According to the common stereotype, everything is very simple: the astronaut flew to the station and performs experiments there. Sometimes his workdays become heroic: there is a fire at the space station, depressurization or something else to attack, and he copes with problems, but in general, neither during nor after the flight, he does not experience any problems with his own health or at least hygiene.

In fact, during long-term space flight, a person experiences various types of physical and psychological stress. There are many negative factors associated with being outside and on Earth’s orbit, and they leave their mark on the body and psyche.

We can protect a person from vacuum and temperature drop in such a way that he doesn’t even feel that he is in space, but the following factors can be dealt with only partially.
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Radiation

Elevated levels of radiation can lead to cataracts. For example, Valentin Lebedev, who set the record for the duration of his stay in Earth orbit (221 days), lost his sight. Radiation really can not be neglected.

Various subatomic particles from the Sun, the stars of the Milky Way and other objects penetrate astronauts' bodies and destroy DNA structures, which leads to an increased risk of developing cancer. From 99.9 percent of these particles we are protected by the magnetic field of the Earth and the atmosphere, but already on the ISS their help is not so great. For comparison: the gas atmosphere of our planet provides protection similar to a sheet of metal with a thickness of 1 meter. The walls of the station are only a few millimeters.

In addition, according to NASA , because of cosmic radiation, the risk of developing Alzheimer's disease is increasing.

The ISS crew has only partial protection by the Earth’s magnetic field. Elevated levels of radiation destroy lymphocytes that ensure the functioning of the immune system. Suppressed viruses in human blood can be activated, and T-lymphocytes will be weakened.

Cosmic rays are one of the reasons that restrain mankind from flying beyond the limits of the magnetic field of the Earth. The readings of the Curiosity sensors indicate that even a short landing on the surface of Mars is fraught with a dose of 0.06 sievert. For comparison: NASA allows astronauts to receive a maximum of 1 sievert for their entire career, and six months on the ISS are fraught with 0.068 sieverts, according to other data , 0.001 sievert is "worth" a day on the ISS. Each sievert increases the risk of cancer by 5.5 percent.

A geomagnetic storm, comparable to the storm of 1859, could easily kill people in space. If we want to go to Mars, then we will have to do something with it, otherwise not the whole crew will reach the red planet.

Microgravity

A set of not always temporary effects is connected with the almost complete absence of attraction.
On Earth, our three-fifths body of water struggles with gravity as it distributes fluids, which pulls blood down. In space, these systems continue to work, so something like the one shown on the left immediately happens (he comically exaggerates the effects). That is why astronauts are puffy and chubby, and fluid accumulates in their nasal sinuses.

Increases intracranial pressure, and with it pressure on the eyeballs, which affects their shape, and also slightly deforms the optic nerve. The effect was observed only in 2012 with tomography a full month after returning to Earth.

Plasma levels in the blood fall by 20%. It is less than blood that needs to be pumped, therefore the muscles of the heart atrophy, resulting in a decrease in blood pressure. Aerobic capacity and blood circulation of the body are reduced.

For reasons unknown so far, some lose their taste and smell. In the conditions of microgravity, people are beginning to actively consume spices and products with a pronounced taste, and some delicacies no longer bring the same pleasure.

The vestibular apparatus, the organ of perception of the body position inside the head, also suffers. When the direction of gravity changes, the effect on the sensitive hairs of the organ filling the fluid changes. On Earth, this organ allows, without an effort of will, to maintain a straight body position and move in space.

In space, this organ is completely useless, because there is neither top nor bottom, so people have to navigate with the help of sight. The muscles of the back and legs, usually supporting posture when a person is standing, are also useless. Under microgravity, the body weighs almost nothing, so you can lose 20% of muscle mass in just 5-11 days.

Not only volume, but also character changes: now these are not long-lasting muscle fibers that support one position, but fast muscles that are not capable of hard work. Immediately after returning to Earth, the astronauts are not able to stand for more than 10 minutes.

Due to impaired recovery processes, an average of 1.5% of bone tissue is lost during each month of its stay in orbit. Particularly affected lower vertebrae, pelvis and thighs. The bones become brittle, the processes occurring are similar to osteoporosis. It is still unclear whether irreparable damage is caused to the body. To combat the effects of atrophy on the ISS, there are two treadmills to which a person is attached with shock absorbing cables.

Approximately 45% of astronauts experience the syndrome of space adaptation, expressed by symptoms of dizziness, loss of appetite, headaches, increased salivation and general discomfort, sometimes vomiting (which is dangerous when wearing space suits) and spatial illusions. Motion sickness occurs in more than half of people in space. As a rule, the body rarely needs more than 72 hours to adapt. Soon, the astronaut feels the bottom, where his legs are, but after returning to Earth he needs time for the reverse process.

With long-term flights, the skin sheds those places that are usually heavily rubbed. The skin of the buttocks and feet becomes soft, fresh and sensitive. Crying in this case is also not recommended - tears from the eyes do not flow .

