Lead
On the evening of June 7, Chang'e-6 successfully returned according to the established flight plan.
When Chang'e-6 burst into the atmosphere, it reached a speed of Mach 31, a speed that almost no one could handle.
Flying in the air, speeds of more than Mach 30 per hour are also the strongest attack speeds that can allow missiles to penetrate targets.
If Chang'e-6 is used to launch an attack on countries around the world, according to the range of 50 kilometers that the Chang'e-6 explosion can reach, then with a super speed of Mach 31, it can cover almost the entire Europe.
What's even more terrifying is that Chang'e-6 is still a "short-range missile", which can hit the target after flying not far, and Chang'e-6 can also strike accurately.
In other words, Chang'e-6 is capable of carrying out global barrier-free strikes without the air defense systems of countries around the world.
Now, even if Chang'e-6 has such a high speed and attack capability, and its explosion range is 50 kilometers, it is actually not capable of striking a hardly tight Europe.
But Chang'e-6 was able to fly around Europe and even directly into the steppes of Inner Mongolia, which means that there is no problem with unobstructed precision strikes on a global scale.
Flight profile.
Chang'e-6 will return from the moon at 6:35 p.m. on June 6.
At this time, Chang'e-6 has a speed of 11.3 kilometers per second and an altitude of 2.9 kilometers.
When Chang'e-6 rushed into the atmosphere, its speed decreased.
At 14:24, Chang'e-6 dropped to Mach 31 and flew at an altitude of 140 kilometers.
At 14:25, the speed of Chang'e-6 dropped to Mach 20, at which time Chang'e-6 entered the airspace again, and at 13:34, Chang'e-6 successfully landed in the Inner Mongolia grassland.
In this flight, Chang'e-6 has crossed a total of 12,000 kilometers of space, and the flight distance is also very long.
The return of Chang'e-6 was also smooth sailing, without any problems, and it was a very perfect flight.
The power of water drifting.
We all know that when Chang'e, Wukong and others left Tiangong-1, the "stone cover" on Tiangong-1 would spray water and blow them to the ground.
However, the water drift of Chang'e-6 mentioned here is just the meaning of entering the atmosphere and then entering space, and Chang'e-6 is not to create water drift in space, but to land on Earth.
But why do they fluctuate back and forth between the atmosphere and space?
This is because Chang'e-6 was very fast when it left the moon and reached the Earth, and it took only a few days to return to Earth from the Moon, with almost no deceleration, and the speed when it returned rushed directly into the atmosphere.
When Chang'e-6 rushed into the atmosphere, the air could not flow past Chang'e-6 in time due to its speed, and was compressed to form plasma.
The plasma production also caused the temperature around Chang'e-6's body to rise rapidly, rising to a very high temperature in an instant, and even being scorched.
Under the action of plasma, Chang'e-6 gained tremendous momentum, and after being pushed away for a distance, the kinetic energy plasma dissipated, and Chang'e-6 was slowed down by air resistance, and the speed also rebounded here, and the air also lifted Chang'e-6 upward, eventually causing Chang'e-6 to fly out into space again.
This is the first "water drift" of Chang'e-6.
However, Chang'e-6 did not have more than one "water drift", because every time it was topped by the atmosphere, it wasted a little speed, so before Chang'e-6 landed, it experienced a total of eight "water drifts".
Qian Xuesen ballistic.
Chang'e-6 is capable of traveling back and forth between the atmosphere and space, which fully demonstrates the effectiveness of Qian Xuesen's ballistics.
The primary goal of ballistics is to fly far and land far, which Qian Xuesen has achieved.
Qian Xuesen's ballistics is actually a set of ballistic theories proposed by Qian Xuesen, which includes parabolic flight, flexible gliding and drifting.
The theory of parabolic flight was put forward by Qian Xuesen in 1949, which is a flight theory for missiles.
It's just that our common space launch flights all use typical ballistic flights, and Chang'e-6 uses parabolic ballistic flights, and even can fly so far, which is no different from the "two bombs and one satellite" missile with a range of 2,000 kilometers.
