The Science Fiction World of Xueba

Pang Xuelin and Watney started working again. They first drew a circle around the Sojourner rover, which was very simple.

But the next step is a bit troublesome, because they need to place 16 cards (hexadecimal) with 0~9 and A~F written on them and a blank card (starting point) evenly around the sojourner unmanned vehicle, Make each card pass through a space of about 21 degrees to ensure that there is no ambiguity in the camera rotation.

It is difficult to arrange this kind of work by hand, so Pang Xuelin needs to show his professional knowledge at this time.

Placing the seventeen cards evenly on the circle around the Sojourner unmanned vehicle is essentially a problem of making a regular heptagon with a ruler and compass.

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

Gauss directly gave the sufficient condition for the number of sides of a regular polygon in ruler-compass construction: that is, the product of the non-negative integer power of 2 multiplied by any number (can be 0) of different Fermat prime numbers.

Pang Xuelin's grandfather taught him to solve this problem when he was in junior high school, so he is familiar with it.

With the help of Watney, Pang Xuelin spent more than ten minutes dividing the circle into seventeen equal parts with the tools at hand, and then placed the cards on the equal points of the circle.

Everything was ready, and after waiting for about half an hour, the camera turned again.

"Watney, you record, I will translate!"

"good!"

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

"The problem has been known, and a reply will be given within two days. Good luck!"

The simple answer made Pang Xuelin and Watney smile at each other and clap their hands in celebration.

...

JPL Mars Pathfinder Command Center.

Venkat set up a desk for himself in this accusation center converted from a temporary warehouse, and Tian Mu sat opposite him.

Since contacting Pang Xuelin and Watney through the Mars Pathfinder landing module, Venkate and Tian Mu have almost locked their homes here in the past two days, waiting for news from Mars at any time.

Except for being too sleepy to take a nap in the lounge next to them, they stared at the scene most of the time.

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

For example, after a sandstorm, how they survived after being knocked unconscious by a blown down satellite dish.

For example, how they use the residual hydrazine of MDV (Mars Landing Vehicle) to make water, and then transform the Martian soil to grow potatoes and so on.

Even if Pang Xuelin didn't express the various difficulties experienced during the period, everyone present can imagine them.

The only regret is that they couldn't move the rover to the planting cabin to take pictures of the sprouted potatoes (the habitat cabin shields the signal), otherwise they could win this year's Pulitzer Prize with this photo alone.

Even so, after the news that Pang Xuelin and Watney planted potatoes on Mars came out, it became popular in major media around the world.

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

Boom boom boom... boom boom boom...

Venkate, who was resting on the desk, was woken up by the sound of knocking on the desk, and saw Bruce leading a slender man with a pale face to the desk.

Bruce said: "Karp, I'm sorry to interrupt, this is Jack Trive from our software engineering department, he has fixed the source code of the communication system of the Sojourner unmanned vehicle!"

"Triff, you've worked hard!"

Venkate was taken aback when he heard the words, he quickly got up and shook hands with Trive, then drank the rest of the coffee in the cup in one gulp, rubbed his temples and said, "Bruce, make arrangements as soon as possible,

Pass the code to Pang! "

Trive said: "Dr. Karp, I did get the source code of the Sojourner unmanned vehicle, but there are problems in it."

"what is the problem?"

Venkate was slightly taken aback.

Trive said: "Although the source code of the communication system of the Sojourner unmanned vehicle is not large, it still has three megabytes. Now we can transmit one byte to Pang and the others on average every four seconds. Even if we don't sleep, it will take at least half a year." In order to pass all the documents, this plan is obviously not feasible!"

Venkate couldn't help but frowned, thought for a moment, then turned to Bruce and said, "Go and get me Tian!"

Soon, Tian Mu, who had only slept for less than an hour in the lounge, appeared in front of Venkat, yawning profusely.

Venkat repeated the current dilemma to Tian Mu and asked him for advice.

Tian Mu thought for a while and said, "Karp, I think we should listen to Pang's opinion. He is our best mathematician and communication expert. Maybe he has a solution!"

Venkate and Bruce looked at each other and nodded.

In the current situation, it had to be like this.

...

Mars, Arcidalia Planum.

In front of the habitat cabin, Watney and Pang Xuelin couldn't help but look at each other when they saw the information from the JPL accusation center.

Watney frowned slightly, looked at Pang Xuelin and said, "Pang, what should we do?"

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

With that said, Pang Xuelin returned directly to the habitat cabin.

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

Afterwards, he also ended the EVA mission, returned to the habitat, and saw Pang Xuelin in front of the computer in the habitat, seemingly looking for something.

Watney asked curiously, "Pang, what are you doing?"

Pang Xuelin said: "Let me take a look at the source code of the habitat module communication system."

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

Therefore, in the world of The Martian, Pang Xuelin is really a communication expert.

The only pity is that these memories will be deleted by the system after leaving the plane. For example, in the Three-Body World, Pang Xuelin is also a communication expert in the Adventist faction, but after leaving, his knowledge about communication is lost. The system is completely deleted.

Pang Xuelin sat on a chair and meditated deeply.

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

Pang Xuelin's eyes lit up, he snapped his fingers and said, "Watney, I have a solution!"

"So fast?"

Watney was slightly taken aback. It took less than half an hour, and the problem that plagued JPL was solved by Pang Xuelin?

Pang Xuelin quickly wrote down his solution on a cardboard and sent it back to Earth.

