Chapter 92: Giving Comrade Korolev A Lesson
You’re actually a comrade?
I’ve worked in the Soviet Union for so many years, with my authority, I shouldn’t be unaware that we have a comrade on the secret front working hard like this. Now it was Korolev’s turn to be surprised and uncertain.
He didn’t ask why the other party knew he was Russian, after all, with Sergei and Vichi, these names sounded like they were from the Soviet Union at first hearing.
“Professor Lin, how do you know the Russian language?” Korolev was quite curious about this question, even if it meant losing the initiative.
Lin Ran wasn’t playing tricks either; he originally wanted to find an opportunity to pass important information from his plan to the Soviet Union side.
There’s no time like the present.
Korolev himself had come, which meant this timing was just right.
“I studied the Russian language when I was in university.” Lin Ran answered.
Korolev nodded, Göttingen? They did teach the Russian language there.
Göttingen underwent reconstruction after 45, and since the Soviet Union was a victorious nation, German universities gradually attached importance to research on the Russian language and Slavic culture.
Combining history, it was normal for Lin Ran to learn the Russian language in Göttingen, but Korolev could never have imagined that Lin Ran learned the Russian language in a Chinese university campus 60 years later.
“Randolph, congratulations to NASA on the successful moon landing, I saw this news in Moscow, feeling that the moon landing is no longer the Soviet Union’s own game.
NASA can finally join this competition.
Including your design for the space station, I think it’s very good, we internally have similar plans too.
The space station is just a bigger satellite, the space city is just a bigger space station, I really like this viewpoint.”
Korolev said, these weren’t any secrets, all congressmen participated in the hearing, and under American media reports, NASA’s ambition had long been announced to the world.
“I’m old, the Soviet Space Agency needs a successor, do you have any idea of becoming the next chief designer?”
That’s right, the purpose of personally coming to London at risk was to recruit talent for the Soviet Union.
Lin Ran had fully proven his ability, and the title of great mathematician added a halo to him.
In Moscow’s view, Lin Ran was simply a combination of Euler and Korolev, if they could recruit him to Moscow, taking some risk was worthwhile.
“I’m just going with you like this?” Lin Ran asked doubtfully, “Won’t I be intercepted by the London or American side?”
Korolev didn’t take them seriously at all: “You don’t need to worry about that.
As long as you’re willing to come to Moscow, we naturally have ways to bring you back safely.”
Korolev didn’t take London’s security seriously, in his view, this was just a public place, come when you want, leave when you want.
“Compared to becoming the next chief designer, I still prefer to be the one and only Randolph.” What Lin Ran said was a tactful refusal.
Lin Ran wasn’t worried that refusing the other party would make them act, after all, if they made a move and caused a commotion, Korolev couldn’t leave either.
“Mister, can you guarantee how much dialogue time we have?” Lin Ran then asked.
Korolev glanced at the Kirov watch on his hand, “At least 20 minutes.”
Lin Ran stood up and looked outside, although there were still two security personnel standing at the door, their appearances had changed from Germanic people to Slavs.
After Lin Ran closed the door, he said:
“Then we don’t have much time, let’s make a long story short.
With current technology, is it possible to launch tens of thousands of satellites into low Earth orbit?”
Korolev said without thinking: “Impossible, cost too high.”
Lin Ran asked: “What if it can create revenue?”
Korolev thought a bit: “Still impossible, cost is still too high, I can’t imagine what kind of revenue satellites would need to generate for countries to launch tens of thousands of satellites.”
Lin Ran asked: “What if rocket launch cost could be reduced to one-fifth, or even one-fiftieth, one-five-hundredth of now?”
Although Korolev didn’t know what Lin Ran wanted to express, he still couldn’t resist following the other’s logic, “One-fiftieth would be possible.”
Because the temptation was too astonishing.
“Good, now let’s assume in the future we need to use tens of thousands of satellites to build a network that all humanity can use, where everyone exchanges information through this network.” Lin Ran said, “Then because rocket launch cost is too high, we need to develop a technology called reusable rocket.
We design the rocket into a multi-stage ignition structure, first, second, third stages, after the first two stages ignite and send the rocket into the predetermined orbit, they return to the ground, and can be used again.
Later on, even the boosters of the first, second, and third stages can achieve recovery.”
Korolev thought about it: “Theoretically possible, but still too difficult.”
Lin Ran continued: “Right, what I want to prove now is that from a mathematical perspective, it can be achieved, this is my latest research achievement, I call it:
Lossless convergence of non-convex control sets and pointing constraints.”
Lin Ran didn’t expect that before coming to London to exchange number theory content with London mathematicians, he had to first give Korolev a math lesson.
“We simplify rocket staged recovery into a benchmark problem in optimal control theory
That is, how to make the spacecraft reach a specified position on the planetary surface in a limited time in the optimal way, usually minimizing fuel consumption, while satisfying various state and control constraints.
The soft landing problem can be modeled as an optimal control problem with a finite time horizon, which includes state constraints like altitude, velocity, and control constraints like thrust magnitude and thrust direction.
The core difficulty of this problem lies in the non-convexity of the control constraints, specifically manifested as: non-convex constraint on thrust magnitude: thrust magnitude has a non-zero lower bound and an upper bound, making the feasible control set non-convex.
Non-convex constraint on thrust direction: thrust direction is usually restricted by pointing constraints, for example, the thrust vector must lie within a certain non-convex geometric region like a cone.
These non-convex constraints make traditional optimal control solving methods unable to guarantee a global optimal solution, or even fail to converge to a feasible solution.
Therefore, we need to transform the non-convex problem into a convex problem, and prove that this transformation is lossless, meaning the solution to the convex problem coincides with the global optimal solution of the original non-convex problem.
I call this method lossless optimization.”
This mathematical paper that laid the foundation for SpaceX’s successful reusable rocket research and development was taken out early by Lin Ran as a great gift to Korolev and even the Soviet Space Agency.
As long as the other party remembers it, with Korolev’s ability, at most three years, the Soviet Union could achieve manned moon landing.
Because it directly points to the core of soft landing.
However, making the Soviet Union achieve moon landing wasn’t the most important purpose, preparing for a more distant future in advance was his real purpose.
Korolev had completely forgotten his original intention, fully focused on listening to what Lin Ran was going to say:
“What’s next?”
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