranial pressure, then one possible solution would be to create artificial gravity conditions, every day for eight hours, while the astronauts sleep. However, it is too early to say whether this method will help or not.

“This problem needs to be addressed, because otherwise it could be the main reason for the impossibility of long-term space travel,” says scientist Mark Shelhamer.

Second half of the 20th century was marked not only by the conduct of theoretical research to find ways to explore outer space, but also by the practical creation and launch of automatic vehicles into near-Earth orbits and to other planets, the first manned flight into space and long-term flights at orbital stations, and the landing of man on the surface of the moon. Theoretical studies in area space technology and the design of controlled aircraft sharply stimulated the development of many sciences, including a new branch of knowledge - space medicine.

The main tasks of space medicine are the following:

ensuring the life and safety of the cosmonaut at all stages of space flight, maintaining his state of health and high efficiency;

study of the influence of space flight conditions on the human body, including the study of the phenomenology and mechanisms of the occurrence of shifts physiological indicators in space flight;

development of methods for prevention and provision of medical assistance to an astronaut in the event of adverse events associated with the impact of flight conditions on the human body;

development of methods for selection and training of cosmonauts;

Space medicine in its historical development has gone from modeling the factors of space flight in laboratory conditions and during animal flights on rockets and satellites to research related to long-term flights of orbital stations and flights of international crews.

In the formation and development of space biology and medicine in the USSR, the works of the founders of cosmonautics K.E. Tsiolkovsky, F.A. Tsander and others, who formulated a number of biological problems, the solution of which was to be a necessary prerequisite for the exploration of outer space by man. The theoretical aspects of space biology and medicine are based on the classical provisions of such founders of natural science as I.M. Sechenov, K.A. Timiryazev, I.P. Pavlov, V.V. Dokuchaev, L.A. Orbeli and others, in whose works the doctrine of the interaction of the organism and the external environment is reflected, the fundamental questions of the adaptation of the organism to changing environmental conditions have been developed.

An important role in the formation of a number of provisions and sections of space medicine was played by the work performed in the field of aviation medicine, as well as research carried out on biophysical rockets and spacecraft in the 50-60s.

The practical exploration of outer space with the help of manned flights began with the historic flight of Yu.A. Gagarin, the world's first cosmonaut, committed on April 12, 1961 on the Vostok spacecraft. We all remember his simple human phrase. “Let's go”, uttered during the launch of the Vostok spacecraft, this phrase succinctly and at the same time quite capaciously characterized the greatest achievement of mankind. Among other things, the flight of Yu.A. Gagarin was a maturity test for both astronautics in general and space medicine in particular.

Biomedical studies carried out prior to this flight, and the life support system developed on their basis, provided normal living conditions in the spacecraft cabin, necessary for the astronaut to complete the flight. The system of selection and training of cosmonauts created by that time, the system of biotelemetric monitoring of the state and working capacity of a person in flight and the hygienic parameters of the cabin determined the possibility and safety of flight.

However, all previous work, all the numerous flights of animals on spaceships, could not answer some questions related to human flight. So, for example, before the flight of Yu.A. Gagarin, it was not known how the conditions of weightlessness affect purely human functions: thinking, memory, coordination of movements, perception of the surrounding world, and more. Only the flight of the first man into space showed that these functions do not undergo significant changes in weightlessness. That is why Yu.A. Gagarin is known all over the world as the discoverer of "star roads", the man who paved the way for all subsequent manned flights.

Over the 20 years that have passed since the flight of Yu.A. Gagarin, humanity steadily and comprehensively continued to explore outer space. And in connection with this glorious anniversary, there is an opportunity not only to analyze today's achievements in space medicine, but also to make a historical digression into the past and preceding decades.

Space flights throughout their development can be conditionally divided into several stages. The first stage is the preparation of a manned flight into outer space; it covered a significant period of time. It was accompanied by such studies as: 1) generalization of data from physiology and aviation medicine, which studied the influence of adverse environmental factors on the organism of animals and humans; 2) carrying out numerous laboratory research, in which some factors of space flight were imitated and their influence on the human body was studied; 3) specially prepared experiments on animals during rocket flights into the upper atmosphere, as well as during orbital flights on artificial Earth satellites.

The main tasks then were aimed at studying the question of the fundamental possibility of manned flight into space and solving the problem of creating systems that ensure that a man stays in the cockpit of a spacecraft during an orbital flight. The fact is that at that time there was a certain opinion of a number of fairly authoritative scientists about the incompatibility of human life with conditions of prolonged weightlessness, since this could allegedly cause significant violations of the function of respiration and blood circulation. In addition, they feared that a person might not be able to withstand the psychological stress of the flight.

In our country, since the beginning of the 1950s, a series of studies has been carried out with animals with vertical rocket launches at altitudes of 100, 200, and 450 km. In total, 52 dogs were launched on rockets in the Soviet Union, and the duration of weightlessness, depending on the flight altitude, ranged from 4 to 10 minutes. An analysis of the results of these studies showed that when flying on rockets, only moderate changes in physiological parameters were observed, manifested in an increase in heart rate and an increase in blood pressure when exposed to accelerations during takeoff and landing of the rocket (with a tendency to normalize or even decrease these indicators during stay in weightlessness). ).

In general, the impact of rocket flight factors did not cause significant disturbances in the physiological functions of animals. Biological experiments with vertical rocket launches have shown that dogs can satisfactorily endure fairly large overloads and short-term weightlessness.

