After the successful manned orbit test of the Tongtianqiao plan, the latter item in the plan, the "Tiangong-1 plan", was fully launched.

This "Tiangong-1" is actually a low-orbit space station. Like the International Space Station in the original space-time, the tubular structure is mainly built on the ground and then launched into space to assemble. But there is a huge difference in nature between the two. The building materials of the International Space Station, which had to be launched into orbit by a space shuttle or a heavy rocket, were severely limited in weight and volume, and the construction cost was extremely high.

From the launch of the first component in 1998 to 11 years later in 2009, the ISS has a total weight of 303 tons, a living compartment of 358 cubic meters, a total of about 430 cubic meters of cabins, a crew of only six people, and nearly 100 billion US dollars. If inflation is taken into account, it is equivalent to about $6 billion in 1937.

However, the "Tiangong-1" single habitation module weighed 505 tons, the volume reached 3,000 cubic meters, and the launch was completed, and on the same day, the Hanging Garden base carried out a total of six projections, launching six cabins, including four living cabins, a command module, and a fuel and engine compartment, a total of 3,300 tons, and the total cost was less than 2.6 million Chinese yuan. The main reason for this is not only the low cost, but more importantly, the low launch acceleration, so the structure and parts do not need to be significantly reinforced. In addition, because the bridge has the ability to quickly launch various cabins to fill the position, the safety redundancy factor of the overhead crane can be slightly lower, which also saves a lot of costs.

And this is not over, the second day, the third day, the fourth day, the subsequent cabins and parts of various functions are launched one after another. Among them, when the living compartment in front of the third day was assembled, the command center of the bridge launched a passenger car and sent a total of 300 workers to assist in the construction, and the scene of more than 200 people walking in space at the same time was very spectacular.

On December 20, 1937, two months after the Tiangong Project was launched, the Tiangong-1 base was officially completed. It is a large 41,000-ton space station consisting of a total of 76 various cabins, including 40 living compartments, which can accommodate 1,600 permanent residents, and can quickly launch new living modules to increase space in a short period of time. The usual permanent staff of Tiangong-1 is 400 people, and the total planned investment is only 200 million yuan. The launch success rate is extremely high, the process is safe, the cost is low, the throw volume is large, and the reaction speed is fast, which is the great advantage of the mass projector.

Although Tiangong is a space station mainly for scientific research, there are also troops stationed on it. The Chinese Air Force has a 30-member team stationed in it, and the task of this team is a maintenance team, but they do not repair Tiangong, but use Tiangong as a base to refuel, repair and upgrade China's satellites on orbital spacecraft. We all know that satellites are very expensive things, and it can be refueled regularly, slow down the parts, and upgrade and repair from time to time, which can greatly increase the service life, which is very helpful in alleviating the pressure on the budget.

The bridge is indeed very expensive, much more expensive than the launch vehicle, and the entire bridge project plus various supporting facilities has burned more than 18 billion. But this is expensive mainly in the construction cost, and the use cost is much cheaper.

The bridge project includes an ultra-large high-energy battery array and two charging nuclear power plants, with four 1.2 million kilowatt units and an output of 4.8 million kilowatts. Every three and a half hours of charging, a 720-ton full-load cargo projection can be carried out, and a full-load passenger car projection can be carried out every three and a half hours of charging.

The nuclear power plant that comes with Tongtianlu is the latest fourth-generation value-added reactor nuclear power unit, and its electricity cost plus 10% net profit is 1 cent and 2 yuan per kilowatt-hour. Therefore, the energy cost of projecting a fully loaded wagon is 20. 160,000 yuan, plus the cost of operation and maintenance is about 250,000 yuan. A full load of trucks is 660 tons of payload, which equates to a cost of 380 Chinese dollars per ton, or eight cents per kilogram. The projection cost of the bus is the same, but the maintenance cost of the car body is slightly higher, a fully loaded bus costs about 300,000 yuan, and the cost is about 300 yuan per passenger.

For comparison, at present, China's heavy-lift launch vehicle Shenglong II pushes 20 tons of payload to low orbit at a unit price of 3 million Chinese yuan, and the cost is about 150,000 Chinese yuan per ton, a difference of 395 times. If you consider the transportation of people, the difference is even greater, even if all the spaceships are changed to passenger type, there will be a maximum of 12 people on board. The unit price of the spacecraft is 600,000 yuan, that is to say, together with the cost of the rocket, it costs 3.6 million yuan to transport 12 people to orbit, and 180,000 yuan for one person, a difference of 1,000 times.

