"Wait!"
Jinling University.
Since Jinling was not along the launch trajectory, Shao Kaiwang had not prepared a space telescope this time. Instead, he gathered with Wu Ande, Lin Qian, and several others to watch the livestream.
When Chen Yi initiated full acceleration and the Lunar Lander Drone's exhaust plume surged, stretching several times longer, Shao Kaiwang instinctively checked the speed and pressure altitude displayed on the avionics interface.
That glance was all it took.
The moment he saw the rapidly climbing speed reading, Shao Kaiwang immediately noticed something was wrong.
"The number of Mach rings in that exhaust plume doesn't match its speed!" Shao Kaiwang shouted.
"It really doesn't. There are far too many Mach rings."
Lin Qian roughly counted the Mach rings, then compared them against the drone's speed and altitude, confirming Shao Kaiwang's judgment.
Mach rings were bright, dazzling halos formed in the exhaust of jet engines, rocket engines, ramjet engines, and other engines operating within the atmosphere.
To put it more professionally.
Mach rings were a standing-wave phenomenon created by the interference between compression waves and expansion waves in an engine's supersonic exhaust.
After the air inside a supersonic engine had done work, it became low-pressure, high-speed exhaust—or exhaust flame—and was expelled from the engine nozzle.
Because the exhaust pressure was lower than the surrounding atmospheric pressure, it was compressed by the surrounding air after leaving the nozzle.
Once compressed to a certain point, the exhaust expanded again. After expanding, it was compressed once more by the ambient air.
During this repeated process of expansion and compression, the supersonic exhaust generated a series of complex shock waves.
For example, Prandtl-Meyer expansion waves, Prandtl-Meyer compression waves, oblique shock waves, normal shock waves, and so on.
These complex shock waves caused the temperature at the boundaries between expanding and compressed exhaust to rise sharply, igniting residual fuel in the exhaust and forming distinct rings of light.
Those halos were the rings of Mach rings normally seen within an engine's exhaust plume.
Based on how Mach rings formed, it was not hard to infer.
The number of Mach rings was related to an aircraft's speed, as well as the ratio between jet pressure and the atmospheric pressure of the surrounding environment.
Experts could use an aircraft's pressure altitude, speed, and the number of Mach rings in its exhaust plume to roughly calculate the engine's efficiency and specific impulse.
But now, the number of Mach rings in the Lunar Lander Drone's exhaust plume clearly did not match its current speed and altitude.
If one reverse-calculated based on that number of Mach rings.
The Lunar Lander Drone's engine efficiency and specific impulse would surpass every current type of jet engine.
It would even exceed the theoretical efficiency limits of modern ramjet and rocket engines.
"There's something off about this Lunar Lander Drone's engine."
Shao Kaiwang captured a screenshot, enlarged the image of the drone's engine nozzle, then found footage from before Chen Yi had begun full acceleration, before the exhaust plume had surged.
After carefully comparing them, Shao Kaiwang was certain.
The engine used by this Lunar Lander Drone was unusual.
It was not any currently common turbojet, ramjet, or rocket engine.
A section of black cone was visibly protruding from the Lunar Lander Drone's engine nozzle.
"This..."
At that moment, Lin Weijie seemed to think of something. Pointing at the small protruding cone on the Lunar Lander Drone's engine nozzle, he said, "Could that be a rotating detonation engine?"
A rotating detonation engine?
Everyone froze for a moment, then immediately came to the same realization.
That engine structure with a protruding conical section was indeed the nozzle structure of a rotating detonation engine.
"It really is the nozzle structure of a rotating detonation engine, but isn't that type of engine still in the laboratory stage?"
Wu Ande swallowed. "How did Yifei produce a mass-manufactured version and even build it into a drone?"
"Wangwang, where did you find this god-tier uploader?"
Lin Qian stared at the livestream, listening to Chen Yi explain things while controlling the drone. She said in awed disbelief, "No wonder he dared to claim he could reach the moon with a single drone."
"I don't know either. I watched all his previous videos, but I couldn't tell he was this amazing."
"We still can't be sure whether it really is a rotating detonation engine. There's no point in making too many guesses."
Shao Kaiwang was equally baffled.
As he spoke, he opened WeChat, clipped a section of the Lunar Lander Drone's ascent video, and sent it to his mentor along with the screenshots and their speculation. His mentor was an Academician and a National Scholar Unparalleled.
"Professor, I found footage of an aircraft test flight. The engine appears to be a rotating detonation engine. Could you take a look and see if I'm right?"
Less than ten seconds after he sent the message.
A call came in from a number that was not displayed, clearly a classified line.
Seeing the call, Shao Kaiwang suddenly felt his scalp tingle as he reached out and answered it.
"Hello."
"What laboratory did this classified video leak out of?"
"Where are you right now? Don't show the video to anyone else. I'm coming over immediately!"
A series of urgent yet familiar questions came from the other end of the call.
The moment he heard that voice, Shao Kaiwang relaxed and hurriedly replied, "Professor, it isn't from any laboratory. It's a livestream. This is footage from a livestream—the Yifei uploader's stream I showed you a few days ago!"