But we all know that most of the kinetic energy of the rocket is used to break the gravitational pull of the earth and enter space, so the kinetic energy of the missile after entering space is very small, so the fact that Chang'e-6 can fly so far also proves the accuracy of Qian Xuesen's theory.
Qian Xuesen's theory applies not only to missiles, but also to other objects such as spacecraft, which is reflected in Chang'e-6.
The theory of flexible gliding was proposed by Qian Xuesen and von Kármán after an academic exchange in 1945.
At that time, the two were returned scholars studying in the United States, and because of their special status, they received the attention of the U.S. government.
At that time, the United States was still conducting research on the development of the atomic bomb, and Qian Xuesen, von Kármán and others were sent to the Los Alamos laboratory for research.
There, Qian Xuesen and von Kármán exchanged scholarship with other scientists, and they noticed an atomic bomb test that had just been conducted by the United States.
At that time, the temperature of the hydrogen bomb exploded to millions of degrees, which caused the surrounding air to be heated and plasma was generated, forming an instantaneous heat pile.
This thermal reactor is capable of not only illuminating almost all of the United States, but also being able to knock bullets out of the air through the air.
Qian Xuesen found that this phenomenon was somewhat similar to the state of the rocket after it rushed into the atmosphere, so he discussed it with von Kármán.
With the experience of the atomic bomb test at that time, the two of them decided to use the existing data to study the movement of rockets in the atmosphere according to the equations.
A few days later, the duo discovered an astonishing phenomenon.
They found that by adjusting the angle of incidence of the rocket, the rocket glides flexibly in the atmosphere, extending the distance of the flight, and also increasing the uncertainty of the rocket's landing point.
This is the ballistic flight theory proposed by Qian Xuesen later, which is the so-called water drift.
With such a rocket with an indefinite landing range, it is possible to allow the target to be attacked without the complete knowledge, which is the so-called "barrier-free".
This was also widely used in World War II, and it also gave the Allies a great advantage in the war.
Chang'e-6's "water drifting bomb".
When Chang'e-6 flew over Europe, it reached a speed of Mach 31.
This point embodied the theory of missile attack put forward by Qian Xuesen at that time, that is, flying far and landing accurately.
The speed of Mach 31 is equivalent to 12.6 kilometers per second, which is still very fast, and it can almost allow the missile to penetrate the target directly.
If Chang'e-6 were to attack, it would be able to reach a speed equivalent to 45,000 kilometers per hour, covering almost all of Europe.
What's even more terrifying is that Chang'e-6 is able to accurately hit targets.
This point requires the use of Qian Xuesen's other theory, that is, drift.
The so-called drift means that there is a rotating force in the parabolic flight, which causes the missile to shake during the flight, which leads to the inaccuracy of the calculated landing point, and eventually produces drift.
This is influenced by factors such as the rotation of the Earth.
There was also a large drift during the flight of Chang'e-6, with six water drifts.
This also reflects how accurate Qian Xuesen's ballistic theory is, and there is also the uncertainty of drift, which can also increase the uncertainty of the landing point.
It was with the effect of these theories that Chang'e was able to drift greatly during the flight, so that she could fly over Europe and finally land in the steppes of Inner Mongolia.
It can be said that the first stroke that Chang'e-6 brought back from the moon was this set of Qian Xuesen's ballistic theory.
epilogue
Qian Xuesen's ballistic theory is still very good, and we are using it in both civil aerospace and military fields.
Of course, Qian Xuesen's theory can only be applied to objects such as rockets and missiles, but can also be applied to other fields such as high-speed transportation.
The development of space exploration on the mainland is also very fast, we also have hypersonic missiles, and of course, the return of Chang'e-6 can make everyone look at the mainland's hypersonic technology more impressively, and it can also shine on a global scale.
It is precisely because of Qian Xuesen's theory that Chang'e-6 was able to float in the atmosphere and finally land accurately in the Inner Mongolia grassland, which can also explore new ideas for the mainland's future technological development in the aerospace field.