In Chen Yue's memory, only more than 20 years before the explosion of the earth and the demise of human civilization, human beings can be regarded as mastering a relatively mature rocket recovery technology, that is, after the rocket launches a payload such as a satellite or spaceship, it can return to the ground on its own, and it can be used for a second time after overhaul.

This technology greatly reduces the cost of launch and provides more convenience for human beings to set foot in space. Even the manned landing plan of the Luminous spacecraft on Mars was proposed after the technology of the recyclable rocket matured.

The importance of this technology can be imagined. In order to master this technology, human civilization does not know how many hardships it has gone through, how many rockets have been dropped and blown up, how much effort it has taken scientists and engineers, and how much money and time has been spent before it finally mastered it.

But on Europa, for Chen, the technology is simple. It was so simple that with his simple aviation technology at the moment, when the first "rocket" was launched, he directly mastered the recyclable rocket technology.

Or is it because Europa is too small and has almost no atmosphere. The difficulty of mastering this technology here is many times easier than on Earth.

At this moment, the table-shaped "Wooden Five" rocket landed steadily on the launch site. The robots waiting next to it swarmed up, and all kinds of equipment and instruments rushed over one after another, giving it a comprehensive overhaul from the inside out.

The results of the overhaul made Chen Yue quite satisfied. This launch did not cause any damage to it at all. At the moment, it only needs to refill the fuel repeatedly, and it can perform a second flight, not even a major overhaul.

As a result, a train drove out of Chen Yue's newly built satellite factory, carrying one of Chen Yue's latest satellites.

The satellite is boxy, with a volume of less than one cubic meter and a mass of 1.7 tons. Of this weight, about 600 kilograms are liquid hydrogen and liquid oxygen. They slowly begin to burn and propel generators under the control of a controller to generate electricity to power the instruments in question.

Again, this is a very different place from the earth.

Satellites on Earth are either powered by solar panels or nuclear fission batteries. Powered by chemical fuels, there is no such a loser.

Because chemical fuels are too low in energy. The Earth orbits there, and it is not convenient to refuel satellites. As a result, once the fuel runs out, which won't be too long, the satellite will have to be scrapped.

But here at Callisto, the environmental conditions are reversed.

The sunlight here is too weak for solar panels to supply electricity. Nuclear fission battery power supply, Chen Yue has not yet mastered this technology. On the contrary, the technology of chemical fuel power supply is mature, and it is very convenient to refuel chemical fuel here - it is a big deal to let the Mu-5 rocket go to the sky again, and it is not difficult at all.

And so it happened.

Also, this satellite is a satellite, which seems to be very high-tech, but in fact, this thing is a signal amplifier, but it is just running in space, and it has no technical content at all. Even the ice-to-solid oxygen power plant is more technical than this thing.

So the satellite was tied to the Wooden 5 rocket by a wire rope - indeed a wire rope, just like a truck would use a rope to tie wood.

Igniting again, the Wood V rocket rose again, steadily sending it into the Ganymede orbit.

The next moment, Chen Yue immediately noticed that the quality of communication between himself and those factories, bases, and robots that were far away had improved several times. Command is more like an arm.

"Not bad."

Chen Yue made persistent efforts and launched dozens of satellites, so he achieved full signal coverage for Ganymede.

Now, there is no need to worry that the robot will not find its owner.

Solving this shortcoming, Chen Yue once again poured his energy into the ongoing large-scale construction.

Time passed quietly, and in the blink of an eye, decades passed.

If you are an ordinary person, you may feel the vicissitudes of life, and the babbling child may have become a gray-haired old man.

But Chen Yue didn't feel this way at all.

Decades are just a few moments in the air for him. As long as the computer doesn't break, he has an infinite lifespan.

Now, it is the 76th year of the new calendar.

Chen Yue set the moment of his arrival on Ganymede at 0:00 in the first year of the new calendar. And then it still took the same way as on Earth, 24 hours a day, 60 minutes per hour, 60 seconds per minute.

At this moment, it is 0:00 in the 76th year of the new calendar.

The New Year has just passed.

Chen Yue, who was addicted to work and couldn't extricate himself, did not hold a New Year's celebration, and the continuous development of the industrial base just made him take stock of himself at this New Year's moment, and he deserved to celebrate.

After 76 years of endless day and night, the number of robots owned by Chen Yue has skyrocketed to 20 million. The total length of the railway is as high as 190,000 kilometers, forming a complete layout of 11 horizontal and 8 vertical, covering the whole world of Ganymede, connecting all factories above designated size, mines and bases.

At this moment, the total number of various types of factories, power plants, mines, chemical plants, foundries, machinery factories, vehicle factories, robot assembly plants, wafer factories, etc., has reached more than 70,000, and the annual power consumption has exceeded 100 billion kWh.

The whole of Europa has completely changed. Now it is no longer desolate, no longer dead and silent.

Heavy-haul trains roar through the land at any time, and a large number of robots are moving around like ants. Under the light, the land is bright, and countless factories show the power of technology like a jungle of steel.

It is particularly noteworthy that after decades of uninterrupted research and development, as well as a huge amount of resource investment, the semiconductor process that is the most important for Chen Yue has developed to the point where it can produce 130-nanometer chips on a large scale.

Although the 130-nanometer chip process is still about 50 years behind the time of the extinction of mankind, it can already play a great role for Chen Yue. At least, the chips used in the robot are already up to the task.

After all, the robots under Chen Yue's command do not need to perform intelligent calculations by themselves, and only need to receive Chen Yue's commands.

Because of this, Chen Yue was able to increase the number of robots to more than 20 million and the number of factories to more than 70,000.

Otherwise, relying on the little chip scavenged from the Martian base, one robot will not be enough.

Chen Yue felt that his development of Ganymede had reached a point. In the future, it is time for new goals and directions.