PS: 6000 words big chapter, ask for tickets

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"Our journey is the sea of stars", this is a classic line from a certain novel. It also illustrates one of humanity's greatest dreams.

Since the beginning of civilization, human beings have been full of curiosity and longing for the mysterious starry sky. For human beings, soaring in the sea of stars is an innate dream, and it has been a fascinating hot topic since ancient times, which has made countless people feel excited.

However, it is very difficult to realize this dream, the sea of stars is on the head, but if human beings want to conquer it, then the first problem they have to face is how to "go to the sea"? That is, how to rush out of the earth and reach space?

The laws of physics have given several key elements of "going to sea" early on. When the object reaches 7 per second. The first cosmic velocity of 9 kilometers can finally get rid of the shackles of gravity and enter space, which is the speed that the spacecraft must have when moving in a circle along the earth's surface, also known as orbiting speed. The object reaches 11 per second. At a second cosmic velocity of 2 km, it can break away from the Earth's gravitational field and travel to other planets in the solar system. When the object exceeds 16 per second. At a third cosmic velocity of 7 kilometers, you can leave the solar system and roam the vast Milky Way. In short, the speed of the spacecraft is the only element to break free from the gravitational pull of the earth and even the sun, as long as it can reach the cosmic speed, it can "go to the sea".

Then the key to "going to the sea" is how to make the spacecraft gain this speed, and the first thing that many people think of should be the rocket. That's right, rockets can indeed reach this speed, so many satellites and spaceships are also hit by rockets. And it's also the lowest tech tree and the most accessible means for humans.

However, launching a spacecraft with a rocket is too expensive, and the cost is really high. For example, at the beginning of the 21st century, from 2007 to 2008, if a rocket was used to launch an item into geostationary orbit, the international quotation was about 2 per kilogram on average. About $10,000 (about 800 grams of gold).

Even if China's own plane is definitely cheaper for various reasons, it is not cheap. At present, China's largest and latest carrier rocket "Shenglong-1" can already send 3 tons of payload to geostationary orbit, but its cost price is as high as 1.8 million yuan. That is to say, regardless of labor, site, equipment depreciation, etc., just counting the cost of the rocket, on average, is 600 Chinese yuan per kilogram of load, and according to the currency value at this time, it is 300 grams of gold.

This price is really too expensive! But like this with chemical rockets, the cost of disposable things will definitely not be cheap.

So is there a cheaper way? Then find a way to use reusable, such as "space elevators", "anti-gravity spaceships", and so on. It is said that once the space elevator is built, the price of access to space can be reduced to one-fortieth of what it would be to use a chemical rocket. However, the technology tree of these things is too high, and Wen Deji can't make it at all, at least for a few decades.

Then the only feasible way at this stage is only one - mass projector. The basic principle of a mass projector, also known as a mass accelerator, is to use a repeatedly changing electromagnetic field to accelerate and project a magnetized object. The principle is similar to that of maglev trains and electromagnetic cannons, to put it bluntly, it is an oversized electromagnetic cannon, or a maglev train that shoots itself into space.

The idea of shooting spacecraft as a cannonball actually existed for a long time, and the science fiction writer Verne had a big brain, and boldly proposed a launch device called "Columbia Cannon" in "From the Earth to the Moon", trying to send the manned vehicle to the moon like a cannonball by the propulsion of gunpowder explosion. Of course, this method is too exaggerated, even if the cannon is powerful enough, the human body and equipment cannot withstand that kind of acceleration. The same is true for mass projectors, which also need long enough rails to maintain a tolerable acceleration increase in spacecraft.

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The code name of China's mass projector project is "Tongtianqiao Project", which means the bridge between heaven and earth. Because there are many ready-made materials from later generations, in fact, the project of this mass projector began in 1909, almost at the same time as the "Lunar Plan" with chemical rockets as the main target. The former is led by the 3309 Institute (Institute of Aerospace Electromagnetics) and the latter is led by the 3301 Institute (Rocket Research Institute).

