Why can astronauts only take wheelchairs when they come back from space? Will air travel affect life expectancy?

Recently, the news of the triumph of Shenzhou 13 unit triggered a heated discussion among overseas experts and the media.

After 183 days of long-distance business trip in space, the three heroic astronauts returned to earth safely and finally went home!

The six-month stay in the space station not only showed the world China's scientific and technological capabilities, but also made everyone in China proud.

Although there is still a big gap between China and the United States in science and technology, especially in rocket manufacturing and research and development, it is the key to future space competition.

But every time I see my country making progress, I can't help but feel excited and proud.

At the same time, I sincerely hope that China scientists will speed up their investment and research in this field. Make better achievements and widen the distance with developed countries as soon as possible!

I hope that one day, we ordinary people can also get on the national rocket, travel in space and walk on Mars.

Humans have always been curious about space.

We in China have had a dream of flying since ancient times.

In 2003, Yang Liwei realized the dream of flying for the people of China. Since then, China's space industry has entered the fast lane of development.

The development of the space industry has also created a number of space heroes. Astronauts bet their lives to win glory for the country and seek happiness for the people.

Is a well-deserved national hero.

As for Shenzhou XIII, I watched many related videos excitedly. I believe everyone has noticed that almost all astronauts were carefully carried out when they left the cabin. So what's this for?

Many people are worried about whether going into space will affect the health of astronauts. Only by knowing, can we deeply understand their hard work and greatness! ! !

First of all! ! !

What we need to understand is:

Astronauts living in space for a long time will really do harm to their bodies, and many injuries can't be compensated by human technology at present.

These injuries mainly include: space diseases, bacterial invasion, space radiation, space toxic dust and so on.

Now astronauts are in a state of weightlessness, and suddenly there is no gravity of the earth, which is unacceptable to the human body for a while, and various changes will occur, such as the internal organs floating up and not in place; Body fluids will flow around and feel top-heavy; Muscle relaxation and so on.

In addition, in space, gravity shifts, and muscles relax when the human body loses weight, instead of being tight on the ground, just like an old man who loses the ability to act. After lack of exercise, his leg muscles look relaxed and slowly contract.

Including but not limited to spatial syndrome, such as dizziness, pallor, nausea and vomiting, salivation, headache and lethargy, burping and farting. There is an adaptation period during which serious situations are likely to lead to danger.

Injury 1: muscle atrophy

The biggest long-term impact is the loss of muscles and bones. When astronauts stay in space 1 month, the average bone loss should reach 1~2%, and the muscle loss should reach 5%.

According to the research, all the 37 astronauts who have worked in the International Space Station for a long time have experienced different degrees of isometric muscle contraction weakening, and most of them have degenerated from 8% to 17%. Even if astronauts undergo rigorous exercise, this degradation is inevitable.

Because calcium in bones is lost to the blood, the risk of kidney calculi will increase, and once you get sick, it will be very painful; Because of the serious calcium deficiency in bones, it is easy to cause fractures, which is also the reason why astronauts need people to carry them back to the ground.

Injury 2: The brain capacity will increase.

After a long space flight, pressure will accumulate in the head.

Under normal gravity, when the human body stands, the liquid in the brain will naturally flow downwards.

But there are also data to prove that microgravity can prevent this from happening, leading to the accumulation of fluid in the brain and skull.

Relevant experts studied the physical condition of 1 1 Russian astronauts, and found that the white matter and gray matter in the brain changed, the ventricles became larger, and cerebrospinal fluid began to increase.

Of course, these phenomena are not permanent, and they will return to normal after returning to earth for seven months.

This is caused by the redistribution of cerebrospinal fluid after entering space, and it will not only affect the brain, but also affect vision and height. The most remarkable thing is that astronauts will increase their height by about 5 cm after entering space.

Injury 3: Space radiation

Astronauts living in the space station can basically isolate space radiation, but nothing is absolute, and this isolation is incomplete.

According to research, astronauts lived in the International Space Station for six months and received a radiation dose as high as 300 Joules.

Living on the earth for six months received only 0.07 joules of radiation. It can be said that it far exceeds the total radiation of normal people.

Astronauts receive much higher radiation in space than the earth, so the longer they stay, the greater the radiation they receive. If the body receives too much radiation, it is likely to cause many diseases and face changes in the central nervous system, and the risk is enormous.

Besides these, there are many potential injuries.

Injury 4: Visual impairment

Weightlessness in the space environment will affect the brain and nervous system. Astronauts who stay in space for a long time may have different degrees of visual impairment, mainly manifested as elevated intraocular pressure and blurred vision. It is suspected that this is related to the influence of increased intracranial pressure on the optic nerve sheath.

