Early the next morning, Pang Xuelin and Watney went on an EVA mission, driving the rover to the radioisotope thermal battery (RTG) burial site four kilometers away.

Given the danger of the battery, Ares III Commander Colonel Lewis sent the RTG removed from the Mars Liftoff Vehicle (MAV) and buried it on the top of a hill four kilometers south of the perch, as soon as they landed, and planted a green flag to warn the mission members not to approach.

After that massive sandstorm, the green flag was blown out of sight, but the hill could be seen at a glance, and Pang Xuelin and Watney easily found the place where the RTG was buried.

The two used shovels to dig through the sand, revealing the cylindrical metal shell of the RTG, the outer side of which was covered with heat dissipation slots, and even through the space suits, the two could still feel the radiant heat emitted by the decay of plutonium-238.

The perimeter of the RTG is covered with thermoelectric elements, and the plutonium-238 in the center of the battery emits high-energy α rays, which use the principle of thermocouples to create potential differences in different metals to generate electricity.

It has the advantage of long working time and is not subject to environmental changes such as external temperature and pressure.

It's just that the efficiency is quite low, the current energy utilization rate is only 10%~20%, and most of the heat energy is wasted.

Pang Xuelin and Watney could just use it as a heater for their rovers.

Watney felt a little furious in his heart: "Pong, wouldn't it be too dangerous to put this thing in the car?" ”

Pang Xuelin said: "Don't worry, under normal circumstances, the radiation shield will not be damaged for decades, which is enough for us to use on Mars for a long time." ”

The two carefully moved the RTG into the car, and Pang Xuelin turned off the on-board air conditioning system, but the temperature in the car did not drop, but rose rapidly at a speed visible to the naked eye, and it rose to 37 degrees Celsius in less than ten minutes.

"No, it's too hot, I'm going to suffocate in a spacesuit."

Watney took off his helmet and spacesuit, leaving him with only a T-shirt and shorts, but still sweating hot.

Pang Xuelin was similar, he said: "Bear with me, let's go back to the perching cabin first, and then remove the insulation layer of the rover, it should be much better." “

Back at the camp, the two began the rover renovation project.

The cabin of the rover is actually a large pressure-resistant cabin, the outer shell is a layer of high-strength carbon fiber material, filled with insulating foam in the middle, and the innermost layer is a layer of insulating plastic.

Pang and Watney first removed the insulating plastic, then carefully removed the insulating foam.

Of course, they didn't remove it all at once, but removed it one by one, until the temperature dropped to about 25 degrees Celsius after the RTG was placed in the car.

Next, they spent three more Martian days reworking the rover, first installing six solar cells on the roof to provide some of the power while the vehicle was moving.

In addition, Pang Xuelin also carried eight solar cells in the car, which can be taken out to charge when repairing.

Secondly, by adding a liquid oxygen tank to the rover, the rover's self-sustaining power can last up to three people for two days, and one person can barely use it for six days.

Therefore, Pang Xuelin carried an additional 25-liter liquid oxygen tank.

The density of liquid oxygen is about 1,000 times that of gaseous oxygen at standard atmospheric pressure, and a 25-liter liquid oxygen tank is equivalent to 25,000 liters of oxygen, and a person's daily oxygen consumption is about 588 liters, so the oxygen content is more than enough.

What really limits the time of Pang Xuelin's mission is the carbon dioxide filter and food, there is no oxygenation machine in the rover, and the carbon dioxide filter is also needed to absorb the carbon dioxide exhaled by Pang Xuelin.

In order to ensure the redundancy of the mission, Pang Xuelin brought a full 500 hours of carbon dioxide filters and enough food for 20 days.

As for drinking water, Pang Xuelin only brought five liters, and as long as the power is not interrupted, the on-board water circulation system can solve the problem of maintaining a sufficient supply of fresh water.

40th Martian day.

Pang Xuelin said goodbye to Wodani and drove the rover to Mars.

What Pang Xuelin didn't know was that his and Wodani's every move was transmitted to the Earth 8,000 kilometers away through the Mars satellite. (Earth-fire distance 0.55~400 million km)

……

Earth.

"Audience friends, good evening, welcome to tonight's "Oriental Time and Space", I am the host Bai Xuesong. Today, we turn our attention again to Chinese astronaut Pang Xuelin and American astronaut Watney, who were left on Mars by mistake, and in the past few days, the two have carried out several EVA activities, what is their purpose? Where is Project Ares' Joint Command rescue plan? What will be the impact of the failure of the Ares III mission on the Ares IV mission? How did the members of the Ares III mission team aboard the Hermes spacecraft feel when they learned that their two teammates were still alive? Next, we will ask Dr. Tian Mu, the Chinese commander-in-chief of the Ares Project Joint Command, on these questions. “

"Dr. Tian Mu, hello, welcome to tonight's "Oriental Time and Space"."

