Why do astronauts come back from space and look down on life and death?

The most precious thing for people is life, and everyone should cherish their own life.

And in a limited life, to make the greatest contribution, then face the choice of life and death. How do astronauts respond?

Life and death, between life and death, is life. And people with great ambitions are even down-looking at life and death.

The year 2003 was an eventful year in the history of the world's space industry. On the first day of the Lunar New Year, the space shuttle Columbia crashed in the United States, killing all seven astronauts; On May 4, the Russian Soyuz spacecraft landed and deviated from the intended landing zone; On August 22, a Brazilian launch vehicle occurred, and 21 astronauts were killed on the spot......

At this time, Chinese astronauts were preparing for their first manned mission. Worried that the haze of the world's successive space failures would have an impact, the leaders gathered the astronauts together to listen to their ideas and encourage them.

Unexpectedly, the symposium turned into an enthusiastic battle meeting

Zhang Xiaoguang was the first to stand up and said, "Who else is me!" ”

Then, Li Qinglong's speech was sonorous, which made the blood of the people present boil"I'm a pilot by training, and I've long since put sacrifices on the back burner. I love this cause more than my life, and no risk can affect my choices and beliefs.

The starry sky is vast, and the exploration never ends! Why explore? Because our journey is a sea of stars!

There is a good saying: "Mankind has not yet reached the level where every individual can explore space or sail far, but it is precisely because of a group of people like them who dare to go to the sky to pick up the stars and go down to the sea to catch the moon that we have the privilege of glimpsing the magnificence and magnificence that the Creator has given us." ”

Soldiers go on the expedition, life and death are uncertain. Only by facing life and death can we live towards death. There is always something more important than life.

For the revolutionary ancestors who sacrificed their lives to die, it was the country and the hope; For astronauts, it is a mission and a responsibility.

Because the astronauts had signed a life and death contract before going to space, they had already thought about the ending of death, so after Ping An came back, he looked down on life and death.

Because they have appreciated the vastness of the universe and realized their own insignificance, this is what happens.

Because they were ready to die before they went to space, it didn't matter.

This is mainly because it is really dangerous to go to space, so I say this.

I think that anyone who has been to space and seen the vastness of the universe naturally feels very small, and life and death are not important.

Because it's very dangerous to go up again, that's why it's like this.

Because I have already experienced life and death, I only know how small human beings are when I go out into space.

Because they have all gone through a very difficult period of time, that's why they have this feeling.

After going to a higher realm and seeing a bigger world, do you still think that people's life and death are so small, is there anything worth caring about?

The horizon determines the pattern, and if you go to the vast space and take a walk, then the horizon is no longer ordinarily wide.

A total of 22 astronauts have died in space, and hundreds of ground technicians have died in accidents. The Soviet Union and the United States began to compete in space in the fifties of the last century, and as a result, some relatively risky space programs were created, and these projects were the main factors in the death of astronauts.

Early rockets were not as safe and stable as they are today, and even safer rockets have been proven by mission after mission. As an important tool to break away from the earth's gravity, the rocket is strongly affected by the earth's gravity during the take-off stage, so the spacecraft will swing violently; When the spacecraft lands on Earth, due to the impact of the atmosphere and the presence of the ionosphere, the spacecraft will also be violently ** and the signal will be lost for several minutes. Therefore, all the early manned flight accidents occurred during take-off or landing, resulting in the death of more than a dozen astronauts.

At present, a total of 22 astronauts have dedicated their lives to manned spaceflight. Among them, one Soviet Union died in the ground experiment, 14 Columbia and Challenger ships of the United States, 7 victims each time, and 3 astronauts were incinerated to death due to the leakage of oxygen tanks during the US ground test; The Soviet cosmonaut accident included 1 Komarov, the protagonist of "Two Hours of Tragedy", who was more familiar to the post-80s and post-90s.

On June 30, 1971, three people were killed in Soviet Union No. 11. A total of 22 astronauts were killed during takeoff, landing or ground tests, and no astronaut has ever died in Earth orbit.

However, there are many small animals, such as monkeys, dogs, cats, orangutans, and thousands of other space experimental animals, large and small, have died in the earth's orbit. Before the Soviet Union and the United States launched manned spaceflight, in order to verify the impact of the space environment on living things, scientists designed many special cabins to carry space experimental animals into space. They were the first victims of human exploration of space, and like humans, many of these animals were killed during the take-off or landing phase of the rocket.

Laika, the world's first space animal, a stray dog, died during takeoff due to the high temperature caused by the friction between the rocket and the atmosphere due to a flaw in the design of the capsule.

Yes, there are still a lot of them, for example, three astronauts from the former Soviet Union arrived at the space station, and when they were on a mission, they died directly in outer space.

Of course, there are such astronauts, because many astronauts do not come back after they set off again, and it is very likely that they have already died in space.

There must have been astronauts who died in space, and there were several failed launches before, and then many astronauts died in space.

