Die on Mars

"So...you pulled out all the cables on the engine?"

The old cat nodded.

"Can it still be repaired?"

"cannot."

"Then can this rocket still be used?"

"cannot."

Tang Yue felt dizzy.

"Old cat, you bastard, I'm going to strangle you to death!"

"Why are you excited? Back off! Don't get close to me... Back off! You just agreed not to do anything drastic." The old cat waved his paws lightly, "It's not a big deal anyway. The downgrade engine is already used. If it’s not upgraded, it’s broken. As long as it’s upgraded, it’ll be fine.”

Tang Yue breathed a sigh of relief and slumped down on the chair.

The old cat had just told him that it had damaged the rocket engine underneath. At that moment, Tang Yue was really frightened, his mind went blank, and his whole body felt cold inch by inch.

If the rocket motor fails, it's all over.

Tang Yue threw the maintenance instruction manual on the console, covered his face with his hands, and took a deep breath.

"Why did you unplug all the cables?"

"Because they all went the wrong way and were arranged in a mess." Old Cat replied, "It is completely inconsistent with what is described on the design drawing. Some lines even go in completely opposite directions. I don't know who assembled this broken engine. The lander is in You're lucky it didn't turn into a big firework during the landing...so I just cleaned them all up and sorted out the engine controls from scratch."

Tang Yue was startled.

"Holy shit, is it so serious?"

"It's that serious." Lao Mao nodded and spoke righteously, "Obviously the assembly worker's education level is very low, and he can't even understand the most basic drawings. SpaceX is a big group after all, how could it recruit this person? Plant people into the workshop...and so on."

The old cat suddenly frowned and realized that the problem seemed not that simple.

"What's wrong?" Tang Yue asked.

"Hmm..." Old Cat hesitated for a few seconds, "Tang Yue, do you know what 'Occam's razor' is?"

"Oh...what? What razor? Is this a new razor brand?" Tang Yue looked confused, "I've only heard of Philips and Feike."

"Occam's razor is an artifact, an artifact for studying problems. It is a philosophical concept: 'Don't add conditions unless necessary.' It means that when you are studying a certain problem or putting forward a certain point of view, add conditions The fewer premises and conditions, the better. The more conditions you add, the more likely your point of view will be untenable." Lao Mao explained, "Occam's razor is used to eliminate conditions and remove all unnecessary Suppose they are all cut off.”

Tang Yue thought for a few seconds, "I probably understand what you mean, right? If I tell a lie, then I have to tell more lies to cover up the lie. In the end, the paper can't contain the fire. So I might as well not lie in the first place.”

"It kind of means that." Old Cat stood on the gangway and nodded.

"But why are you telling me this?"

Tang Yue didn't know why Lao Mao suddenly brought up this Occam's razor. What does this thing have to do with the current situation?

"Regarding the current engine wiring problem, I think the following factors may have led to this result: SpaceX's poor management and management, Americans do things perfunctorily, and the assembly workers' education level is too low and they cannot understand the assembly procedures. The workers drank too much the night before work, and there were errors in the design drawings." Old Cat paused, "But after careful thinking, I found that using Occam's razor can eliminate all the above complex assumptions and get a Very concise and clear result, this result is the real reason.”

Tang Yue nodded.

"So what's the real reason?"

"I took the drawing backwards."

·

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Tang Yue sat in the command module of the Eagle spacecraft, checking the lander's computer system in sequence according to the maintenance manual.

"Navigation... where is the navigation department..."

"Communication, communication channel... OK."

Tang Yue adjusted the buttons on the dashboard. Under normal circumstances, these tasks should be done by the commander. The commander is the driver, and he is just a passenger.

But now that the driver is gone, passengers have no choice but to get there.

Fortunately, although the lander is complex, it is a very highly automated thing. From launch to docking, everything is handled by the computer itself. Tang Yue only needs to ensure that the program parameters in the computer are correct, and then press the button, and the Eagle spacecraft will be launched. Complete all subsequent processes.

This is like a fully autonomous car. The driver only plays an insurance role under normal circumstances. Even if the driver is gone, the car can still be on the road as usual.

If this were a classic car from the last century, someone would have to operate everything from the steering wheel to the brake clutch. If the driver fainted on the way, everyone in the car would be dead.

"Docking...where is the docking control system?"

Tang Yue raised his head, opened his eyes and carefully examined the densely packed buttons on the panel. Most of the buttons on the spacecraft were made large and conspicuous. This was to prevent people from accidentally touching them, but a large number of them would be dazzling, and even more so. What's more, there are various English abbreviations on it. With Tang Yue's English level, he must not be able to recognize them all. Fortunately, he has an instruction manual in his hand, otherwise Tang Yue would be dumbfounded.

"UHF...UHF, ultra-high frequency antenna..."

"Linear quadratic regulator trees...LQR-Trees? There is also a simulation verification process...um..."

"Autonomous orbit change control parameters..."

Tang Yue looked at the maintenance manual in his hand and walked back and forth in the command cabin, surrounded by dense screens and buttons.

"Old Cat, what does GNC mean?"

"Guidance, Navigation and Control, the English abbreviation of navigation guidance and control." Lao Mao answered.

"Where's PPL?"

"Pin-point landing, the abbreviation for precision landing."

"EDL?"

"Entry, descent and landing, entry, descent and landing."

When encountering an English abbreviation that cannot be confirmed, Tang Yue can ask Laomao directly. This is easier than consulting the manual. Laomao can reply in one second. It is indeed a good dictionary.

Although there are more than 10,000 items in the manual, most of them are actually functions that cannot be used - as the old cat said, talking about a lot of nonsense in detail is the way of engineers. , more than half of this manual is functional description related to manual control. There is no doubt that the manual control mode of the Eagle spacecraft is useless. The final spacecraft launched will be unmanned. It is a Pure cargo ship.

Since there is no one in the command module of the spacecraft, the manual control system naturally loses its function. You cannot expect that the sandwich in the box can still climb into the command module and pilot the spacecraft.

This part of the system can be shut down before launch, so Tang Yue does not need to check them. This greatly reduces Tang Yue's work intensity and shortens his working time. He can still complete the mission within two days if he can catch up with the progress.

Whether Maidong can successfully survive this death or not depends entirely on Tang Yue and Lao Mao.