"Hello host, good evening friends from the audience."

Bai Xuesong said: "Dr. Tian Mu, in the past week, the two heroic astronauts Pang Xuelin and Watney have become the focus of global attention, especially after China and the United States held a grand state funeral for these two space heroes, the sudden resurrection of the two heroes caused a huge sensation, to a certain extent, these two space heroes have become the two most concerned human beings in the solar system." I would like to ask what is the attitude of Project Ares Command towards this incident, and will anyone stand up for this incident? “

Tian Mudao: "Host, first of all, I want to correct a detail, this incident is not a mistake, but from an accident, when a large-scale sand city storm broke out on Mars, the Ares 3 mission team faced great danger, and the command command issued an evacuation order was correct, but no one expected that the satellite communication antenna would suddenly fall off and hit our two astronauts, and the life monitoring system at that time showed that the two astronauts had died. Based on the principles associated with the Mars mission, it is understandable that the members of the Ares 3 mission team abandoned the remains of the two astronauts. Of course, the consequences of this series of unexpected events are not what we want to see. “

Bai Xuesong nodded and said, "Dr. Tian Mu, then I want to ask, is the Ares Project Joint Command in touch with the two astronauts at present?" Where is the rescue plan? ”

Tian Mu said: "Because the satellite dish fell off, we can't get in touch with these two astronauts for the time being, but we have mobilized more than 20 satellites over Mars to shoot the inhabitation capsule on the Asidalia Plain, which can basically ensure that a batch of new images can be obtained in three to five minutes." The rescue plan is still in full swing, and the International Astronautical Federation has reached a consensus that it will do whatever it takes to rescue our astronauts. And I believe that Pang Xuelin and Watney are also doing their best to save themselves, and satellite images from the past few days show that they are working on a modification of the rover, and we suspect that they will be heading to the Schiaparelli crater, 3,200 kilometers away, to make contact with Earth through the MAV for Ares IV located there. ”

Bai Xuesong said: "The journey of 3,200 kilometers must be a thrilling adventure. “

Tian Mu said: "Actually, our command is not very approving of the two astronauts carrying out such an adventure, and we prefer that they stay where they are and wait for rescue." But in the current situation, it is understandable that they made such a choice. ”

Bai Xuesong said: "I hope our two aerospace heroes can arrive safely." Finally, I would like to ask the crew of the Hermes how they behaved when they learned that their teammates were still alive. “

Tian Mu pondered for a moment and said, "In order to ensure the safety of the Ares 3 mission team during the return process, we have not disclosed the news that the two teammates are still alive to them for the time being......"

Bai Xuesong was slightly stunned, and just wanted to answer.

At this time, the mobile phone in Tian Mu's pocket suddenly vibrate.

Tian Mu took out his mobile phone and looked at it, and then made a gesture to the director, and the director immediately switched the picture to Bai Xuesong, who understood and took over the words from Tian Mu's mouth: "I think whether it is the audience friends in front of the TV or all the members of the Ares program, we all hope that the two astronauts can return safely, and we also believe that our aerospace experts have enough ability to bring these two astronauts back from Mars." We'll see you later in a little bit of an ad below......"

Tian Mu took the opportunity to walk out of the studio and pressed the answer button.

On the other end of the phone, Liu Wenhong, a subordinate of the Chinese command center of Project Ares, said: "Head, the rover is dispatched, but the strange thing is that the rover is not heading towards the Schiaparelli impact crater in the southeast direction, but in the southwest direction, and there is only one person when it sets off, and the preliminary judgment is that it should be Pang Xuelin, and Watney should stay in the perching cabin." “

A week ago, it was Liu Wenhong, who was in charge of studying the Mars satellite photos, that discovered the anomaly in the camp that made everyone realize that the two astronauts were still alive.

Tian Mu's brows furrowed slightly, and he said, "Does the expert group have any judgments?" Is there any news from NASA? ”

Liu Wenhong said: "It is still being discussed, and NASA is also making further judgments. ”

"Okay, then you keep following up, I'll finish the show......"

Before Tian Mu finished speaking, Liu Wenhong immediately interrupted him: "Wait, head, there is the latest news from NASA, the direction of the rover is aimed at the area where the American Mars Pathfinder probe landed forty years ago, and it is about ...... away from the perching module About 800 kilometers, my God, NASA suspects that Pang Xuelin and Watney want to use the same probe from forty years ago to reconnect with the command. NASA is currently urgently searching for the Mars Pathfinder files, and it is believed that good news will come soon. ”

"Great, remember to keep the information in sync, I'll be right back!"

Tian Mu clenched his fists and said excitedly!