After lunch, some people stayed at the testing site to finish the work, while the main team drove back to the headquarters in separate ways.

Naturally, Li Zheng got into Aunt Shen's familiar white car.

Lin Yujing sat in the passenger seat, and as soon as she fastened her seat belt, she turned around, bared her teeth and shouted, "You are so conscious."

Li Zheng also imitated her and bared his teeth and said with a grin: "Hey, why are you being so polite to Aunt Shen and me?"

"Mom!" Lin Yujing turned to Shen Tinglan and said, "Look at how thick-skinned he is."

"Well... I actually quite like this." Shen Tinglan smiled, started the car and drove away, "Okay, you two, stop teasing, Li Zheng is back too. It’s time to get down to business.”

The two people quickly put away their shouting mood and listened honestly.

"I have asked the secretary for instructions. In order for you to further participate in the work, many technical contents should be opened to you."

"But after it is opened up, it means it will be more difficult for you to go abroad."

"Taking this into consideration, I suggest you put your work aside for the time being and prepare for iPhone. How about you wait until the iPhone ends in November to get into contact with these contents?"

"We have agreed that we won't go." Lin Yujing answered, "I made this clear during the interview."

Li Zheng also nodded: "Well, I just need to ask someone to return the medal to that old man."

"So straightforward?" Shen Tinglan was slightly surprised, "I thought you were a person with a strong sense of purpose, Li Zheng."

"Once you have a more ambitious big goal, you won't be obsessed with the previous small goals." Li Zheng shook his head and smiled, "Contributing 1% to Huang Er's success is more important than 100 international gold medals."

"Ah, this sense of goal is really strong..." Shen Tinglan glanced at Lin Yujing, "What about you, it doesn't matter anymore?"

"The exam is just a means, not an end." Lin Yujing shook her head, "Now that the goal has been achieved, whether it is Huang Er or the astronomy department, I wish I would never take another exam in this life."

"This is your own decision, don't regret it." Shen Tinglan said seriously.

Lin Yujing urged: "Speak quickly, tell us quickly, we have been waiting for the core cause of the failure for a long time."

Li Zheng smiled and said: "I won't regret it. Now I have lost interest in all competitions."

Shen Tinglan asked immediately: "But you took the biology test this morning."

"Ah... well, I like biology." Li Zheng had no choice but to say something very contrary to his will in order to get his fifth son admitted.

"Okay, don't be nervous." Shen Tinglan smiled and said, "It's just a half-day vacation. I'm not Chen Hongbing. You can do whatever you want from now on."

"Sure enough, I'm following the right person." Li Zheng pumped his fist excitedly.

"You're taking advantage of me." Lin Yujing shouted and pumped her fists.

"Why did it start again?" Shen Tinglan asked, "Do you still want to hear the cause of the malfunction?"

"Listen!" they both said in unison.

Next, Shen Tinglan recreated for them the launch center on August 8, that night unknown to outsiders.

…

August 8, 2019, Wenhai Space Launch Site, Command Center.

20 o'clock, 07 minutes, 00 seconds.

"ignition!"

As the messenger gave the order, a thin red line appeared at the tail of the rocket.

Then, the red line suddenly exploded, like a little sun emerging from the sky.

But Shen Tinglan, who was sitting in the front row of the command center, knew very well that these were actually five little suns.

The centerpiece is the core first-stage YF-86 engine of the main body of the rocket. A huge amount of hydrogen and oxygen fuel is injected into the combustion chamber by two turbine pumps, reaching a pressure of 100 atmospheres in just 1 second. In this violent During the combustion, the temperature of liquid hydrogen instantly rose from -253 degrees to over 2,000 degrees.

In the next 500 seconds, the engine will remain in this state, consume all the fuel, and then detach from the main body of the rocket, and the core secondary engine above it will continue to complete its mission.

The four small suns around are Huang Er's four boosters.

