I started with a ship full of max-level veterans, and I'm just a complete noob.

After instructing Lao Sun to guard the testing station, Jiang Ming crossed the factory road and returned to his dormitory.

Moonlight shone on the thin ice that hadn't completely melted on the cement steps. As he pushed open the door, a brown paper envelope slipped out a few inches from under the door. The cover was stamped with a red official seal, and the heading read "Beijing Institute of Mechanics" in lead type.

He picked up the envelope, checked that the sealing wax was intact, closed the door, sat down on the iron bunk bed, cut open the seal, and pulled out six pages of letter paper.

Each page is written in neat penmanship, with the first line reading "Theoretical Derivation of Thermal Expansion Mismatch between Metal Oxide Coating and Kovar Alloy Substrate under Vacuum Interface Conditions".

Qian Xuesen started with a shear stress model, wrote the normal stress distribution during the cooling process of the coating film into an equation, and introduced the slip rate coefficient of the metal lattice in the high temperature region, reducing the microcrack propagation condition to a function of temperature and holding time.

From the third page onwards, the derivation shifts to the interface mismatch strain integral, the continuous cooling is broken down into a step approximation, and the most dangerous temperature window is also deduced.

All the conclusions are listed at the bottom of page five, in a single line of numbers circled in red ink.

When the cooling rate exceeds two degrees per minute, the shear stress at the coating interface will reach a critical value at 378.5℃. An isothermal step of no less than thirty minutes must be set, otherwise the microcracks at the interface will propagate irreversibly.

Jiang Ming stared at the temperature of 378.5℃, his fingers creasing the edges of the letter.

The female pioneer of precision instruments in the psychic communication gave a correction of 380°C, while Qian Xuesen used complete mathematical derivation to arrive at the same point from a different path.

He turned back to page four, where there was a line of small print in the margin.

As noted above, within the cooling range above 378℃, metal oxide coating interfaces that have not undergone isothermal treatment will develop cumulative microcracks that cannot be repaired by subsequent annealing.

As noted below on the same page, alternating electromagnetic fields can induce eddy current thermal stress within metal coatings, causing interface mismatch to expand and resulting in irreversible magnetization drift in precision strain gauges and pressure sensors.

Jiang Ming folded the six pages of letter paper back into the envelope in order.

The combination of Qian Xuesen's handwritten derivation and the confidential stamp of the Beijing Institute of Mechanics meant that the 380°C cooling step now had an origin that the review team could not circumvent, and it also meant that the south side of Workshop No. 1 had a counter-offensive point against Xu Chongwen.

The lights were still on on the second floor of the administration building outside the window.

Jiang Ming glanced at the site requisition notice from the material allocation department in his pocket. Xu Chongwen wanted to use a wind tunnel model to occupy the south side of the site and had to vacate it within three days.

"Three days?"

Jiang Ming opened the metal box under the bed, took out a hard-covered notebook, and listed the physical environment of the south side of Workshop No. 1 on a blank page.

After writing down the electrophoretic deposition tank, pickling area, annealing furnace, high-frequency heater, acetone vapor concentration, acid mist direction, electromagnetic radiation range, and daily monitoring values, he stuffed the notebook and Qian Xuesen's letter into the inner pocket of his work clothes.

"No need to wait three days, he won't be allowed to touch this place tomorrow morning."

At 7:20 a.m. the next morning, intermittent water hammer sounds came from the metal heating pipes in the small conference room of the Third Electronics Factory.

The deputy director of the materials allocation department sat at the head of the long table, with two official documents laid out in front of him.

Xu Chongwen sat on the right, his briefcase resting on his lap.

Factory Director Zhang and Wu Hanzhang sat opposite each other, with a copy of the site requisition notice on the table.

The deputy director picked up his enamel mug, took a sip of tea, and set the tone with his opening remarks.

"Director Zhang, it's not that the allocation department is making things difficult for you. The supersonic wind tunnel model at the Aerodynamics Center is a key project of the Ministry. The Aviation Institute's warehouse is leaking, and we can't let hundreds of thousands of precision models soak in there."

Wu Hanzhang pushed the copy forward half an inch.

"Deputy Director, Workshop No. 1 is a top-secret research site registered with the Commission of Science, Technology and Industry for National Defense. The lifespan test requires 24-hour continuous power supply. If something is put in there now and an accident occurs, who will be responsible?"

Xu Chongwen looked up and replied, his tone leaving room for maneuver, but his meaning remained firm.

"Chief Engineer Wu, there's no need to be nervous. We're only requisitioning the open space on the south side. We won't touch the equipment on the north side. The model will be sealed in a wooden crate, and there will be no electricity or water supply. It's just a temporary placement."

Factory Director Zhang knew the weight of those words.

Once the site on the south side is occupied, there will be nowhere to place the subsequent batch of electric swimming pools and aging test racks, effectively cutting off the mass production route of the Type B pipe.