"A livestream?" The professor did not react immediately.
"Yes, a livestream. This uploader says he's livestreaming a drone flight to the moon!"
Shao Kaiwang glanced at the livestream and hurriedly explained, "The drone has reached the mesosphere and is currently in the parabolic acceleration escape phase. I'll send you the stream link!"
As he spoke, Shao Kaiwang quickly walked over to the computer.
He opened the livestream sharing option in the upper-right corner, sent the livestream room link to his phone, then forwarded it to the professor.
While Shao Kaiwang was sending the professor the link.
On the livestream, the Lunar Lander Drone, which had been continuously ascending.
Suddenly began moving horizontally as well, transitioning from the ascent phase into the parabolic escape phase.
"Accelerate, accelerate!"
"Use parabolic gliding acceleration, use the planet's rotation to accelerate, and break free from the planet in one go!"
"This drone is insanely powerful. Its speed has already exceeded Mach 16, over 5.4 kilometers per second, and it has only consumed one-third of its fuel."
"It's this powerful because it's strictly following an aerospace launch trajectory. Last time?
Last time, the streamer was just flying around like Xijiba. He didn't understand anything.
I've never seen anyone ram straight upward into space.
The key to spaceflight is speed, not altitude. The optimal approach is to make full use of the planet's rotation and accelerate along a parabola, rather than blindly chasing altitude."
"Brother, there's no need to mock him by saying he was flying around like Xijiba.
The streamer can fly a drone to the moon. Do you really think he understood less than you did last time?
All that can be said is that the two flights had different purposes.
Last time was a charge toward space, emphasizing momentum and unstoppable forward drive.
This time is a moon landing, emphasizing energy efficiency and indirect acceleration.
Anyone saying the streamer doesn't understand is the one who truly doesn't understand."
"I wasn't mocking him. I just think it's a pity.
If he had followed an aerospace trajectory last time, he wouldn't have failed to reach first cosmic velocity and could only crash from high altitude."
While Shao Kaiwang was sharing the livestream link with the professor.
The viewers saw that the Lunar Lander Drone had entered the parabolic escape phase and was accelerating to overcome the planet's centripetal force, so they began posting barrage comments.
Some viewers even started arguing over Chen Yi's Xijiba flying during the previous space-charge livestream.
"Enough, stop arguing. We're all here to watch the streamer's drone fly to the moon. What's there to argue about?"
"The drone has entered the skies above Fuhai. Where's our Fuhai observation team? Let's hear you cheer!"
"We're here! The Fuhai Xia University tracking team has successfully locked onto the target. Drone flight normal, tracking footage normal, remote sensing signal normal!"
Several viewers with Fuhai and Xiamen IDs posted a series of tracking images.
In the images, the indigo sky, tinged with a hint of purple and dotted with stars, formed the background as a comet-like streak of light advanced forward.
After the images were enlarged, the silhouette of a drone could be clearly seen, blasting out an exhaust plume, draped in starlight as it raced into the distance.
"What about Bay Central? Where is Bay Central's mountaintop team?!"
"After feeding 180 mountain mosquitoes, Bay Mountain Top Team has successfully locked onto the target. Drone flight normal, tracking footage normal, remote sensing signal normal!"
After waiting several minutes, Bay Mountain Top Team also posted a series of tracking images.
As the altitude increased, the background in the images had shifted from indigo to purple, indicating that the drone had entered the thermosphere.
"Bay North! How is Bay North doing?"
"Everything is normal at Bay North. Target successfully locked. Drone flight normal, tracking footage normal, remote sensing signal normal!"
"As the final stop in this online tracking and remote sensing operation for the Lunar Lander Drone, Bay North University will continue tracking the target until it exceeds first cosmic velocity and enters planetary orbit!"
"Bay North, well done!"
"People on both sides of the strait are one family! Well done!"
As tracking remained normal and remote sensing signals remained normal.
The viewers and university clubs involved in the tracking and remote sensing could no longer restrain themselves and began cheering in celebration.
After the previous two livestreams, they had all been won over by Yifei's drone technology and Chen Yi's skills.
This time, while other viewers were still doubting and shouting.
They had already prepared their recording equipment and, in just two hours, completed equipment setup, camera angle positioning, flight path calculations, tracking and remote sensing plans, and more.
"6.85 kilometers per second, acceleration 10.9 meters per second squared. Estimated to reach first cosmic velocity in three minutes."
Ignoring the barrage comments and the viewers' cheers, Chen Yi focused entirely on the monitoring display before him, constantly watching every high-speed parameter, velocity parameter, angle parameter, and more.
"It's entering the skies above the Pacific Ocean. The control antenna's signal is about to be blocked by the Earth's curvature."
After waiting a moment, Chen Yi looked at the control antenna beside him, which was aimed eastward and lowered almost to its minimum horizontal angle. Without hesitation, he waved at Qin Xiaoyu.
"Launch the drone. Altitude 800 meters, angle 60 degrees, accelerate eastward at supersonic speed."
A 3,000-word chapter. I was a little stuck on the plot, so the update came late.
Before you continue