161: Chapter 161 Twenty-four stars, weaving a space-based quantum star map!

Alien civilization voyage timer, Day 27.

Pangu Laboratory B2 level, secondary screen workstation area.

Academician Qian Zhenhua slammed a stack of A4 paper onto the console.

The paper was densely packed with handwritten formulas, and the bottom right corner of each page had a serial number he had marked in pencil, from 1 to 47.

"The optical axis self-calibration scheme has successfully run through."

The old man pulled a red ballpoint pen from his pocket and drew a circle next to a matrix transformation formula on page 38.

"The optical axis synchronization of the quantum entangled state has a theoretical error convergence of 0.004 arcseconds, which is three orders of magnitude more precise than the ground pre-calibration accuracy of traditional Star Sensors."

Su Che walked over from the main console, the sleeves of his hoodie rolled up to his forearms.

He flipped to page 38 and scanned the derivation process marked by the red circle.

"This term in the convergence condition." Su Che pointed his index finger at an integral symbol. "You used a steady-state approximation. The entangled particle pairs are disturbed by solar wind in the orbital environment, so the steady-state assumption will be broken."

Academician Qian Zhenhua thought for a few seconds, then fished out a cowhide-covered notebook from under the console.

The cover of the notebook was so worn that the writing was barely visible; it was what he had used thirty years ago when working on a project at the Chinese Academy of Sciences' Institute of Optics.

He flipped to a certain page and pointed to a handwritten derivation.

"Add a random perturbation term." Academician Qian Zhenhua picked up his red pen and added a line of small characters next to the integral symbol on page 38. "Use the Wiener process to model the random component of the solar wind, and the convergence condition becomes a stochastic stability criterion."

Su Che looked at it. "That works."

He pulled the stack of papers away and clipped them into his code document folder.

11:00 AM.

Academician Li Zhengyang occupied a folding table in the corner of the testing area.

On the table lay four printed and bound collections of papers and a military-grade encrypted terminal, with a numerical solution model for the three-body problem running on its screen.

The core difficulty of the theoretical model for celestial coordinates in the Earth-Moon system lies in the irregular perturbations of the Moon's orbit.

The Moon does not run along a standard ellipse; it is pulled by the gravity of the Earth, the Sun, and Jupiter, causing its orbital parameters to drift constantly.

To lock down absolute coordinates at the nanometer level in such a drifting environment, the precision of the theoretical model must cover up to the sixth-order perturbation term.

The sixth order.

Traditional aerospace navigation only calculates up to the third order, but Su Che directly demanded the sixth order, which was like asking an abacus master to do the work of a supercomputer.

Academician Li Zhengyang pushed his thermos to the corner of the table, freeing up his left hand to flip through the papers.

His right hand adjusted parameters on the terminal.

"The fifth-order Jovian perturbation has already converged." Academician Li Zhengyang didn't even look up. "The sixth-order solar radiation pressure perturbation is still missing a correction coefficient. The theoretical derivation is fine, but the numerical solution isn't running stably."

Wen Bo walked past holding an enamel mug.

"If the numerical solution isn't stable, try changing the integration step size."

"I've changed it seven times."

"Then change the integrator." Wen Bo took a sip of plain water. "The fourth-order Runge-Kutta is too crude. Use a Symplectic Integrator. For long-period problems in celestial mechanics, Symplectic Integrators have good symplecticity, and energy conservation won't drift."

Academician Li Zhengyang turned his head to glance at Wen Bo.

"You're a materials mechanics guy, and you know this?"

"I took celestial mechanics as an elective during my undergraduate studies and got a score of ninety-two." Wen Bo walked away carrying his enamel mug.

Academician Li Zhengyang switched the integrator from Runge-Kutta to Symplectic.

Three minutes later, the convergence curve of the numerical solution turned from a jagged shape into a smooth monotonic decrease.

"It actually works." After saying that, he continued adjusting the parameters.

Su Che returned to his main console workstation. The screen was split into left and right columns.

The left column showed the core algorithm of the quantum star map he was currently writing, with the lines of code already reaching fourteen thousand.

The right column showed the virtual near-Earth orbit scene in the background of the Mirror World, where he had placed three virtual Quantum Communication satellites on three orbital planes at 120 degrees to each other.

Three were enough to test the basic networking logic, but to cover the entire Earth-Moon system, twenty-four would ultimately be needed.

He pulled up the core module for space-based node collaborative navigation that he had written this morning.

The difficulty did not lie in the positioning accuracy of a single satellite.

It lay in the cross-verification of signals among the twenty-four satellites.

Each satellite maintained quantum entanglement channels with the other twenty-three satellites. For twenty-four satellites, that meant 276 pairs of entanglement channels running simultaneously. If any single pair experienced decoherence, the entire navigation grid would develop a positioning blind spot.

