Lesson 23 A Day in Space / Yang Liwei

Lesson 23 A Day in Space / Yang Liwei

I thought I was going to die

At 9 o'clock sharp, the tail of the rocket emitted a huge roar, hundreds of tons of high-energy fuel began to burn, eight engines simultaneously spewed out hot flames, high temperature and high-speed gas, and in a few seconds thousands of tons of water under the launch pad turned into steam.

The rocket took off.

My whole body was strained, my muscles were tense, and my whole body contracted like a piece of iron.

At the beginning, the spacecraft rises slowly, very smoothly, even smoother than an elevator. I felt far less stressed than I had imagined during training, and I felt a little relieved, and the tense muscles all over my body gradually relaxed.

"Escape tower separation", "booster separation" ...

The rocket gradually accelerated, and I felt the pressure gradually increasing. Because this kind of load we have endured during training, the change is even smaller than when training, so my physical feeling is quite good, and I think there is no problem.

But just as the rocket rose to an altitude of thirty or forty kilometers, the rocket and the spacecraft began to shake sharply, creating a resonance. It pains me a lot.

The human body is very sensitive to low-frequency vibrations below 10 hertz, which resonate with people's internal organs. At this time, it is not only a problem of low-frequency vibration, but this new vibration is superimposed on a load of about 6G. The overlay is so scary that we've never had this kind of training.

Accidents appeared. The resonance changed in the form of curves, the painful feeling became stronger and stronger, and all the internal organs seemed to be shattered. I could hardly bear it, and I felt like I was dying

At the time, my mind was very clear, and I thought that this was how the spacecraft took off. In fact, the resonances that occur during takeoff are not normal.

After the resonance lasts for 26 seconds, it slowly decreases. I was freed from the extremely uncomfortable state, all the discomfort was gone, I felt a sense of ease and comfort that I had never felt before, like a heavy burden, like a rebirth, and I even found the process very intriguing. But at the extreme point of pain, just for a short moment, I really thought I was going to sacrifice.

After returning from the flight, I described this uncomfortable process in detail. After analysis and research, the staff believes that the resonance of the spacecraft mainly comes from the vibration of the rocket. Subsequently, they improved the technical process and solved this problem. During the Shenzhou 6 flight, the situation improved considerably; It was never seen again in later space flights. Nie Haisheng said: "The rockets and spaceships we are riding on are very comfortable, and we can hardly feel vibration. ”

While spending that unbearable 26 seconds in the air, not only did I feel particularly long, but the staff on the ground were also in an unprecedented state of tension. Because through the big screen, the picture transmitted back by the spacecraft was frozen, and my whole person was motionless and my eyes did not blink. Everyone was worried about whether something had happened to me.

Later, the fairing opened, and the light from the outside shone in through the porthole, the sunlight was so dazzling that my eyes couldn't help but blink.

At this moment, someone in the command hall shouted loudly: "Look, he blinked, Li Wei is still alive!" Everyone applauded and cheered.

At this time, I reported the flight status to the ground for the first time: "'Shenzhou V' report, the fairing is open normally!" When I returned to Earth to watch the video, I was so excited that I couldn't say anything.

What I see

The Earth seen from the manned spacecraft is not spherical, but only an arc. Because the radius of the earth is more than 6,000 kilometers, and the orbit of the spacecraft is about 343 kilometers above the ground. The spherical Earth photos we usually see in geography books are taken by synchronous satellites with higher flight orbits.

In space, I can accurately determine the orientation of continents and countries. Because the spacecraft has a predetermined flight trajectory, it can mark in real time where the spacecraft goes, which point it is projected on the earth, and there is a map to follow, at a glance.

Even without the help of instruments and maps, with what we learned in our space courses, from the outline of mountains, the direction of coastlines, and the shape of rivers, I can basically tell which continent the spacecraft is passing over and which country it is passing.

When I passed through Asia, especially over China, I carefully discerned which province I was going to and which region I was flying over.

The speed of the spacecraft is relatively fast, the time it passes over a certain province, a certain place and even China is very short, and after each flight, my heart looks forward to the next one.

I once overlooked our capital, Beijing, and during the day it was gray-white and indistinguishable along the Yanshan Mountains, and at night it was red with my comrades and relatives.

The spacecraft circled the ground 14 times, the first 13 laps flew different trajectories, not repeated, only the 14th lap returned to the position of the first lap, ready to return. At an altitude of more than 300 kilometers above the ground, I have a very wide view when overlooking, and I have seen most of the provinces of the motherland.

However, I did not see the Great Wall.

