Martian Day 1. (That is, a solar day on Mars, which is equivalent to 24 hours, 39 minutes and 35.24409 seconds, is only 2.7% longer than Earth)

When I woke up, Pang Xuelin and Mark Watney sat together again.

"Watney, I think we need to plan our work and life for the rest of our lives!"

Perhaps because Pang Xuelin was too calm, Mark Watney looked much better, and his mood was not as desperate as he was at the beginning!

Mark Watney said, "That's true, no matter what, Pong, we have to find a way to live!" ”

Pang Xuelin said: "We will act separately now, you are responsible for counting the materials in the cabin, and I will carry out a rapid EVA (Extra-vehicular activity, EVA spacesuit is generally used for four hours, so an EVA activity is equivalent to three to four hours), count the loss of materials outside the cabin, and by the way, see if you can get back the butterfly satellite communication antenna that was blown away by the sandstorm!" “

Mark Watney nodded, "Good! ”

……

More than three hours later, Pang Xuelin returned to the perching chamber somewhat tired and took off his heavy EVA spacesuit helmet.

Mark Watney came out of the material cabin and looked at Pang Xuelin with some hope:

"Pang, have you recovered the satellite dish?"

If the satellite dish can be recovered, it is expected that communication with the earth will be restored, which is the premise of whether the two can return to the earth alive.

Pang Xuelin shook his head and said with a wry smile: "I searched all the surrounding three kilometers and found nothing!" ”

The expression on Mark Watney's face froze.

"What about you, how is the inventory of supplies in the cabin?"

Watney said: "I roughly calculated, our Martian surface mission was originally planned to last thirty-one days, in order to prevent accidents, we prepared fifty-six days of food, the previous eight people consumed six days, there are still fifty days left, and now there are only two of us left, enough for us to support two hundred days." “

"That's good news!"

Pang Xuelin laughed.

Watney continued, "We also have nine spacesuits, one in-cabin spacesuit for liftoff and landing, and eight EVA spacesuits. “

Pang Xuelin nodded, there were originally eight of them, and each of them had two sets of spacesuits, one cabin spacesuit and one EVA spacesuit.

The EVA spacesuit is relatively bulky and sturdy, making it suitable for off-the-fly surface operations. Previously, six members of the Ares 3 mission team returned to Hermes in Mars orbit on a MAV, wearing six sets of in-cabin spacesuits, and Watney's own set was punctured by the antenna, so there were nine sets left.

Watney paused and continued: "I also checked the oxygenator and it is working well at the moment, but if there is a problem with the oxygenator, we only have a short-term spare part to spare. This spare part can only be used as an emergency because it is similar to the carbon dioxide filter on the EVA spacesuit, which cannot directly break down carbon dioxide to make oxygen, but can only absorb the carbon dioxide we exhale in the cabin. And the upper limit of this kind of part is only five days, and it will enter an irreversible saturation state, but now there are only two of us, so its upper limit should be twenty days. We had better pray that nothing goes wrong with the oxygenation machine, otherwise, our lives will end in twenty days. “

"The water circulation device works well, even if we exhale half a liter of water vapor every day, the air filtration system in the perch can also recover this water vapor, and the EVA spacesuit also has a certain water vapor recovery capacity, and the reserve water of the perching module reaches 500 liters, as long as there is no problem with the water circulation system, we don't have to worry about running out of water to drink." The only problem is that there are no spare parts for the water recycling system, so let's pray this thing won't have problems! ”

"Plus, we had plenty of medicines, and the dose of morphine was enough for us to die a painless death at the last moment. We also have a lot of multivitamins in large bottles and breadworms in an incubator, both of which can provide us with a lot of protein and vitamins to keep our nutrition balanced on Mars. In addition, we also have seeds from many crops, including potatoes, corn, wheat, cabbage, tomatoes, etc., as well as some mushroom spores. “

"Now, the only trouble is the carbon dioxide absorber of our extravehicular spacesuit, this thing is irreversible, use it once less, we landed on Mars this time, carried a total of eight hundred, twenty-five have been used so far, there are seven hundred and seventy-five left, if calculated by time, we have 3,100 hours of outdoor work. What about you, have you found anything, what about the loss of our extravehicular equipment? “