Each of these four boosters is equipped with two 120-ton YF-90 kerosene engines. Compared with the core-stage rocket, these four guys are the real giants. They will take off during the most difficult 300 seconds of the rocket. It burned savagely inside, supporting more than 90% of Huang Er's takeoff thrust.

They are like two hands of parents, burning themselves up no matter the cost, just to support Huang Er's dream of soaring into the sky, and then let go, no longer adding another kilogram of burden to this child.

Looking at the little sun in the picture, Shen Tinglan clasped his hands and thought silently in his heart.

Fly, fly.

Xiao Huang Er, fly upwards with all your strength.

Not only her, but everyone in the entire command center seemed to be thinking silently.

No one spoke, everyone was welded to their posts like nails. There were only screens and data in front of them, data refined hundreds of times.

They were staring at a newborn baby, even a weak cough would make them extremely nervous.

They seemed to be staring at a dying old man, hoping that he could survive the last 2,000 seconds.

In this silence, the "tracking normal" broadcast every 10 seconds is like the "beep-beep" sound of an electrocardiogram. Although it is just boring and repetitive, it is the sound that everyone wants to hear most.

This broadcast was like a basic rhythm, leading Shen Tinglan to scan the core data on the main monitor screen every 10 seconds.

Just do this about 200 times and you're done.

But on the 18th time, something strange happened.

The core stage consists of two YF-86 engines. The instantaneous thrust of one of the engines has been reduced from 518kn to 506kn.

This is a small change, like a baby's cough.

But Shen Tinglan knew that the baby would not cough at this moment.

At this stage, as the altitude increases, the air gradually becomes thinner and the resistance gradually decreases. The instantaneous thrust of the hydrogen-oxygen engine should increase at a slow speed and should not drop significantly.

Just like the two-part machine, its thrust force remains at a high of 522kn.

Of course, this may just be a short-term uneven combustion, or a small gap in the instantaneous fuel injection density. After all, drinking mineral water sometimes takes one big bite and one small bite. Physics always makes such a little joke occasionally.

But Shen Tinglan's eyes were still fixed on this data.

After 10 seconds, the data is refreshed.

[Core level a thrust: 506 → 214]

[Core level 1 b thrust: 522→529]

Shen Tinglan was suffocated.

Without any preparation for gradual change, cut it in half directly.

The alarm sounded immediately, and the monitor tried to report in a calm voice: "A significant decrease in the thrust of the first engine of the core first-stage engine has been detected."

The person who was suffocating together with Shen Tinglan was Chen Hongbing beside him.

But Chen Hongbing's breathing only stopped for three seconds.

He had already rehearsed various scenarios, and this was not the worst.

"Ballistic group." Chen Hongbing said into the microphone, "At this stage, if the core one is separated in advance, will the redundant fuel of core two and three be able to successfully push the satellite into orbit?"

"After calculation, core one needs to persist for 70 seconds in its current state, and core two and three can complete the task."

The ballistic team engineers responded almost instantly, which showed that they had started the software calculations long before Chen Hongbing asked.

As soon as he finished speaking, new data came in.

[Core first stage thrust: 214→37]

Almost as soon as the data appeared, Chen Hongbing spoke again: "Ballistic group, recalculate."

5 seconds later.

"Report, with the current arrow conditions, Huang Er will not be able to enter the planned orbit."

The scene fell silent again.

[Core first level thrust: 37→6]

"Report, core first engine...extension...has...shut down."

This time, the monitor could no longer maintain a calm mood.

Even Shen Tinglan found that she was just a fragile little girl. Faced with such a situation, she couldn't say a word and her mind went blank.

Chen Hongbing asked again: "Can the satellite be sent into low orbit by forced separation?"

"Report, with the current rocket conditions, the rocket cannot reach the first cosmic speed."

[Core first level thrust: 8→null]

"Conduct ballistic analysis on the existing surveillance." Chen Hongbing ordered.

The wait this time was a bit long, but it was only about ten seconds.

