The old cat left the crutches to Tang Yue and asked him to make fine-tuning according to Mai Dong's height and size, while the old cat himself went out to check the landing site first. The Ihidi Plain is flat, and the area around the Kunlun station is a natural good landing field, and the Mars landing plan has drawn five landing fields with the Kunlun station as the center, numbered L1 to L5, and the previous landers and cargo spacecraft can land directly on the deserted beach.

The Mars landing program has been going on for decades, and there have been a dozen disposable cargo spacecraft abandoned near Kunlun Station, three of the five landing sites have been abandoned, and Tianzhou 37 is about to land at the L4 landing site, adjacent to the Eagle spacecraft, 50 meters in front of Kunlun Station.

"Mr. Cat is out?"

"It's out, it's going to check the landing site of the cargo ship." Tang Yue turned around and sat back in his chair, placing the two crutches flat on his knees, "Girl, can you estimate your current height?" ”

"But the last lap has just been estimated."

"That's the last lap." Tang Yue emphasized, "The altitude of the last lap is different from the current lap, and the situation may change every lap, and we need to monitor the orbital altitude of the joint space station in real time." ”

"Hmm...... Then you wait. There was silence in the channel for a few minutes, "It's about one hundred and ten kilometers, it's still at this altitude, and nothing has changed." ”

"Remember that 100 kilometers is a safe altitude and 80 kilometers is a dangerous height." Tang Yue reminded.

"Mr. Cat said that sixty kilometers is a dangerous height."

"Sixty kilometers is not a dangerous height, it is a deadline, and if you fall to sixty kilometers, you can't be saved!" Tang Yue corrected, "In any case, we can't let it fall to sixty kilometers." ”

"But what are we going to do?"

Tang Yue was stuck.

What are we going to do to keep the Union Space Station at a safe enough altitude? This is an unsolvable question, whether 80 kilometers is a dangerous altitude or not, 60 kilometers is a dead line, and even if they can detect in advance that the space station is about to crash, there is no way to save it.

The old cat has long told Tang Yue that from the moment the electric rocket runs out of propellant, the end of the space station is already doomed, which is like the end of the college entrance examination The test paper has been handed in, no matter what you do before the score is announced, it is impossible to affect the final score, in this case, the best way to deal with it is actually to sleep with your head covered, sleep with him for ten days and ten nights, and wake up after ten days The results are out, and the long tension and torment are avoided.

Both fell silent, and after the silence the girl whispered, "Today is the sixth day."

"Well, today is the sixth day." Tang Yue said.

"It's the sixth day...... the girl sighed faintly in the channel, "my clock here is broken, I don't know what time it is, the sun will rise and set in less than an hour...... Also, I'm so hungry......"

"How much food do you have left?"

"The last cookie is gone."

"How can you eat so much?"

"I ...... I...... There aren't many cookies in the space station, so I'm already saving, okay? The girl was not angry, "Yesterday was the hardest, I was so hungry that I couldn't sleep at night, and I didn't feel anything when I woke up this morning, but I was a little dizzy, maybe low blood sugar...... Tang Yue: You should pay attention to the fact that you are talking to a patient with low blood sugar. ”

"So what?"

"So you should talk sweeter!"

·

·

·

"I said Tang Yue."

"Huh?"

"Did Mr. Cat say before that the remaining lifespan of the Joint Space Station could be seven to eleven days?"

"Yes."

"Tomorrow will be the seventh day."

"Don't worry, tomorrow will be fine." Tang Yue comforted her, "According to the orbital altitude you estimated before, the orbital descent speed of the joint space station is slower than we imagined, not only will it be fine tomorrow, but it will also be fine the day after tomorrow, it may drop below eighty kilometers on the tenth day, but at this time, the Tianzhou-37 cargo spacecraft should also arrive, we can't save the space station, but we can save you back." ”

"Can you get it back if you are 80 kilometers away?"

