Von Kármán pursed his lips, then stood up and walked to the blackboard behind Lin Youde, and drew a schematic diagram on it, and when he drew the picture, he habitually put one hand in his pocket, looking like he was lecturing to students in school.

"The physical model of this system has been repeatedly verified and theoretically feasible," von Kármán said as he wrote down a large number of formulas, in which Lin Youde only recognized the formula of uniform circular motion, "As long as the weight of the counterweight configured on the track is large enough, there will be no situation where the rising cargo pulls the hammer down." This is because ......"

The next round of von Kármán's explanation was terrifyingly abstract, but the scientists were all nodding, and Lin Youde could only nod his head, anyway, he knew that the balance hammer was big enough and would not be pulled down.

"So, if we want to build an elevator that can lift the m mass in one pass, we must have a km-mass counterweight in space, and the value of the k-coefficient depends on the orbit we choose. After considering the various tracks, we decided that the counterweight should be placed on a synchronous track at an altitude of 35,786 km. Let's say we need to lift 1,000 tons of cargo at a time, then we might have to fly 400 missions to get all the counterweights into orbit and assemble. If the mission is flown once a month, the project will take 30 years. ”

"Do you have to put a counterweight that big in space?" Lin Youde couldn't help but ask, the counterweight of the synchronous rail elevator in his memory should not be big.

"If we develop a larger rocket, the number of missions will of course be reduced."

Lin Youde couldn't help but touch his chin, the mass of the balance hammer he had just heard was far more than that of the "International Space Station" in another time and space, and it seemed that even if he wanted to build a rail elevator, it would not be a simple matter. Lin Youde couldn't help but think that thirty years later, he would probably be an old man who couldn't even take care of himself, and this plan could only be completed by his daughters......

"In addition to this huge counterweight, we also needed a material that was tough enough and light enough that not only would the rope crowd out the available carrying capacity, but the whole system would have become unstable due to the lower center of gravity, and we would have to keep growing the weight. In addition, the cable is either an insulator or has the ability to superconduct at room temperature, otherwise, even if it has only a little resistance, the strong current generated by cutting the magnetic inductance line will create a large amount of resistive heat, which will melt the entire system. We were pessimistic about finding the right material, which even exceeded the standard of alchemical materials we had seen. ”

After von Kármán finished speaking, the atmosphere in the entire conference room was very heavy.

Von Kármán seemed to feel that this was not enough, so he continued: "In addition to these two big problems, the system also has the problem of how the cable will cope with the meteorological problems caused by atmospheric convection in the troposphere below the stratosphere. Because the cable is to be connected to the ground base station, in bad weather, the ground base station may face super tension from the cable, and the strength of the joint between the base station foundation and the cable must be very large. There are also questions about how the lifted cargo crosses the troposphere and how the motor pulls the load. You know, it's not just lifting the object up, the motor has to drive the wheels and something like that, and it's going along the cable. This means that the friction between the wheels and the cable must be able to support a weight of 1,000 tons. In fact, it should be more than a thousand tons ......"

Von Kármán seemed to have finished, and after a moment someone summed it up: "There are as many technical bottlenecks as a mountain." ”

Immediately someone said, "But this is the easiest solution I've heard so far." ”

"I wish I could have developed the anti-gravity engines described in those sci-fi works, so that it would be easy." Others say so.

"I think the idea proposed by the American named Heinlein to concentrate a group of gods and use the power of gods to put spacecraft into orbit seems to be a good idea."

"Don't be stupid, you need to gather all the gods in the world to send it once."

At this time, Lin Youde coughed, and after attracting everyone's attention, he said: "A journey of a thousand miles begins with a single step. Let's start building the counterweight. ”

The scientists looked at each other, and finally everyone's eyes converged on Lin Youde again, and von Kármán asked on behalf of everyone: "Is it really going to be built?" ”

"Of course. However, it is not a simple balance hammer, every part we send it should have its own purpose, such as a space room, a large space telescope, a military module equipped with a real laser, and an electronic reconnaissance cabin that listens to ground radio waves, all of which are sent up and installed together as a counterweight. Even if it takes thirty years, it must be made. While we make it, we look for ways to solve other problems. Thirty years should be enough time for us to find something. ”

The scientists looked at each other again, and this time, they finally realized that Lin Youde was real, and he really wanted to build such a Babylonian Tower of Babel to open the path of mankind to space.

"So, let's make sure I'm going to put the counterweight there." "Because the counterweight will be placed in a synchronous orbit, we have to consider where to build a ground base station in the future, otherwise after the counterweight is built, it will consume a huge amount of fuel to make something so big fly in orbit." ”

Spacecraft orbit changes to consume their own substances, such as satellites, most of which have fuel reserves to adjust their orbits during service. Once a satellite runs out of fuel, its role will be much reduced, especially those remote sensing satellites that need to adjust their position from time to time.

Therefore, it is simply domineering to be able to adjust the orbit of a satellite in order to find a missing flight, and you must know that the loss of the life of the satellite if converted into money, may be dozens of times the insurance compensation for the entire flight.

Therefore, a large orbital object such as a counterweight must be placed in the right place from the start, with just the right amount of land underneath for the construction of a ground base station.

"I've already thought about the location of the rail elevator. The only options available are the areas near the equator, which are unfortunately now largely underdeveloped and have almost zero infrastructure. Lin Youde stood up and made a gesture for the staff on call to hang the world map on the blackboard, "Because of this, for the convenience of the construction of the elevator and the subsequent transportation of aerospace materials, the location of the ground station should be on the seaside, so that it is also convenient for the naval fleet to go to protect the safety of the base station." When you exclude the whole of America, there aren't many options.

"First of all, near the Gulf of Guinea, which is less than 4,000 kilometers away from the closest place to the American-controlled continent and about 9,000 kilometers from the coast of Florida in the United States, this is not a safe distance. The point is that if our fleet is going there, it will inevitably be intercepted by the American fleet in the Atlantic.

"Then there are the coasts of Somalia, Kenya and Tanzania, which are even more backward than around the Gulf of Guinea, and the Somali faith is now our enemy, and the Americans have a large number of military bases and garrisons on the Arabian Peninsula, which is not a good option.

"That's all that's left."

Lin Youde nodded to Southeast Asia.

"Although it is very close to Australia, an ally of the Americans, the sea area is narrow, suitable for land-based aviation operations, and at the same time, it is very close to the new Ming Dynasty, and some surrounding countries were still vassal states of the Ming Dynasty 20 years ago, including French colonies, and the Philippines has just become independent from the Americans, and anti-American sentiment is very high. If the fully revived Xinming expands in this direction, with the support of the entire Human Innovation Alliance, it will be difficult for the Americans to stop it. ”

Lin Youde paused and added: "By the way, the French colonial rule here is almost untenable, let Xinming intervene to help, and you can sell a favor to the French." ”