In 1957, the USSR launched the second artificial satellite Lands with dog Laika. This event was of fundamental importance for space medicine, since for the first time it allowed a highly organized animal to stay in weightlessness for quite a long time. As a result, the animals were found to be satisfactorily tolerant of space flight conditions. Subsequent experiments with six dogs during the flights of the second, third, fourth and fifth Soviet satellites returning to Earth made it possible to obtain a large amount of material on the reactions of the main physiological systems organisms of highly organized animals (both in flight and on Earth, including the post-flight period).

The cabins of these satellites housed biological objects of various complexity: microorganisms, seeds of various plants, cultures of human epithelial tumor cells, small preserved areas of rabbit and human skin, insects, black and white laboratory mice and rats, guinea pigs. All studies carried out with the help of satellite ships provided extensive experimental material that firmly convinced scientists of the safety of human flight (from the point of view of health) into space.

Similar conclusions were reached by American scientists, who later carried out research on monkeys during suborbital and orbital (two orbits) flights of spacecraft (1961).

In the same period, the tasks of creating life support systems for astronauts were also solved - a system for supplying oxygen to the cabin, removing carbon dioxide and harmful impurities, as well as nutrition, water supply, medical control and disposal of human waste products. Specialists of space medicine took the most direct part in these works.

The second stage, coinciding with the first decade of manned flights (1961-1970), was characterized by short-term human space flights (from one orbit in 108 minutes to 18 days). It begins with the historical flight of Yu.A. Gagarin.

The results of biomedical studies carried out during this time have reliably proved not only the possibility of a person being in space flight conditions, but also the preservation of sufficient working capacity for him when performing various tasks in a spacecraft cabin limited in volume and when working in an unsupported space outside the spacecraft. . However, a number of changes were revealed in the motor sphere, the cardiovascular system, the blood system and other systems of the human body.

It was also found that the adaptation of cosmonauts to the usual conditions of terrestrial existence after space flights lasting from 18 days proceeds with certain difficulties and is accompanied by a more pronounced tension of regulatory mechanisms than the astronaut's adaptation to weightlessness. Thus, with a further increase in flight time, it was necessary to create systems of appropriate preventive measures, improve medical control systems and develop methods for predicting the condition of crew members in flight and after it.

During the manned flights under these programs, along with medical studies of the crews, biological experiments were also carried out. So, on board the ships Vostok-3, Vostok-6, Voskhod, Voskhod-2, Soyuz, there were such biological objects as lysogenic bacteria, chlorella, tradescantia, hella cells; human normal and cancer cells, dried plant seeds, turtles.

The third stage of manned space flights is associated with long-term flights of cosmonauts aboard orbital stations; it coincides with the past decade (1971-1980). Distinctive feature manned flights at this stage, in addition to the significant duration of a person's stay in flight, is an increase in the amount of free space in living quarters - from the cockpit of a spacecraft to extensive habitation areas inside the orbital station. The latter circumstance had a dual significance for space medicine: on the one hand, it became possible to place on board the station a variety of equipment for biomedical research and means of preventing the adverse effects of weightlessness, and on the other hand, to significantly reduce the impact on the human body from factors limiting motor activity - hypokinesia (i.e. associated with the small size of free space).

It should be said that more comfortable living conditions, personal hygiene, etc. can be created at orbital stations. And the use of a complex of prophylactic agents can largely smooth out the adverse reactions of the body to weightlessness, which has a great positive effect. However, on the other hand, this, to a certain extent, smooths out the reactions of the human body to weightlessness, which makes it difficult to analyze the shifts that occur for various systems of the human body that are characteristic of weightless conditions.

For the first time, a long-term orbital station (Salyut) was launched in the USSR in 1971. In subsequent years, manned flights were carried out aboard the Salyut-3, -4, -5, -6 orbital stations (moreover, the fourth main expedition of the Salyut- 6” was in space for 185 days). Numerous biomedical studies performed during the flight of orbital stations have shown that with an increase in the duration of a person's stay in space, no progression in the severity of the body's reactions to flight conditions was generally observed.

The complexes of prophylactic measures used ensured the maintenance of a good state of health and working capacity of the cosmonauts during such flights, and also contributed to the smoothing of reactions and facilitated adaptation to terrestrial conditions in the post-flight period. It is important to note that the conducted medical studies did not reveal any changes in the body of the cosmonauts that prevent a systematic increase in the duration of flights. At the same time, from the outside, some body systems were found to have functional changes that are the subject of further consideration.

Second half of the 20th century was marked not only by the conduct of theoretical research to find ways to explore outer space, but also by the practical creation and launch of automatic vehicles into near-Earth orbits and to other planets, the first manned flight into space and long-term flights at orbital stations, and the landing of man on the surface of the moon. Theoretical research in the field of space technology and the design of controlled aircraft sharply stimulated the development of many sciences, including a new branch of knowledge - space medicine.

The main tasks of space medicine are the following:

study of the effects of space flight conditions on the human body, including the study of the phenomenology and mechanisms of the occurrence of shifts in physiological parameters in space flight;

development of methods for selection and training of cosmonauts;

In the formation and development of space biology and medicine in the USSR, the works of the founders of cosmonautics K. E. Tsiolkovsky, F. A. Zander and others, who formulated a number of biological problems, the solution of which was to be a necessary prerequisite for the exploration of outer space by man, were of great importance. The theoretical aspects of space biology and medicine are based on the classical provisions of such founders of natural science as I. M. Sechenov, K. A. Timiryazev, I. P. Pavlov, V. V. Dokuchaev, L. A. Orbeli and others, in whose works the doctrine of the interaction of the organism and the external environment is reflected as a red thread, and the fundamental questions of the adaptation of the organism to changing environmental conditions are developed.