"Yes! Not to mention 80 kilometers, 60 kilometers will do! Tang Yue took out a few sheets from the stack of scratch paper in front of him, and spread them out on the table one by one, the paper was densely packed with formulas and numbers, "I've done it...... The Tianzhou-37 cargo spacecraft has the ability to safely enter the atmosphere, as long as we are bold enough and precise enough to control it to dock in a high-speed fall! ”

"This ...... Is it possible? The girl was a little surprised.

"Of course it's possible! Of course it's possible! Girl, listen to me, you listen to me......"

"Uh-huh, I'll hear you."

"The strength of the body of the Tianzhou cargo spacecraft is sufficient, and the core module of the Crystal is the strongest module of the United Space Station, at an altitude of sixty to eighty kilometers - if the atmospheric environment is ideal enough, if the atmospheric environment is ideal enough, after all, this altitude is actually not the normal reentry altitude......"

Tang Yue took out his pen and quickly wrote on the manuscript paper, in the past two nights he was thinking about this problem except playing cards, racking his brains and losing a lot of hair.

Although Mai Dong couldn't see what Tang Yue wrote on the paper - he could increase his confidence by copying his calculation process on the paper, this time he also had a rigorous calculation, and he was no longer shouting empty slogans.

"There is no doubt that the attitude of the United Space Station is completely out of control, but the Tianzhou spacecraft is controllable, and our only hope is on the Tianzhou spacecraft! We can maneuver the ship close to the crystal bay and choose a forward-facing docking attitude...... It sounds incredible, whimsical, but my calculations support this result, and it's very difficult, but it's possible, and I certainly can't do it, but the old cat should be able to. ”

"We are clear about the data of the Tianzhou spacecraft, as long as the maximum temperature does not exceed 1000K and the maximum heat flux density does not exceed 300KW/m2 in this process, then it has almost no impact on the spacecraft, according to the usual data, the maximum temperature at this stage is actually only 800K...... We can complete the rescue before the space station falls sixty kilometers, and as long as you cooperate well enough, the whole process will not take more than three minutes. ”

Tang Yue's pen walked like a dragon and snake, and the speed of his speech was almost incoherent, but fortunately, the confusion of the order did not affect the expression of meaning.

"The real thermal barrier occurs at an altitude of forty kilometers, but at this time the Tianzhou spacecraft has already rescued you, and then the Tianzhou spacecraft immediately switches to the normal reentry procedure, entering the Martian atmosphere at an altitude of forty kilometers, the empty Joint Space Station will burn up in the atmosphere, and the cargo spacecraft can let you land safely! The only problem is that the propellant consumption is a bit excessive, so the final landing speed of the Tianzhou spacecraft will be relatively large, and there is a possibility of breaking the landing gear. ”

"Another problem is that this may not guarantee a precise landing near Kunlun Station, but there are enough supplies in the Tianzhou cargo spacecraft, where you can eat and drink while waiting for rescue with peace of mind."

Tang Yue spit out the entire plan in one go, and after he finished speaking, he gasped and rested, waiting for Mai Dong's response.

The girl held her breath.

"Did you figure it out?"

"Yes."

"Does Mr. Cat know?"

"I haven't had time to tell it yet."

Tang Yue...... You're just a mechanical and electrical engineer. ”

"What happened to the electrical engineer?" Tang Yue said, "Let me tell you, a serious aerospace engineer will definitely not dare to do this!" But I dare. ”

"Because doing so may destroy the Tianzhou spacecraft." "It's too risky. ”

Tang Yue's idea is indeed incredible, he wants to let the Tianzhou 37 cargo spacecraft dock with the crystal cabin in a very unstable situation, the risk is extremely high, and if he is not careful, he will lose his wife and lose his soldiers, and the bamboo basket will be empty.

"But that's the only way to save you, girl." Tang Yue said, "We are not concerned about risk, but hope, as long as there is 1 in 10,000 hope, it is worth our 10,000 percent effort." ”