In the modern era of extremely rich material life, everyone has their own pursuit.

Many people are addicted to the virtual world, because it is easy to do things that are difficult or even impossible to do in reality: war, magic, warships, other worlds...

But there are also people who love the most realistic game - reality.

For example, extreme sportsmen who take pleasure in challenging their limits.

They say: what is the limit of challenging in the game.

With the improvement of physical fitness and the changes in the physiological structure of new humans, the regular extreme sports on the blue star can no longer meet their hedonistic needs, and they set their sights on the vast universe.

Downhill, surfing, tornado gliding..., for the new humans, the dangers contained in these extreme sports on the ground are not worth mentioning compared to the dangers contained in extreme sports in the universe.

Conquering and overcoming this danger has become a source of happiness for some people, and fighting with the heavens is endless.

One of the more popular extreme sports in the universe is the desperate sport called crash landing on a comet.

The so-called forced landing of a comet refers to an artificially piloted spacecraft that departs from the tail of the comet and lands on the comet's nucleus.

A comet consists of two parts, the head and tail of the comet.

The coma head includes the comet and the comet nucleus, among them, the comet nucleus is the core of the comet, generally composed of stones, iron, dust, ammonia, methane, ice and other substances, it is very small in diameter, the largest is a few kilometers to more than ten kilometers, the smallest is only a few hundred meters.

The tail of the comet begins to appear when the comet is only 300 million kilometers away from the sun, and gradually changes from small to large, from short to long.

The tail of the comet is composed of carbon dioxide, hydrogen, dust, etc., with a length of more than 300 million kilometers, and landing on the core of the comet from the tail requires the speed of the spacecraft to exceed the speed of the comet, the resistance of the dust needs to be overcome, and the influence of the complex environment needs to be corrected at all times.

If you are not careful, the ship will be wrecked and people will die, and the mortality rate will be extremely high.

It usually takes years for extreme sportsmen to build a small, nuclear-powered spacecraft, usually around 20 tons.

With the monthly credits, they order a variety of materials and instruments, rent the best industrial equipment, and build their own cars little by little.

Each of these people is the top elite of human civilization, because they don't have a few doctorates, and the credit they issue every month is not enough to buy nuclear fusion fuel.

Back in the year 202 of the crisis era, a year before the Trisolarans descended, Renault, an explorer and wilderness survivor, set out from Jupiter to challenge.

Renault lived alone in an abandoned city for three years before returning to the human settlement in a hand-built helicopter and is one of the best survival masters.

The comet he was going to challenge was named Temple Tuttle, with a diameter of nearly two thousand meters and a tail of tens of millions of kilometers.

The orbital period is about 33 years, and the closest time to the Sun is only one astronomical unit, about the same distance from the blue star to the Sun, which is responsible for the Leonid meteor shower.

According to the black box found, Renault piloted the spacecraft, speeding through the comet's tail at a speed far exceeding the comet's, ignoring the gas and dust, but the spacecraft had a problem when it landed.

The specific reason is unclear, and experts speculate that it should be a problem with a sensor, which caused Renault to not make a correct judgment in time, resulting in the ship's destruction and death.

This is normal, it is strange that something as delicate as a spaceship can operate in a complex environment like a comet's tail, and there is no problem.

In this way, there is another pile of scrap iron on the comet, and there is a large amount of superconducting materials and scarce nuclear fuel in the scrap iron.

The protection of nuclear fuel is always tight, and even a stall, a fall, a collision, and a container that contains it cannot be damaged.

The nuclear fuel contained in these containers is reserved for repatriation.

In the solar system, there are about hundreds of millions to billions of short-period comets, with a regression period of less than two hundred years, most of them within ten years, and the diameter of the comet nucleus is between a few hundred meters and several kilometers.

On the eve of the Battle of Doomsday, hundreds of people go every year to challenge the forced landing of the comet, and it is unknown how many of them are left-behind factions.

After the Battle of Doomsday, human civilization no longer has enough resources to support individual super extreme sports, and the glorious cosmic extreme sports for half a century have declined in an instant and cannot be recovered in the short term.

The area around the comet became a no-man's land.

……

In the 9th year of the crisis era, the bill for the dirty bombing of extraterrestrial planets was passed, and anyway, after the completion of the nuclear weapons industry, it was almost fully automatic, and everyone worked hard for 3 or 4 years.

