The Science Fiction World of Xueba

Pang Xuelin and Watney started working again. They first used the Mars rover as the center and drew a circle around it. This is very simple.

But the next step is a bit cumbersome, because they need to place 16 cards (hexadecimal) with 0 ~ 9 and A ~ F and a blank card (starting point) evenly around the driver's self-driving car. Make each card pass about 21 degrees of space to ensure that there is no ambiguity in camera rotation.

This kind of living is difficult to place by hand. At this time, Pang Xuelin needs to show his professional knowledge.

Placing seventeen cards evenly on the circle around the Sojourner drone is essentially a ruler making a regular heptagon.

问题 This problem has plagued the mathematics community for more than two thousand years, and was finally solved by the famous little prince Gauss.

Gaussian directly gives the sufficient conditions for the ruler to draw the number of sides of the regular polygon: that is, the product of the non-negative integer power of 2 multiplied by any number of fermat primes.

题目 This problem was taught by Pang Xuelin when he was in junior high school.

沃 With the help of Watney, Pang Xuelin spent ten minutes to divide the circle seventeen with the tool at hand, and then placed the card on the circle's halving point.

Everything is ready. After waiting for about half an hour, the camera turns again.

"Wattney, you record, I translate!"

"it is good!"

Soon, Pang Xuelin and Watney converted the strings into corresponding information.

"The problem is known and will be answered within two days. Good luck!"

Wu's very concise reply made Pang Xuelin and Watney smile and high-five.

Uh ...

指控 JPL Mars Pathfinder charges center.

Wenwen Carter pressed himself to a desk in the temporary accused center rebuilt, and Tian Mu was sitting opposite him.

联系 After contacting Pang Xuelin and Watney through the Mars Pathfinder Landing Module, in the past two days, Wen Carter and Tian Mu have almost pressed their homes here, waiting for news from Mars at any time.

In addition to being too sleepy to take a break to the lounge next to them, most of the time they stared at the scene.

Although the communication with Pang Xuelin and Watney is still relatively inefficient under the current conditions, they still basically know the situation of Pang Xuelin and Watney in the past two days.

For example, how did they survive after being hit by a blown-out satellite dish after a sandstorm.

For example, how do they use residual hydrazine from MDV (Mars Landing Vehicle) to make water, then transform the Martian soil and plant potatoes?

The various difficulties experienced during the encounter, even if Pang Xuelin did not say clearly, everyone here could imagine.

The only regret is that they can't move the Mars rover to the planting cabin to take pictures of the potatoes that have emerged (the shelter capsule signals), otherwise this picture alone will win the Pulitzer Prize this year.

Even so, after the news of Pang Xuelin and Watney planting potatoes on Mars spread, it spread to all major media around the world.

This is the first time in history that human beings have actually carried out agricultural activities on an alien planet, and Pang Xuelin and Watney will also be recorded in history because of this move.

咚咚咚 …… 咚咚咚 ……

Uncle, who was lying on his desk, was awakened by the sound of knocking on the desk, and saw Bruce leading a thin, pale man to the desk.

Bruce said: "Carp, sorry to disturb, this is Jack Treff of our software engineering department, he has got the source code of the communication system of the sojourner!"

"Treeve, hard work!"

When Wen Carter heard a word, he quickly got up and shook hands with Treve, then drank the remaining coffee in the cup and rubbed his temples: "Bruce, arrange now as soon as possible and pass the code to Pang!"

Trevef said: "Dr. Karp, I did get the source code for the sojourner, but there are problems in it."

"what is the problem?"

Wen Carter froze slightly.

Trevor said: "Although the source code of the communication system of the Sojourner self-driving car is small, there are also three trillion. We can now send Pang them one byte every four seconds. In order to pass all the documents, this solution is obviously not feasible! "

Wen Carter could not help frowning, pondering for a moment, he turned to Bruce and said, "Go and find me!"

Soon, Tian Mu, who had slept less than an hour in the lounge, yawned and appeared in front of Wen Carter.

Owen Carter repeated the current dilemma to Tian Mu and asked him for opinions.

Putian Mu thought about it and said, "Kapu, I think we should listen to Pang's opinion. He is our best mathematician and communication expert. Maybe he has a solution!"

Evenwen Carter and Bruce looked at each other and nodded.

这个 At this moment, this has to be the case.

Uh ...

