Dreaming about space

Chapter 44
Manned spaceflight is an idea that has been engraved in the bones of Chinese astronauts since Liang Tian was born.

If you think about it seriously, this is actually an idea that the Chinese have had since ancient times.

Pangu opened the sky, and Chan'e flew to the moon.

Su Dongpo's sentence "When will the bright moon come?" is not only a beautiful poem, but it is actually an astronomical question - when was the moon born?

Before Su Dongpo, there was a famous astronomer named Wang Ximing in the Tang Dynasty.

He is committed to popularizing space knowledge through popular songs.

The name of this ballad is "Bu Tian Ge", and it has gone through dozens of versions since its birth.

To say it was popular was, of course, for people of that era who were used to ancient prose.

If we continue to push forward, there is also the mural of the Flying Lady in the Mogao Grottoes in Dunhuang.

Many people in modern times believe that astronomy is an "imported subject" that was first studied by Westerners.

In fact, our country has a truly long history in the study of stars.

Still in the 20s.

In a place called Puyang, an ancient tomb was unearthed.

This ancient tomb has a history of more than 7000 years.

Inside the ancient tomb, there are patterns of green dragon and white tiger made of clam shells.

The use of four images to represent astrology has been a tradition of Chinese civilization since ancient times.

This ancient tomb dates back to 5000 years before the birth of Chinese culture.

The clam shells [blue dragon on the left, white tiger on the right] unearthed from this ancient tomb were buried with them, which directly pushed the starting date of the tradition of four-symbol representation of astrology to 2000 prehistoric years.

Fang Yuan was not that interested in history that was too long ago.

In other words, he doesn't think he should be interested in these.

His [ignorance] in this regard is all caused by his lack of brains.

When the brain set is in place, the content that comes with these basic set encyclopedias will not be a problem at all.

In contrast, Fang Yuan preferred to hear what happened to Liang Tian and whether it was written down in his memoirs.

"Old man Liang, you said before that after [Mabuhai 97] in 1, our country has experienced three years of sound development. What happens after that? You and Brother Dong will study manned spaceflight together. went?"

"No, Brother Dong missed the opportunity with [Project 921]. When the manned space project began to advance, wasn't China's international commercial space going through its darkest moment?"

"That's a pity."

Fang Yuan couldn't bear to hear anything like missing out on his dream, so it was easy for him to empathize with it.

"I do feel sorry for Brother Dong, but Brother Dong is very open-minded. He always says that he has caught up with good times."

"Is this a good time?"

"Well, three years of continuous success has made our country want to have its own global satellite navigation system."

"Beidou Navigation, right?"

"You're talking about the year 2000, right? I remember that the Beidou project was established in 1994, right?"

"The project initiated in 1994 was Beidou-26, which is regarded as the navigation system used by our country. At the beginning, we did not intend to build a global satellite navigation system. Beidou Navigation took [-] years to complete the global network."

"I have seen this in history books. Beidou in our country was developed in three steps."

"Xiao Fangyuan has read quite a few history books!"

"Then these are all compulsory exams. You must remember them." Fang Yuan recited the original words from the history book: "Beidou Navigation is the second national aerospace strategy of our country after [Two Bombs and One Satellite]. The [Beidou Spirit of the New Era] has emerged, and its influence has penetrated into all aspects of life.”

"Every aspect of life..." Liang Tian thought for a while and commented: "This sentence sums it up very well. You people born in 2050 will not have a clear perception of the changes that Beidou Navigation has brought to your life. of."

“How come you see?”

"Since you were born, many things have been directly around you. To you, they may exist as normally as air, but we are watching Beidou step by step, changing every aspect of our lives."

"What about?" Fang Yuan asked Liang Tian to give an example.

"Let's put it this way, when we were young, it was difficult to know the accurate time. My parents often had to find a place to read the time on their watches. They would often stop because the watch or the clock at home stopped. Knowing the specific time, with Beidou navigation, we can have high-precision timing services all day and night."

"Uh……"

Fang Yuan really couldn't imagine that answering a question like "What time is it now" would still be technically difficult.