However, the bill to promote comet impact on planets and stars did not pass, and the support rate was only about 50 percent, because the construction of a large number of comet engines required the industrial strength of mankind in its heyday, which was not realistic at all, and would threaten the survival and development of civilized individuals.

The left-behind faction was very pleased with this result.

The industry of making nuclear bombs could not be placed on Blue Star, so it moved to Jupiter's asteroid belt.

Since it is going to be blown up, it is necessary to blow it up thoroughly, the stellar-level nuclear bomb is buried deep underground, and a large number of dirty bombs are detonated on the ground, vowing to leave a tattered tatter for the Trisolarans.

Everyone is doing this in earnest, whether or not they know about the Snow Mark Project? The real strategic purpose of the plan.

The Trisolarans don't care, they can't blow up the sun, their attention is all on the Star Alliance Fleet at the moment.

Digging wells requires industry and personnel, so after the nuclear fuel extraction industry and the civilian spacecraft maintenance industry were restored, the coalition government began to emigrate.

Immigration is dangerous, and it's all voluntary, but there are still many people who are willing to go: please, the stars are super handsome.

It was also in this year that Ding Yi returned to the moon and began the collision experiment of particles around the moon.

Humans have succeeded in unfolding protons in a low dimension, and it is a two-dimensional expansion, but the expansion alone is useless, and humans do not have the ability to re-ascend protons to a higher dimension, nor do they have enough time to etch circuits.

At the same time, the curvature engine research and development project was launched, and at the request of Tomoko, it was built on the moon, because the water droplets are located between the earth and the moon, and if there is a problem, it can immediately destroy the human laboratory.

After Venus completed the emigration, everyone tried to repair the relatively intact dock and build new warships, and as soon as they made a move, the water droplets flew slowly to Blue Star, without informing the coalition government of the reason.

The coalition government was taken aback, and instantly understood that someone had violated the ban, and hurriedly notified the extraterrestrial base to stop the illegal acts, and later punished a group of people severely, thinking that there were no casualties, but only imprisoned them for life.

After this temptation, the left-behind faction determined that the Zhizi of the solar system had probably been nailed to water, metal, earth and moon, fire, wood, and Neptune, just seven, and even if there were one or two idle Zhizi, they probably would not wander around the solar system.

……

In August of the 10th year of the era of crisis, the Navigator formation, the Natural Selection, everyone woke up from hibernation.

At this moment, the three warships have completed their deceleration, and they will search for tombstones8 in the vicinity to take away the civilization inheritance on it.

The radar soon spotted the ship.

The radio was sent, but the brains of the tombstone did not reply.

Zhang Beihai put on a spacesuit and asked worriedly: "Dongfang, that unmanned ship has been operating for more than half a century, and its computer has been damaged, right?" I remember you said that the lifespan of an electronic chip is only twenty years. ”

All warships use electronic computers, and photonic computers will be affected by the optical path of Zhizi, which is not safe.

Dongfang shook his head and said: "I don't know, but the database should be fine, its way of recording data is very primitive, in short, it is to engrave the words on the stone, according to the design standards of the database, it is not a problem to retain information for hundreds of millions of years." ”

Dozens of people rode in small flying machines, approaching ancient warships that were significantly smaller than stellar class battleships.

The tombstone hull is cratered, full of rust, traces of micrometeorite impacts, and it has no laser weapons to clear obstacles.

After looking around, but finding no door, the group stopped on the deck and carefully cut the armor of the battleship with the laser weapons that came with the aircraft.

After half an hour of busy work, everyone entered the tombstone, which was extremely dark and there was no electricity supply.

Zhang Beihai called up the design of the tombstone, compared the signs, and confirmed the location, "We are now in the aisle between the industrial area and the material storage area, and under our feet is a nuclear fusion reactor. ”

"Passing through the industrial area, it's the database."

Someone raised the lamp and looked at it for a moment, pulled out a metal jar from the wall, observed it for a moment, and said: "There is also liquid helium three, it seems that there is a problem with the intelligent central control." ”

"Do you want to restart the reactor?"

Dongfang shook his head: "To be safe, don't activate it, in case it blows up, we all have to die." ”