The practical exploration of outer space with the help of manned flights began with the historic flight of Yu. A. Gagarin, the world's first cosmonaut, on April 12, 1961 on the Vostok spacecraft. We all remember his simple human phrase. “Let's go”, uttered during the launch of the Vostok spacecraft, this phrase succinctly and at the same time quite capaciously characterized the greatest achievement of mankind. Among other things, Yu. A. Gagarin's flight was a test of maturity for both cosmonautics in general and space medicine in particular.

However, all previous work, all the numerous flights of animals on spaceships, could not answer some questions related to human flight. So, for example, before the flight of Yu. A. Gagarin, it was not known how weightlessness conditions affect purely human functions: thinking, memory, coordination of movements, perception of the surrounding world, and more. Only the flight of the first man into space showed that these functions do not undergo significant changes in weightlessness. That is why Yu. A. Gagarin is called all over the world the pioneer of "star roads", the man who paved the way for all subsequent manned flights.

In the 20 years that have passed since the flight of Yu. A. Gagarin, mankind has steadily and comprehensively continued to explore outer space. And in connection with this glorious anniversary, there is an opportunity not only to analyze today's achievements in space medicine, but also to make a historical digression into the past and preceding decades.

Space flights throughout their development can be conditionally divided into several stages. The first stage is the preparation of a manned flight into outer space; it covered a significant period of time. It was accompanied by such studies as: 1) generalization of data from physiology and aviation medicine, which studied the influence of adverse environmental factors on the organism of animals and humans; 2) carrying out numerous laboratory studies in which some factors of space flight were imitated and their influence on the human body was studied; 3) specially prepared experiments on animals during rocket flights into the upper atmosphere, as well as during orbital flights on artificial Earth satellites.

moreover, the duration of weightlessness, depending on the flight altitude, ranged from 4 to 10 minutes. An analysis of the results of these studies showed that when flying on rockets, only moderate changes in physiological parameters were observed, manifested in an increase in heart rate and an increase in blood pressure when exposed to accelerations during takeoff and landing of the rocket (with a tendency to normalize or even decrease these indicators during stay in weightlessness). ).

In 1957, the USSR launched the second artificial Earth satellite with the dog Laika. This event was of fundamental importance for space medicine, since for the first time it allowed a highly organized animal to stay in weightlessness for quite a long time. As a result, the animals were found to be satisfactorily tolerant of space flight conditions. Subsequent experiments with six dogs during the flights of the second, third, fourth and fifth Soviet satellite ships returning to Earth made it possible to obtain a lot of material on the reactions of the main physiological systems of the organism of highly organized animals (both in flight and on Earth, including the post-flight period) .

small preserved patches of rabbit and human skin, insects, black and white laboratory mice and rats, guinea pigs. All studies carried out with the help of satellite ships provided extensive experimental material that firmly convinced scientists of the safety of human flight (from the point of view of health) into space.

It was also found that the adaptation of cosmonauts to the usual conditions of terrestrial existence after space flights lasting from 18 days proceeds with certain difficulties and is accompanied by more pronounced stress. regulatory mechanisms than the astronaut's adaptation to weightlessness. Thus, with a further increase in flight time, it was necessary to create systems of appropriate preventive measures, improve medical control systems and develop methods for predicting the condition of crew members in flight and after it.

The third stage of manned space flights is associated with long-term flights of cosmonauts aboard orbital stations; it coincides with the past decade (1971-1980). A distinctive feature of manned flights at this stage, in addition to the significant duration of a person's stay in flight, is the increase in the amount of free space in living quarters - from the cockpit of a spacecraft to extensive living areas inside the orbital station. The latter circumstance had a dual significance for space medicine: on the one hand, it became possible to place on board the station a variety of equipment for biomedical research and means of preventing the adverse effects of weightlessness, and on the other hand, to significantly reduce the impact on the human body from factors limiting motor activity - hypokinesia (i.e., associated with the small size of free space).

It should be said that more comfortable living conditions, personal hygiene, etc. can be created at orbital stations. And the use of a complex of preventive measures can significantly smooth out the adverse reactions of the body to weightlessness, which has a great positive effect. However, on the other hand, this, to a certain extent, smooths out the reactions of the human body to weightlessness, which makes it difficult to analyze the resulting shifts for various systems of the human body, characteristic of the conditions of weightlessness.

To date, 99 people have already made space flights. various countries there are 78 spacecraft and 6 long-term orbital stations on board2. The total travel time was about 8 man-years. As of January 1, 1981, 46 manned space flights were carried out in the USSR, in which 49 Soviet cosmonauts and 7 cosmonauts from the socialist countries. Thus, over the course of two decades of manned space flights, the pace and scale of human penetration into outer space has been rapidly increasing.

Next, we consider the main results of space medicine research carried out during this time. During space flights, the human body can be exposed to various adverse factors, which can be conditionally divided into the following groups: 1) characterizing outer space as a kind of physical environment (extremely low barometric pressure, lack of oxygen, ionizing radiation etc.); 2) due to the dynamics of the aircraft (acceleration, vibration, weightlessness); 3) associated with the stay of astronauts in the pressurized cabin of the spacecraft (artificial atmosphere, dietary habits; hypokinesia, etc.); 4) psychological features of space flight (emotional tension, isolation, etc.).

life support creates the necessary conditions for living and working in the cockpit space. An exception in this group of factors is cosmic radiation: during some solar flares, the level of cosmic radiation can increase so much that the cabin walls cannot protect the astronaut from the action of cosmic rays.

and that scientists have not yet learned how to simulate the full spectrum of cosmic radiation under Earth conditions. This naturally creates significant difficulties in studying the biological effect of cosmic radiation and in developing protective measures.