Astronauts are an enviable job where we can fly into space and see our Earth from a distance. But astronauts also pay a great price, they have to undergo very harsh physical training between going to space, and they also have to be familiar with a large number of complex operations, and they must have excellent psychological quality. After returning, their bodily functions have also undergone a series of changes.

First of all, staying in space for a long time can lead to osteoporosis, which is very deadly, and the human skeleton is constantly renewed, of which two types of cells are the most important: osteoblasts and osteoclasts. However, due to long-term life in space, osteogenic activity will decrease, which will lead to the loss of bone tissue and brittle bones, as if entering old age early.

Therefore, astronauts need regular exercise to slow down this process.

Then, like bone loss, because people are in the weightless environment of space, it will also cause people's muscles to lose the corresponding force, so the astronauts' muscles will atrophy. When these astronauts return to the ground, they will experience all kinds of fatigue, fatigue, and even inability to walk, so those humans who come back from space basically have a long recovery period.

As gravity decreases, the pressure provided by the heart decreases, blood pressure decreases, and the amount of blood transfused decreases, causing the left and right ventricles to shrink slightly.

Besides, when astronauts are out and about, they use kangaroo walking, and the famous cosmonaut Gagarin In space, you have to give up human walking and learn again"Walking"So when astronauts return to Earth, they walk like lame, which is why you see astronauts sitting on chairs when they first arrive on Earth, and they can't walk on their own.

The next half is about living things, the human spine is segmented, because of the gravitational pull of the earth, the human spine has a height ceiling, but there is no gravitational restraint in space, and then there is a section of the spine that can be increased, so it is temporarily increased, but after returning to the earth, it is completely restored to the original state.

The more obvious change is the formation of "space feet", because there is no gravity in space, the astronauts' feet will not be used basically, and every day when sleeping, astronauts will use their feet to hook the sleeping place in order to avoid floating around, and over time, the astronauts' feet will appear powerless, and hook the railing for a long time, there will be deformation, forming a "space foot".

The compressive force of the bone is significantly reduced, the muscles are degenerated to varying degrees, and the electrical activity of the bone tissue is significantly reduced due to the reduction of the external force borne by the bone, which will cause the aggregation of osteoclasts and lead to the destruction of normal bone tissue.

Bones and muscles will be in a state of tension and contraction, strongly compressing the blood vessels and lymphatic tissues, losing body balance, muscles will degenerate to varying degrees, and bone density will decrease.

Bone density is reduced, he will be a little younger than before he went to space, and it is possible that the muscles will degenerate to varying degrees as they grow taller The compressive force of the bones is significantly reduced Due to the space environment, the force of blood and body fluids on the surrounding supporting tissues changes from the downward to isotropic from the downward of the earth, which causes the upward backward flow of blood and body fluids and the flow of the surrounding areas, and the center of gravity of the body moves upward, which causes a series of problems such as the upper body becoming larger, the body shape becoming rounder, the head and face swelling, the intracranial pressure increasing, and varicose veins.

The most tragic astronaut in history: After being sent to space, the man has not returned to Earth, but the country is gone.

Theoretically, astronauts will be younger than the average person. Einstein's theory of relativity states that time passes differently at different velocities and in gravitational systems, and there is a time dilation effect. Specifically, in a high-speed system, the passage of time slows down; In a gravitational field system, the larger the gravitational field, the slower the flow rate.

This theory has been widely verified in space practice such as GPS positioning satellites. Now I will not go into the formulas of these two time dilation effects, but only the results. According to these two formulas, astronauts move at speed on the International Space Station, and the passage of time slows down every day; International space, on the other hand, is moving at an altitude of about 400 km, where gravity is smaller than that of the Earth, so the passage of time is speeding up, every day.

Space sickness. Since space is weightless, the human body that adapts to the gravity of the earth will undergo various changes, such as the internal organs are floating up and will not be in place; Body fluids will flow in all directions and feel lightheaded; muscle relaxation and so on. In this way, space syndrome will appear, such as dizziness, paleness, nausea and vomiting, increased saliva, headache and drowsiness, constant belching and farting, etc., and there will be an adaptation period, during which severe cases are likely to lead to danger.

Astronauts can come back in the return capsule. Before the astronauts officially return, the crew on Earth needs to find a suitable place to land on the return capsule to return, and also keep an eye on the weather, and the astronauts in space need to check that the instruments on the spacecraft are functioning properly.

The angle of the re-entry capsule must be adjusted before entering the atmosphere, if the angle is too large, the spacecraft will return too fast and will be burned in the atmosphere like a meteor, if the angle is too small, the spacecraft will pass by the edge of the atmosphere and cannot return.

Most of the capsule land, sometimes the capsule will also land on the sea, the capsule will release dye into the water, dye the surrounding sea water fluorescent, and send out GPS positioning signals in time.

In order to avoid the high heat caused by severe friction with the atmosphere from burning through the bulkhead, the surface of the return capsule is coated with ablative materials, and the pyrolysis, melting, and evaporation of the materials are used to dissipate heat.