For many of us, space is something unknown, new.
Today we are going to tell you about what can expect a human in outer space in examples of scientific searches.
A group of scientists from the Space center NASA decided to find out if staying in outer space affects the functioning of the human immune system. Anteriorly such studies have never been made: the experts had information only about how the organism could protect from diseases, which was a little time in space. The results of the research were published in the journal “NPJ Microgravity”.
Scientists say that their scientific discovery implies a long stay in space which significantly weakens the health of astronauts, and also it can provoke other complications and problems with staying in orbit. It should be noted that after the return of man to Earth his immune system didn’t restore immediately, that is seen in the analyses of blood, which were taken immediately after landing, and after a month of life on Earth.
So, the scientists examinated 23 astronauts (18 men and 5 women), they worked on the International space station. The average age of participants was 53 years. Sixteen astronauts arrived on the space on the Russian spacecraft "Soyuz" and stayed about six months in space. The other seven astronauts arrived on the American shuttles. The mission of astronauts lasted over a hundred days.
Scientists took blood for analysis before the flight (180 and 45 days before him) and found out the number of cells which were responsible for the immune system.
Those astronauts, who carried out in the space for about six months, took their blood three times more: two weeks after arrival, then on the second or third month of staying at the station and by the end of the mission.
And now you will see the result of this investigation.
There are 4 parameters that affected the organism of astronauts during staying in space and then after arrival on the Earth.
Let’s see the most widespread astronaut health risks!
1. Overload during the start and landing
At the start of the spacecraft there are overloads in the range from 1g to 7g. This is extremely dangerous, if an overload acts on the vertical axis, that is, from head to feet.
In this position, even in case of overload in the 3g acting just for three seconds, there are serious violations of peripheral vision. When the limits are exceeded, changes can be irreversible, and people guaranteed lose consciousness.
Therefore, the chair takes special place in the space ship so that the acceleration acts in a horizontal plane. Also, the astronaut uses a special compensation suit. This gives them the ability to maintain normal cerebral blood circulation during prolonged overloads in 10g and for short periods up to 25g. it’s very important also the rate of rise of acceleration. If it exceeds a certain border, it is injurious even a minor overload for the astronaut.
After a long staying in orbit the organism withstands overload worst than it was at the start. Therefore, the astronaut, planning his flight back, is preparing by special method including physical exercise and medications.
Weightlessness is a much more difficult test for the body than overload is. Because it lasts for a long time and continuously, causing changes of a number of important vital functions in the human body. So, weightlessness puts the Central nervous system and receptors of many analyzer systems (vestibular, muscular and articular apparatus, blood vessels) in the unusual conditions of functioning. As a result the bloodstream slows, and the blood accumulates in the upper part of the body.
However, the organism quickly gets used to zero gravity: the dizziness, other negative consequences disappear. But unfortunately, these symptoms can return by coming on Earth.
If in the orbit astronaut does not use any methods to resist the destructive influence of weightlessness, then during first days we can observe the following changes:
1. Violation of metabolism, especially water-salt metabolism, which is accompanied by dehydration of tissue, decrease of circulating blood volume, a decrease of a number of elements in the tissues, especially potassium and calcium;
2. Disorder of the oxygen regime of the organism during exercise;
3. An astronaut loses the ability of maintain a vertical position in static and dynamic exercises, also he loses a sense of gravity (the surrounding objects are perceived as unusually heavy;
4. It’s probably to faint after the transition from horizontal to vertical position;
5. Low immunity.
In the orbit scientists use a range of measures to prevent destructive effect to the organism by weightlessness. The astronauts consume medicines with high amount of potassium and calcium. Also they wear special clothes. They always do physical exercises.
To prevent the physical inactivity they do exercises, run, jump, and so on. In orbit the hypodynamia is inevitable because the movement require much less effort in weightlessness than on earth. In addition, physical activity has a beneficial effect on the heart, which, as you know, is also a muscle.
4. The radiation
The effect of this factor on the human body is already well-studied. The world health organization has established the standards for doses of radiation, the excess of which is harmful for health. But astronauts have other standards.
It is believed that a person can undergo fluorography once a year. However, he gets a dose of 0.8 mSv (millisieverts). Astronaut’s daily dose is up to 3.5 mSv. However, according to the standards of space medicine this level of radiation is considered to be acceptable. The daily dose is not a constant. Each astronaut has his personal dosimeter, which counts the accumulation of radiation in the organism. In one year in space one person can get from 100 to 300 mSv.
Meanwhile the annual dose of radiation for astronauts is 500 mSv. It exceeds in 25 times the annual dose for employees of nuclear power plants, which is 20 mSv.
Well, the total dose, after which the astronaut is not allowed to fly is 1000 mSv. At the same time, when the famous cosmonaut Yuri Gagarin flew in the space, his organism was exposed by 4000 mSv.
As you see to be an astronaut is a very dangerous job. Not everyone can deal with it. In my opinion people, that choose this profession is very brave, they are ready to give their lives in the honor of science. We must respect these heroes, because they do very important things!