Su Che simulated a set of decoherence perturbations in the Mirror World.

The entanglement channel of Satellite No. 2 among the three virtual satellites was forcibly interrupted.

The navigation accuracy instantly dropped from the nanometer level to the centimeter level.

It wasn't robust enough.

Su Che deleted the original redundant switching strategy and replaced it with a "dynamic entanglement redistribution" logic.

When a certain pair of entanglement channels decohered, adjacent satellites would automatically take over the idle entangled particle pairs, rebuilding the channel within 0.1 milliseconds.

He plugged the modified code into the virtual scene to run.

The channel of Satellite No. 2 was interrupted.

After 0.08 milliseconds, Satellite No. 1 and Satellite No. 3 took over simultaneously.

The accuracy restored to the nanometer level.

Su Che wrote a line in the code comments: "Decoherence fault tolerance passed, pending verification for expansion to the full 24-satellite network."

The expansion verification could not be rushed; the networking logic for three satellites was completely different from that of twenty-four.

He needed to wait for Liu Huaqiang to finish adapting all the underlying Quantum Communication interfaces of Pangu OS before he could build a complete 24-satellite virtual environment.

He saved the code and stood up to stretch his shoulders.

Lin Waner walked in from the side door, holding two kraft paper bags in her hand.

She placed one bag on Su Che's desk and delivered the other to Academician Li Zhengyang.

Su Che opened the paper bag.

Two Donkey Burgers and a carton of yogurt.

"Changed your taste?" Su Che took a bite of the burger; the pastry was crispy and the donkey meat was hearty.

"I learned it from the housekeeper." Lin Waner collected a stack of used paper cups into a trash bag.

Su Che chewed on his burger and glanced at the monitoring wall.

The footage of the Dry Dock ran day and night.

The completion progress of the keel truss and the laying progress of the enclosed final assembly cabin shell were both accelerating.

Five hundred robots had their plasma welding torch consumables replaced, which were delivered by the luan bird verification ship over two sorties yesterday.

No malfunctions had occurred over the past few days, and the scheduling algorithm had already self-optimized through three versions in actual combat.

Su Che poked a straw into his yogurt and turned his head to look at the other side of the main console.

Liu Huaqiang was hunched over his keyboards, his hands jumping back and forth between two of them—one running the underlying code of Pangu OS, and the other running the protocol stack adaptation for the Quantum Communication signal link.

"Dean Liu, what's the progress on the Pangu OS side?"

"The underlying interface adaptation has reached sixty-three percent."

Liu Huaqiang pressed Enter with his index finger, and a section of compilation logs scrolled rapidly up the screen.

"There is a timing conflict between the Quantum Communication protocol stack and the kernel scheduling of Pangu OS. I'm writing a middleware to isolate it, which should be resolved before tonight."

Su Che took a sip of yogurt.

"Once that's resolved, set up the 24-satellite virtual networking environment for me. My core algorithm's three-satellite test has successfully run through, and I need to do a full-network expansion verification."

"I'll have it for you tomorrow." Liu Huaqiang's left hand had already dropped back onto the other keyboard.

Alien civilization voyage timer, Day 29.

6:10 PM.

The fluorescent lights in the B2 level hall had been on for forty-eight hours without being turned off.

On the screen in front of Su Che, twenty-four virtual Quantum Communication satellites were evenly distributed across six orbital planes of the Earth-Moon system.

The entanglement channels between each satellite and the other twenty-three were represented by thin, light-blue lines, with the 276 lines weaving the screen into a glowing spiderweb.

He launched the full-network joint debugging test.

Round One: Perturbation-free baseline test.

Simultaneous positioning of the twenty-four satellites, outputting coordinates.

Compared with the preset standard coordinates in the Mirror World, the error was: plus or minus 0.04 nanometers.

Standard met.

Round Two: Single-satellite decoherence fault tolerance test.

Randomly interrupt all entanglement channels of Satellite No. 7.

0.08 milliseconds, adjacent satellites finished taking over, and accuracy was restored.

Standard met.

Round Three: Simultaneous multi-satellite decoherence.

Simultaneously interrupt three satellites: No. 7, No. 13, and No. 21.

Su Che's finger hovered directly above the Enter key.

Simultaneous decoherence of three satellites meant thirty-three pairs of entanglement channels snapped instantly, and the remaining twenty-one satellites had to complete the redistribution of sixty-six channels in an extremely short time.

He pressed Enter.

On the screen, the indicators of the three satellites turned red.

Three black holes appeared in the spiderweb.

0.12 milliseconds.

The dynamic redistribution logic of the twenty-one satellites was activated.

The light-blue lines reorganized rapidly, filling the severed areas.

0.19 milliseconds.