"Old man Liang, I would rather not know what night it is, just cover my head and sleep in the dark. If there is no time at this time, it is not important." Fang Yuan habitually argued.

"Xiao Fangyuan, to calibrate the time, I specifically mentioned it in a small way to give you an example."

"What about when it's older?"

"Taking it to the big picture, the precise time of stock trading, the precise time of high-speed trains, the specific height of Mount Everest, and the melting speed of Tianshan Glacier No. [-] all have to be measured by Beidou navigation."

"Oh. Okay. I have no capital in stocks, and I have no interest in Everest and glaciers. As for the high-speed trains, all the trains are now driverless. It doesn't matter whether you arrive early or late. It doesn't matter if it's a second and a half. What a difference."

Habitual arrogance ×2.

"Unmanned driving itself is also realized through Beidou."

"Is that so? I am just a simple human brain. It is normal to have incomplete knowledge."

It's useless to argue, there are always excuses.

"In the final analysis, it is too common for you. For us, similar situations have experienced many historic moments. When I started shopping online, Beidou Navigation could tell me where the express delivery was. In Liang Hangyu When I take an online ride-hailing service to deliver my pet to my home, Beidou Navigation can let me know when to pick it up."

"Old Man Liang, do you call your son's ride-hailing for pets a historic moment?"

"No matter how ordinary it is in the future, as long as it has not happened before, it can be called a historic moment."

"Okay. I'll try my best to pretend that I'm convinced by you." Fang Yuan said in a rather earnest tone: "I hope you and your family will try not to take a taxi alone for your pet. It's easy to be alone in the car. I thought I was abandoned.”

"Little doll, your focus is a bit strange."

"What's weird? The law stipulates that owners should be fully responsible for the behavior and safety of their pets. It is their responsibility not to let their pets hurt others, and it is also their responsibility not to let their pets take transportation independently."

"When Liang Hangyu took a ride-hailing service to send his dog to me, the car was still driven by a driver. It was not considered an independent ride."

"Then it's still easy to have accidents, right?" After asking, Fang Yuan even laughed: "Did I go too far?"

"It's okay." Liang Tian didn't mind, and returned to the previous topic naturally: "You know, Xiao Fangyuan, our country was not able to legally have its own navigation system. At one time, there were less than 4 hours left. time."

"Four hours?" Fang Yuan expressed doubts: "If I remember correctly, Beidou Navigation took 30 to 44 years to build, using the [Chang Sanjia] rocket, 100 launches, an astonishing [-]% accuracy. hair."

"Xiao Fangyuan still knows a lot about Beidou navigation." "I don't have a brain, but it's not that I don't have a brain. The Xichang Satellite Launch Center where you first drove the specially equipped truck is also known as the Beidou home port. "

"Thank you, little doll, for caring so much about my growth experience."

Fang Yuan wanted to make a face.

This fits his state of mind at this time.

But it didn't fit the character he wanted to create.

The mature vice-captain pointed out the important point directly: "From the time the project was established in 1994, it obviously took 26 years to successfully establish a global network. How come you are here, and the legitimacy is calculated in hours?"

"The Beidou four hours I said is not what you understand." Liang Tian explained aloud, "It is the time to obtain the construction permit before the Beidou global positioning and navigation system is established."

"If we build our own navigation system, do we still need a permit?" Fang Yuan had never been exposed to this period of history.

"Of course, the orbital resources of navigation satellites are limited. In 2000, when our country wanted to have its own satellite navigation system, 80% of the good positions were already occupied by the two countries that first started the space race. .”

"According to what you said, since there is already a global positioning and navigation system, why not just use it? Why do you have to have your own?"

"Before the Beidou navigation system was established, our country used GPS. Think about it, if what you need to navigate is not a ride-hailing service, but a missile, using someone else's navigation is equivalent to being able to navigate at any time. Is it possible to be totally blind?”

"Old Liang's height is just different!" Fang Yuan would not have thought of this.

"The same is true for civilian use. Without Beidou navigation, there would be no [far ahead] in the 2020s when you can make satellite calls at will." Liang Tian concluded: "No matter from which perspective, navigation must be independently owned. system."

[Far Ahead] This meme will probably only resonate with people who have used the first batch of mobile phones that can make satellite calls.