The bridge is also a super project, and it is not impossible to do it for decades. So at the beginning, the 3309 Institute only built a small mass projector with a ratio of one thousandth, nicknamed "Little Bridge", for various technical verification and testing. Although it is small, it is only compared to its finished product, and its orbit is also 1000 meters long, which is actually a super-large electromagnetic cannon.

This experimental "small flyover" is located in the Gobi Desert north of Jiuquan in Gansu Province, not far from the test base of the Rocket Research Institute. It was built in August 1914, and operational tests began that month, with a power plant to provide it with electricity. If you don't count the satellites that can operate, the first thing to put the object into orbit should be the Aerospace Electromagnetic Research Institute, not the Rocket Research Institute. Between 1914 and 1915, the 3309 Institute had already used their one-thousandth mass projector to hit multiple objects into space.

But it's just an ordinary payload, and I didn't hit the detection instrument. The reason is very simple, in addition to the one-thousandth ratio of the "small flyover", which represents only one thousandth of the load weight, the acceleration is also a thousand times, about 3000 times the acceleration of gravity (3000G), which lasts for about 0. About 3 seconds. At present, there is no instrument that can withstand such a large acceleration and still operate normally, so it can only fire some solid metal blocks and other items to measure the trajectory, ablation and the perfection of the related tracking system, and to study and improve the appearance of high-speed flying objects.

However, because of this, the objects that are put into orbit quickly fall back into the atmosphere and burn clean, without emitting any signal, and therefore not being detected by other countries. Even if it is seen by observatories in various places, it is just thought that it is a meteor.

Most of the tracks of the "Little Flyover" are built 30 meters underground, and the exit section protrudes 40 meters above the ground at a small angle. The most special thing is that this track is closed and a cooling system is arranged. During operation, it will be pumped into a vacuum, in fact, the air is extremely thin and not an absolute vacuum, which is to prevent the load from rubbing against the air to produce high temperature damage to the electromagnetic track.

However, after the completion of the "small flyover", the progress of the 3309 Institute lagged far behind that of the 3301 Institute. When the 3301 Institute had only planned manned spaceflight, the work in the aerospace field of the 3309 Institute was almost still in place. It's something that can't be helped. Because there are several troublesome problems in this.

The first problem is that the official version of the bridge is too big, even if it does not consider manning and only launches cargo, this orbit will be more than 100 kilometers long. Otherwise, unless it is a solid metal block, it will definitely be directly crushed by the huge acceleration G-force, such as sending a satellite to the sky, you must accelerate slowly, and control the acceleration within 30G, which requires a 130-kilometer-long orbit. If it were manned, the length would have to be increased tenfold.

The final version of Moon Dehei's "Sky Bridge" must be able to be used to carry people, and he also intends to make it accessible to ordinary people without professional training. Therefore, it is necessary to extend the acceleration orbit and reduce the gravitational acceleration during the acceleration launch, so that it can reach a level that ordinary people can bear. Of course, the lower the acceleration, the longer the track and the higher the construction cost. According to the plan, the uniform acceleration of the passenger spacecraft was set at 2. 75 times the acceleration due to gravity (2. 75G), the required orbital length is about 1486 km. Together with the station and maintenance area at the front, as well as the protection section at the exit, the total length is 1,500 kilometers.

It's a big project. Of course, this is only the final form of the "bridge to the sky", it does not need to be done in one step, a section can be used to build a section, just like a railway. When the length is not enough, it is used to transport goods, and when it is enough, it is good to transport people.

The second question is where to build this "bridge to the sky"? This thing is not a little big, it can be placed there, and it cannot be built anywhere. In the history of the original space-time, this manned version of the mass projector was jointly built by several countries. There is no way, the territory of a country is not enough, even if it is a big country, the land span is enough, but not everywhere is suitable.

In addition to these two big problems, there are several small problems such as energy, superconducting materials, supercapacitors, etc., these things are big problems for people at that time, but for Wen Desi, it can only be regarded as a small problem, the formula and production process of these things are ready-made materials, as long as the production process is upgraded, it can be realized immediately.

