Chapter 223: Fusion
Dojin Frontier, Foundry Hangar.
Half of the massive Leviathan’s propellant tank, measuring over a dozen meters, was mounted on a large jig.
The digital clock on the wall read 04:57.
Despite the early hour, numerous engineers had gathered around it.
“You need to use the American TIG welding method to get a stable weld pool!”
“No, with high-strength alloys, the thermal strain rate is lower. Russian electron beam welding is far more efficient.”
“Don’t you know that electron beams can’t be run at once due to vacuum chamber capacity limits?”
“That’s because the equipment is outdated. With the new model from Japan, it’s entirely possible.”
Germany, Russia, Japan, India, the United States…
Each country’s engineers, with their distinct accents, argued that their technology was the ‘right answer.’
As evidence, the blueprint was plastered with various processing icons.
“Sheesh, what’s the use of genius and technology if we can’t unify on one method?”
Chilbong shook his head at the ongoing dispute.
“At this rate, we won’t be able to build the Leviathan in six months.”
Kim Se-bin also sighed.
He had tried to mediate several times.
But with such strong opinions and pride, his efforts were in vain.
Then, a man holding a megaphone entered the hangar.
“Everybody stop!”
Peeeee-!
The megaphone’s sharp sound echoed through the hangar.
As the surroundings fell silent, I pointed to one man.
Wearing a welding mask and crossing his arms as if he held authority here, the man was Rajesh Kumar, an aerospace structural expert recruited from India’s HAL.
“Rajesh, did you just mention TIG for the propellant tank welding?”
“Yes. If not TIG…”
I cut him off.
“Using TIG, the weld pool collapse rate is over 3% at 1.9 times the pressure. What do you think about this result?”
Rajesh immediately reacted with disbelief.
“That can’t be right. From what I verified at HAL…”
“How did you set the environmental variables then?”
“…”
Rajesh was momentarily speechless at the unexpected question.
“It must have been 1 atm pressure, standard temperature, and moisture content below 0.1%, right?”
Rajesh’s expression hardened.
“It… it was.”
“The Leviathan isn’t just a toy for the ground. The 1.9 times pressure I mentioned simulates the internal peak pressure at sea level plus acceleration, including how the alloy’s microstructure deforms. This is the result.”
I held up a tablet, showing Luna’s real-time FEA (Finite Element Analysis) data.
The predicted defect points in the weld, marked in red, all matched the TIG-only method areas.
“…”
Setting aside the flustered Rajesh, I turned to Sergei Andreyevich, the chief engineer from Russia’s Khrunichev Space Center.
“You’re suggesting electron beams?”
Sergei slowly nodded.
“Yes. Electron beams minimize structural deformation. However…”
Sergei glanced at the tablet screen and continued.
“If this data is accurate, it could be problematic. I don’t fully trust it.”
He meant he couldn’t believe the results I had shown.
Nearby, Friedrich Bauer, a structural analysis expert from Germany’s DLR, chimed in.
“I agree with Sergei. To analyze this, you’d need at least a multimillion-node finite element model, coupling dynamic thermal stress and microstructure changes in real time. Even NASA’s supercomputers take over three hours for that.”
“And to simulate real-world conditions, you’d need to account for material-specific boiling points, solidification points, and residual stresses.”
Sato Hiroshi from Japan’s Mitsubishi Heavy Industries raised an eyebrow.
“So, you don’t believe the results I showed?”
“Frankly… no.”
These experienced and proud engineers couldn’t easily believe what they hadn’t seen with their own eyes.
With everyone’s attention on me, I swiped the tablet screen to access Luna.
“Luna!”
Luna’s voice came through the tablet speaker.
[Please tell me what you need.]
Her voice was even more natural than during the recent EV-Nova cognitive test.
At Luna’s unexpected appearance, murmurs and gasps filled the room.
“What…?”
“Is the AI’s voice really that natural?”
“Wait, is that… the AI talking to the boss?”
Everyone knew I was developing Luna, as I’d mentioned it several times on the feed.
But they didn’t know Luna was already at a practical stage.
I gave Luna a direct command.
“Leviathan Stage 1 propellant tank, alloy code AL-Li 2195. Conditions: sea level + 4.3G acceleration, 1.9 times internal pressure, 0.15% surface moisture, weld pool temperature deviation ±12°C. Compare and analyze TIG, electron beam, and hybrid methods.”
Luna responded immediately.
[Collecting data… Analysis results will be displayed in 15 minutes.]
In just 15 minutes, interpretation data for all three methods appeared on the screen connected to the tablet.
Each graph included thermal strain rate, microstructure crack occurrence rate, production time, and estimated maintenance costs.
TIG: Crack rate 3.12% / Production days 182 / Cost 1.0x
Electron Beam: Crack rate 1.23% / Production days 204 / Cost 1.4x
Hybrid: Crack rate 0.23% / Production days 134 / Cost 1.15x
Luna calmly continued her analysis.
[The hybrid method has the lowest crack rate and reduces production time by 27%. It also has the most uniform residual stress distribution under high temperature and pressure, ensuring higher structural stability during reignition.]
Her natural response drew gasps from the crowd.
“…Such precise calculations in just 15 minutes?”
“This is at least 50 times faster than the simulation tools we’ve been using.”
Friedrich asked in astonishment.
“Can we really trust this analysis?”
“You can trust it!”
I replied.
“It’s based on predictions from the vast data compiled by countless engineers.”
No matter how skilled these engineers are, they can’t predict every scenario.
But Luna, leveraging data from KTalk, Feed, Quantum, and Lunar, could produce results faster than anyone.
Sato Hiroshi bit his lip.
“So, Luna’s output isn’t just a simulation… it integrates all experimental and operational data from around the world?”
I nodded.
“It’s not just faster calculations; the data depth is different. For example, it includes Japan’s 15-year-old microstructure change patterns for AL-Li 2195 and Russia’s stress distribution data from launch vehicle reignition tests.”
Sergei narrowed his eyes and looked at the screen again.
“…Our existing methods can’t match this level of predictive precision.”
“That’s why I said this isn’t just an argument—it’s a fusion of experimentation, operation, and analysis.”
I slowly continued, looking around.
“Everyone here is undoubtedly the best in their field, but individual knowledge can’t solve these vast conditions simultaneously. But as you can see, Luna can.”
Kim Se-bin, who had been quietly listening in a corner of the hangar, smiled and joined the conversation.
“So, the conclusion is that the hybrid method is the best way forward?”
It seemed like an attempt to lighten the mood.
But I shook my head firmly.
“No! From now on, if opinions differ, everyone must follow Luna’s and Director Kim Se-bin’s judgment. That’s today’s conclusion.”
“…”
As expected, they didn’t agree immediately.
So, I spoke even more firmly.
“If anyone disobeys my instructions, no matter how skilled they are, they should pack their bags immediately. Understood?”
As I looked around, the engineers of various nationalities replied with surprised expressions.
“Understood!”
For salaried workers, the threat of losing their job was more effective than Luna or persuasion.
Three months later.
I posted on the feed.
[KTalk Feed] - @Kang Tae-joon | Followers: 132,982,172
Leviathan Goals
Engine Restarts: 5
LEO/GTO Payload: 100t/35t
Reusable Stage 1 Booster Recovery
Turnaround Time: 7 Days
#OverwhelmingPerformance #FirstLaunchIn3Months
The short but incredibly ambitious goals immediately focused the world’s attention on Kang Tae-joon and Dojin Frontier.