When it comes to astronauts, many people cast envious glances.
After all, there are only a few more than 500 people in the world's billions of people who can go into space.
Of course, there are two sides to everything, there are good and bad.
Compared to the aura of the astronaut profession, they are also the most dangerous profession in the world.
For example, the current International Space Station has encountered a gas leak, which is a direct result of the astronauts inside who want to return to the ground, which has become difficult.
Therefore, the standard for selecting qualified astronauts is very high, they must not only master a lot of knowledge and become professional talents in all walks of life (such as physics, chemistry and other experiments), but most importantly, strong physical fitness.
If nothing else, astronauts need the help of others when they return to the ground from space and get out of the capsule.
If you spend too much time in space, a simple walk can cause them to break bones.
But here's the problem.
Forty years ago, when the Americans returned from space, astronauts could not only come out of the capsule on their own, but also move around as freely as people who had been on the ground, without the slightest discomfort.
Could it be that American technology at that time had reached a terrifying level?
So let's talk about these things today.
Why do astronauts need to be physically fit?
Astronauts have to overcome overload, a headache for all scientists, when they enter or return to space.
According to the technical terminology of astronauts, it is necessary to overcome the special mechanical environment of the aircraft.
Many people should have experienced the feeling of sitting in a small car, the car accelerates, and the body has a feeling of being pressed against the seat, which many people call the feeling of back thrust.
The speed of the aircraft is much faster than the speed of the car, so the feeling of back thrust is nothing.
On a high-speed aircraft, this feeling of pressing on the seat will make people unable to do any action, whether it is a kind of pressing by the air or the kind of pressing without leaving gaps.
The blood is concentrated in one direction, and there is red or black vision, and when you open your eyes, you are red or you can't see anything.
Many ordinary people encounter this situation, imagine how their hearts feel, and the fragile ones will collapse.
When selecting pilots, it is also required that the pilots should not have wounds on their bodies, for fear that the blood will be too concentrated and the wounds will collapse and heal.
And the selection criteria for astronauts are stricter than those of pilots, so you know how terrible the so-called back thrust feeling is.
In addition, when you enter space, you are faced with a small movable space, and you have to face the vast universe to put it mildly, and to put it bluntly, there is darkness up and down, and there is a feeling of falling into a bottomless pit.
Many people should have dreamed of falling from a height, right?
The feeling of working out of the cabin is even more serious than this.
Because all problems need to be dealt with by one person, once they are not handled well, the results should be imaginable.
In this environment, the average person will collapse.
Think about the International Space Station, where an American astronaut destroyed equipment, and all she needed was to get back to the ground as quickly as possible.
Because in a weightless environment, the body will have various changes, such as the swelling of the skull several times, the loss of calcium during each examination, and various cosmic radiation irradiating the body, etc.
They are all extreme tests of human endurance.
This is actually very superficial, and perhaps only the astronauts themselves understand in their hearts what kind of feelings they are facing.
Behind the aura is a huge effort.
Therefore, manned spaceflight requires astronauts not only to be physically strong, but also to be psychologically strong.
For them to really enter space, they need to go through various examinations, basic qualification examinations, spiritual bed medical examinations, mental selection, and so on.
Therefore, the requirements for astronauts in various countries are basically the same, because they are all harsh to the extreme.
Training of astronauts.
Many people know that astronauts need to go through very strong physical training, and basically they will not stop every day, so I will not introduce them here.
Say some concrete examples to get a feel for it.
The United States was the first to land people on the moon.
In order to train astronauts who can adapt to activities on the moon, do you know how they trained on the ground?
Let the astronauts wear spacesuits weighing tens of kilograms to the moon and walk 20 to 30 kilometers in the desert every day.
Many people don't understand, isn't the gravity of the moon one-sixth that of the Earth? Why?
I don't know the specific reason, but from this training program, you can know that the physical fitness required by astronauts is not ordinarily strong.
Then in 1975, the United States and the Soviet Union organized an experiment in the orbital docking of Soyuz-19 and Apollo 18.
In response to this experimental project, the Soviet Union allowed astronauts to run 2,000 kilometers of trail running, 1,000 kilometers of bicycle riding, and more than 3,000 kilometers of skiing in a year and a half.
So the training of astronauts is not known to everyone, sitting in a swivel chair for 360 degrees of rotation without dead angles, and there are more unimaginable exercises.
As mentioned above, if you want to become an astronaut, you must not only exercise, but also study various subjects, and it is said that there are hundreds of subjects to study, so that there are exams every week, and there are final exams every week.
Mental power and physical strength cannot be bad.
After all, when they go on a business trip, they not only have to face various tasks, but also face various diseases, and the people they can rely on are basically single digits, or even only themselves.
For example, feel the dangers of the astronaut profession
Before I get into this example, let's talk about a little knowledge.
When the rocket lifts off, no scientist can guarantee that any flight is 100% safe.
So in the rocket liftoff stage, a set of life-saving measures is needed.
In the beginning, this life-saving measure was actually a set of ejection seat system, just like the pilot's ejection chair, once the situation was found to be wrong, ejection escape.
