Reborn in 2011, I am the chief designer of aerospace.

Cao Que gently pounded his slightly sore thighs and let out a long sigh.

"After all this back and forth these past few days, we finally have a satisfactory formula. What's next, Song Shen?"

Song Xingye rested his chin on his hand and pondered, "Let's try a few more times and try to adjust the proportion of the medicinal pillars to the optimal level."

Jiang Mian nodded, rubbing the calluses on her fingertips, and eagerly went to move the asphalt again.

After a full morning of meticulous calculations and proportioning tests, the final solution has been finalized:

70% Shell No. 60 bitumen mixed with 30% Mobil No. 1 lubricating oil.

This is a recipe that can be described as the 'golden ratio'.

After heating the mixture of asphalt and lubricating oil to about 120 degrees Celsius in a small pot, Song Xingye took the mortar and pestle handed to him by Jiang Mian, which contained potassium perchlorate powder.

Once they're fully mixed, it looks like a thick, stringy black poop...

This is how Cao Que used the metaphor.

"Can't you stop being disgusting?" Jiang Mian rolled her eyes at him. "This is clearly melted dark chocolate cake~"

In short, whether it was poop or dark chocolate, Song Xingye poured it into the cavity of the steel pipe and waited for it to cool and solidify. The first stage propellant of their little rocket was then complete.

Reignite.

boom--

The small test bench was almost shaking, and the exhaust gas discharged from inside the steel pipe rushed to the end of the guide channel in just a few seconds.

The thick white smoke from the potassium chloride rose into the air, almost enveloping half of the workshop.

Even the experienced workshop workers couldn't help but exclaim in amazement.

After collecting the data generated by the test bench, Jiang Mian exclaimed with delight:

"Specific impulse 186 seconds! Jet velocity 1.8 km/s! Thrust exceeding 900 Newtons!"

This means that "Wild Donkey No. 1" can easily break through the flight altitude of several thousand meters, and may even reach a higher level.

After seeing the data, Song Xingye was very satisfied with the black fuel rod made of asphalt.

What they need to figure out next is what to put into the combustion chamber of the second-stage rocket.

The initial plan was to add nitrogen dioxide and methanol.

However, this plan was rejected by Cao Que and Jiang Mian as soon as it was proposed.

It's highly poisonous and too dangerous.

So Song Xingye turned his attention to gasoline.

He led the two men to first test gasoline and red fuming nitric acid.

After eliminating several different formulations, it was discovered that the byproducts of propellant combustion always caused the electric motor to vibrate uncontrollably.

Song Xingye speculated that it might be related to gasoline, and after consulting some literature, he replaced gasoline with aniline.

However, the problem remains unresolved.

Because aniline and nitric acid often cannot burn simultaneously, meaning their combustion rates are inconsistent.

Unless an additional auxiliary ignition system is added inside the combustion chamber.

This is clearly undesirable for a miniature rocket that strives for extreme simplicity.

Ultimately, after much deliberation, Song Xingye decided to use a mixture of hydrocarbon fuels to power the second-stage rocket.

They inject this hydrocarbon fuel mixture into one end of the combustion chamber, then inject oxygen into the other end, and finally ignite it with an electric spark.

This time, Lady Luck finally smiled upon them.

The ignition of the second-stage rocket was unexpectedly successful. When the igniter was activated, the 2-kilogram rocket, relying on the 200-gram force provided by the liquid fuel, seemed to be suddenly pulled into the sky!

So far, the dust has settled.

……

One week later, the ninth round of assessments ended.

Each team has completed its task and built a variety of simulated launch vehicles.

However, building it is one thing, whether it can fly is another.

The Dongyu Group's bus carried everyone away from the city and plunged into the deep mountains bordering Miyun and Chengde.

A place known as Test Station No. 802.

When I got off the bus, I saw that the surrounding mountains were continuous and lush, like a sea of ​​green, making it a perfect test flight site.

Li Ang walked ahead and introduced:

"In the beginning, this place was the drill ground of the Qing Dynasty's Yi Army. In the 60s, it was transformed into a test site for anti-aircraft missiles and sounding rockets were also launched. It has not been used for many years."

"Thanks to you guys today, I'm even able to stroll around this old base. The air traffic control has already implemented temporary restrictions here. Now it's up to you whether your homemade little rockets will perform well..."