Therefore, it was not until the Russian Revolution and the recovery of the Anxi region that Wendeji started the official version of the "Tongtianqiao Project". The planned bridge starts in central Kazakhstan with a total length of 1,500 kilometers and exits at an altitude of 3,120 meters above sea level on a mountain peak in the Altai Mountains on the border between Xinjiang and Mongolia. In addition, for the sake of safety and confidentiality, as well as not affecting the planning of the ground, the main body of the bridge is 100 to 140 meters underground, and its culvert diameter is 15 meters, which is equivalent to the construction of an extra-long subway.

The project began in April 1919 with a multi-stage construction method and a total of 38 construction nodes in between. By 1931, most of the tunneling work was complete. Beginning in 1930, the laying of the electromagnetic track system for 200 kilometers from the Altai export section began, and by April this year, this section of the electromagnetic track system was completely completed and ready for use.

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September 19, 2774 (1933), Xinjiang, Tianlu No. 1 Base.

The Tianlu No. 1 base is north of the Junggar Basin, at a depth of 85 meters underground. Its export has a railway to Dihua (Urumqi), passing through Karamay, Shihezi and other places, and this railway is also the main way for materials and personnel to come and go. It was also the first "station" of the "Tsutenbashi" to be opened.

At this time, Wen Desi and several senior military and political officials of the central government rushed here to inspect and watch an actual launch.

Now they were looking around at something like an oversized cannonball, 5 meters in diameter and about 25 meters long, like a battleship's hood armor-piercing projectile. This is the spacecraft launched with the "Tongtianqiao", this vehicle was named the "Sky Crane" by Mr. Wen, and now this is an experimental version of the Sky Crane.

The overhead train is different from the maglev train, the maglev train only relies on the bottom track to provide thrust, and the track of the overhead train is a circular pipe, which is equipped with six groups of four-track thrusters, that is, its thrust is six times that of the maglev train of the same level.

At this time, it is levitating in the middle of the annular track by a powerful electromagnet, and behind it is a radial object similar to a wheel, but only the axle and spokes, and no outer ring outline. This is the main power provider of its propulsion wheel, and the electromagnet at the end of the twenty-four pillars protruding from the propulsion wheel on all sides extends into the electromagnet track arranged on the circumference of the pipe, and its action produces thrust.

Wei Ken, the person in charge of the base, introduced next to him: "Mr. Wen, at present, due to the limitation of the length of the track, we can only launch trucks, and the passenger cars will have to wait for a few years. This is the [Feitian-1] return truck that we are preparing to launch this time. The size of the cargo compartment of the truck is 3 in diameter. 5 meters long and 18 meters, the empty weight is 15 tons, and the maximum load is 40 tons. ”

“...... In other words, you can hit 55 tons of stuff?" asked Xin Jie, the chief of the General Staff, next to him.

Wei Ken replied: "Yes, but this time it is an experimental nature, we did not put too many payloads in it, only four Beidou navigation satellites, and two remote-controlled robots, with a total weight of 35 tons." ”

"So what is its maximum load?" and what is the maximum size of the crane?"

"Mr. Wen, if the road to heaven is fully completed, the full load can be standard 2. 75G projects a 720-ton overhead crane. At present, we can project a 260-ton overhead crane at a high speed of 20G. The maximum length of the crane size is 66 meters, the shortest is 6 meters, the maximum diameter is 12 meters, and the minimum diameter is 2 meters. The experimental unmanned spacecraft we launched last time was the smallest in size, weighing 1,500 kilograms......"

"Well, what are you going to do with this launch?" Wen Deji pointed to the large cannonball in front of him.