He looked at Xu Chongwen.

"Dr. Xu, how much space does the model take up?"

Xu Chongwen answered decisively.

"The main body is 6.4 meters long and has a wingspan of 3.2 meters. With the base and shock-absorbing frame, it is about 40 square meters."

Just as Director Zhang was about to speak, the conference room door was pushed open.

Jiang Ming stood at the door wearing his old work clothes that he hadn't changed out of after working all night, the collar still smelling of burnt rosin solder from Workshop No. 1.

Without exchanging pleasantries, he walked to the end of the long table and took out a hardcover notebook and a kraft paper envelope from his inner pocket.

"I'm late, the test data was just filled in."

Jiang Ming opened his notebook and pushed it in front of the deputy director.

"Deputy Director, before discussing the site, let's first assess the physical environment on the south side of Workshop No. 1."

Xu Chongwen leaned forward, his gaze fixed on the notebook.

The deputy director glanced down at the data page, and the three lines highlighted in red pencil stood out.

Jiang Ming didn't give him time to think it over.

"First, the south side of the site is less than four meters away from the electrophoretic deposition tank. The anhydrous acetone in the tank evaporates at room temperature, and the concentration of acetone vapor in the air has been maintained at 80 to 120 parts per million for a long time."

He flipped to the next item.

"Secondly, the pickling area operates for at least six hours a day, and the exhaust system sends the airflow containing dilute nitric acid droplets to the south ventilation opening, resulting in the air on the south side of the site being acidic for a long time."

Jiang Ming continued clicking.

"Third, the annealing furnace and high-frequency heater in Workshop No. 1 operate for more than twelve hours a day, with a working frequency covering 30 to 500 kilohertz. The southern area is within the near-field radiation range, and the measured alternating magnetic field strength exceeds two amperes per meter."

He pushed the notebook closer to the deputy director.

"Dr. Xu, what material is the surface coating of the supersonic wind tunnel model made of?"

Xu Chongwen looked at him.

"Nickel-chromium alloy coating".

Jiang Ming's fingertips landed next to the data.

"In acidic mist environments with a pH below 5.5, the intergranular corrosion rate of nickel-chromium coatings will enter an accelerated phase within 72 hours. This is publicly available data from the materials handbook, and I don't need to teach Dr. Xu about it."

The deputy director put down the enamel mug, the bottom of which tapped on the table with a muffled thud in the conference room.

Jiang Ming pulled out the six pages of letter paper from the kraft paper envelope, turned to the fourth page, and placed it face up next to the notebook.

"This is an academic derivation sent by Comrade Qian Xuesen through the confidential channel three days ago. The main text discusses the thermal expansion mismatch between high-temperature metal oxide coatings and Kovar alloy substrates, and the fourth page contains side notes on the interface mismatch problem under alternating electromagnetic environment."

His finger paused beside the red ink annotation.

Mr. Qian pointed out that high-frequency alternating magnetic fields can induce eddy currents inside the metal coating, and the eddy current thermal effect is sufficient to create accumulated thermal stress at the interface between the coating and the substrate.

"The precision strain gauges and pressure sensors inside the wind tunnel model will also experience irreversible magnetization drift in this environment."

Jiang Ming looked up at Xu Chongwen.

"Dr. Xu has a background in fluid mechanics, so the boundary layer stress analysis and metal lattice slip theory in these few pages of derivation should be within your knowledge."

Xu Chongwen gripped the edge of his leather briefcase.

"An electromagnetic shielding cover can be installed."

Jiang Ming turned to the bottom of the fifth page and pointed to the conclusion circled in red.

"Mr. Qian's conclusion is clear: when the frequency of the alternating magnetic field covers more than 30 kHz, the attenuation of conventional industrial-grade shielding is insufficient to suppress the induced eddy currents below the safety threshold."

"Unless a multi-layered composite shielding made of permalloy is used, Dr. Xu knows the cost of that kind of shielding better than I do."

Xu Chongwen shut his mouth and didn't reply.

Jiang Ming withdrew his hand and turned his gaze to the deputy director.

"Deputy Director, I'm not going to discuss which defense mission is more important or less important; I'm only talking about the risks on site."

"If the wind tunnel model is placed on the south side of Workshop No. 1, under the current operating conditions, the surface coating will begin to corrode within 72 hours, and the precision sensors will become magnetized and unusable within two weeks."

He placed his hands on the edge of the table and delivered his final words to the deputy director.

"If hundreds of thousands of models are destroyed, who will bear the responsibility—the materials allocation department or the aerodynamics center?"

The meeting room fell silent, with only the intermittent sound of water hammer from the heating pipes remaining.

Sweat beaded on the deputy director's forehead as he turned to look at Xu Chongwen, scrutinizing the man who had put him in such a precarious position for the first time.