Beacon, Plain of Asidalya.

In front of the perch, looking at the message from the JPL allegation center, Watney and Pang Xuelin couldn't help looking at each other.

Wotney frowned slightly, watching Pang Xuelin said, "Pang, what shall we do?"

Pang Xuelin groaned for a moment and said, "I have to think about this issue, tell them, give me some time!"

He said, Pang Xuelin returned directly to the habitat.

Watney nodded, wrote a line on the cardboard with a large pencil, and placed it in front of the sojourner's camera.

Subsequently, he also ended the EVA mission and returned to the habitat. He saw that Pang Xuelin was looking for something in front of the computer in the habitat.

Watney wondered, "Pang, what are you doing?"

Pang Xuelin said: "Look at the source code of the pod communication system."

In reality, this kind of living Pang Xuelin can't do it, but after entering the system plane, the system will instill corresponding knowledge to him, but these memories are like a book, which can be opened only when Pang Xuelin needs it. appear.

Therefore, Pang Xuelin is really a communication expert when he rescues the world on Mars.

The only pity is that these memories will be removed by the system after leaving the plane. For example, in the three-body world, Pang Xuelin is also a communication expert in the Adventist group, but after leaving, his knowledge about communication is lost. The system was completely erased.

Pang Xuelin sat in a chair and meditated.

"The Mars Pathfinder Landing Module has two communication systems. The low-gain one is connected to the Sojourner, and the high-gain one can contact the Earth. The lander module wants to identify the signal of the lander module. There must be a special byte sequence in the signal. If the byte sequence does not match, the landing module will ignore it. This shows that there must be a program in the source code of the sojourner communication system to encode the corresponding If I hack into the second-level communication system of the habitat, before the system checks the legality, write the parsed byte sequence into the log first, and disguise it as a sojourner unmanned vehicle. Can you fool the landing capsule? And this byte sequence will not be too long, at most a dozen or twenty lines, it can be passed through the current communication system, yes, that's it! "

Pang Xuelin's eyes lighted up and she snapped and said, "Wattney, I have a way!"

"So fast?"

Watney took a moment, but it was less than half an hour. The problem that plagued JPL was solved by Pang Xuelin?

Pang Xuelin quickly wrote his solution on cardboard and passed it back to Earth.

"Dear Dr. Carp and Dr. Tian Mu, I need you to provide the serial number of the sojourner unmanned vehicle and the control rights of the pod main system. I believe you must have backed up a set of how to hack the pod host in an emergency. System plan. At that time, as long as I write the communication sequence number into the log of the pod communication system before the system checks the legality, the problem can be solved perfectly! "

指控 JPL Mars Pathfinder charges center.

Wenwen Carter and Tian Mu looked at the message from Pang Xuelin on the big screen. Wen Carter turned his eyes to Jack Treff next to him and asked, "Treve, is this feasible?"

Trevor's eyes sparkled, and he patted his head and said, "Why didn't I think of it! Pang's scheme is great. The sojourner's self-driving car communication sequence code has only about twenty instructions. We just need to put these twenty Send instructions to Pang, and tell Pang how to hack into the habitat control system! "

Wenwen Carter and Tian Mu glanced at each other, and they both saw affirmative glances from each other's eyes.

Sven Carter clapped her hands and said, "Okay, just do it! Guys, work is starting!"

虽然 Although there are only 20 lines of the communication sequence code, it took a long time to send it. In addition, the methods of how the cartons hacked into the habitat communication system were also sent to Pang Xuelin and Watney at the same time.

"Run hexedit in the pod control system, open the file / usr / lib / located in this directory, and drag down until the number on the left side of the screen is 2AAE5. Replace the bytes here with 141 sent by JPL. Byte sequence! "

These messages don't seem to be long, but Pang Xuelin and Watney spent two full EVA time.

到 Until 10:30 in the evening on Mars time, the sky was full of stars, and the two men ended their long work.

翻译 After translating all the hexadecimal information, Pang Xuelin opened the control system of the perch, hacked into the system according to the method given by JPL, and then wrote the serial number into the log of the perch communication system.

With all the work done, Watney performed another EVA mission, moving the Sojourner Mars rover into the habitat and then shutting it down completely.

Next, Pang Xuelin opened the pod communication system.

一行 Lines of information begin to appear on the computer screen.

The system is initializing ...

loading finished……

Detection of radio signals ...