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After the celebration of the completion of Tiangong No. 1, Qian Xuesen found Wen Desi after the banquet and said very seriously:

"Mr. Wen, I admit that the budget for the bridge has been reduced by at least one-third compared to the schedule. But Mr. Wen, I still insist on my opinion, I am afraid that it will be difficult to recover the cost of this plan itself. I'm afraid you've made a mistake this time. ”

"Oh, Director Qian, why do you have such thoughts?" asked Wen Desi with some surprise.

"Mr. Wen, I calculated. If we charge 1,050 Chinese yuan per ton of goods, that is, 200% of the profit, and project it day and night, although we can recover the construction cost of more than 18 billion yuan after 18 years. But that's a total projection of 26 million tons, but how can we have so much cargo to be projected into orbit? Even the projected orbital solar power transfer system won't need that much. The planned orbital photovoltaic power station plus the support system does not exceed 50,000 tons, which can already produce nearly one million kilowatts of electricity, which is equivalent to a nuclear power unit. Even if you build 100 seats, it will only be a projection of 5 million tons. Besides, the photovoltaic panel itself is also very expensive, and it will never recover the cost by relying on this. You see, this is the result of my calculations. Qian Xuesen took out a letterhead full of words and handed it to Wen Desi.

"Hmm......" Wen Desi took it and looked at it, Director Qian calculated very carefully, and counted the maintenance time. Qian Xuesen suffered a loss at the Tongtianqiao at that time, and after discussing it with his colleagues after going back, he found this problem. According to their algorithm, the cost of the bridge is too high, and it will not be possible to recover the cost according to the current method of use.

"Mr. Wen, although our country is much richer than before, it is also very difficult to invest such a large amount. Qian Xuesen said very seriously, he is not grabbing funds now, but out of a sense of responsibility, he feels that it is a pity that the country has spent so much money.

Wen Desi smiled and said, "Director Qian, you are a very good scientist, but you are not a good businessman. Why do you only give us 200% of the profits from the bridge? This is the exclusive monopoly of the world, and other countries don't even have launch vehicles. We say how much this shipping cost, that's how much. A profit of 200% is too conservative, and in my opinion, a profit of 1,000 percent or even 10,000 percent is very appropriate. ”

"Mr. Wen, if you are making money from foreigners, it doesn't matter how high the profit is. But if we use it for our own country, it is not appropriate to set such a high profit margin......" Qian Xuesen thought for a while and said.

"You're right, the most important purpose of our bridge is to achieve China's scientific and technological take-off, so of course the profit margin of the internal price cannot be so high, too expensive people can't afford to use it, so at most it is 300% to 500% of the profit. So we have to think of other ways to make money, to increase the total freight volume, instead of just focusing on the unit price. For example, the development of a new space industry. In my opinion, this is the beginning of the Fourth Industrial Revolution. Wen Desi also said seriously.

"The Fourth Industrial Revolution?" Qian Xuesen was stunned.

"Yes, the Fourth Industrial Revolution. The first industrial revolution was the steam engine, the second industrial revolution was the electric revolution, and the third industrial revolution is already underway, which is the information revolution brought about by the computer industry. And the fourth industrial revolution depends on the space industry. ”

Qian Xuesen asked curiously: "So what do you think are the contents of these industries?"

"New materials, new energy and new tools. Mainly these three aspects. Seeing that Qian Xuesen was a little hesitant, Wen Desi smiled very kindly: "Let me give you a few specific examples." For example, new materials, let me tell you a secret information, our more than a dozen materials research institutes have actually invented many kinds of new materials now, many of which are new materials that everyone has never heard of before, and their performance is far beyond the imagination of contemporary people. But less than a fifth of what they have done is now put into practice. Do you know why? Because there are a lot of things that are extremely expensive to produce on Earth, otherwise they can't be produced on Earth with current technology, but if they are produced in outer space orbit, it's completely different. ”