"Due to the independent shutdown of the first engine, Huang Er has deviated from the established trajectory. If the situation remains unchanged, the rocket body will accelerate and fall into the Eastern Pacific Ocean under the independent thrust of the second engine."

This time, Chen Hongbing did not speak immediately. Instead, after struggling for a few seconds, he looked seriously at Zhao Zhenhua beside him.

Zhao Zhenhua's expression didn't change much, but his eyes turned red.

"Get ready to salvage with all your strength."

"Yes." Chen Hongbing ordered at this point, "The launch failed. All engines were turned off in an emergency to allow the rocket body to fall into the closer sea. Urgently contact the Oceanographic Bureau and Meteorological Bureau. Do your best to salvage it."

At this moment, everyone seemed to be distracted.

The baby didn't survive.

The old man couldn't hold on either.

Before Chen Hongbing stood up, he held the back of Shen Tinglan's hand and shook it heavily.

"I can't stand it. There are many people who can replace me."

"But no one can replace you."

"Don't resign, don't run away."

"I agree."

…

In the car, Shen Tinglan's eyes turned wet red.

Even though so long had passed, that night was still enough to cause her a lifetime of heavy pain.

"Well..." Lin Yujing gently put her hand on her mother's arm, "Thank you for your hard work... Mom."

This was the first time in a long time that Shen Tinglan told her what happened that night.

Although Li Zheng is also sad, this does not affect his basic analysis.

"It took about 30 seconds from the onset of the warning sign to complete shutdown. Although the process was very fast, it was still a linear process."

"No changes can be seen in the appearance, and there is no explosion. It can be seen that there is no fuel leakage, the combustion chamber is not damaged, and there is no early contact in the pre-combustion chamber. This eliminates many faults."

"Under this premise, if the thrust continues to decrease...then there can only be a problem with the fuel injection." Li Zheng nodded and said, "Well, this is consistent with the parameters given by the algorithm."

"Your time in the test team is indeed not in vain." Shen Tinglan wiped his eyes and gradually returned to a calm mood, "In the design of 86, liquid hydrogen and liquid oxygen are stored separately, and they are stored separately. When the turbine pump and the oxygen turbine pump are injected into the combustion chamber, my first reaction is that there is a problem with one of the pumps. From experience, the oxygen pump is more likely to have problems because it is born to withstand a strong oxidizing environment. This is It is also the basis for our first fault model.”

"But... I haven't had this kind of problem in all the ground testing for so long." Lin Yujing said reluctantly, "And doesn't the core have two engines? Under the same environment, doesn't the other one work just fine? of."

"If the Ocean Administration can salvage Huang Er, your questions will probably be answered." Shen Tinglan sighed, "But now, we have answered it based on simulation. The force and heat of the rocket after takeoff is extremely complicated, and there are still many problems. There is a vibration problem that gives everyone a headache. It is impossible for our test run to simulate all environments, so we can only explain that about 180 seconds after liftoff, the thermal environment of the rocket engine reached a test level The harsh conditions that cannot be simulated cause abnormalities in the local structure of the turbine device, making it impossible to inject fuel into the combustion chamber."

"That's all we can do..." Li Zheng also lowered his head and sighed, "It would be great to salvage it... You'll know it once it's dismantled... But it's really difficult to locate it... Even if it's correct, you don't know where it will be swept away by the waves. "

"Perhaps Mingri sneaked away first." Lin Yujing shouted again, "Bad!"

"Okay, stop with the conspiracy theories." Shen Tinglan turned around and drove back to the first hospital. "The diagnosis that you two and Eleven gave us is indispensable for the smooth reset. Based on the test results, we The fault point has been locked on the oxygen turbine pump. Under a special environment, the shaft system will indeed crack or even break. As you know, in pursuit of greater thrust and specific impulse, the pressure in the combustion chamber is The pressure is over a hundred atmospheres. To inject fuel into it, the turbine speed and the pressure of the pre-combustion chamber must be greater. In addition, the low temperature environment and strong oxidation properties make this turbine pump one of the most difficult points in aerospace engineering. difficulty."

