Pasadena, California, USA.

With a population of just 130,000, this town is famous for the California Institute of Technology and the Jet Propulsion Laboratory (JPL) that are located here.

Although JPL is a research institute under NASA, it is administratively affiliated with the California Institute of Technology, founded in 1936 by Theodore von Kármán, the greatest aerospace engineer of the 20th century, and his disciples of the famous Chinese scientists Qian Weichang, Qian Xuesen, and Guo Yonghuai.

At this time, Tian Mu, accompanied by Vencarter, director of NASA's Ares program, walked into a temporary Mars Pathfinder command center that was temporarily converted from a warehouse.

The command center is very simple, with two rows of long tables and more than 20 computers on them, and various wiring scattered on the ground.

The table was littered with cigarette butts and empty coffee cups, and the staff inside had unkempt hair and bloodshot eyes.

Bruce, director of the JPL laboratory in charge of the project, said: "We set up a team of more than 30 engineers, according to the technical data of the year, spent half a month to rewrite the system software, and used these waste components to rebuild a set of Mars Pathfinder ground command and control system, which is connected to the Earth's deep space tracking and control network, and then we can only wait to see if Pang and Watney can repair the Mars Pathfinder's communication system, as long as the Mars Pathfinder is activated, We'll be the first to hear it! “

Tian Mu and Wen Carter nodded frequently.

The CNN-CCTV co-production team, which was allowed to enter JPL, focused the camera on the staff at the scene.

In the past half month, Pang Xuelin's adventure in the rover has become the focus of global attention.

Every day, the Ares project command will release photos taken by the Mars satellite, and then the major media will invite some experts and scholars to interpret these materials to tell the public what Pang Xuelin is going to do and what his next move will be.

The dust storm that erupted on Mars a few days ago made it impossible for satellites to photograph the rover's tracks.

Almost everyone in the world is worried about Pang Xuelin.

Fortunately, the sandstorm passed quickly, and Pang Xuelin also returned to the habitat module with the Mars Pathfinder successfully.

As a result, there is great public interest in whether Project Ares Command will be able to reconnect with Pang Xuelin and Watney.

This is also the reason why the CNN and CCTV teams were licensed by NASA to shoot in JPL.

Just as Bruce took Tian Mu and Vencart to introduce the situation, a huge cheer suddenly came from the scene, and then applause also rang out.

"We ...... We received a signal from the Mars Pathfinder...... OK, OK is the pathfinder! ”

Venkart was slightly stunned, glanced at Tian Mu, and walked up first.

The escorts behind them were also like wolves that had seen lambs, and quickly surrounded them.

The camera teams of CCTV and CNN hurriedly took their places and pointed the pictures at the first engineer to speak.

"Well done man, how's it going?"

Venkart slapped the unkempt engineer on the shoulder.

The engineer said: "Our deep space TT&C received the signal of the Mars Pathfinder, and the system has just automatically sent the telemetry signal back, and it is estimated that it will be able to reach Mars in 5 minutes, and once the signal is received, the Mars Pathfinder can immediately turn on high-gain communication, so after 10 minutes, we can receive feedback from the Pathfinder again." ”

"What was the content of the communication you just received?"

Tian Mu asked.

When the engineer saw that he was a Chinese, he couldn't help but hesitate.

Venkart said: "This is Dr. Tian Mu, the Chinese commander-in-chief of the Ares project, you can say it directly. ”

The engineer said: "The information coming back now is a summary of some hardware self-tests, and there are many invalid subsystems, which should have been dismantled when Pang transported back to the Pathfinder." ”

"What about the Sojourner rover, can it be connected?"

"It is impossible to contact for the time being, but the Pathfinder has two communication systems, the low-gain antenna is responsible for communicating with the Sojourner unmanned vehicle, and the high-gain antenna is responsible for communicating with the earth......

Venkat shrugged his shoulders at Tian Mu and said, "It seems that we have to wait, it is three o'clock in the afternoon East Coast time in the United States, and it should be midnight on the Asidalia Plain, Pang and Watney are probably still sleeping, let's wait for them to wake up and see the situation!" ”

……

"Pang, the antenna is moving, the antenna is moving!"

Pang Xuelin opened his eyes in a daze, and saw Watney wearing an EVA spacesuit, shouting at him.

Pang Xuelin looked at the time and said, "It's only five o'clock in the morning, you went out to watch it so early?" ”

In order to ensure the astronauts' concept of time on Mars, the experts of the Ares program specially formulated a set of Martian time for them, a Martian day is equivalent to 24 hours, 39 minutes and 35 seconds on Earth, and a Martian hour is equivalent to one hour, one minute and 40 seconds.

"I couldn't sleep since last night, and I was dazed until the early hours of the morning, so I couldn't help but get up and take an EVA trip," Watney said. The Pathfinder's high-gain antenna moved, indicating that Earth knew we were trying to contact them and responded to the Martian Pathfinder. That means we can get in touch with the Earth, and we can be rescued! ”

Pang Xuelin was mentally prepared for this situation, and said with a smile: "Okay, Watney, don't be too excited, now the earth can only send relevant instructions to the landing module of the Pathfinder at most, and nothing else can be done, so leave it to me next!" “

"Yes, you're our communications expert, so it's your turn!"