In this direction, various studies are being carried out to create an electrostatic protection for a spacecraft, that is, attempts are being made to create an electromagnetic field around the spacecraft, which will deflect charged particles, preventing them from passing to the cabin. A large amount of work is also carried out in the development of pharmacochemical means for the prevention and treatment of radiation injuries.

Most of the factors of the second group are successfully modeled under the conditions of the terrestrial experiment and have been studied for a long time (vibration, noise, overloads). Their effect on the human body is quite clear, and, consequently, the measures for the prevention of possible disorders are also clear. The weightlessness factor is the most important and specific factor in space flight. It should be noted that in the case of a long-term action, it can only be studied under real flight conditions, since in this case its simulation on Earth is very approximate.

Finally, the third and fourth groups of flight factors are not so much cosmic, but the conditions of space flight contribute so much of their own, inherent only to this type of activity, that the study of the psychological characteristics that arise in this case, as well as work and rest regimes, psychological compatibility and other factors is a separate and very complex problem.

It is quite obvious that the versatility of the problems of space medicine does not allow us to exhaustively consider all of them, and here we will focus only on some of these problems.

Medical control and in-flight medical research

In the complex of measures that ensure the safety of cosmonauts in flight, an important role belongs to medical control, the task of which is to assess and predict the health status of crew members and issue recommendations for preventive and therapeutic measures.

A feature of medical control in space flight is that the "patients" of doctors are healthy, physically well-prepared people. In this case, the task of medical control is mainly to identify functional adaptive changes that may occur in the human body under the influence of space flight factors (primarily weightlessness), to evaluate and analyze these changes, to determine indications for the use of prophylactic agents, and also V; choosing the most optimal modes of their use.

Generalization of the results of medical research in space flights and numerous studies with modeling of flight factors under Earth conditions makes it possible to obtain data on the effect of various loads on the human body, on the permissible limits of fluctuations in physiological parameters, and on the characteristics of the body's reactions under these conditions.

It should be emphasized that such research in space medicine, which refines our knowledge of the normal manifestations of the vital activity of the human body and more clearly draws the line between its normal and altered reactions, is of great importance for identifying the initial signs of deviations not only in spacecraft crews in flight, but also in clinical practice, in the analysis of initial and latent forms of diseases and their prevention.

As sources of information, data from conversations between a doctor and astronauts, astronauts' reports on their well-being and the results of self- and mutual control, analysis of radio conversations (including spectral analysis of speech) are used. Important sources of information are the data of objective recording of physiological parameters, environmental indicators in the cabin of the spacecraft (pressure, oxygen and carbon dioxide content, humidity, temperature, etc.), as well as analysis of the results of the most complex ship control operations and scientific and technical experiments. .

This information with the help of telemetry systems enters the flight control center, where it is processed using computers and reviewed by physicians. Physiological parameters to be recorded and transmitted to Earth are determined in accordance with the features of the flight program and the specifics of the crew's activities. When assessing the health status of astronauts, information about the state of the most vital systems of the human body (respiration and blood circulation), as well as changes in the physical performance of astronauts, is of paramount importance.

in an unusual habitat, they help to elucidate the mechanisms of changes in physiological functions and adaptation of the body to conditions of weightlessness. All this is necessary for the development of preventive measures and for planning medical support for subsequent flights.

The volume of medical information transmitted by biotelemetry to the Earth was not the same in different flights. In the first flights under the Vostok and Voskhod programs, when our knowledge of the effect of space flight factors on the human body was very limited, a fairly wide range of physiological parameters was recorded, since it was necessary not only to monitor the health status of astronauts, but also to study it extensively. physiological responses to flight conditions. During flights under the Soyuz program, the number of physiological indicators transmitted to Earth is limited and was optimal for monitoring the health of cosmonauts.

which was before, during flights at the orbital stations, periodic in-depth medical examinations were carried out every 7-10 days. The latter included clinical electrocardiographic examinations (at rest and during functional tests), registration of arterial and venous pressures, study of the phase structure of the cardiac cycle according to kinetocardiography, studies of stroke and minute volume of the heart, pulse blood filling. various areas body (method of rheography) and a number of other examinations.

As functional tests, a dosed physical load of the cosmonaut's body on a bicycle ergometer ("space bike"), as well as a test with the application of negative pressure to the lower body, were used. In the latter case, with the help of the “Chibis” vacuum set, which is a corrugated “trousers”, negative pressure was created in the lower abdomen and lower extremities, which caused a rush of blood to these areas, similar to that which occurs on Earth during a person’s stay upright.

Such an imitation of a vertical posture allows you to get Additional information about the expected state of the crew in the post-flight period. This circumstance seems to be extremely important, since, as was established in previous flights, a long stay in weightlessness is accompanied by a decrease in the so-called orthostatic stability, which manifests itself as pronounced shifts in the indicators of the cardiovascular system when a person is in an upright position.

