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!
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