Watney has full confidence in Pang Xuelin.

Pang Xuelin said: "You first take the recharged Sojourner unmanned vehicle to the outside of the perching module, the landing module can't move, but the Sojourner unmanned vehicle has a camera, and it can also move, I estimate that our perched cabin blocks the low-gain signal from the landing module, as long as the Sojourner unmanned vehicle is moved out and the contact with the landing module is automatically turned on, the earth side can control the Sojourner." “

Watney was slightly stunned: "Are you going to do it?" ”

Pang Xuelin smiled: "I'll get a few pieces of cardboard, I'm going to write something to greet the headquarters!" ”

……

Half an hour later, Venkat, who had just returned to the accusation center from the press conference, saw the beaming appearance of the accusation center, and couldn't help but say a little strangely: "What's wrong?" What's the good news? ”

Tian Mu said with a smile: "The landing module and the Sojourner unmanned vehicle have been contacted, and we have just given the order to turn on the camera!" It takes five minutes for the command to reach Mars, but it will take at least ten minutes to actually see what the camera is seeing. By the way, how did the launch go? “

Venkart took the coffee from his colleague's hand, took a sip lightly, and complained: "What else can these reporters say, it's nothing more than a set of old tunes, and they actually want photos of Pong and Wotney, saying that the public especially wants to know about Wotney and Pong's current situation." Even if we activated the Sojourner, all we could get was images of them in spacesuits, and with the capabilities of that antique camera, we don't know how high the quality of the photos would be! ”

Tian Mu nodded and said: "Reporters are like this, the most important thing for us now is how to find a way to communicate directly with Pang and Watney, not these trivial things." ”

The two stood on the sidelines and chatted for a while, and soon Tim, the JPL engineer who was the first to spot the Mars Pathfinder feedback signal, exclaimed, "Here, the camera is on, there is a picture...... It should be a panorama! ”

On the large screen at the center of the accusation, the first image of the dusky surface of Mars appeared, and the camera slowly rose, and the rover, landing module, and perching module all appeared in the footage.

As the image slowly emerges, a handwritten note is held up in front of the camera by a thin metal stick.

There was a line on the note: "[Yes]...... Can you see it...... [No]! “

Thunderous applause flooded the entire center of accusations, and everyone cheered and hugged each other.

Venkart reacted immediately and said, "Quick, Tim, quickly control the camera to turn and point to [yes]!" ”

"Understood!"

Tim quickly gave the order!

"Pang, do you think they can receive our message?"

In front of the perching pod, since Pang Xuelin put the note in front of the camera of the Sojourner's unmanned vehicle, Watney fell into a state of unease.

Pang Xuelin said confidently: "Don't worry, didn't you check all the unmanned vehicles of the Sojourner?" No problem! It will take at least 10 minutes for them to respond to the signal, we just need to be patient! ”

In the movie, Watney got in touch with the earth very smoothly, and Pang Xuelin knew the plot in advance, so naturally there was no psychological burden.

Sure enough, ten minutes later, the camera rotated and pointed the camera at [yes].

"They got it! They received it! ”

Watney excited!

Pang Xuelin smiled slightly, and unhurriedly removed the note and replaced it with a new one.

……

JPL Mars Pathfinder Command Center.

The second photo slowly appeared on the big screen again.

This time, there were a lot of words on the note, but fortunately, after being enlarged on the large screen, I could barely see it clearly.

Venkart stared at the big screen tightly and read out Pang Xuelin's words word by word.

"Hello everyone, Ares Project Commanders, it's a pleasure to get in touch with you again, and if it weren't for your rescue, Watney and I would like to greet your whole family. Watney and I are doing very well now, Watney is a genius botanist, and we've planted potatoes on Mars, and the food problem has become less urgent. There are about 2,500 hours left in the CO2 absorber, and the oxygenator and water circulation system are in good condition, so we won't have an existential crisis anytime soon. I'm going to tell you how to restore communications......"

“oh，shit！”

The card space is limited, and there is only so much text on this card, Wenkat and Tian Mu can only wait for the next photo.

A few minutes later, the third photo was sent back without any problems.

"Because the 26 letters are placed around the unmanned vehicle, each card can only get a viewing angle of about 13 degrees, and the information transmission is not accurate enough, I will use ASCII code to manage the letters, each letter can be expressed in hexadecimal, and then you can not only send us letters and numbers, but even punctuation marks. However, this is only a short-term expedient method, and the signal transmission rate is too low, so I came up with a new solution, I need to make the secondary communication system of the perch module connect to the low-gain communication system of the Pathfinder landing module, that is, let the perch module replace the Sojourner unmanned vehicle, so that we can not only communicate directly with text, but also send documents and photos......"

……

The fourth photo.

"But I don't have the source code of the underlying communication system of the Sojourner unmanned vehicle, I need you to pass this thing over, with this, I can modify the communication system code of the roost pod, so that the Pathfinder landing module thinks that the roost is the Sojourner unmanned vehicle. That's about it. Finally, say hello to my colleagues on the Hermes! ”

Venkart and Tian Mu looked at each other.

Venkart sighed: "Pang is really a genius, I was thinking about how to establish a real communication with them, but I didn't expect Pang to directly give a solution." ”