At the Salyut-6 orbital station (see table), a person's body weight was measured, the volume of the lower leg was studied, and the state of the vestibular apparatus and the function of external respiration were also studied. During the flight, samples of blood and other body fluids were taken, the microflora of the external integument, human mucous membranes and station surfaces were studied, and air samples were analyzed. Materials taken in flight for research were delivered with visiting expeditions to Earth for detailed analysis.

Research methods in space flights

Spacecraft Launch years Physiological measurement methods

"Easts" 1961-1963 Electrocardiography (1-2 leads, pnemography, seismocardiography and kinetocardiography (characterize the mechanical function of the heart), electrooculography (registration of eye movements), electroencephalography (registration of biocurrents of the cerebral cortex), galvanic skin reflex.

"Sunrise" 1964-1965 Electrocardiography, pneumography, seismocardiography, electroencephalography, registration of motor acts of writing.

single 1967-1970 Electrocardiography, pneumography, seismocardiography, body temperature.

tachooscillography (for measuring blood pressure), phlebography (for recording the jugular vein pulse curve and determining venous pressure, regraphy (for studying the stroke and minute volume of the heart and pulse blood supply to various areas of the body), measuring body weight, shin volume, blood sampling, studying external respiration, microbiological studies, as well as studies of water-salt metabolism, etc.

During long flights on the Salyut-Soyuz orbital complexes, great importance was attached to medical management. Medical management is a part (subsystem) of more common system"crew - ship - flight control center", and its functions are aimed at maintaining the maximum organization of the entire system as a whole by maintaining the good health of the crew and its necessary performance. To this end, the medical service worked closely with the crew and flight program planners. The working body of control was the medical support group in the flight control center, which entered into mutual contact with the crew, with the advisory and forecasting group and with other groups of the flight control center.

The results of the examinations and the recommendations formed on their basis on the use of prophylactic agents, the regime of work and rest, and other medical measures were systematically discussed with the crew and accepted by them for execution. All this created an atmosphere of benevolence and business-like cooperation between the medical support group and the crew in solving the problem of maintaining the health of the crew in flight and in preparing for its meeting with the Earth.

Means of prevention

a prerequisite for the development of preventive measures and a rational system of medical control in long-term space flights. The data available to date allow us to formulate some working hypotheses that can be considered as a blueprint for further research.

The main link in the pathogenesis of the effect of the weightlessness factor is, apparently, a decrease in the functional load on a number of systems of the human body due to the lack of weight and the associated mechanical stress of body structures. The functional underload of the human body in a state of weightlessness manifests itself, probably, as a change in afferentation from mechanoreceptors, as well as a change in the distribution of liquid media and a decrease in the load on the astronaut's musculoskeletal system and his tonic muscles.

there is always a tension of structures due to the force of weight. At the same time, a large number of muscles, as well as ligaments, some joints, counteracting this trend, are constantly under load, regardless of the position of the human body. Under the influence of weight, the internal organs also tend to shift towards the Earth, stretching the ligaments that fix them.

Numerous nerve perceiving devices (receptors) located in muscles, ligaments, internal organs, blood vessels, etc., send impulses to the central nervous system, signaling the position of the body. The same signals come from the vestibular apparatus located in the inner ear, where carbon dioxide salt crystals (stolites), shifting the nerve endings under the influence of their weight, signal the movement of the body.

However, during a long flight and its indispensable attribute - weightlessness - the weight of the body and its individual parts is absent. The receptors of muscles, internal organs, ligaments, blood vessels, while in weightlessness, work, as it were, “in a different way”. Information about the position of the body comes mainly from the visual analyzer, and the interaction of space analyzers developed throughout the development of the human body (vision, vestibular apparatus, muscle sensation, etc.) is disrupted. Muscle, tone and load on the muscular system as a whole are reduced, since there is no need to resist them with the force of weight.

As a result, in zero gravity, the total volume of impulses from the perceiving elements (receptors), which goes to the central nervous system, decreases. This leads to a decrease in the activity of the central nervous system, which, in turn, affects the regulation of internal organs and other functions of the human body. However, the human body is an extremely plastic structure, and after a certain time of a person's stay in a state of weightlessness, his body adapts to these conditions, and the work of internal organs is already taking place at a new, different (compared to the Earth) functional level of interaction between systems.

due to its weight tends to the underlying parts of the body (legs, lower abdomen). In this regard, the astronaut's body develops a system of mechanisms that prevent such a movement. In weightlessness, there is no force, except for the energy of the heart impulse, which would contribute to the movement of blood to the lower parts of the body. As a result, there is a rush of blood to the head and chest organs.

veins and atria. This is the reason for the signal to the central nervous system about the inclusion of mechanisms that help reduce excess fluid in the blood. As a result, a number of reflex reactions occur, leading to an increase in the excretion of fluid, and with it, salts from the body. Ultimately, body weight may decrease and the content of some electrolytes, in particular potassium, may change, as well as the state of the cardiovascular system.

The redistribution of blood apparently plays a certain role in the development of vestibular disorders (cosmic form of motion sickness) in the initial period of stay in weightlessness. However, the leading role here still belongs, probably, to the violation of the well-coordinated work of the sense organs in conditions of weightlessness, which carry out spatial orientation.

to a corresponding change in the so-called anti-gravity muscles, a decrease in their tone, atrophy. A decrease in muscle tone and strength, in turn, contributes to a deterioration in the regulation of the vertical posture and a violation of the astronaut's gait in the post-flight period. However, these phenomena can also be caused by restructuring motor stereotype in progress.

