If Wu Hao and others want to develop the retractable technology of the second-stage rocket, they must first solve a problem to prevent the second-stage rocket from burning up in the atmosphere.
If this problem is solved, it is actually very simple. That is to cover the rocket body of the two-stage rocket with thermal insulation material, or to design and manufacture the rocket body to resist high temperature burning.
Currently, there are two technologies or two ideas for this kind of return spacecraft in this field. One is the idea of the Mi Space Shuttle, which is to cover the surface of the spacecraft with insulation materials. In this way, the contact between the spacecraft and the atmosphere can be reduced, thereby preventing it from being burned upon return.
The second method is to directly use high-temperature resistant materials to make the outer shell of the spacecraft, and then let the shell directly contact the atmosphere and burn. This technology is mainly used on Soviet-style spacecraft and our spacecraft. Currently, most of the new generation spacecraft return capsules in various countries use this technology.
But for Wu Hao and others, no matter what kind of technology it is, the first biggest impact, or what they have to solve, is the weight issue.
Whether it is a heat-resistant shell or heat-insulating tiles, the first thing to solve is the weight issue.
If the weight is too heavy and takes up too much rocket thrust, it is not cost-effective. But if these two technologies are not used, the rocket may be burned.
So is there a third way that can allow a two-stage rocket to land from space without being burned by the atmosphere?
Yes, speed is key.
The primary reason why a spacecraft is burned by the atmosphere is speed. If the speed is fast enough, the friction of the spacecraft in the dense atmosphere will be greater. 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 of the surface of the rocket body can be greatly reduced, allowing the rocket to return to the atmosphere safely.
If you want to reduce the speed of the rocket, there are several ways. 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 begins 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 the parachute must also have strong heat resistance, otherwise the parachute may be burned after a long landing.
Moreover, it is still very difficult to implement this technology to open an umbrella at the edge of the atmosphere.
In addition, the parachute is opened too early and the landing location is uncontrollable, so the meaning of recovery is lost.
The second method is to use rocket engine reverse thrust technology to slow down and land like a Falcon rocket.
This technology is feasible, but it means that the rocket has to carry more fuel, and too much fuel will occupy the rocket's carrying capacity, thus losing the recovery value.
The third technology is gliding landing, which is similar to that of the space shuttle. It uses gliding to slow down and gradually land, thereby reducing the rocket's descent speed.
The fourth method uses a floating landing method similar to that of Chang'e 5. However, this has certain requirements for the strength of the spacecraft itself. Obviously, the rocket body is not suitable.
So Wu Hao and the others focused on the third technology, using gliding technology to slow down the rocket.
But this alone is not enough. The rocket must also be equipped with a layer of insulation material, commonly known as insulation tiles.
Although this thing is not new, and because of this insulation tile, several space shuttles suffered major accidents.
However, rocket bodies are different from space shuttles, and rockets are mostly unmanned payloads, so safety is also guaranteed to a certain extent.
In addition, today's technology is not the same as it was a few decades ago. The project R&D team chose a special light and thin thermal insulation material this time.
This material is very light and thin, weighing about the same as ordinary foam, or even lighter. Keqi itself has very good thermal insulation properties. Even if it is burned on a fire, it will not be affected by the temperature of ordinary fire.
And when encountering high temperatures, this thermal insulation material also has a characteristic. It can gradually dissolve slowly from the surface layer, and after dissolution, it will also dissipate a large amount of heat. It is a very ideal thermal insulation material.
Moreover, this material is usually in a liquid state when stored, and when needed, it can be sprayed onto relevant objects using a spray gun.
In this way, its use cost will be reduced a lot, and the insulation material only needs to be re-sprayed each time.
This material is also the latest scientific research achievement successfully developed by Wu Hao and his team of researchers from the Materials Research Institute under Wu Hao's "instruction".
At present, this technological achievement is still strictly confidential, but relevant material samples and some data have been sent to the military's materials laboratory for testing.
Judging from the preliminary test results, they are still very amazing. This has also made many departments and institutions salivate, and they are seeking to cooperate with Wu Hao and others.
However, the initiative rests with Wu Hao and the others, so naturally he is not in a hurry. After all the relevant test results were released, he was sharpening his knife and waiting for the arrival of these institutions and departments so that he could "hospitally entertain" them.
This time, Wu Hao and the others sprayed this new type of heat insulation material on the secondary body of the Jianmu-2 modified rocket that was about to be launched.
Moreover, the entire second-stage rocket has also been changed. Folding flying wings similar to those of a cruise missile have been added to the body of the second-stage rocket.
During launch, the flying wings are folded and do not affect normal launch. When it lands, the flying wings will bounce off and then drive the entire rocket body to glide.
Even though this is just a folding flying wing, the technology used on it is also very complex.
For example, first of all, it must be light enough, because the weight it occupies is the payload weight of the rocket.
Secondly, it must be strong and stable enough to withstand the huge force of the arrow body itself.
Finally, it must be reliable enough, able to open normally when landing, and must be reusable, which naturally makes it more difficult.
Of course, for Wu Hao and others, they challenged it precisely because it was difficult.
After calculating the model data of their own Tao super photon computer and conducting several consecutive tests, the project R&D team felt that this technical solution was feasible and reliable, and Wu Hao approved its use for testing on this important launch mission. .
Logically speaking, this was very risky, but seeing the confident look of the project R&D team, Wu Hao finally approved it, and he was also very confident in "his own technology."
