【Earth】

"Professor, the planetary mining project has been successfully completed."

The synthesized electronic voice rang out in the laboratory, interrupting Lü Yongchang's work of writing and drawing.

"Is it finished...?" Lu Yongchang looked up and glanced at the holographic clock on the wall, a hint of confusion in his eyes. "It's pretty fast."

"What about the Kepler-452C? Has it been destroyed?"

“Yes, there are currently only five planets left in the Kepler-452 star system.” Zero responded quickly, while simultaneously projecting a scene of the Kepler-452c explosion onto the holographic projection.

"How is the gravity compensation ship operating?" Lü Yongchang asked Zero as he walked toward the porthole next to him.

As a member of the star system, the sudden disappearance of Kepler-452c will inevitably have some impact on the operation of other celestial bodies in the star system.

At that time, Kepler-452b might encounter considerable "trouble" in human habitation areas.

For current human civilization, it is virtually impossible to completely eliminate this influence.

However, minimizing this negative impact is something that human civilization can do.

Gravity compensation ships were built for this purpose.

With the help of several large gravitational field generators, it can produce a gravitational field with an intensity similar to that of Kepler-452c.

If it simply replaces Kepler-452c and continues to operate in its original planetary orbit, it can reduce or even eliminate most of the negative effects caused by gravitational disturbances.

"Operating normally," Zero's response came from behind. "No abnormal celestial movements have been detected within the star system so far."

Lü Yongchang nodded slightly, placed his hands on the windowsill of the porthole, and turned his gaze toward the location where Kepler 452c had originally been.

In the dark universe, a few scattered red and purple lights flickered.

That was the light of molten iron and high-energy laser light mixed together.

This is the final statement a planet that has existed for billions of years sent to the universe.

Just as Lü Yongchang was staring blankly at the flickering lights, the synthesized electronic voice sounded again.

"Professor, Academician Wang Man has sent a communication request. Should we answer it?"

Lu Yongchang snapped out of his daze, glanced at the holographic projection behind him, nodded, and replied, "Connect me."

The next second, a large, wrinkled face appeared in front of him.

Looking at that joyful face, Lü Yongchang's lips curled up slightly, and his mood improved unconsciously.

"Academician Wang seems to be very happy."

"Hey! Professor Lü, what are you saying?" Wang's smile grew even wider. "What a bumper harvest, Professor!"

"The Kepler 452C directly filled the gap in the fleet's basic metal supply. Not to mention the current circular living quarters, it could easily support another mega-construction!"

Lu Yongchang looked at Wang Man, whose face was beaming with a bright smile, with great interest: "Is this really true?"

Upon hearing this, Wang Man felt a jolt in his heart.

Before the smile on his face could fade, Lü Yongchang said, "Perfect timing, I have another mega-structure project here."

"I'll have Academician Tang Hairong start preparing in a couple of days."

"Ahem... Professor..." Wang Man gave a slightly embarrassed smile and asked in a low voice, "May I ask what kind of mega-structure it is?"

“Of course,” Lü Yongchang said casually. “It’s something we’ve made before.”

"Planetary fortress, do you remember it?"

"thump!"

Wang Man plopped back down in his seat.

Planetary Fortress!

It's no exaggeration to say that all the projects currently under construction by the People's Federation combined don't even come close to the resource consumption of that thing!

This... this is going to kill him!

At this moment, the smile on his face had completely disappeared.

"What's wrong, Academician Wang?" Lu Yongchang looked at Wang Man with a smile in his eyes and said in a teasing tone, "You weren't like this just now."

Wang Man swallowed hard, raised his hand to gently wipe the cold sweat from his forehead, and said with a wry smile, "Professor, I was just saying it casually, please don't joke with me."

Lu Yongchang looked at Wang Man in the holographic projection with a half-smile.

After a moment of silence, he said softly, "Who said I was joking?"

"Once the starship replacement project is completed, the construction of the planetary fortress will be put on the agenda."

"As we can see from the last war with the Bosa civilization, although planetary fortresses consume a lot of resources, their effectiveness in interstellar warfare is far superior to that of one or a few starships."

"Previously, due to technical limitations, the planetary fortress was only a semi-finished product."

"This time, I want to build a true planetary fortress."

"At the very least, it has to move!"

"Hiss!!!" Wang Man gasped upon hearing this.

He silently calculated a very rough account in his mind.

To achieve the goal Professor Lü mentioned, we must at least add a propulsion system to the planet.

This would require hollowing out the interior of the planet.

Simply hollowing it out won't do; we need to install various fixing and support devices inside, otherwise this planetary fortress will just become a hollow stone shell.

If it breaks at the slightest touch on the battlefield, it will become a huge joke!

In addition to weapon systems, defense systems...

After settling the accounts, Wang Man looked at Lü Yongchang with a deathly pale face: "Professor, we...we don't have that many resources either!"

"If there are no resources, then mine them on-site!" Lü Yongchang looked at Wang Man with astonishment. "Why aren't you using such a useful resource extraction method? Are you just going to leave it there to admire?"

“No, that’s not the problem…” Wang Man’s expression grew increasingly bitter. “In our star system, besides Kepler-452b, there’s only one rocky planet left!”

"According to the exploration report, the mineral resources on this rocky planet are not abundant. If we were to mine them, it might be a losing proposition."

Hearing this, Lü Yongchang became even more surprised.

"Who said it was in our star system?"

"Huh?" Wang Man was slightly taken aback, a look of confusion on his face.

"The curvature probe we sent out recently has successfully transmitted back its report." Lü Yongchang smiled as he transmitted a document to Wang Man on the other side of the camera. "According to the report, in that star system 6.71 light-years away from us, there are three iron planets and two rocky planets, and the metal mineral resources are quite abundant."

"Furthermore, the probe did not find any trace of extraterrestrial civilization."

Wang Man suddenly realized.

"Professor, do you mean to send a fleet to mine in the surrounding star systems?"