The above ideas about the mechanism of change in some functions of the human body under weightless conditions are, of course, rather schematic, and have not yet been experimentally confirmed in all their links. We have carried out these discussions only with the aim of showing the interconnectedness of all the functions of the astronaut's organism, when changes in one link cause a whole range of reactions of various systems. On the other hand, it is important to emphasize the reversibility of changes, the wide possibilities for adapting the human body to the action of the most unusual environmental factors.

The described changes in the functions of the astronaut's body in a state of weightlessness can be considered as a reflection of the adaptive reactions of a person to new conditions of existence - to the absence of weight force. Naturally, these changes largely determine the corresponding reactions on the part of the human body that take place when an astronaut returns to Earth and during the subsequent adaptation of his body to Earth conditions, or, as doctors say, during readaptation.

The shifts in a number of functions of the cosmonaut's organism revealed after short-term flights into space, progressing with increasing duration of flights, raised the question of developing means of preventing the adverse effects of weightlessness. Theoretically, it could be assumed that the use of artificial gravity (IGF) would be the most radical means of protection against weightlessness. However, the creation of ICT gives rise to a number of physiological problems associated with staying in a rotating system, as well as technical problems that should ensure the creation of ICT in space flight.

In this connection, researchers, long before the start of space flights, began to search for other ways to prevent adverse changes in the human body during space flight. In the course of these studies, numerous methods for preventing the adverse effects of weightlessness, not related to the use of ICT, were tested. These include, for example, physical methods aimed at reducing the redistribution of blood in the astronaut's body during or after the end of the flight, as well as at stimulating the neuroreflex mechanisms that regulate blood circulation in the vertical position of the body. For this purpose, the application of negative pressure to the lower body, inflatable cuffs applied to the arms and legs, suits for creating a positive pressure difference, rotation on a small radius centrifuge, inertial impact effects, electrical stimulation of the muscles of the lower extremities, elastic and anti-g suits, etc. .

Among other methods of such prevention, we note physical activity aimed at maintaining the fitness of the body and stimulating certain groups of receptors (physical training, load suits, load on the skeleton); impacts associated with the regulation of nutrition (adding salts, proteins and vitamins to food, rationing nutrition and water consumption); purposeful influence with the help of so-called medications and a modified gas environment.

Prophylactic agents against any unfavorable changes in the cosmonaut's body can be effective only if they are prescribed taking into account the mechanism of these disorders. With regard to weightlessness, prophylactic measures should be aimed primarily at replenishing the deficiency of muscle activity, as well as at reproducing the effects that, under Earth conditions, are determined by the weight of blood and tissue fluid.

physical exercises on a treadmill and a bicycle ergometer, as well as strength exercises with expanders; 2) creating a constant load on the musculoskeletal system and skeletal muscles of the astronaut (daily stay for 10-16 hours in load suits); 3) training with the application of negative pressure to the lower body, carried out at the end of the flight; 4) the use of water-salt additives on the day of the end of the flight; 5) the use of a post-flight anti-g suit.

With the help of special suits and a system of rubber shock absorbers, when performing "space charging", a load of 50 kg was created in the direction of the longitudinal axis of the body, as well as a static load on the main groups of anti-gravity muscles.

Physical training was also carried out on a bicycle ergometer - a device similar to a bicycle, but standing still. On it, the astronauts pedaled with their feet or hands, thereby creating an appropriate load on the corresponding muscle groups.

Load suits reproduced a constant static load on the astronaut's musculoskeletal system and skeletal muscles, which to a certain extent compensated for the absence of Earth's gravity. Structurally, the suits are made as semi-adjacent overalls, which include elastic elements such as rubber shock absorbers.

To create negative pressure on the lower part of the body, a vacuum set was used in the form of trousers, which are a hermetic bag on a frame in which vacuum can be created. With a decrease in pressure, conditions are created for the outflow of blood to the legs, which contributes to its distribution, which is typical for a person who is in a vertical position under Earth conditions.

Water-salt supplements were intended to retain water in the body and increase blood plasma volume. The post-flight prophylactic suit, worn under the suit before descent, was designed to create excessive pressure on the legs, which prevents the accumulation of blood in the lower extremities on Earth in a vertical position of the body and favors maintaining normal blood circulation when moving from a horizontal to a vertical position.

Changing the basic functions of the human body in weightlessness

The main result of the study of outer space (from a medical point of view) was the proof of the possibility of not only a long stay of a person in space flight conditions, but also his versatile activities there. This now gives the right to consider outer space as the environment for the future human habitation, and the spacecraft and the flight itself into space as the most effective, direct way to study the reactions of the human body under these conditions. To date, quite a lot of information has been accumulated on the reactions of various physiological systems of the cosmonaut's body in different phases flight and in the post-flight period.

A symptom complex outwardly similar to motion sickness (decreased appetite, dizziness, increased salivation, nausea and sometimes vomiting, spatial illusions) is observed in varying degrees of severity in approximately every third cosmonaut and manifests itself in the first 3-6 days of flight. It is important to note that at present it is still impossible to reliably predict the degree of manifestation of these phenomena in cosmonauts in flight. Some cosmonauts also showed signs of motion sickness on the first day after returning to Earth. The development of the symptom complex of motion sickness in flight is currently explained by a change in the functional state of the astronaut's vestibular apparatus and a violation of the interaction of his sensory systems, as well as by hemodynamic features (blood redistribution) under weightless conditions.