"For example, Super Alloy. Alloys are made on earth, because different metals have different specific gravity, so when melting, the mixed alloy components will sink and float lightly, so they are not very uniform. For example, our iron-aluminum conjugated alloys, which have taken a lot of effort to solve this problem and require special equipment, have been limited in production. But in a gravity-free environment on the track, alloys of any metal composition can achieve a perfectly homogeneous mix. Originally, it was difficult to make metal alloys with too different specific gravity on the earth, but they can be easily made in orbit. ”

"The second is the problem of impurities, in the smelting of metals on the earth, the mixing of air alone will cause impurities, such as nitrogen, hydrogen, etc. These problems are cumbersome to deal with, and the cost of setting up a vacuum environment in a steelmaking furnace is quite high. However, in orbit, it is originally a vacuum environment, so it does not cost anything to create a vacuum. In addition, the cost of orbital melting is relatively low, because there is no air, and the heat energy is not easily lost due to convection. ”

"There are also alloys with special structures, such as metal foam...... "Wen Desi naturally used his most familiar old profession as an example, no one in the world is better at mining and metallurgy, especially in mining and metallurgy outside the earth. He continued: "For example, have you seen I-rails? Mesh steel plates, and even honeycomb metal structures in airplane wings, these are all ways to try to reduce the weight of the material while maintaining its strength. But in a gravity-free environment, it is easy to make metal foams that are ten times stronger than these. ”

Qian Xuesen thought for a while and said: "Foam metal, I have heard of this material, and this information has been published in previous scientific journals. It is said that this kind of thing can greatly reduce the weight of the material without losing too much performance. However, this kind of thing can only be produced in small quantities in the laboratory, and it is completely unpractical. "People in the rocket industry are used to "calculating", and they are very sensitive to the weight of materials.

"Yes, that's it. Wen Deji nodded.

"Because it's hard to smelt metal foam on Earth. Because of gravity on Earth, once gas is injected into molten metal, the bubbles will quickly float up and there is no way to distribute them evenly. However, there is no gravity in space, so the stirred bubbles can be evenly distributed in the metal solution, and when they cool, they are filled with perfectly circular bubbles. For example, the simplest foam steel in foam metal, this kind of thing can be made lighter than water, can float on water, its load-bearing capacity and endurance is not much smaller than the same volume of steel, the point is that it is very cheap and can save materials. That's incredible material. If it is used to build cars, ships, aircraft, and equipment, there will be a huge leap in performance. ”

Another example is the ball bearing, which is a key industrial product, during the First World War, when the Entente and the Central Powers carried out strategic bombing against each other, the ball bearing factory was the first to be bombed. The key to ball bearings is balls, this kind of thing looks simple, but it is quite technical, and there will be no more than 20 countries in the world that can manufacture qualified ball bearings, and the manufacturing process is very cumbersome. But if it is in space, the cost of manufacturing this thing is very low, the process will be greatly simplified, and there is no need to even grind, and directly drip the molten alloy liquid out of the appropriate amount, and it will shrink into a perfect circle in the air by itself, with an accuracy several orders of magnitude higher than the best products ground in factories on Earth. ”

After a pause, he said: "Then there is the pharmaceutical industry, which requires a very high dust-free vacuum environment to avoid contamination, and the cost of maintaining a dust-free vacuum environment is extremely high. But space does not cost anything, and the dust-free vacuum is several orders of magnitude higher than that on the ground. ”

"The last one that you may not know is the computer industry. The manufacture of computer CPUs also requires an extremely high dust-free vacuum environment. In addition, there is the problem of the growth of semiconductor silicon wafers, the larger the wafer, the lower the cost of semiconductors. We can only make wafers with a diameter of 200 mm at the moment. Therefore, today's processors are more expensive than the same weight of gold, that is, the so-called expensive than gold. In addition, the current cost of solar panels is extremely high, and silicon-based solar wafers are also cut out of silicon wafers. ”

"Although the wafer diameter can continue to increase after efforts, it will take a lot of money and time. For example, if you want to produce 300 mm, 400 mm or even 500 mm wafers, it may take more than ten or twenty years of research time and tens of billions of investments. However, there is no gravity in space, and there is almost no limit to the diameter area of this wafer that can grow in theory in this ultra-vacuum, ultra-dust-free, gravity-free and even vibration-free environment for monocrystalline silicon growth. This will enable us to significantly reduce the cost of integrated circuits and solar panels. ”

"As for energy, the orbital photovoltaic power station is just one of them. In addition, there is another project, which is also proposed by Mr. Tesla, which is an orbital magnetic power station, which uses the magnetic field lines generated by satellites to cut the earth's magnetic field to generate electricity. In addition, the controlled nuclear fusion project we are working on now must also be fueled from space......"

