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

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

Lin Yujing sat down in the passenger seat, turned around as soon as he fastened his seat belt, and shouted with bared teeth: "Conscious enough." ”

Li Zheng also followed her example and bared his teeth and grinned: "Hey, what are you being polite to Aunt Shen with me." ”

"Mom!" Lin Yujing turned her head and said to Shen Tinglan, "You see if he has a thick skin." ”

"Is this...... I'm actually quite quite a bit of a eater. Shen Tinglan hid his face and smiled, then started the car and drove out on wheels, "Okay, don't tease you two first, Li Zheng is also back, it's time to get down to business." ”

The two hurriedly put away their clamor and listened honestly.

"I have asked the secretary to further involve you in the work, and a lot of technical content should be open to you. ”

"But after opening up, it means that it will be more difficult for you to go abroad. ”

"With that in mind, I suggest you put your work aside for the time being, prepare for the IPHO, and wait until the IPHO ends in November before you touch on the content, how about it?"

"It's all said okay, don't go. Lin Yujing answered, "I made this clear when I was interviewed." ”

Remember http://m for a second

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

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

"Once you have a bigger goal, you don't have any attachment to the previous small goal. Li Zheng shook his head and smiled, "Do 1% of your strength for Huang Er's success, and its weight is more than 100 international gold medals." ”

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

"Exams are a means, not an end. Lin Yujing shook his head, "Now that the goal has been achieved, whether it is Huang Er or the Department of Astronomy, I wish I wouldn't have to take another exam in this life." ”

"It's your own decision, don't regret it. Shen Tinglan said quite solemnly.

Lin Yujing urged: "Say it quickly, say it quickly, wait for the core cause of the failure for a long time." ”

Li Zheng smiled: "I won't regret it, now I have lost interest in all competitions." ”

Shen Tinglan immediately asked, "But you went to take the biology exam this morning." ”

"Ah...... Well, I love biology. "Li Zheng had to say something very contrary to his will for the sake of [Fifth Son Dengke].

"Okay, don't be nervous. Shen Tinglan smiled, "It's just a half-day vacation, and I'm not Chen Hongbing, so you can do whatever you want in the future." ”

"Sure enough, I followed the right person. Li Zheng threw his fist excitedly.

"It's my light. Lin Yujing shouted and waved his fist.

"How it started again. Shen Tinglan asked, "Do you want to hear the cause of the failure?"

"Listen!" the two said in unison.

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

......

August 8, 2019, Wenhai Cosmodrome, command center.

20:07:07, 00 seconds.

"Ignition!"

With the herald's order, a thin red line appeared at the tail of the rocket.

Then, the red line suddenly exploded, like a small sun being born out of thin air.

But Shen Tinglan, who was sitting in the front row of the command center, knew very well that this was actually 5 little suns.

The most central is the core stage YF-86 engine of the main rocket body, a huge amount of hydrogen and oxygen fuel is injected into the combustion chamber by two turbopumps, and the pressure of 100 atmospheres is reached in only 1 second, and the temperature of liquid hydrogen instantly rises from -253 degrees to more than 2000 degrees in this violent combustion.

For the next 500 seconds, the engine will remain in this state, draining all fuel, before detaching itself from the rocket body and continuing its mission with the core second stage engine above it.

And 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 to the core-stage rocket, these four guys are the real giants, they will be savagely burned in the most difficult 300 seconds of the rocket's take-off, supporting more than 90% of the take-off thrust for Huang Er.

They are like the two hands of their parents, burning themselves out at any cost, just to support Huang Er's dream of soaring to the sky, and then let go of their hands and no longer add a kilogram of burden to this child.

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

Fly, fly.

Xiao Huang Er, try to fly upwards.

Not only her, but the entire command center, it seems that everyone is silently reading.

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

They were staring at a newborn baby, and even the slightest cough would make them nervous.

They were staring at a dying old man, hoping that he would survive the last 2,000 seconds.

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

This broadcast is like a basic rhythm, with Shen Tinglan scanning the core data on the main monitoring screen at a frequency of 10 seconds.

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

But on the 18th time, there was an anomaly.

The core stage consists of two YF-86 engines, and the instantaneous thrust of one of the extensions is reduced from 518KN to 506KN.

It's a big 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 thins and the drag gradually decreases, and the instantaneous thrust of the hydrogen-oxygen engine should increase at a slow rate and should not decrease significantly.

Just like the double extension, its thrust is still maintained at a high of 522KN.