How do people eat food in these conditions, why doesn't it go up? In fact, it does not have to go up, it just soars. We can even eat upside down , so pushing food with the esophagus and intestines in the absence of gravity is not such a big problem. Menstrual blood also does not go up and does not fall into the fallopian tubes.

In addition, in space, a person grows up to 103% of his norm. This happens because of the increase in the space between the vertebrae. This can lead to pain during exercise. Astronaut Clayton Anderson writes that in order to combat this sensitivity, he and other crew members were squeezing their backs with their arms and legs on the ceiling and floor. A few minutes of such exercises helped to ease the pain.

Psychological effects

They are also positive: astronauts begin to appreciate the nature of our planet and other people more. But there are many negative effects, like those of the earth, and unique, not showing anywhere else. Some of them are described in this article .

It is rather strange to expect the absence of problems if you put three or more people of different professions, nationalities, native languages, cultures into a metal bank for six months, launch it into near-earth orbit and force them to perform everyday work under unusual conditions. The influence of space flight on the human psyche is perhaps the most important question among all the others. Astronaut Valery Ryumin quotes the book of O. Henry in his diary : “If you want to encourage the craft of homicide, block two people in a hut eighteen twenty feet for a month. Human nature will not endure. "

Ordinary human relations arise with outcasts and leaders, but the novelty of the conditions of the cosmos also contributes. All this can be expressed in weakness, fatigue, loss of appetite, sleep deprivation, irritability, problems with concentration and attention.

In general, it is difficult for a person to sleep without organizing artificial day and night. And irregularities on the ISS occur regularly due to the need for maneuvers and the arrival of crews or cargo ships. Constant noise of life-support system fans and excellent audibility interfere. As a result, many sleep an average of 6 hours at a rate of about 8.5, and half of the Shuttle astronauts take a sleeping pill.

Length of stay in orbit is very stressful. Three expeditions to Skylab lasted for 1, 2 and 3 months, respectively, on Salute-6, Salute-7 and ISS, this period is 5-6 months. On the "World" flights lasted longer.

Flying outside the circumterrestrial space will be associated with long-term isolation, which is only aggravated by the complete lack of real-time communication with the house — after a certain stage of removal, the signal will be delayed for a few seconds. A well-known experiment in this area is Mars-500, during which the crew were isolated in conditional flight for 14, 105 and 520 days.

Hygiene and washing clothes

This is far from the most important question can easily scare off many who want to fly to the ISS or go farther, beyond the limits of the Earth's orbit. The cost of each kilogram displayed in space is precious, so water has to be greatly saved.

While shaving and combing is easy, washing remains a difficult task. In microgravity conditions it is impossible to open the tap and wash your hands - water will float in the surrounding space. Problems are added multiplying with greater speed microorganisms.

It is known that the residents of the ISS wipe their bodies with towels soaked in a special soap solution. Special types of toothpaste and shampoo are used.

At Skylab-2, there was a real shower; it was a cylindrical plastic construction that did not allow water to go beyond its limits. An astronaut inside it applied water to his body and removed it at the end of the procedure. There was also a shower at Salute-3, which astronauts used every month, but this operation involved many actions both before and after a shower and took almost a whole day.

How to erase things on the ISS? No, they are simply worn until they become so dirty that it is time to throw them out. Garbage is collected in the Russian "Progress" and the European AGK / ATV. Trucks with their contents later burn in the upper atmosphere.

If you run a clean underwear on the ISS for each of the three crew members for a daily shift for 6 months, this will take 540 pairs, and the launch price of each kilogram of cargo is measured in tens of thousands of dollars. You can guess what is the way out of this situation. On the "World" astronauts wore underwear sometimes for a week.

Things are getting better on the ISS: Don Pettit wrote that he was changing his underwear every 3-4 days, and in February he wore the same pair of shorts as he arrived in November. Shirts are changed once a month, socks - once a week .

It doesn't sound too nice. But on the space station things are not so quickly stuffed as on Earth: the temperature is maintained at a certain, controlled and comfortable level, the humidity is low, and microgravity does not require much effort to move the body in space. However, in order to maintain bones and muscles at the proper level, astronauts still have to work on special simulators twice a day. A separate line is the problem of women's menstruation hygiene.

Not everything is so bad, for example, Kenneth Duane Bowersox even tried to wash things in a plastic bag. Donald Pettit grew seedlings using dirty clothes instead of soil. Back in the times of Mira, Russian scientists experimented with methane fermentation of cotton and paper, which not only eliminates waste, but also provides biogas that is potentially useful for the station. But as long as this remains a promising direction, it may take years to search for the desired bacteria. In addition, NASA in 2011 thought about the washing machine for the ISS, working with steam, air and microwaves.

Due to microgravity in space, the sense of smell is dulled , but astronauts and astronauts still prefer to observe the boundaries of their personal space so as not to smell each other.

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Cosmos gives an ultimatum to man: either an astronaut can exist according to the laws of airless space, or he will die and the man adapts. But for the further development of manned space flight the biological limits of the human body will be lacking. Only flying to Mars and back will require 18 months and can go beyond the current knowledge of space survival.

According to en.wikipedia.org , Race To Mars .