Detection of radio signals ...

Detection of radio signals ...

Signal acquisition ...

Signal is connected!

Uh ...

JPL accusation center.

"Habitat communication system is online!"

"God, we can finally type and talk to them easily!"

"Every time we see them return a lot of information, but we have to input byte by byte, we are depressed and die!"

The accusation center once again gave a warm applause, everyone cheered and hugged each other!

Wenwen Carter and Tian Mu shook hands tightly and patted each other on the shoulders.

"Well, guys, after so many days of dumb work, it's our turn to start work!"

Soon, Wen Carter grabbed a computer and typed, "Pang, Watney, hello, my name is Wen Carter Cap, NASA Ares project director. We have noticed you from the 39th Mars day. Now, you are the focus of the global media. You are doing a good job, whether you find Pathfinder or grow potatoes on Mars. In short, we are proud of you. Ares Project Command is trying to rescue you, we Experts plan to modify the Aris 4 MDV to have a certain near-ground flight capability. In this case, when the Aris 4 land, they will first land on the Asidalya Plain and then take you with you. Fly to the Schiaparelli Crater. We are also integrating resources to carry out a resupply mission so that you can support the arrival of Ares 4. "

Looking at the information appearing on the screen, Watney's eye circles turned slightly red.

Pang Xuelin stood up with a smile and said, "Wotney, come on!"

Wattney was a little surprised that this time he was able to resume communication. Pang Xuelin was extremely successful. He did not expect that Pang Xuelin actually gave himself the opportunity to communicate with JPL for the first time.

"Ok!"

Watney nodded, sat down in the seat, and typed, "Hello Dr. Karp, I'm Watney! I'm glad to hear the news. To be honest, if it's not Pang, I'm afraid I will be on the day of the sandstorm. I really died, and my lower abdomen was pierced with an antenna, and it was Pang who saved me. We are in good condition now, and the potatoes have sprouted, but there are more than two months before the harvest. This accident with Pang and I The teammates have little relationship, and their actions are correct. Pang and I don't blame them. I hope they don't have any psychological burden and tell them that I am proud of them. Besides, are my wives and children okay? My parents how about it?"

Wen Carter: "Your parents are very good. Your wife and children are happy when they learn the news that you are still alive. At the appropriate time, we will let them come over to communicate with you. What about your food reserves, planted potatoes Is it enough? "

Watney: "Thank you, tell them I miss them too. The potatoes are growing very well and can sustain me and the huge 1,000 Mars days we need to survive. We will not be bothered by plant shortages for now. Next I will hand over time to Pang. If you have any questions, you can ask Pang. "

Soon, new news came from JPL.

Putian Mu: "Xue Lin, it's me, Tian Mu ~ www.readwn.com ~ How are you now?"

Pang Xuelin: "Lao Tian, ​​I'm fine, and I'm a good partner with Watney. He is an excellent botanist, and without him we might starve to death."

Tian Mu: "You did a great job this time. We can restore communication. You are doing great work. Next, we will try to restore video and image transmission. Our botanist will help you manage your farmland. Nutritionist Your optimal daily food intake will be established. We will launch the supply spaceship in the second half of this year, about nine months later, and we expect to arrive in the Asidalya plain in two years. Your food reserves Let us have a lot of redundant time. In addition, if it is convenient to take a photo of you and Watney, and remember to take a photo of the planting cabin, the media is driving our Dr. Karp crazy! "

Pang Xuelin and Watney smiled at each other. Pang Xuelin input: "Okay, I'll send you the pictures as soon as possible! That's the way to start. Today we are exhausted. We are going to eat first, then rest! Say hello to everyone! "

好 "Okay, you and Watney have a good rest, good luck!"

Xi Pang Xuelin chose to go offline.

Wotney froze slightly, wondering, "Pang, why don't you greet your family?"

Xi Pang Xuelin smiled and said, "I was born as an orphan. I grew up in an orphanage and grew up. The only dean, the old relative, has died ..."

"Sorry, Pang!"

Watney is a little embarrassed.

Xi Pang Xuelin didn't care: "It's all right, I'm used to it!"

Whether in the three-body world or the Mars rescue world, the system arranged Pang Xuelin's identity as an orphan, and Pang Xuelin was also happy, otherwise if a lot of unknown friends and relatives appeared in this world, Pang Xuelin would have a headache.