"Dear Dr. Garp and Dr. Tian Mu, I need you to provide the communication serial number code of the Sojourner unmanned vehicle and the control authority of the Hab Master system. I believe you must have a backup set of how to hack into the Hab Master in an emergency. System plan, when the time comes, I only need to write the communication serial number into the log of the communication system of the habitat module before the system checks the legality, and the problem can be perfectly solved!"

JPL Mars Pathfinder Command Center.

Venkate and Tian Mu looked at the message sent by Pang Xuelin on the big screen, and Venkate turned his gaze to Jack Trive beside him, and asked, "Treve, is this method feasible?"

Trive's eyes sparkled, he patted his head and said, "Why didn't I think of that! Pang's plan is great. The Sojourner unmanned vehicle communication sequence code only has about 20 instructions. We just need to put the 20 Send a command to Pang, and then tell Pang how to hack into the habitat control system!"

Venkat and Tian Mu looked at each other, and they both saw affirmation in each other's eyes.

Venkat clapped his hands and said, "Okay, let's do it! Guys, start working!"

Although the communication sequence code is only 20 lines, it took a long time to send it. In addition, Venkat and the others also simultaneously sent the method of how to hack into the communication system of the habitat module to Pang Xuelin and Watney.

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

The information does not seem long, but Pang Xuelin and Watney spent two full EVA time.

It wasn't until 10:30 p.m. on Mars time, when the sky was full of stars, that the two of them finished their long work.

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

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

Then, Pang Xuelin turned on the habitat communication system.

Lines of information began to appear on the computer screen.

The system is initializing...

loading finished……

Detect radio signals...

Detect radio signals...

Detect radio signals...

The signal gets...

Signal connected!

...

JPL accusation center.

"The habitat communication system is online!"

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

"Every time I see them send back a lot of information, but we have to input byte by byte, I'm so depressed to death!"

The accusation center burst into warm applause again, and everyone cheered and hugged each other!

Venkat and Tian Mu shook hands tightly and patted each other on the shoulder.

"Okay guys, after so many days of being dumb, it's time for us to get to work!"

Soon, Venkate grabbed a computer and typed: "Pang, Watney, hello, I'm Venkate Karp, NASA Ares Project Director. We have noticed you since the 39th Martian day. , now you are the focus of the global media, you have done a good job, whether it is retrieving Pathfinder or growing potatoes on Mars, in short, we are proud of you. Ares Project Command is trying to rescue you, we Experts in the field plan to modify the MDV of Ares 4 to make it capable of flying near the ground. In this way, when Ares 4 lands, they will first land on the Asidalia Plain and then take you with them. Flying to Schiaparelli crater. We are still putting together resources for a resupply mission to keep you going until Ares 4 arrives."

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

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

Watney was taken aback for a moment, and Pang Xuelin contributed a lot to the restoration of communication this time. He did not expect that Pang Xuelin would give him the opportunity to communicate with JPL for the first time.

"Um!"

Watney nodded, sat down on the seat, and typed: "Dr. Karp, hello, I'm Watney! I'm glad to hear the news. To be honest, if it wasn't for Pang, I'm afraid I would I really died. An antenna was pierced into my lower abdomen. It was Pang who saved me. We are in good condition now, the potatoes have sprouted, but there are still more than two months before the harvest. This accident and Pang The teammates don’t matter much, their actions are correct, and Pang and I don’t blame them, hope they don’t have any psychological burden, tell them I’m proud of them. Also, are my wife and children okay? My parents How about it?"

Venkate: "Your parents are fine. Your wife and children are overjoyed to hear that you are still alive. In due course we will have them come and talk to you. How is your food stock, the potatoes you planted? Is there enough to eat?"

Watney: "Thanks, tell them I miss them too. The potatoes are growing well enough to sustain me and Pang for about 1,000 Martian sols, and we won't be plagued by plant shortages for a while. Next I will give the time to Pang, you can ask Pang if you have any questions."

Soon, new news came from JPL.

Tian Mu: "Xuelin, it's me, Tian Mu, how are you doing now?"

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

Tian Mu: "You did a great job this time. We were able to restore communication. You have contributed a lot. Next, we will try to restore video and image transmission. Our botanists will help you manage your farmland, nutritionists Your daily optimal food intake will be determined, and the supply spacecraft will be launched in the second half of this year, about nine months later, and it is expected to arrive at the Arsidalia Plain in two years. Your food reserves Saved us a lot of redundant time. Also, take a picture of you and Watney if it's convenient, and remember to take a picture of the planting chamber, the media is driving our Dr. Karp crazy! "

Pang Xuelin and Watney looked at each other and smiled, Pang Xuelin typed: "Okay, I will send you the photos as soon as possible! Let's do this first, we are exhausted today, we are going to eat first, and then rest! Say hello to everyone for me! "

"Okay, you and Watney have a good rest, best wishes!"

Pang Xuelin chose to go offline.

Watney was taken aback for a moment, and asked doubtfully, "Pang, why don't you greet your family?"

Pang Xuelin smiled and said: "I was born as an orphan. I grew up in an orphanage since I was a child. The only relative, the old director, has passed away..."

"Sorry, Pang!"

Watney was a little embarrassed.

Pang Xuelin said indifferently: "It's okay, I'm used to it!"

Whether in the Three-Body World or the Martian World, the system has arranged for Pang Xuelin to be an orphan, and Pang Xuelin is also happy to relax. Otherwise, if there are a lot of unknown relatives and friends in this world, Pang Xuelin will have a headache instead.