The symptom complex of redistribution of blood to the upper part of the body occurs in almost all astronauts in flight, occurs on the first day and then at various times, on average within a week, gradually smoothes out (but does not always completely disappear). This symptom complex is manifested by a sensation of a rush of blood and heaviness in the head, nasal congestion, smoothing of wrinkles and puffiness of the face, an increase in blood supply and pressure in the veins of the neck and indicators of blood filling of the head. The volume of the leg is reduced. The described phenomena are associated with the redistribution of blood due to the lack of its weight in weightlessness, which leads to a decrease in blood accumulation in the lower extremities and an increase in blood flow to the upper body.

some work operations and it is difficult to assess the muscle effort required to perform a number of movements. However, already during the first few days of flight, these movements regain the necessary accuracy, the necessary efforts to perform them decrease, and the efficiency of motor performance increases. When returning to Earth, the weight of objects and one's own body subjectively increases, and the regulation of the vertical posture changes. A post-flight study of the motor sphere in cosmonauts reveals a decrease in the volume of the lower extremities, some loss of muscle mass, and subatrophy of the anti-gravitational muscles, mainly the long and wide muscles of the back.

Changes in the functions of the cardiovascular system during long-term space flights manifest themselves as a tendency to a slight decrease in certain indicators of arterial pressure, an increase in venous pressure in the region of the veins of the neck and its decrease in the region of the lower leg. The ejection of blood during the contraction of the heart (stroke volume) initially increases, and the minute volume of blood circulation tends to exceed the preflight values during the flight. The indicators of blood filling of the head usually increased, their normalization occurred at 3-4 months of flight, and decreased in the shin area.

The response of the cardiovascular system to functional tests with the application of negative pressure to the lower body and physical activity underwent some changes in flight. During the test with the application of negative pressure, the astronaut's reactions, in contrast to the terrestrial ones, were more pronounced, which indicated the development of orthostatic detraining phenomena. At the same time, exercise tolerance during six-month flights was assessed as good in almost all surveys, and reactions did not qualitatively differ from the pre-flight period. This indicated that with the help of preventive measures it is possible to stabilize the body's response to functional tests and even in some cases achieve their lesser severity than in the pre-flight period.

In the post-flight period, during the transition from a horizontal to a vertical position, as well as during an orthostatic test (passive vertical position on an inclined table), the severity of reactions is greater than before the flight. This is explained by the fact that under Earth conditions, blood regains its weight and rushes to the lower limbs, and as a result of a decrease in the tone of blood vessels and muscles in astronauts, more blood can accumulate here than usual. As a result, there is an outflow of blood from the brain.

blood pressure may drop sharply, the brain will experience a lack of blood, and therefore oxygen.

salt after the flight. Immediately after flights, the excretion of fluid by the kidneys decreases and the excretion of calcium and magnesium ions, as well as potassium ions, increases. A negative potassium balance combined with an increase in nitrogen excretion probably indicates a decrease in cell mass and a decrease in the ability of cells to fully assimilate potassium. Studies of some kidney functions using stress tests revealed a mismatch in the ionoregulation system in the form of multidirectional changes in the excretion of fluid and some ions. When analyzing the obtained data, one gets the impression that the shifts in the water-salt balance are due to changes in the regulatory systems and hormonal status under the influence of the flight factor.

A decrease in the mineral saturation of the bone tissue (loss of calcium and phosphorus in the bones) was noted in a number of flights. Thus, after 175- and 185-day flights, these losses amounted to 3.2-8.3%, which is significantly less than after prolonged bed rest. This relatively small decrease mineral components in bone tissue is a very significant circumstance, since a number of scientists considered demineralization of bone tissue as one of the factors that can be an obstacle to increasing the duration of space flights.

Biochemical studies have shown that under the influence of long-term space flights, the metabolic processes are reorganized, due to the adaptation of the cosmonaut's body to conditions of weightlessness. In this case, no pronounced changes in metabolism are observed.

and recovers approximately 1-1.5 months after the flight. Studies of the content of erythrocytes in the blood during and after flights are of great interest, since, as is known, average duration the life of erythrocytes is 120 days.

blood plasma volume. As a result, compensatory mechanisms are activated, seeking to maintain the basic constants of circulating blood, which leads (due to a decrease in blood plasma volume) to an adequate decrease in erythrocyte mass. A quick recovery of the erythrocyte mass after returning to Earth is impossible, since the formation of erythrocytes occurs slowly, while the liquid part of the blood (plasma) is restored! significantly faster. This rapid restoration of circulating blood volume leads to an apparent further decrease in the red blood cell count, which is restored after 6-7 weeks after the end of the flight.

Thus, the results of hematological studies obtained during and after long-term space flights make it possible to optimistically assess the possibility of an astronaut's blood system adapting to flight conditions and its recovery in the post-flight period. This circumstance is extremely important, since in the special literature the possible hematological changes expected in long-term space flights are considered as one of the problems that can prevent a further increase in the duration of flights.

after the flight. Nevertheless, it must be said that we still do not know everything about the reactions of astronauts in a long flight, not with all adverse events we can fight. There is still a lot of work to be done in this regard.

SPACE MEDICINE, a field of medicine that studies the characteristics of human life under the influence of space flight factors in order to develop means and methods for maintaining the health and performance of crews of spacecraft and stations. The main tasks of space medicine: study of the influence of space flight (SF) factors on the human body; development of means of prevention and protection against the adverse effects of their impact; physiological and sanitary-hygienic substantiation of the requirements for the life support system of manned aircraft, as well as for crew rescue equipment in case of emergency. Important areas of space medicine; development of clinical and psychophysiological methods and criteria for the selection and preparation of cosmonauts for flight; development of means and methods of medical control at all stages of flight; addressing the issues of prevention and treatment of diseases in flight and elimination of the adverse effects of long-term flight landings. Space medicine is closely related to space biology, space physiology and psychophysiology, space radiobiology, etc.