The astronauts' brain volume increased by 2% on average, and this increase still existed even after returning to Earth for one year, which led to the increase of intracranial pressure on the astronauts' optic nerve, which led to the astronauts' vision damage. Astronauts often report this situation after returning to earth.

After returning to the earth to rest, vision changes and intracranial pressure will gradually recover. Many astronauts will have mild or severe headaches in space, which is largely due to increased intracranial pressure, including internal environment disorder. Therefore, it is necessary to undergo strict astronaut selection and training and prepare anti-motion sickness drugs for prevention and treatment.

Remember Yang Liwei?

June 5438+October 2003 10, China's first manned spacecraft "Shenzhou 5" successfully returned to the ground, and the picture of astronaut Yang Liwei's disembarkation was broadcast live to the whole world.

So far, China has successfully completed its first manned space flight, becoming the third country in the world to independently carry out manned space activities.

If you watch the live broadcast at that time carefully, you will find that Yang Liwei, who just left the cabin, looks pale, but his physical condition looks completely fine.

In fact, this is only superficial, in order to have a good image in front of the people of the whole country and not to scare the people of the whole country.

In fact, Yang Liwei in the eyes of all of us has been treated: he opened the hatch with blood all over his face, and then the blood on his face dried up and the picture of leaving the cabin was reshaped.

In order to show the perfect image of "China's first astronaut", we did deal with some details, but everyone was still curious. How can there be blood on Yang Liwei's face?

Post a memoir "Nine Days of Heaven and Earth" written by Yang Liwei for everyone:

At first, the spaceship was smooth, rising slowly, even smoother than the elevator. I thought to myself: this is normal, and there is not much strength!

Later, I learned that the take-off of the spacecraft is a process of gradual acceleration, and all kinds of loads are gradually increasing, so we should make preparations in advance. But at that time, no one had the real experience of riding a rocket, and it was not clear that there would be such a change. When I looked at the situation, I was far less nervous than I thought in training. My heart is a little relieved, and my tight muscles are gradually relaxed.

"escape tower separation" and "booster separation" ...

The rocket accelerated gradually, and I felt the pressure increase gradually. Because we have endured this kind of load in training, and the curve change is smaller than that in training, so my body feels quite good and I feel no problem.

But then the rocket rose to the height of thirty or forty kilometers, and the rocket and spacecraft began to shake violently, causing * * * vibration. This makes me feel very painful.

The human body is very sensitive to the low-frequency vibration below 10 Hz, which will cause the internal organs to vibrate. At this time, it is not only a problem of low-frequency vibration, but the new vibration is superimposed on the load of about 6 g. This superposition is terrible. We have never done this kind of training. Things happened unexpectedly.

* * * The vibration changes in the form of a curve, and the feeling of pain is getting stronger and stronger. My internal organs seem to be broken, which makes me almost unbearable. I feel that I am dying, and I can't bear it.

At that time, my mind was still very clear, thinking that this was the case when the spacecraft took off. In fact, the * * * vibration in the take-off phase is not a normal phenomenon and should not happen.

* * * The vibration lasted for 26 seconds, and then gradually weakened. When I got out of that uncomfortable state, all the discomfort disappeared. I feel relaxed and comfortable, relieved, like being reborn, and I even think this process is very intriguing. But in the extreme of pain, for such a short moment, I really thought I was going to sacrifice.

In his book, he publicly introduced the reasons for his face injury:

"The huge impact when landing, because the microphone has irregular edges and corners, makes my mouth hurt. If it is on my neck, the consequences are unimaginable. "

As the first astronaut in China, Yang Liwei's life is indeed worthy of pride, and it is also a symbol of the national space cause.

After all, China people may not remember or name the astronauts "Shenzhou VI", "Shenzhou VII" and "Shenzhou IX", but I believe China people will never forget Yang Liwei's name.

Salute! Experiment with life!

There are indications that ordinary people may die on the rocket, but astronauts can successfully complete various tasks and leave the cabin on their own after landing!

Off-topic:

How awesome is the astronaut's physical quality? ! !

Astronauts should have no trauma and sequelae, no potential diseases, no deformity on the body surface, no accessibility to limbs, no family genetic history, no smoking or drinking,

Strong heart function, super high-gravity tolerance, first-class sports balance function, super low-pressure hypoxia tolerance.

But also have a strong psychological quality.

Can withstand overweight, weightlessness, vibration and noise.

It can be said that astronauts are the perfect masterpieces of the creator. Physiologically, they are perfect.

However, astronauts are not superhuman as everyone thinks. They can't run as fast as Liu Xiang, lift weights like Long Qingquan and swim like Sun Yang. They don't have any special skills, but their overall physical fitness is perfect.