Of course, this may be just a brief uneven combustion, or a small gap in the instantaneous fuel injection density, after all, drinking mineral water sometimes takes a sip of a small sip, and physics will always make such a little joke once in a while.

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

After 10 seconds, the data is refreshed.

[Core 1st A thrust: 506→214]

[Core 1st B thrust: 522→529]

Shen Tinglan was suffocated.

Without any preparation for the gradient, it is cut in half.

The alarm sounded, and the monitor reported in a steady voice: "A significant drop in thrust of the first phase engine of the core has been detected. ”

Suffocating with Shen Tinglan was Chen Hongbing beside him.

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

He's already rehearsed all sorts of situations, and that's not the worst.

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

"After calculation, the first level of the core needs to hold on to the existing state for 70 seconds, and the second and third cores are likely to complete the task. ”

The engineers of the ballistic group replied almost instantly, which shows that they had started the software calculations long before Chen Hongbing asked.

As soon as the words fell, new data came.

[Core 1st thrust: 214→37]

Almost at the moment when the data appeared, Chen Hongbing spoke again: "Ballistic group, recalculate." ”

After 5 seconds.

"Report, with the current arrow situation, Huang Er will not be able to enter the established orbit. ”

The scene fell silent again.

[Core 1st thrust: 37→6]

"Report, core first stage engine ...... Extension ...... Already...... Stoppage. ”

This time, the monitor was no longer able to keep his mood calm.

Even Shen Tinglan found that she was just a fragile little girl, and in the face of such a situation, she couldn't say a word, and her brain was even more blank.

Chen Hongbing asked again: "Can the satellite be put into low orbit by forcibly separating?" ”

"Report, the current state of the arrow, the rocket is not able to reach the first cosmic velocity. ”

[Core 1st thrust: 8→null]

"Ballistic analysis of existing surveillance. Chen Hongbing ordered.

This time the wait was a little long, but it was only a dozen seconds.

"Due to the separate shutdown of the first extension, 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 separate thrust of the second extension. ”

This time, Chen Hongbing did not speak immediately, but after a few seconds of brief entanglement, he looked at Zhao Zhenhua beside him heavily.

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

"Fully prepared for salvage. ”

"Yes. Chen Hongbing ordered, "If the launch fails, all engines will be urgently shut down to allow the rocket body to fall into the near sea, and the Oceanic Bureau and the Meteorological Bureau will be contacted urgently." Do your best to salvage. ”

At this moment, everyone seemed to be evacuated.

The baby didn't survive.

The old man didn't hold on.

Before getting up, Chen Hongbing grabbed the back of Shen Tinglan's hand and shook it heavily.

"I can't stand it, there are a lot of people who can replace me. ”

"But no one can replace you. ”

"Don't quit, don't run away. ”

"I top. ”

......

Inside the car, Shen Tinglan's eyes were wet red.

Even if so much time has passed, that night is still enough to cause so much pain in her life.

"Hmm......" Lin Yujing's hand gently put on her mother's arm, "It's hard...... Mom. ”

This is the first time in so long that Shen Tinglan told her about that night.

Li Zheng is also sad, but this does not affect his fundamental analysis.

"It takes about 30 seconds from the appearance of the warning to the complete shutdown, which is a linear process, although it is fast. ”

"There was no change in appearance, there was no explosion, there was no fuel leakage, there was no damage to the combustion chamber, and there was no pre-contact in the pre-combustion chamber, which eliminated a lot of faults. ”

"Under this premise, the thrust continues to decline...... Then it can only be a problem with fuel injection. Li Zheng said and nodded, "Well, this matches the parameters given by the algorithm." ”

"You really haven't worked in vain in the test team during this time. 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, respectively, by hydrogen turbine pump and oxygen turbine pump, injected into the combustion chamber, my first reaction is also that one of the pumps has a problem, from the empirical point of view, the oxygen pump because it is born to withstand a strong oxidation environment, the probability of problems is greater, which is also the basis of our first failure model." ”

"Yes...... I've never had this kind of problem in the interview car for so long. Lin Yujing said unwillingly, "And isn't there two engines in the core level, and in the same environment, the other one is not fine." ”

"If the Oceanic Bureau can salvage Huang Er back, your question will probably be answered. Shen Tinglan sighed, "But now, we have solved based on simulation, the force heat after the rocket takes off is extremely complex, and there is a headache for everyone, and our test run cannot simulate all the environment, so we can only explain that in about 180 seconds of liftoff, the force and heat environment of the rocket engine has reached a severe state that cannot be simulated in the test, resulting in an abnormal local structure of the turbine device, and then it is impossible to inject fuel into the combustion chamber." ”

"It's only like this...... Li Zheng also bowed his head and sighed, "How good it is to be salvaged back...... You'll know it as soon as you dismantle it...... But it's really hard to locate...... I don't know if I'm going to be swept away by the waves. ”

"It's not good that Magnesium Day sneaked away first. Lin Yujing shouted again, "Bad!"