There was once a widespread saying that the only building astronauts could see in space was the Great Wall. I share everyone's mood and would love to test this statement, I tried several times to find the Great Wall, but to no avail. When Shenzhou 6 and Shenzhou 7 flew, I told the astronauts to take a closer look, but they didn't see the Great Wall either.

In space, there are actually no single artificial structures in sight, and I have asked many astronauts internationally, and no one can produce conclusive evidence to say what they saw. Even huge cities are only a faint red when seen at night.

In space, I also saw cotton-like objects floating past the portholes, small as grains of rice and large as fingernails, unable to hear any sound or feel any impact of these things.

I don't know what it is, but I think maybe it's dust, maybe it's not so pure at high altitude, there will be some impurities, it may be space junk. The objects were suspended outside the spacecraft, and I couldn't catch them, and I still haven't figured out what they were.

Mysterious knocking sound

As the astronaut of the first flight, there were some small problems, and there were many other sudden, unexplained, and unplanned situations.

For example, when the spacecraft has just entered orbit and is in weightlessness, 890% of astronauts will have an illusion of "putting the cart before the horse". This illusion is very uncomfortable, obviously sitting upwards, but feeling the head rushing down. If you do not eliminate this illusion of inverted suspension, you will feel that you have been flying upside down, which is very uncomfortable, and in severe cases, it may also induce space motion sickness and affect the completion of the task.

No one on the ground has mentioned this situation, and even if someone knew, training could not be simulated. I expect that foreign astronauts who have traveled in space before me will have similar experiences, but they have never told me about it.

In this case, there is no other way but to overcome this illusion entirely by willpower. Imagine yourself training on the ground, with your eyes closed and thinking, constantly thinking, giving your body an adaptation process. After dozens of minutes, I finally adjusted.

After "Shenzhou 6" and "Shenzhou 7" were launched, the astronauts had this illusion, but they were mentally prepared because I told them carefully. Moreover, the spacecraft cabin has also been improved, the inner wall is painted with different colors, the ceiling is white, and the floor is brown, which is convenient to help astronauts quickly adjust the feeling.

Another situation I encountered in space that is still unknown is the occasional knocking sound. This sound appeared suddenly, not all the time, but bursts of time, day or night, irregular, not sure when to ring a few times. Neither the sound coming in from outside, nor the sound inside the spacecraft, as if someone was knocking on the hull of the spacecraft outside. It is difficult to describe it exactly, not ding, not dangding, but more like hitting an iron bucket with a wooden hammer, knock ... Knock knock...

Given that the spacecraft has been operating normally, I did not report this to the ground. But I was still very nervous, because I was flying for the first time, for fear that something would go wrong. Whenever the sound came, I would lie on my stomach in the porthole, listening and watching, trying to find out where the sound was, but I couldn't find anything.

After returning to the ground, many speculations have been made about this mysterious voice. The technician tried to figure out where it came from, so they simulated it in various ways, holding the recording for me to listen to again and again, but I always felt like it. The most basic requirement for astronauts is rigor, not the voice at that time, I can't sign, so I listened to it repeatedly, intermittently for more than a year. But until now there was no confirmation, and the mysterious voice was not accurately reproduced in my ears.

During the flight of Shenzhou 6 and Shenzhou 7, this voice appeared again, but I told the astronauts: "Don't be afraid of this sound, it is normal." ”

The journey home was so thrilling

At 5:35, the Beijing Aerospace Command Center issued a "return" command to the spacecraft. The spacecraft began braking on a 343-kilometer-high orbit, like braking.

The spacecraft first performs a 180-degree attitude adjustment in orbit - returning with the propulsion module in front, which requires a 180-degree "U-turn".

"Brake engine off!" At 5:58, the speed of the spacecraft decreased to a certain value, and it began to deviate from its original orbit and enter an unpowered flight state.

At 6:04, the spacecraft flew 100 kilometers above the ground and gradually entered the dense atmosphere.

At this time, the spacecraft was still flying fast, and after encountering air resistance, it slowed down sharply, resulting in an overload of nearly 4G. I was under a lot of pressure on my chest and back. We have been trained to deal with this situation, so we are physically able to cope with it and not mentally nervous.

There is another reason why I am nervous and panic.

The first is the friction between the fast-moving spacecraft and the atmosphere, and the high temperature generated burns the outside of the porthole red; Then, outside the red porthole, red and white fragments kept streaking. The outer surface of the spacecraft has an anti-ablation layer, which is resistant to high temperatures, and as the temperature rises, it begins to peel off, and takes away some of the heat in the process of peeling. I've learned about it, seen it, and know what's going on.