"This mission is to lay satellites and recycle end-of-life satellites...... Wei Ken opened the touchscreen next to him, and after a few clicks, a three-dimensional animation of an aircraft resembling an airplane appeared. "This is the unfolding form of the [Feitian-1] sky crane, which is actually a space shuttle-like aircraft. The crane itself carries a certain amount of fuel, and after reaching the geostationary orbit, it will continue to use its own power to place the Beidou navigation satellite in a predetermined position. Then, according to the plan, it will use the robot it carries to recover the three scrapped communications satellites in synchronous orbit and bring them back to the ground. ”

"By the way, Mr. Wei, how many other cranes do you have?" asked Zhang Lizheng.

"There are two types of trucks: one-way and return-way. The one-way truck does not consider returning, has a simple structure, can carry more things, and after the goods are delivered, they will automatically fall into the atmosphere and burn up. The return type can be subdivided into a variety of styles such as free parachute return and gliding return, depending on the type of need, plus return heat shield, reinforced structure, additional parachute bag, controller, and even wings and small engines, etc., so the load capacity of the return truck will be lower, depending on the type. As for the buses in the future, they will all be return-......"

"Got it, please continue ......"

“...... Ladies and gentlemen, each kilometre in the middle of the bridge is divided into sections, separated by airlocks and vacuum maintained by extractors. If fully completed, there will be 1,488 sections and 1,489 airlocks. When the crane is launched in the bridge, it will accelerate all the way, and the airlock within a certain distance in front of it will open, and the passing airlock will close. Generally speaking, only the section of the head and tail part needs to let the overhead crane enter and exit, and it needs to be opened and closed frequently for pumping, and the middle section is to maintain a vacuum for a long time after the completion of pumping. ”

Wei Ken continued: "...... Mr. Wen, many of the performances in our Tongtianlu system are dynamic. For example, when a truck is loaded with lighter goods, it can enter the track at a higher speed, so that it can go up to a relatively high track. In addition, if there is a heavier cargo, or if there are special passengers on the bus that require low acceleration, then we can also enter the orbit at a low speed, but at this time, a rocket must be connected to the rear of the truck and the bus as a booster. For safety reasons, we will be using a honeycomb solid-state rocket as a booster. In addition, the rear of the truck and passenger car body is also equipped with a solid-state rocket engine as auxiliary thrust, which is used to accelerate when the speed is insufficient, and to move and change the track on the track. ”

"How's the energy problem?" asked Wen Deji continued.

"The energy system of the bridge consists of a very large high-energy battery array and two nuclear power plants for charging. The nuclear power plant that comes with the system is the latest fourth-generation gas-cooled fast reactor nuclear power unit, with four 1 million kilowatt units, which can carry out 720 tons of full-load cargo projection every 4 hours of charging, of course, we can't use so much electricity now. Only one nuclear power plant has been built. ”

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9:55 a.m. Tianlu No. 1 Base Control Center.

This is a fairly advanced control center, the style is very sci-fi, and the entire hall is dominated by silver and blue gray. There were hundreds of computers and many instruments in the hall, as well as many large screens, one of which showed a map, the other an exit. There are also rows of more than 1,000 small screens, showing the status of each airlock area in the track. There are also multiple cameras in the room, recording the situation in the control center and also recording this history.

"Mr. Wen, everything is ready...... Wei Ken reported.

"Okay, let's get started!" Buntokuji nodded.

Numerous staff members began to get busy.

"The track test is normal. ”

"Airlock testing is normal. ”

"Flying One...... The propulsion system is engaged. The inspection is normal, and the Feitian-1 is in place. ”

"The countdown begins...... Ten, nine, eight, seven, six, five, four, three, two, one. Flying One, go!"

The Flying One slid out silently. This projection is a remote-controlled unmanned truck, so a high acceleration of 20G can be used. Feitian-1 moved rapidly, increasing at a constant rate of nearly 200 meters per second, and the speed became faster and faster.

The camera on the main screen quickly switches as the Flying One advances, always following the train closely. The lights on the wall are constantly flashing, indicating that the airlock in the airlock area through which the crane passes is open and closed. Finally, the screen switches to the exit. The cameras are protected by triple bulletproof glass, allowing them to be used in the face of sonic booms.

