Military Technology

Wu Hao and the others wanted to develop the retractable technology of the second-stage rocket, so they had to solve a problem first, so that the second-stage rocket would not burn up in the atmosphere.

If this problem is solved, it is actually very simple, that is, to cover the rocket body of the second-stage rocket with heat-insulating material, or to design and manufacture the rocket body itself to resist high-temperature burning.

At present, there are a total of two technologies or two ideas in this field for this returnable spacecraft. One is the idea of ​​the Mi Space Shuttle, which is to cover the surface of the spacecraft with heat-insulating materials. In this way, the contact between the spacecraft and the atmosphere can be reduced, thereby preventing it from being burned when returning.

The second method is to directly use high-temperature resistant materials to make the spacecraft shell, and then let the shell directly contact the atmosphere and burn. This technology is mainly used in Soviet-style spacecraft and our spacecraft, and most of the return capsules of the new generation of spacecraft in various countries currently use this technology.

But for Wu Hao and the others, no matter what kind of technology it is, the first major impact or what they want to solve is the weight problem.

Whether it is to use a heat-resistant shell or a heat-insulating tile, the first thing to solve is the weight problem.

If it's too heavy and takes up too much rocket thrust, it's not worth it. But if these two technologies are not used, the rocket may be burned.

So is there a third way to allow the secondary rocket to land from space without being burned by the atmosphere?

Yes, speed is key.

The primary cause of the spacecraft being burned by the atmosphere is the speed. If the speed is fast enough, the friction of the spacecraft in the dense atmosphere will be greater, and the friction will generate heat, so the rocket will naturally be burned.

Therefore, if the return and landing speed of the second-stage rocket can be controlled, the temperature on the surface of the rocket body can be greatly reduced, so that the rocket can return to the atmosphere safely.

If you want to reduce the speed of the rocket, there are several ways. First of all, the first one is the parachute that everyone can think of first. Use a parachute to slow down.

When the rocket reaches the edge of the atmosphere, it starts to throw out the parachute, using the air resistance of the parachute to slow down the rocket.

Can this situation be realized, yes, but first of all the parachute must also have strong heat resistance, otherwise the parachute may also be burned after a long landing.

Moreover, it is still very difficult to open the umbrella at the edge of the atmosphere, and the difficulty is very high.

In addition, the parachute was opened too early, and the landing site was uncontrollable, so it also lost the meaning of recovery.

The second method is to use the reverse thrust technology of the rocket engine to decelerate and land like a Falcon rocket.

This technology is feasible, but this means that the rocket has to carry more fuel, and too much fuel will also squeeze the rocket's carrying capacity, thus losing its recycling value.

The third technology is gliding landing, similar to the space shuttle, using gliding to decelerate and gradually land, thereby reducing the rocket's descent speed.

The fourth way is to land in a way similar to that of Chang'e-5, but this has certain requirements for the strength of the spacecraft itself, and obviously the rocket body is not suitable.

So Wu Hao and the others set their sights on the third technology, using gliding technology to slow down the rocket.

But this alone is not enough, and a layer of heat insulation material, commonly known as heat insulation tiles, must be attached to the rocket.

Although this thing is not new, and because of this insulation tile, several space shuttles have had major accidents.

But the rocket body is different from the space shuttle, and the rocket is unmanned most of the time, so there is a certain degree of safety guarantee.

In addition, the current technology is not the same as it was decades ago. The project research and development team chose a special light and thin heat insulation material this time.

This material is very light and thin, which is about the same weight as ordinary foam, or even lighter. Keqi itself has good heat insulation performance, even if it is put on fire,

The temperature of the general fire can't do anything with it.

And when it encounters high temperature, this kind of heat insulation material has another characteristic, it can gradually dissolve slowly from the surface layer, and after dissolving, it will emit a lot of heat, which is a very ideal heat insulation material.

Moreover, this material is usually stored in a liquid state, and when needed, it is sprayed on related objects with a spray gun.

In this way, its use cost is also reduced a lot, and it is only necessary to re-spray the insulation material every time.

This material is also the latest scientific research achievement successfully developed by Wu Hao's research team of related projects in the Material Research Institute under Wu Hao's "teaching".

At present, this technological achievement is still strictly confidential, but relevant material samples and some data have also been sent to the military's material laboratory for testing.

Judging from the preliminary test results, they are still very amazing, which has also made many departments and institutions salivate, seeking to cooperate with Wu Hao and the others.

But, the initiative is in the hands of Wu Hao and the others, so naturally he is not in a hurry. After all the relevant test results are released, he is sharpening his knife and waiting for the arrival of these institutions and departments. He is so "warmly entertaining".

This time, Wu Hao and the others sprayed this new type of heat-insulating material on the second-stage rocket body of the Jianmu-2 modified rocket that is about to be launched.

Moreover, the entire second-level rocket has also undergone changes. On the body of the second-level rocket, folding flying wings similar to those of cruise missiles have been added.

When launching, the flying wings are folded up, which does not affect the normal launch. When it lands, the flying wings will bounce off, and then drive the entire rocket body to glide.

Although this is just a pair of folding flying wings, the technology used on it is also very complicated.

For example, first of all, it must be light enough, because the weight it occupies is the load weight of the rocket.

Second, it must be strong enough to withstand the enormous force of the arrow body itself.

In the end, it must be reliable enough to be able to open normally when it lands, and it must be reusable, which naturally increases the difficulty.

Of course, for Wu Hao and the others, they challenged it precisely because it was difficult.

After calculating the model data of their own Dao super photon computer, and after several consecutive tests, the project development team felt that the technical solution was feasible and reliable, and Wu Hao approved it to be used on this important launch mission for testing. .

It stands to reason that this is very risky, but seeing the confident eyes of the project R\u0026D team, Wu Hao finally approved it, and he is also very confident in "his own technology".