All channels were completely rebuilt.

Accuracy output: plus or minus 0.07 nanometers.

Slightly higher than the baseline value, but still within the nanometer range.

Su Che saved the test report into an encrypted folder.

Three-satellite fault tolerance passed.

But interference in the real environment was far more complex than in simulations.

Solar wind, cosmic rays, sudden temperature changes—any single factor could cause entangled particles to decohere.

Academician Qian Zhenhua's optical axis self-calibration scheme, now with the random perturbation correction term added, needed another round of numerical simulation.

Academician Li Zhengyang's sixth-order perturbation model was also still being polished for its final correction coefficient.

Liu Huaqiang's Pangu OS middleware was finished, but the end-to-end latency testing for the signal link had not yet wrapped up.

With four threads twisted together, whichever reached the finish line first would have to wait for the other three to catch up.

Su Che stood up and rolled his sleeves back down.

In the corner of the hall, Academician Qian Zhenhua was squatting next to an Optical Calibration Instrument, shining a flashlight on a loose fastening screw on the instrument's base.

He pulled out a Swiss Army knife, flipped out the smallest screwdriver bit, and gave it two turns.

Sitting behind the folding table, Academician Li Zhengyang watched the Symplectic Integrator on the terminal screen spit out a new convergence curve.

He picked up his thermos to drink water, but the lid fell to the floor and rolled under the table.

When he bent down to pick it up, his head bumped against the edge of the table.

"Hiss!"

Wen Bo kicked the lid as he passed by, sending it rolling right to Academician Li Zhengyang's hand.

"Buy one with a latch next time." Wen Bo didn't stop walking.

Lin Waner pushed open the door and entered, carrying a large insulated container in her hand.

She set the insulated container on the communal dining table and lifted the lid, revealing a pot of steaming tomato beef brisket.

"Time for dinner."

Dean Liu, Academician Li Zhengyang, and several others put down their work and gathered around.

Su Che took a disposable bowl and ladled out half a bowl of beef brisket.

The tomatoes were stewed to a pulp, the broth was thick, and the beef chunks melted in the mouth.

The six of them ate around the communal dining table.

The fourteen researchers went to the cafeteria in batches, leaving the hall unusually quiet for a moment.

"I've estimated the steps for the final full-link joint debugging of the navigation system."

Su Che swallowed a piece of beef.

"The full-network verification of the core algorithm will take two days, Academician Qian's optical axis scheme simulation will take one day, Academician Li's perturbation model wrap-up will take one and a half days, and Dean Liu's end-to-end signal link testing will take one day."

"Some processes can run in parallel, while others must be in series. In total, we still need about three days."

Liu Huaqiang adjusted his glasses.

"The signal link testing can run in parallel with the optical axis simulation."

"Once the final parameters of the perturbation model are out, I have to feed them into the core algorithm to run a regression test." Su Che stirred the soup in his bowl with a spoon. "This step must be done in series."

Academician Qian Zhenhua mumbled something while chewing on a piece of beef, but no one could hear him clearly.

He swallowed and said it again.

"I can deliver my part of the serial work tomorrow morning."

Su Che nodded.

After dinner, as Lin Waner was clearing the dishes, she placed a plastic bag next to Su Che's hand.

Inside the bag was a pair of new cotton slippers.

The heels of the slippers Su Che was wearing had already been trodden flat, making a pitter-patter sound as he walked on the laboratory's alloy floor.

He changed into the new slippers and threw the old ones into the trash can.

On the monitoring wall, four hundred kilometers above.

The laying of the outer shell of the Dry Dock's enclosed final assembly cabin was progressing steadily.

Swarms of robots shuttled and worked against the dark background of space, the light of their plasma welding torches flickering like a swarm of fireflies foraging in a metal jungle.

The luan bird verification ship was docked at the edge of the Dry Dock, and the cargo sent up from Earth was being unloaded.

Su Che sat back down at the main console.

He opened the code repository for the core algorithm and flipped to the third sub-function of the dynamic entanglement redistribution module he had written this morning.

This sub-function was responsible for handling extreme situations. When the number of decohered satellites exceeded a quarter of the total, the remaining satellites' entanglement resources would not be enough for one-to-one takeovers, and they would have to enable a "many-to-one shared entanglement" mode.

Su Che had previously left an interface unfilled.

He placed his hands on the keyboard and began writing.

The lighting on the B2 level was very even, making it impossible to tell day from night.

The sound of the keyboard clattered intermittently.

In the outside world, the second batch of two hundred million pairs of Star Sea Glasses for the Mirror World was being distributed globally, and the numbers in the virtual ecosystem's independent points pool were rising every minute.

In orbit, the Dry Dock grew bit by bit.

Underground, Su Che wrote code line by line.