Forty and fifty years have passed, and Fang Yuan does not know the hidden meaning in Liang Tian's words.
Fang Yuan was more concerned about what Liang Tian mentioned before.

"Old man Liang, what exactly do you mean by Beidou four hours?"

"As mentioned before, when our country started to build a global satellite navigation system, there were not many good locations in the geosynchronous orbit left. The ITU's principle for applications for navigation satellite orbit resources is first-served, first-served, and invalid after the deadline. .”

"First-served, first-served?" Fang Yuan added his own understanding and asked aloud: "It's not in the order of application, right?"

"Yes. In 2000, ITU identified three available locations. At that time, we also applied together with the European Union."

There are so many countries in the world, and not just one or two want to have their own navigation.

Many countries have applied successively.

The ITU requires China Aerospace to accurately launch navigation satellites to specified locations and return signals within seven years.

This process is similar to the fact that after Dongfanghong-[-] is launched, an electronic signal must be transmitted back to be considered successful.

However, what we want this time is not trembling electronic music, but clear navigation signals.

If it can be done, these three good positions identified by the ITU belong to China.

If you can't do it, it belongs to someone else.

Moreover, it is very likely that our country will never be able to have an independent satellite navigation system because of this.

Beidou Navigation in the eyes of the public and Beidou Navigation in the eyes of astronauts have never been the same thing.

From 2000 to 2007.

Seven years sounds a bit long.

I was still in the sixth grade of elementary school in 2000, but I had completed the college entrance examination in 2007.

But for Chinese astronauts, they must race against time.

"There are not only technical problems that we need to overcome, but also embargoes and technical blockades that may come at any time."

"Your generation has been stuck in various ways, haven't you?"

"Yes, the first one to bear the brunt is the rubidium atomic clock."

"What are rubidium atomic clocks used for?"

"The rubidium atomic clock is a spaceborne accessory with the core of navigation satellites. A rubidium atomic clock that meets the requirements of navigation satellites must have an error of one million years, within one second."

"Uh... In one million years, I don't know how many have been found on the other side. If humans still exist, they should have stopped living on the earth long ago. What's the point of counting those one-second in a million years?"

Fang Yuan was very disapproving: "Old man Liang, you can't impose your father's desire for precise timing on satellites."

"Little baby, you were admitted to college at the age of 14. Did you really use some back door?" Liang Tian raised some doubts about Fang Yuan's reserve.

"Don't you know better than me if there is a back door for me to leave?" Fang Yuan stared, a little angry.

"Hey, look at my old eyesight. Xiao Fang originally studied materials, not space technology. I almost forgot."

Liang Tian gave lectures to young people on Earth and had never encountered such a problem before.

In the brainy generation, everyone automatically masters common sense, but it is difficult to specialize in technical fields.

Fang Yuan was just the opposite.

He can study his field to the extreme.

I don’t know anything about the common sense that many peers automatically trigger.

Fang Yuan squinted at Liang Tian without saying a word, only expressing his attitude with his eyes.

Liang Tian patiently gave Fang Yuan some popular science.

The basic principle that satellites can achieve positioning is based on time calculation.

The distance between the satellite and the user terminal can be calculated from the time it takes for the satellite to send a signal to the user terminal to receive the signal.

Taking this distance as the radius, a virtual sphere can be formed.

When the user terminal connects 4 satellites at different locations at the same time to form 4 virtual spheres, there will be a meeting point.

This intersection is where the exact location lies.

Position is space, but this position measures distance through time.

The accuracy of the rubidium atomic clock determines the accuracy of navigation.

After saying this, Liang Tian looked at Fang Yuan and asked aloud: "Xiao Fang Yuan, do you still understand what the old man said?"

　As mentioned yesterday, the first one to answer correctly will receive a mysterious gift.

　　I just took a look and decided to expand the scope of rewards to the top three.

　　The first three accounts with correct answers are [Northern Latitude Meow], [Q Moyu], and [Zhezhiluomeng].

　　Friends, please confirm again~
　　If there is no problem, Piaopiao will start preparing the mysterious gift soon~
　　
　
(End of this chapter)