At this point, Shen Tinglan stopped the car, turned sideways and said seriously.

"If aerospace engineering is a test paper used to test a country's cutting-edge industrial strength, then this pump is the final question of the paper."

"Hmm!" Lin Yujing became more and more excited as she listened, "The heaviest jewel in the aerospace crown!"

Li Zheng, however, punched Lin Yujing's armchair with great reluctance: "So in the end, is it actually a process issue...or is it a materials issue?"

"No, no, no, blindly complaining about technology and materials is the biggest misunderstanding of engineering." Shen Tinglan was not in a hurry to get off the car, and explained on the spot, "Engineering is a whole, and our job is to work under the existing technology and conditions. , use our knowledge and brains to design a rocket that can successfully lift off. When facing failure, don’t put all the responsibility on the process and materials. They have been strictly tested when they leave the factory and meet our engineering standards. Of course, in breakthrough projects, we still have the right to demand more advanced technology and better materials, but don’t put all the blame on them. After all, there is no indestructible steel plate in the world. Even if there is, we should use it. I'm sorry."

"Ah..." Li Zheng sighed after thinking, "I am narrow-minded... Teacher Shen is right, the cook should not complain about the ingredients."

"Cook..." Shen Tinglan was stunned for a moment, and then couldn't help laughing, "It turns out that engineers can be compared to cooks... I also learned something."

"If nothing else, Li Zheng's fried fish steak is delicious." Lin Yujing, perhaps thinking of the delicious food experience, said something nice unexpectedly, "Let him cook it for you later."

"In two days, when the zero reset is completed, I'll treat you to dinner." Shen Tinglan shook the car keys and said, "During this period, the Sixth Institute must work hard to improve the oxygen pump part of the engine. We can't be idle and strive to improve the overall performance." Further optimization of the structure is required to further enhance vibration suppression."

"Shocked?" Li Zheng asked.

"Ah, you haven't learned this yet. Let's go upstairs and teach you." Shen Tinglan stretched and was in a good mood. "The rocket most of the time runs at ultra-high speed and breaks through the air resistance. During this process The vibration generated in the rocket will affect the operation of every component of the rocket. It can be said to be the first enemy of the rocket. One of our design difficulties is to resist vibration and better protect the operating environment of each part. Now we know Why do you want to recruit people who are studying?"

"That's it." Li Zheng followed Shen Tinglan and got out of the car excitedly, "It's too rude to call you teacher, I'll just call you master's wife!"

"Ah..." Shen Tinglan was stunned again, "This..."

"Give me the 'master'!" Chen Hongbing suddenly appeared in a swaggering manner, "How many times have I told you to just call me mom? Why are you being so polite here?"

This time Shen Tinglan was used to it and did not run away: "Go, leave us alone."

"No, no, no, no, you have to come." Chen Hongbing waved his hand, "We have a summary meeting with the Sixth Academy, so you have to come."

"Yes." Shen Tinglan responded and handed the office key to Lin Yujing, "Go to my office first and quietly give Li Zheng the recent study materials. Study hard and don't fight."

"oh."

"yes."

After the two left, Chen Hongbing sneered: "Why are you acting like a summer day care class...don't fight? Gan Chai Lihuo is in your office, is that a fight?"

"Ah." Shen Tinglan also covered her mouth and quickly took out her mobile phone, "Those who have monitors... I have to tell them..."

"Oh, let's go." Chen Hongbing waved his hand and whispered in Shen Tinglan's ear, "Aren't you curious about what they are doing together? Don't worry, I will take care of this matter. I will accompany you to watch the surveillance later. .”

"!" Shen Tinglan was startled at first, and then backed away, "You don't often watch my office surveillance, do you?"

"I'm free!" Chen Hongbing cursed and waved his hands, "Besides, it's really supervision work."

"It's too scary. I will be transferred when the Huang Er project is over..."
Chapter completed!