"Bang ......" is located at the exit on the Altai Mountains. Suddenly, there was a loud bang, and Feitian-1 rushed out at a speed of nine kilometers per second, carrying a large sonic boom cloud.

The crane shrank into a small dot of light with a flash on the camera, and an object with a speed of nine kilometers per second was almost impossible for the naked eye to follow. On the top of a hill west of the exit of the bridge there is a radar station dedicated to this purpose, which contains a powerful tracking radar, and as soon as Feitian-1 flies out, it immediately begins to finalize.

Everyone immediately turned their attention to the other two screens. The first is a radar image from the radar station, and the second is a tracking of a telephoto camera controlled by the tracking radar.

Wen Desi and the others watched quietly with bated breath.

"Feitian-1 is out of view of radar station No. 1. Height 80 km. ”

"Radar Station No. 2 took over the tracking. ”

"Feitian-1 is ascending normally, out of the field of view of the No. 2 radar station. Height 120 km. ”

"Radar Station No. 3 took over the tracking. ”

"Feitian-1 is about to get out of the field of view of radar station No. 3 at an altitude of 230 kilometers. ”

"The Yuanwang-1 satellite took over the tracking. ”

"Feitian-1 is about to reach its intended orbit. At an altitude of 340 km, the main engine was started, orbit correction was carried out. ”

Under the ground remote control, Feitian-1 constantly adjusts its posture and corrects its orbit.

"Arrive at the predetermined position and start laying the satellite ......"

The cargo compartment of Feitian-1 opened, and a manipulator grabbed a Beidou satellite and stretched it out, and then released it. Subsequently, Feitian-1 sent an activation signal to the satellite, and the satellite was started according to the program, the solar panels were deployed, and the machine was turned on.

"The signal of Beidou-1 has received ......" a staff member shouted in surprise, and then immediately sent the signal to the big screen, only to see a line of words displayed on it: "Hello everyone, I am Beidou-1!" There is also a smiley face icon behind it.

"Papapa......" The hall burst into warm applause.

More than an hour later, the four Beidou navigation satellites were laid and all of them were normal. Subsequently, Feitian-1 began to recycle end-of-life satellites. Two desk-sized robots popped up in the cargo hold. They say they are robots, but they don't look like people at all, but more like spiders, and with a wire attached to the crane at their tails, they look more like spiders.

Relying on their own jet power, the two metal spiders quickly approached a scrapped communication satellite, adjusted their posture and firmly sucked the satellite's shell with the suction cups in their hands. The cargo hold then slowly retracts the wires, while the two metal spiders act as pose controllers, adjusting their posture with their own engines. Ten minutes later, the satellite was successfully recovered from the cargo hold.

Next, after the three scrapped communications satellites were recovered, Feitian-1 began to return. At 2:12 p.m. that day, Feitian-1 landed smoothly on the airport of Tianlu No. 1 base.

That night, Mr. Wen said at the banquet of Zhu Jie: "Everyone, with the road to heaven, we can be regarded as the real start from the sea of stars!" In addition, the rear of the truck and passenger car body is also equipped with a solid-state rocket engine as auxiliary thrust, which is used to accelerate when the speed is insufficient, and to move and change the track on the track. ”

"How's the energy problem?" asked Wen Deji continued.

"The energy system of the bridge consists of a very large high-energy battery array and two nuclear power plants for charging. The nuclear power plant that comes with the system is the latest fourth-generation gas-cooled fast reactor nuclear power unit, with four 1 million kilowatt units, which can carry out 720 tons of full-load cargo projection every 4 hours of charging, of course, we can't use so much electricity now. Only one nuclear power plant has been built. ”

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9:55 a.m. Tianlu No. 1 Base Control Center.

This is a fairly advanced control center, the style is very sci-fi, and the entire hall is dominated by silver and blue gray. There were hundreds of computers and many instruments in the hall, as well as many large screens, one of which showed a map, the other an exit. There are also rows of more than 1,000 small screens, showing the status of each airlock area in the track. There are also multiple cameras in the room, recording the situation in the control center and also recording this history.