After saying that, he pointed to the opposite hillside.

Following the gesture, Song Xingye saw two Iveco radar vehicles painted in camouflage parked there, their antennas slowly rotating.

"See those two vehicles? We've brought you a radar control vehicle and an optical tracking theodolite. The group has been taking good care of you, hasn't it? Fly as high as you can later, and let me see the real skills of you PhDs!"

Someone started arguing, "Instructor Li, what if it flies out of the von Kármán line? We didn't report it to the International Telecommunication Union!"

"Wow...you've got a big mouth!"

Li Ang chuckled, hands on his hips, and said, "Want to fly 100 kilometers? If you can fly 10 kilometers, I'll treat you to a big meal tonight! If you accidentally end up in space, I'll go to the ITU and apologize for you, then walk back to Beijing with my tail between my legs!"

"Hahaha……"

The laughter dissipated the tense atmosphere considerably.

Six teams lined up, and six different simulated rockets gleamed coldly under the blazing sun.

During the lottery, Song Xingye drew number 4.

Xu Zhe, who was next to him, was holding the number 3 lottery ticket. He quietly leaned over and nudged his arm, looking curious.

"Hey, you're about to go on the court, can you give us a sneak peek? What kind of amazing stuff is your rocket carrying?"

Song Xingye smiled, lifted his foot, and stomped hard on the asphalt road. "This is it."

Xu Zhe was stunned, staring at the dark road surface for a long time before deciphering the unbelievable answer:

"Holy crap...you didn't actually use asphalt as fuel, did you?"

Song Xingye nodded. "What do you think? Doesn't it seem a bit far-fetched?"

"Not at all." Xu Zhe stared at their rocket with surprise. "I just admire your imagination. You're so talented! Asphalt has a very high carbon content and is indeed highly combustible. How come I didn't think of that!"

He then broke into a smile, "But we're not bad either. We used magnesium powder and ammonium perchlorate, and even added some catoxin as a catalyst. We'll have a competition later to see who comes in first today."

"Magnesium powder? That's pretty violent. Can your arrow's structure withstand it?"

"Don't worry, it's been reinforced; it cost a lot of money!"

Song Xingye smiled and said, "Alright, I'll wait and see."

Amidst the pleasantries, the launches of the first two groups were completed.

There's nothing particularly noteworthy about the whole process; at least a rocket made by professionals won't explode right after takeoff.

According to observations from the telemetry and control vehicle and the optical tracking theodolite, the first group of rockets eventually reached an altitude of over 4,000 meters, which is similar to the highest peak in eastern China, Yushan.

The second team's rocket performed exceptionally well, breaking through the 5,000-meter mark in one go, drawing envious applause.

Immediately afterwards, Xu Zhe and his team came out carrying the rocket.

After the countdown ended, the rocket shot up in a thick cloud of white smoke, like a sharp arrow piercing the sky.

The addition of magnesium powder made the tail flame dazzlingly bright.

Ultimately, the parabola's vertex reached 7500 meters, breaking the previous team's record.

The audience gasped in amazement.

After Xu Zhe and the others came down, Song Xingye, along with Cao Que and Jiang Mian, carried the unassuming "Wild Donkey No. 1" to the launch position.

They deployed "Wild Donkey No. 1" on a makeshift launch rail, connected the ignition circuit, and slowly retreated to a nearby position built with sandbags.

10, 9, 8, 7, 6, 5, 4, 3, 2, 1...

"ignition!"

As the ignition button was pressed, a crackling sound of sparks came from the launch base, followed by a muffled boom.

Rumbling--

A thick plume of smoke billowed from the nickel-steel nozzle; it was a dense, heavy, oily, yellowish-white column of smoke.

Accompanied by the thick smoke, Wild Donkey No. 1 launched itself into the air with great speed.

The hissing sound gradually evolved from a muffled roar to a piercing shriek that tore at the eardrums.

hiss--

Rumble rumble rumble!

The scene was like a curtain of heaven falling, and the dazzling firelight could almost dazzle the observer's eyes.

The wild donkey flew higher and higher, its trail of flames and exhaust fumes covering half the sky.

Before long, it disappeared into the cloudless sky, leaving only spirals of gray smoke.