"Alright, stop conspiracy theories. Shen Tinglan hit a wheel, and the car had driven back to the hospital, "The zero can be so smooth, the diagnosis given by the two of you and the eleven is indispensable, based on the test results, we have locked the fault point on the oxygen turbine pump, in a special environment, its shaft system will indeed crack, and even break." As you know, in the pursuit of greater thrust and specific impulse, the pressure of the combustion chamber is more than 100 atmospheres, and to inject fuel into it, the speed of the turbine and the pressure of the pre-combustion chamber must be greater, plus the low temperature environment and strong oxidation, this turbo pump can be said to be the most difficult in aerospace engineering. ”

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

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

"Hmm!" Lin Yujing listened more and more, "The heaviest jewel in the crown of aerospace!"

Li Zheng was extremely reluctant to slam Lin Yujing's chair: "So in the end, it's actually a process problem...... Or is it a matter of materials science?"

"No, no, no, blaming about processes and materials is the biggest misunderstanding of engineering. Shen Tinglan was not in a hurry to get out of the car, and explained on the spot, "The project is a whole, and our job is to use our knowledge and minds to design a rocket that can be successfully launched under the existing technology and conditions." In the face of failure, don't put the blame on the process and materials, they are all rigorously tested and meet our engineering standards when they leave the factory. Of course, in breakthrough projects, we still have the right to demand higher craftsmanship and better materials, but don't put the blame on them, after all, there is no such thing as an indestructible steel plate, and even if there is, we should not be able to use it. ”

"Ah...... Li Zheng sighed thoughtfully, "I'm narrow-minded...... Mr. 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 the engineer can be compared to a cook...... I learned it too. ”

"Not to mention anything else, Li Zheng's fried fish steak is delicious. Lin Yujing may have thought of the food experience, and unexpectedly said good things, "Go back and let him make it for you." ”

"In two days, when it's over, I'll invite you to dinner. Shen Tinglan shook the car key and said, "During this time, the Sixth Academy should pay close attention to improving the engine oxygen pump part, and we can't be idle, and strive to further optimize the overall structure, and it is best to further strengthen the vibration suppression." ”

"Shock?" Li Zheng asked.

"Ah, you haven't learned this yet, go upstairs and teach. Shen Tinglan stretched his waist, it can be said that he was in a good mood, "Most of the time the rocket is running at ultra-high speed, and the vibration generated in this process will affect the operation of every part of the rocket, which can be said to be the first enemy of the rocket.

"I see. Li Zheng followed Shen Tinglan and got out of the car excitedly, "It's too empty to call the teacher, I'll call you the teacher directly!"

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

"Give me the 'division'!" Chen Hongbing suddenly swaggered, "How many times have you said it, just call Mom, what are you doing with being polite here." ”

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

"Don't, don't, you have to come. Chen Hongbing waved his hand and said, "I have a summary meeting with the Sixth Academy, you have to come." ”

"Hmm. Shen Tinglan answered, handed the office key to Lin Yujing, "Go to my office first, quietly give Li Zheng the recent study materials, study hard, don't fight." ”

"Oh. ”

"Yes. ”

After the two left, Chen Hongbing sneered: "How can it be like a summer care class...... Don't fight, dry wood and fire in your office, is that a fight?"

"Ahh Shen Tinglan also covered his mouth and quickly took out his mobile phone, "There is a monitor...... I've got to tell them ......."

"Well, let's go. Chen Hongbing waved his hand, leaned into Shen Tinglan's ear and whispered, "Don't you wonder what they are doing together?" Don't worry, I'll take care of this matter, and I'll accompany you to watch the monitoring when I get back." ”

Shen Tinglan was first startled, and then retreated, "You don't often look at my office surveillance, do you?"

"I'm idle!" Chen Hongbing scolded and waved his hand, "Besides, I really think it's also supervision work." ”

"It's terrible, I'll transfer ...... after the end of the Huang Er project"

"Oops, no, no, no, just kidding. ”