But then what happened made me very nervous - cracks began to appear in the porthole on the right. Outside the window burned like a steelmaking furnace, the glass window began to crack, that kind of grain is the same as the tempered glass after the small broken lines, this fine broken lines, seeing more and more people say not afraid that it is a lie, you think, outside is 1600-1800 °C ultra-high temperature.

My sweat came out. At this time, the temperature in the cabin was also rising, but it was not to the extent that I sweated instantly, in fact, it was mainly because of nervousness.

I can still recall the situation at that time: the rapid descent of the spacecraft, the shock wave generated by friction with the air, not only had extremely high temperature, but also accompanied by a sharp whistling sound; The spacecraft carries a lot of overload, and it keeps vibrating, and the inside creaks. It's hot outside, don't be afraid! There are debris scratched through, do not be afraid! Overload can also be tolerated! But seeing that the porthole glass began to crack, I got nervous and thought: It's over, this porthole is not working.

At that time, it suddenly occurred to me, isn't this how the US "Columbia" space shuttle happened? A crack appears in a heatproof plate, and then the high heat disintegrates the spacecraft. Now, such a big porthole is broken, then it is worth it!

First there was a crack in the right porthole, and when it was halfway cracked, I turned my head to look at the porthole on the left, and it also began to crack. At this point I was a little relieved: oh – maybe nothing wrong! Because if it is a failure, the probability of recurrence is not high.

After returning, I learned that a burn-proof coating was made on the porthole of the spacecraft, and it was this coating that burned, not the problem with the glass window itself. Why didn't cracks appear on both sides at the same time? Because different materials are used on both sides.

In the past, every time the spacecraft launch and return experiment was carried out, the returning spacecraft capsule was cauterized by high temperature, and the portholes were black, and the staff could not see these cracks. And if it wasn't for seeing it with their own eyes inside the spacecraft, no one would have thought of such a situation.

At this time, the spacecraft is in the "black barrier" area, about 80 to 40 kilometers above the ground. When flying 40 kilometers above the ground, the spacecraft flies out of the "black barrier" area, the speed has decreased, and the abnormal movement mentioned above has also been reduced.

A key operation, parachute throwing, is about to begin. By this time, the porthole had burned black, and I sat inside, holding the operation box in my arms, waiting with bated breath to cooperate with the procedure: where to do what to do, what instructions to give, judgment and operation must be accurate.

At 6:14, the spacecraft was 10 kilometers above the ground, and the spacecraft threw off the parachute cover and quickly brought out the parachute.

It's a drastic move. A "bang" can be heard, very loud, 164 decibels. I felt like I was being dragged hard inside, and the instant overload was great, and the impact on my body was also very strong. This was followed by a series of quick moves. After the parachute comes out, follow the parachute page to bring out, the parachute slows the spacecraft down, and then brings the main parachute out after 16 seconds.

In fact, the most torturous thing is this process. With a loud bang, you will feel a sudden slowdown; As soon as the guiding umbrella is opened, it is very vigorous and will startle people; As soon as the parachute was opened, it was dragged to that side; The main umbrella pulls you to the other side when it opens. Each time the force was quite heavy, and the spaceship swayed very much. People don't know what's going on.

I later asked Russian astronauts, and they never told new astronauts about the process, fearing that the novices would be afraid. When I came back, I told every step to my comrades in arms of "Shen 6" and "Shen 7", so that they could be mentally prepared and told them not to be nervous, it was normal.

We astronauts attach great importance to this process: a good umbrella opens equals safety and security, at least to ensure life. So I was dragged by seven seven eight eight, but after the stability I was really solid - the data came out, and the speed was controlled within the specified range. I know this umbrella must be open!

When 5 kilometers above the ground, the spacecraft threw off the heatproof outsole, revealing the buffer engine. At the same time, the main umbrella also has an action, it becomes a double hoist, the spacecraft is straightened, and it dangles to the ground in the wind.

The spacecraft was 1.2 meters above the ground and the engines were buffered to ignite. Then the spacecraft landed with a "tom".

I felt like I landed hard and the ship bounced. On its second landing, I quickly pressed the umbrella cut. The spacecraft stopped. It was 6.23 a.m. on 16 October 2003.

At that moment, there was silence all around, and the portholes were dark, and nothing could be seen outside.

After a few minutes, I faintly heard shouting outside, and the beam of the flashlight blurred through the porthole. I know: they've found the spaceship, and there's someone outside!