Space medicine goes back to aviation medicine, and its development is due to the creation of rocket technology and the achievements of astronautics. Biological and physiological studies on animals and with the use of rockets and satellite ships made it possible to test life support systems, study the physiological effects of CP factors and substantiate the possibility and safety of it for humans. The activities of domestic scientists made it possible to solve a number of fundamental and applied problems of space medicine, including the creation of an effective system of medical support for health and active human activity in manned spacecraft. This was facilitated by a large amount of research and experiments performed in our country in the 1960-1990s, both in ground model conditions and in the spacecraft on the Vostok, Voskhod, Soyuz spacecraft, orbital stations of the Salyut series, "Mir" and automatic devices (biological satellites) of the "Bion" series.

In a space flight, the human body is affected by factors associated with flight dynamics (acceleration, noise, vibration, weightlessness, etc.); factors associated with staying in the so-called hermetically sealed premises of small volume with an artificial habitat. The complex effect of these factors during the flight does not always allow establishing strict causal relationships of recorded deviations of physiological parameters in humans at different stages of flight.

Among all the factors of CP, weightlessness (microgravity) is unique and practically unreproducible under laboratory conditions. In the initial period of its action, there is a displacement of body fluids in the cranial (toward the head) direction due to the removal of hydrostatic pressure, as well as signs of the so-called motion sickness due to a mismatch in the activity of sensory systems, etc. Medical and biological studies have shown that the development of adaptive reactions is practically of all physiological systems of the body to stay in conditions of prolonged weightlessness can lead to adverse consequences - cardiovascular decompensation, orthostatic instability, muscle atrophy, osteoporosis, etc. vibration stands, pressure chambers, immersion stands, etc.).

The creation, launch and expansion of the ISS required the development and implementation of a common system of medical support for the spacecraft. Medical support is a system of organizational, medical, sanitary-hygienic and medical-technical measures aimed at preserving and maintaining the health and performance of cosmonauts at all stages of their activity. Includes: medical selection and examination of astronauts; medical and biological training of crews; medical and sanitary support for the development of manned spacecraft; development of onboard means of medical and biological support; medical support for the health and performance of cosmonauts; monitoring the health of the crew and the environment in the living compartments of orbital stations (sanitary and hygienic and radiation control); prevention of adverse effects of CP factors on the body, medical care according to indications; medical support for the health of crew members in the post-flight period, including medical rehabilitation measures.

To prevent adverse reactions of the human body at different stages of the flight (including the post-flight rehabilitation period), a set of pre-flight preparatory and preventive measures and means is used: a treadmill, a bicycle ergometer, a vacuum suit that simulates negative pressure on the lower half of the body, training load suits, expanders, water salt additives, pharmacological agents, etc. The main goal of preventive measures is to counteract adaptation to weightlessness, which is achieved by creating an axial load on the body, physical training, simulating the effect of hydrostatic blood pressure, balanced nutrition with its possible correction. The effectiveness of these measures is confirmed by long-term CPs of domestic crews.

High biological activity various kinds cosmic radiation determines the importance of measures for the creation of dosimetry tools, the determination of permissible doses during the spacecraft, the development of means and methods for the prevention and protection against the damaging effects of cosmic radiation. Ensuring radiation safety is of particular importance with an increase in the range and duration of spacecraft, especially interplanetary ones. To ensure the performance of work in open space or on the surface of planets, as well as to save life in the event of depressurization of a ship or station, space suits with a life support system are used.

Space medicine also studies the development mechanisms and methods for preventing decompression sickness; the effects of reduced (hypoxia) and increased (hyperoxia) oxygen content; change in daily regimes; psychology of compatibility of crew members. The provision of human life on manned spacecraft and orbital stations is created by a set of equipment, the effectiveness of which is monitored by sanitary-hygienic and microbiological studies of the atmosphere, water, interior surfaces, etc. A special section of space medicine is dedicated to the selection and training of cosmonauts.

The Russian Space Agency coordinates all space activities in Russian Federation, including medical support of the CP. The Institute of Biomedical Problems is the State Research Center that studies the problems of space medicine and is responsible for the health of cosmonauts in the spacecraft. The Yu. A. Gagarin Cosmonaut Training Center is the lead organization at the stages of selection and medical and biological preparation for the spacecraft and post-flight rehabilitation. A section on space biology and medicine operates as part of the RAS Scientific Council for Space. The journal "Aerospace and Ecological Medicine" is devoted to the problems of space medicine. Special courses in space physiology and medicine are included in learning programs Faculty of Medicine and Biology of the Russian State medical university and Faculty of Fundamental Medicine of Moscow State University.

In the United States, NASA coordinates work on space medicine problems; in Europe, the European Space Agency (ESA); in Japan, the Japan Space Exploration Agency (JAXA); in Canada, the Canadian Space Agency (CSA). The largest international organizations are the Committee on Space Research (COSPAR) and the International Astronautical Federation (IAF).

Lit.: Brief reference book on space biology and medicine. 2nd ed. M., 1972; Fundamentals of space biology and medicine. Joint Soviet-American edition: In 3 volumes / Edited by O. G. Gazenko, M. Calvin. M., 1975; Space biology and medicine: Joint Soviet-American edition: In 5 vols. M., 1994-2001.