"Mr. Wen, everything is ready...... Wei Ken reported.

"Okay, let's get started!" Buntokuji nodded.

Numerous staff members began to get busy.

"The track test is normal. ”

"Airlock testing is normal. ”

"Flying One...... The propulsion system is engaged. The inspection is normal, and the Feitian-1 is in place. ”

"The countdown begins...... Ten, nine, eight, seven, six, five, four, three, two, one. Flying One, go!"

The Flying One slid out silently. This projection is a remote-controlled unmanned truck, so a high acceleration of 20G can be used. Feitian-1 moved rapidly, increasing at a constant rate of nearly 200 meters per second, and the speed became faster and faster.

The camera on the main screen quickly switches as the Flying One advances, always following the train closely. The lights on the wall are constantly flashing, indicating that the airlock in the airlock area through which the crane passes is open and closed. Finally, the screen switches to the exit. The cameras are protected by triple bulletproof glass, allowing them to be used in the face of sonic booms.

"Bang ......" is located at the exit on the Altai Mountains. Suddenly, there was a loud bang, and Feitian-1 rushed out at a speed of nine kilometers per second, carrying a large sonic boom cloud.

The crane shrank into a small dot of light with a flash on the camera, and an object with a speed of nine kilometers per second was almost impossible for the naked eye to follow. On the top of a hill west of the exit of the bridge there is a radar station dedicated to this purpose, which contains a powerful tracking radar, and as soon as Feitian-1 flies out, it immediately begins to finalize.

Everyone immediately turned their attention to the other two screens. The first is a radar image from the radar station, and the second is a tracking of a telephoto camera controlled by the tracking radar.

Wen Desi and the others watched quietly with bated breath.

"Feitian-1 is out of view of radar station No. 1. Height 80 km. ”

"Radar Station No. 2 took over the tracking. ”

"Feitian-1 is ascending normally, out of the field of view of the No. 2 radar station. Height 120 km. ”

"Radar Station No. 3 took over the tracking. ”

"Feitian-1 is about to get out of the field of view of radar station No. 3 at an altitude of 230 kilometers. ”

"The Yuanwang-1 satellite took over the tracking. ”

"Feitian-1 is about to reach its intended orbit. At an altitude of 340 km, the main engine was started, orbit correction was carried out. ”

Under the ground remote control, Feitian-1 constantly adjusts its posture and corrects its orbit.

"Arrive at the predetermined position and start laying the satellite ......"

The cargo compartment of Feitian-1 opened, and a manipulator grabbed a Beidou satellite and stretched it out, and then released it. Subsequently, Feitian-1 sent an activation signal to the satellite, and the satellite was started according to the program, the solar panels were deployed, and the machine was turned on.

"The signal of Beidou-1 has received ......" a staff member shouted in surprise, and then immediately sent the signal to the big screen, only to see a line of words displayed on it: "Hello everyone, I am Beidou-1!" There is also a smiley face icon behind it.

"Papapa......" The hall burst into warm applause.

More than an hour later, the four Beidou navigation satellites were laid and all of them were normal. Subsequently, Feitian-1 began to recycle end-of-life satellites. Two desk-sized robots popped up in the cargo hold. They say they are robots, but they don't look like people at all, but more like spiders, and with a wire attached to the crane at their tails, they look more like spiders.

Relying on their own jet power, the two metal spiders quickly approached a scrapped communication satellite, adjusted their posture and firmly sucked the satellite's shell with the suction cups in their hands. The cargo hold then slowly retracts the wires, while the two metal spiders act as pose controllers, adjusting their posture with their own engines. Ten minutes later, the satellite was successfully recovered from the cargo hold.

Next, after the three scrapped communications satellites were recovered, Feitian-1 began to return. At 2:12 p.m. that day, Feitian-1 landed smoothly on the airport of Tianlu No. 1 base.

That night, Mr. Wen said at the banquet: "Everyone, with the road to heaven, we can be regarded as the real start from the sea of stars!"