After bidding farewell to the China Space Station, where they lived at work for 183 days, the three astronauts of Shenzhou XIII finally went home. On the morning of April 16, Shenzhou 13 manned spacecraft with astronauts Zhai Zhigang, Wang Yaping and Ye Guangfu safely returned to the landing site of Jiuquan Satellite Launch Center.
As can be seen from the live video, the pilots of the three roles are all carried out by the staff of four service projects with a stool with a distinctive appearance. When Wang Yaping's daughter rushed to hug her mother, Wang Yaping shed tears. She took out a big "star" to fulfill her daughter's service promise, but she still didn't jump off the stool. Are they too tired? Don't want to go?
There are many factors to express here. Space is a vacuum, which is very different from the natural environment of the earth. There are many obvious basic characteristics: microgravity, low pressure, strong radiation source and low temperature. Astronauts have lived in space for more than half a year. After landing, their brains can blend into the natural environment on land, but their bodies can't.
Astronauts' human bones are particularly sensitive when they first return to earth, and their limbs may or may not be paired. They can't stand up on their own, and their bones will crack if they exercise hard. Because on the earth, everyone's body standing or behavior depends on people's bones to support the body. But in space, it is in a weightless natural environment, so astronauts are floating in the air, so that under the long-term lack of physical strength and gravity, human bones and somatic cells in various fields of the body are in a state of semi-rest. It's like a person lying in bed for several months, and you suddenly let him get up and jog, which is definitely not acceptable. The human body has been developing in the natural environment of the earth and has long been accustomed to the attractive natural environment.
If you suddenly want to live in a weightless space, the body will lose weight for a long time, the quality of muscle tissue and human bones will naturally decline, and even aging will occur. Long-term weightlessness will lead to the disorder of bone salt metabolism in bones, and nutrients such as calcium and phosphorus will be excreted with urination. In the weightless space, because people don't need human bones such as feet to carry weight and force for a long time, the plasma supply in the legs will be reduced, the function of osteoblasts will be enhanced, and the role of osteoblasts will be weakened, which will eventually lead to osteoporosis. The most important thing is the "spacesuit" worn by astronauts, but it weighs about tens of kilograms. They are our treasures, and if our bodies are damaged, it is a great thing.
Astronauts live in a weightless natural environment. In weightlessness, it is harmful to human blood and endocrine system, because the gas pressure transmitted from the cardiovascular system to the whole body in blood night is also different. There is a lot of air pressure on the road, but there is not so much air pressure in space. This transformation will lead to a certain pressure on the cardiovascular system. It is equivalent to standing for a long time, often turning the body all around. At this time, the blood night, cardiovascular and cerebrovascular systems of the body will be "disordered", but this situation is completely reversible. With the change of time, we must let this human organ slowly integrate into the weightless natural environment and keep practicing to ensure a better physical condition.
The astronauts sat down for the first time on their way back, which is also the reason. It is not easy to integrate into the first time because of the harm of gravity, cardiovascular and cerebrovascular diseases, etc., and it must be delayed for a while to recover. If you go back to the road and stand up at once, you will faint and feel sick. So that's why astronauts must sit down or be supported when they return to earth. Therefore, astronauts must sit in a chair after landing.
How harmful is space life to astronauts' health? In the natural environment of weightlessness in space, the working pressure of astronauts' human bones is not great, even almost zero. When the human bone of the body is not squeezed by gravity, the human bone can be stretched better.
God 12 astronauts stayed in space for three months, and their bodies were 3-5 cm taller than before. This is indeed an effective way to improve, but most people don't have this opportunity. Astronauts Zhai Zhigang, Wang Yaping and Ye Guangfu on Shenzhou XIII have been in space for a longer time, and how much their height will be improved is waiting for everyone.
There are strong cosmic rays in space, and the radiation source particles in this X-ray have high heat and penetration. Long-term radiation source and its microgravity natural environment will cause certain damage to normal somatic cells of human body, and usually this physiological damage will be repaired after returning to Earth.
An experiment by NASA shows that astronauts will change redundant genes in their bodies during their long life in space, especially the telomere length at the end of tissues and cells. Similarly, this change is reversible, and after several months of recovery practice, the physical transformation brought about by space life will gradually fade away.
Astronauts in the space station have to deal with the natural environment with low gravity, low pressure, strong radiation source and low temperature. In addition to scientific research, they also need to deal with other unexpected accidents. This time, a small communication satellite planned by Musk Star Chain almost knocked down everyone's space station. It's okay. Everyone immediately bypasses according to the change of the track, otherwise the result is unpredictable. Finally, celebrate the successful return of astronauts to China!