The Science Fiction World of Xueba

The launch time of the 921 rocket was scheduled for the afternoon of the second day, that is, at 5:30 pm on October 30.

The entire launch center has been busy preparing for this important launch as early as a month ago.

Pang Xuelin was just a guest who was invited to observe the rocket launch. Apart from visiting the launch center and cheering up the staff involved in the launch mission, he had nothing else to do.

At six o'clock in the morning the next day, Pang Xuelin changed into a T-shirt, shorts and tracksuit, ready to go for a run.

Although the gene optimizer has greatly improved his body, as long as he has time, Pang Xuelin will still stick to the habit of getting up early and running.

When he was in Jiangcheng, he took Qi Xin to run with him every day, and occasionally Zuo Yiqiu and Zhou Chen would join in.

Here, only Zuo Yiqiu followed him.

When Pang Xuelin opened the door, he saw Zuo Yiqiu, who lived across from him, also came out wearing tight sportswear.

"Professor Pang, good morning!"

"Good morning! Xiao Zuo, let's run for two laps together?"

"good."

The two left the expert building and trot along the asphalt road.

The air in the morning is fresh and humid, and the sea breeze is blowing, refreshing and cool, and I feel very comfortable.

Wenchang Satellite Launch Center is close to the coastline, surrounded by lush tropical vegetation, the environment is very good

The two trot along the asphalt road near the rocket assembly plant, and they came to the vicinity of the launch tower without knowing it.

The huge 921 rocket stands majestically. Below the rocket is a large water tank deep in the ground. The temperature of the rocket is as high as 3,000 degrees Celsius during launch. Therefore, an inverted triangle-shaped water guide tank is set up under the launch pad. Twenty-two meters around the bottom of the launch tower, the temperature will drop to 1,000 degrees after the rocket is launched to ensure the safety of the ground equipment.

The rocket's fuel filling port still emits white mist from time to time.

That is the white mist produced by the condensation of nearby water vapor after the boiling and vaporization of liquid hydrogen and liquid oxygen.

The first and second stages of the 921 rocket are liquid oxygen kerosene engines, and the third stage uses a hydrogen-oxygen engine. Since the liquid hydrogen and oxygen will continue to volatilize after being filled,

So cryogenic refueling will continue until an hour before launch.

Pang Xuelin and Zuo Yiqiu ran around the launch tower before returning to the expert building.

Nothing happened in the morning, Pang Xuelin stayed in the room until three o'clock in the afternoon, he went to the command and control center accompanied by Tao Yongchang.

Although Pang Xuelin has experienced many adventures in the sci-fi world, this is the first time he has seen a rocket launch mission like the real world.

The launch command and control hall was in order, and everyone was busy with their own affairs. Pang Xuelin's arrival did not cause much commotion.

"Boost 1 and 3 suspected liquid oxygen leakage faults have been eliminated, and each number will follow up the status and enter the -3 hour program."

"Reset ignition time to 18:01."

"clear!"

The sound of passwords sounded in the hall from time to time.

Seeing that Pang Xuelin was a little curious, Tao Yongchang explained: "Professor Pang, there should have been some glitches just now, but it doesn't seem to be a serious problem, and it won't affect the normal launch."

Pang Xuelin smiled and nodded.

Aerospace is inherently a high-risk project. It is normal for various minor problems to occur during the launch preparation process, and generally it will not affect the normal launch.

At this time, Liu Xuesong also found that Pang Xuelin had come to the accusation hall, and took the initiative to greet him: "Professor Pang, welcome to come and guide us."

Pang Xuelin said with a smile: "I'm just a layman. I brought my eyes here today. It's ridiculous to give advice."

Liu Xuesong smiled and didn't say much.

Tao Yongchang said: "Old Liu, what happened to the liquid oxygen failure just now?"

Liu Xuesong said: "There is a problem with the connection of the liquid oxygen filling port on the 1st and 3rd side, and it has been resolved."

Tao Yongchang said: "That's good, I hope this launch goes well."

The 921 rocket is a new rocket. Generally, the launch risk of this brand-new type of rocket is relatively high.

For example, in the past few years, the second launch of the Long March 5 failed, which directly led to the delay of key projects such as the Chinese space station, Chang'e 5, and the Mars rover for two years.

This time the 921 rocket was launched, and the aerospace aircraft demonstration aircraft built by China with all its strength was the first launch. Whether it was Tao Yongchang or Liu Xuesong, the pressure on them was not small.

If it was put in the past, it would be impossible for high-level executives to directly take such precious payloads as the aerospace aircraft demonstrator to the new rocket for testing.

It is also because Pang Xuelin's Jinlong battery harvests global capital and makes money too easily, so China is so rich that it directly installed an aerospace aircraft verification machine on the first launch of the 921 rocket.

Liu Xuesong chatted with Pang Xuelin and Tao Yongchang for a while.

Although he is the chief designer of the 921 rocket, he doesn't have to worry about the launch process.

His work at the scene was similar to that of Pang Xuelin, so he also played the role of a mascot.

The time passed by every minute and every second, and before I knew it, it was past four o'clock in the afternoon.

The command of the commander sounded from time to time at the scene.

"Fuel filling complete, filler port disengaged."

"Conning tower staff evacuated."

"90 minutes to prepare."

"The latest weather forecast shows that everything is normal for the launch window."

"The engine is starting to warm up."

...

Various instructions sounded from time to time.

At this moment, an alarm suddenly sounded at the scene.

"Didi, the first level of precooling failed, the engine is overheated, the first level of precooling failed, the engine is overheated..."

The atmosphere in the hall suddenly became tense.

Soon, the commander of the No. 01 launch issued an order: "110 suspends the discharge of liquid oxygen, suspends the filling of kerosene, and maintains the status of each system. We will not enter the 60-minute program for the time being."

Pang Xuelin, Tao Yongchang, and Liu Xuesong also stopped talking. Liu Xuesong had a serious expression on his face and said, "Professor Pang, I'm sorry, I'll go over and see what's going on."

Pang Xuelin and Tao Yongchang looked at each other, and quickly followed.

Experts in the hall of the command and control center quickly gathered and began to discuss the malfunction.

Pang Xuelin still has a certain understanding of the problem of engine pre-cooling failure and overheating.

For the liquid oxygen kerosene engine and the liquid hydrogen liquid oxygen engine, the boiling point of the cryogenic propellant is very low, and it is in the gaseous state at room temperature, and it is easy to vaporize during storage and transportation, and a gas-liquid two-phase flow occurs, so it is easy to adverse or even destructive effects on the engine and boost delivery system.

To avoid these effects, the engine should be operated with the propellant in a liquid state.

Therefore, the engine and its boost delivery system must be sufficiently pre-cooled before starting.

If there is no pre-cooling or insufficient pre-cooling, the temperature of the pipeline and pump components will be much higher than the temperature of the liquid propellant. In this way, when the engine is started, the propellant will be in the form of a gas phase or a gas-liquid two-phase mixed fluid. status into components such as lines and pumps.

The engine and pump cannot work normally under this condition, which will cause cavitation and spin of the pump, or prolong the start time and thrust climb time, resulting in pressure and flow fluctuations, stall operation, oxygen-enriched combustion, etc., serious It is possible to make the startup fail completely.

And pre-cooling is to use the medium in the storage tank or other low-temperature medium on the ground to cool the conveying system and the engine before the engine is started, so as to reach the allowable temperature and ensure the reliable operation of the pump.

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