Pang Xuelin said: "Our perching cabin is basically intact, and the three main cabins, the living cabin, the material cabin, and the energy cabin are all very complete. After the Mars Liftoff Vehicle (MAV) takes off, it still has a partial base, including the landing gear, fuel storage tanks, and supply pipelines, and some fuel storage tanks are still in the fuel storage tanks. In addition, our Mars landing vehicle (MDV, equivalent to a landing module, mainly used for personnel landing, when landing, the main and auxiliary parachutes are opened one after another, and when three meters close to the surface, the rocket engine at the bottom of the MDV is started to cushion the impact force of landing) is mostly buried in sand, and the soft landing nozzle has been completely damaged, but the main and auxiliary parachutes are still intact, and we should be able to recycle them. “

"Two rovers are in good condition, half-buried in the sand, I've cleared them out and drove one of them around the perimeter of our camp. Two of the four weather stations we had set up a kilometre around the camp disappeared in the sandstorm, and I found two. Most of the solar panels around the camp were buried in the sand and were in a state of failure, and I cleaned them out as well. In addition, our nickel-metal hydride battery is also in good condition, and under normal use, it can reach the limit of 5,000 times of charge and discharge. ”

"The biggest trouble now is that we don't have a satellite communication antenna, I checked our residual communication array, and if there is no antenna, there is basically no possibility of repair!"

Watney frowned, "Is there a way to piece together an antenna out of aluminum foil or some broken copper and iron around our base?" ”

Pang Xuelin shook his head and smiled bitterly: "You think too much, the communication between Mars and the Earth and deep space communication is not so simple, even if I make it, it can be used as a walkie-talkie at most." ”

Watney sat down in his chair and said: "Communication is the most critical, we must find a way to restore communication with Earth, in addition, if the Earth does not cancel the follow-up Ares program because of our death, then in four years, the Ares 4 spacecraft will land in the Schiaparelli impact crater, about 3,200 kilometers away from the Asidalia Plain where we are now, it is impossible for us to reach there by our own strength, if we can contact the Earth, we may be able to hope for rescue." ”

To establish the problem of communication, Pang Xuelin actually has the bottom in his heart.

More than 800 kilometers away from their camp is a Mars Pathfinder rover launched in 1996.

In the movie, Mark Watney found the rover again and established contact with Earth.

Now, though, this guy has clearly not thought of this section yet.

Pang Xuelin said: "Watney, I'll find a way to solve the problem of communication, the most critical thing now is food, our food can only last for two hundred days, even if we try to save as much as possible, it can only last for a year at most, and Ares 4 will not arrive until four years later, and for the remaining three years, we have to find a way to grow food by ourselves." You're our botanist, and it's up to you! “

Watney nodded: "We need food for at least three years, 1095 Earth days, which is equivalent to 1067 Martian days, we have enough vitamins to guarantee, and the protein can be provided by breadworms and some of the space protein we store, the only shortage is calories." Among our seeds, potatoes have the most calories, containing 810 calories per kilogram of potatoes, but according to our height and weight, even if we are a little hungry, we have to consume 1500 calories every day, that is, about four kilograms of potatoes a day, or about 1.5 tons of potatoes a year. The yield of potatoes per mu is only 1.5 tons, and our material tank is about 100 square meters, even if it is all used to plant potatoes, the output is probably only 250 kilograms, which is only enough for us to eat for 90 days. “

Pang Xuelin said: "Watney, you forgot one thing, in many places on the earth, potatoes can only be planted once a year due to climate reasons, but we can provide a constant temperature and humidity environment here, and we can even harvest three to four seasons a year!" In addition, the branches and leaves of the potatoes can be used to feed the bread worms, which can also be a great source of calories. ”

Watney's eyes couldn't help but light up, so that although there was still a gap between the expected annual output of 1.5 tons, it could barely guarantee that the two would not starve to death.

But then, Watney frowned again: "If we plant, we need soil, at least forty liters of water per cubic meter of soil, and a hundred square meters of planting area, almost twenty cubic meters of soil, equivalent to eight hundred liters of water, where does our water come from?" There are only 500 liters of water in the water recycling system, and we have to leave at least 200 liters, so where do we get the remaining 500 liters? ”

Pang Xuelin laughed and said, "The problem of water can be solved. The fuel station under the take-off base of the MAV can produce carbon dioxide for us at a rate of two liters per hour as long as we provide electricity, and we can collect this carbon dioxide and then produce oxygen through the oxygenator. As for the issue of hydrogen, do you remember our teammate Friedrich? When we landed in the MDV, he handled it beautifully, leaving us at least a few hundred litres of fuel left. Those hydrazines can be broken down into hydrogen and nitrogen, and then we can collect the hydrogen and burn it with oxygen, can't we make water? “

Watney looked at Pang Xuelin and said with a smile: "Pang, you are really a genius!" If we can do what you say, we might be able to live until the day Ares 4 arrives on Mars! ”