But soon scientists found that this set of measures is the same with or without, the ejection range of the ejection chair is too small, once the rocket explodes, it can definitely be affected, after all, the explosion produces a lot of fragments.
So a life-saving device called an escape tower was developed.
To put it bluntly, the Escape Tower is a small solid rocket located at the head of the rocket.
If something dangerous happens to the rocket, then the rocket engine on the escape tower ignites.
Then, at the fastest speed, pull the ship and the rocket away by a certain distance.
Later, the escape tower was developed more professionally, and once the detector on the top found a problem, it would automatically start the escape tower without manual operation.
Say examples.
On September 26, 1983, the Soviet Union wanted to send two cosmonauts to Salyut 4.
During the launch of the rocket, there was an accident, and one of the four boosters of the rocket stage had a fuel leak.
Then the pipes of the fuel also ruptured, so that the fuel in the thrusters leaked towards the launch pad, which eventually led to a fire on the launch pad.
That's hundreds of tons of fuel, and the scheduled launch time is only ninety seconds.
Don't think about the control of the fire, the rocket explosion is also a matter of time.
Then it became inevitable to start the escape tower to escape, and as a result, the starting line of the escape tower had been burned out in this fire.
So there's only one way left, manual start.
The escape tower is a rocket after all, and it has to be separated from the original rocket, so the process is very tedious, and it takes 90 seconds to complete.
Fortunately, six seconds before the explosion, the process was completed.
The fire burned for twenty hours, and if it had been six seconds late, one can imagine what the outcome would have been.
And when the escape tower was launched, the bodies of the two astronauts were subjected to an overload of fourteen to seventeen Gs.
This means that the escape tower puts fourteen to seventeen times the pressure on the two astronauts as much as their body weight.
There are a lot of things like this.
For example, on October 11, 2018, there was also an accident when the alliance MS-10 was in the league.
Originally, after completing the mission, the four boosters would move away from the rocket, but it turned out that at the same time as the boosters separated, various debris and debris appeared.
In the end, also with the help of the escape tower, the rocket that was about to explode was escaped.
Dangers faced by astronauts returning to the surface.
Why do astronauts returning to the ground need to be supported?
Many people know that because of the problem of weightlessness, without the restraint of gravity, the two feet are basically useless in space.
Limbs that are not used regularly will inevitably cause osteoporosis and muscle atrophy.
This situation can also be found on the ground, such as patients who have been bedridden for a long time.
In fact, weightlessness brings not only that, but the excessive concentration of blood in the brain will illuminate the vestibular disorder of the brain.
The result of this is that the perception of space declines, and there is no distinction between up and down, so the feet will become non-perceptive, and no matter where you go, you will have a feeling of stepping on cotton.
In fact, there are many such examples, such as an astronaut named Andrew, who stayed in space for 197 days, and when he returned to the ground, he was already unable to walk and needed to do recovery training.
Therefore, when astronauts return to the ground, they not only need to be carried away, but also need to be isolated for training.
This isolation training includes physical response, as well as psychological and behavioral facilitation tests.
In general, this quarantine training takes three to seven days.
Many people listened to it and felt that it should be nothing?
Thinking wrong, if it is an ordinary person, he can't even hold up for an hour in this kind of isolation training.
If the quarantine training is not passed, then it means that the astronaut will not have a chance to be in this profession in the future.
There is no way to do this, these processes are valuable experience gained in the tasks again and again, and they are exchanged for blood.
For example, when human beings first entered space, they did not realize the impact of space on people, and the mission time was sometimes very long, half a year.
In the process of such a long mission, astronauts will have various problems, easily angry, easily anxious, and even suffer from claustrophobia.
For example, in 1985, an astronaut on the Salyut 7 soon fell ill after entering the space station.
Eventually, the mission was terminated and returned to the surface.
After examination, it was found that the astronaut not only had a physical illness, but even suffered from severe depression.
In addition, the special environment in space, such as radiation exposure, high-intensity work, etc., will cause problems with the body's immune system.
So astronauts are more susceptible to disease.
On the other hand, in space, because it is a confined space, there is no way to ventilate the operation, and bacteria, viruses, etc. are more likely to grow in this environment.
And they're also particularly susceptible to mutation.
Under this double attack, the astronaut's body is easily sick.
For example, in the last century, the Soviet Union took note of this detail and later observed 29 cosmonauts, and found that 15 of them were infected within a week of returning to the surface.
So now astronauts have to quarantine not only after returning, in order to get fewer bacteria into the space station, but also implement a one-week quarantine requirement when they go into space.
This is called medical isolation, and the long-term observation of astronauts ensures the safety of astronauts, and the second ensures that no strange and mutated germs enter the earth.
In short, astronauts returning to the ground should pay attention to a lot.
So why did American astronauts return to Earth forty years ago, and why did they bounce?
Because they are inexperienced and do not notice the physical harm that is done by doing so.
Then there is the fact that they fly for a short time, and space has too little effect on them.
As for the other reasons, why don't you think about it?