"Finally, in terms of new tools, spaceships, space stations, etc., are good tools in themselves, and they have many ...... uses," Wen Desi said a lot, and he personally poured Qian Xuesen a cup of tea.

"The bridge itself may not pay for itself in the 18 years you expected, or even in the estimated 30 years of life," he said with a smile. Of course I think there should be a chance, but even if it can't, it's well worth it. Because it's our ticket to the Fourth Industrial Revolution. In the past 100 years, we in China have missed becoming the leader of the first and second industrial revolutions, and we have already grasped the third industrial revolution, but the fourth industrial revolution is the key to the sublimation of mankind. So we must not give up!"

Of course, in addition to these things, there are other uses that Wen Deji did not say, and that is military use. With the Sky Bridge, it is very convenient to deploy large orbital bombers and missile interception platforms. In addition, the bridge itself is a super giant electromagnetic cannon, of course, it can also be used to fire giant guided projectiles.

Because this kind of giant guided projectile does not require energy during the take-off stage, only a small amount of fuel for orbit change and correction, compared with conventional ballistic missiles, it also saves at least ninety percent of the weight, and one shot is a 720-ton guided projectile, which is sour to think about. If you replace it with a nuclear warhead......

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It is not impermeable that China is so intensively conducting space projection and building a huge Tiangong-1 in low-earth orbit.

In December 1937, several astronomers at the Hungarian National Astronomical Observatory stumbled upon the artificial artifact while making routine observations of the Moon. At the time, they were shocked, thinking that they had seen it wrong. By the time they remembered to take pictures with their cameras, Tiangong-1 had already flown out of their telescope field of vision.

Anyone who has ever made astronomical observations knows how difficult it is to capture an artificial object orbiting the Earth in the vast expanse of space, because they are so fast that the time to pass through the sky is often only a few minutes. Unless you know their orbit and running time in advance, you have a chance to capture them.

Of course, there are so many observatories and astronomy enthusiasts on Earth, and there are always lucky people.

On February 7, 1938, when a Swiss astronomer was photographing sunspots, he inadvertently took the famous photograph that was later called the "obscuration of the heavenly palace". At that time, "Tiangong-1" happened to pass the outer side of the sun, and although it was completely out of shape due to light refraction and other reasons, it could also be seen that it was an obvious artificial creation. And because of its out-of-shape, the "Heavenly Palace" in the photo looks like an alien spaceship from a science fiction movie. After the photo was released, it caused an uproar in the world, and people believed that aliens were coming, and a sci-fi craze arose. , one shot is a 720-ton guided projectile, which is sour to think about. If you replace it with a nuclear warhead......

..................................................................

It is not impermeable that China is so intensively conducting space projection and building a huge Tiangong-1 in low-earth orbit.

In December 1937, several astronomers at the Hungarian National Astronomical Observatory stumbled upon the artificial artifact while making routine observations of the Moon. At the time, they were shocked, thinking that they had seen it wrong. By the time they remembered to take pictures with their cameras, Tiangong-1 had already flown out of their telescope field of vision.

Anyone who has ever made astronomical observations knows how difficult it is to capture an artificial object orbiting the Earth in the vast expanse of space, because they are so fast that the time to pass through the sky is often only a few minutes. Unless you know their orbit and running time in advance, you have a chance to capture them.

Of course, there are so many observatories and astronomy enthusiasts on Earth, and there are always lucky people.

On February 7, 1938, when a Swiss astronomer was photographing sunspots, he inadvertently took the famous photograph that was later called the "obscuration of the heavenly palace". At that time, "Tiangong-1" happened to pass the outer side of the sun, and although it was completely out of shape due to light refraction and other reasons, it could also be seen that it was an obvious artificial creation. And because of its out-of-shape, the "Heavenly Palace" in the photo looks like an alien spaceship from a science fiction movie. After the photo was released, it caused an uproar in the world, and people believed that aliens were coming, and a sci-fi craze arose.