Chapter 1542: Bad guys

Regarding the major issue of the choice of powertrain technology route, Ren Xinming naturally has to be cautious, but this does not prevent him from discussing another technical issue with Tan Zhenhua-although it is also a technical issue, whether it is using hydrogen-oxygen engine or liquid oxygen kerosene The engine, this problem is a hurdle that cannot be overcome. Although Tan Zhenhua is not a person in the industry, it can be used as a stone of the mountain. He can take this opportunity to listen to different ideas.
"Dr. Tan, I understand your intentions." Ren Xinming said: "It seems that you are planning to take the technical route of liquid oxygen kerosene, but I need to remind you that even if we finally agree to your plan, it will not be possible in the short term. Developed an engine as powerful as the RD-170, and there is one more thing. The RD-170, after all, is a product of Rakshasa. We have a good relationship with them now. We can no longer carry out surveying, mapping and copying of their products as we did in the past. Either we will find a way to get authorization from Rakshasa, or buy this engine from them, but I don’t think the Rakshasa people will agree to sell us such cutting-edge technology, and it is unlikely that our country will purchase foreign engines. Come to develop rockets, so your technical route to be truly realized is not much simpler than our development of a new type of high-power hydrogen-oxygen engine, and this difficulty is not only technical."
"I have no plans to imitate the R-170 for the time being, nor have I thought about buying a ready-made one to use." Tan Zhenhua replied: "That's why I got the RD-8. I hope we can build on this engine. , Continue to improve a model with greater thrust, and then use multiple engines in parallel to increase thrust. It should be easier, right?"
"RD-8 already has the original drawings, design, and test parameters. Of course it will be easier to imitate and develop further. From a technical point of view, the liquid oxygen kerosene engine itself is slightly less difficult than the hydrogen oxygen engine." Ren Xinming nodded. Said: "However, this involves a very important issue, the safety of aviation launch."
After thinking about it, he went on to explain:
According to the internationally popular evaluation standards, manned rockets require a large total engine thrust, and must also have an emergency escape system, which has the three major requirements of high reliability, high safety, and high quality. The rocket reliability requirement of the satellite is about 0.9, and there is no special requirement for safety, but the reliability of the rocket for launching manned spacecraft must not be less than 0.97, and the safety requirement must reach 0.997. The reliability of the rocket engine has always been in the whole system. Relatively low, if multiple engines are used in parallel, the safety and reliability will be reduced by a multiplier. Therefore, in the design of manned rockets adopted by countries around the world, in order to improve the high reliability and high safety indicators of the rocket, they are all adopted To achieve the demand for manned spaceflight by reducing the number of engines and high-thrust rocket engines, after all, for traditional rockets,
complementing the number of insufficient thrust
is a forced method, because this method will greatly reduce the reliability of the rocket. The failure of any one of the engines will pose a fatal threat to the successful launch of the rocket. Also, if too many engines are connected in parallel, unpredictable coupling vibrations will also occur between them. Therefore, the more engines are connected in parallel, the worse the reliability. A typical example: the Soviet-Russian N-1 moon landing rocket used 30 engines at the core stage. As a result, all 4 launches ended in failure. In the end, the project had to be dismantled. So your multi-engine parallel plan, It looks good, but it may not be appropriate to do it."
"In addition to the development of a more advanced rocket power control system, I think this is still a mathematical problem." Tan Zhenhua replied: "The safety factor of multiple engines in parallel, it actually has a critical point, when the required thrust is exactly equal to multiple engines in parallel. At the end of the total thrust, the problem you mentioned naturally exists. An engine working abnormally will cause the entire system to fail to complete the task. However, if we set more power redundancy, for example, increase the number of redundant engines. To 3 or more, then, if one engine is stopped, the impact on the entire system can be completely ignored. In this case, the safety and reliability of multi-engine parallel technology is even higher than that of a few high-power The condition of the engine, Mr. Ren, do you think this person cares?"
Ren Xinming nodded slightly. Tan Zhenhua’s thoughts coincided with him. In fact, although he prefers the hydrogen-oxygen engine solution, he is also very clear that the YF-73 engine that he presided over the development of the "Long March 3" upper stage is used The vacuum thrust is only 4.5 tons, and the planned YF-75 engine is only a thrust of 50 tons. With China’s capabilities, it is possible to develop a hydrogen-oxygen engine with a thrust of more than 100 tons within ten or even twenty years. The performance is minimal, just because the efficiency of the hydrogen-oxygen engine is more than 30% higher than that of liquid oxygen kerosene. Once several major technical difficulties are overcome, the future development space is greater, which is the main reason that attracts him.
Therefore, the fact is that if based on China’s own existing and already included in the development catalog, the "921 Rocket" must use multiple engines in parallel regardless of whether the core stage uses a hydrogen-oxygen engine or a liquid oxygen kerosene engine. This also means that the rocket flight control system and fuel delivery system must be designed based on this reality, so there are naturally several major technical difficulties that need to be overcome: power redundancy technology, multi-engine parallel computer attitude control Technology, fuel cross delivery technology, core-level high-thrust engine technology, high-altitude secondary ignition technology, high-strength ultra-lightweight rocket body technology...
Well, after Ren Xinming made a long list of technologies that need to be broken through and marked the expected investment amount and completion time schedule, in Tan Zhenhua's eyes, this is a lot of bad money. list……
Nima finally found a toy that burns more money than playing with aero engines, that is, playing with rockets!
That Alan. Why did Musk play this business as a good one? Master, I have to remember my memories, and see if I can steal a few tricks...
But when Tan Er started his little brain full of bad water and began to work hard to remember how the real "Iron Man" turned a business that seemed to lose his pants into a capital market star , His phone rang unexpectedly.
This phone is not an ordinary mobile phone, but a handheld personal receiving device for the "Asia One" communication satellite. Tan Zhenhua chose this portable communication method because he owns and operates the "Asia One" communication satellite. The controlling shareholder of is the well-known CITIC Group, one of Xiangjiang’s two real giants, the Rong family; and the other shareholder, originally the US General Electric Group, but later, after Tan Zhenhua resumed public activities, he opened He bought all of these shares at a good price. Therefore, this satellite can also be regarded as his own industry. Of course, he is more assured in terms of communication security.
However, I know that there are not many people who are cooperating on his phone. Generally, there are no particularly important things. These people will not bother him. Who will call at this time?
He picked up the phone, pressed the answer button, and heard a girl's soft voice from the microphone: "Brother Zhenhua, there is a bad guy who wants to bully us!"