Siheyuan (traditional courtyard house): Starting with the Korean War, returning home to take charge

"Three months? You're going to kill me."

Chief Engineer Liu slammed a wrench on the table, the clanging of metal echoing in the conference room. He didn't look at He Yuzhu, his head down, staring at the blueprint on the table, his short, stubby fingers tapping it twice. He Yuzhu didn't reply. Five seconds of silence followed. Chief Engineer Liu looked up, a wry smile playing on his lips. "I'm not backing down. The spindle precision of the CNC winding machine is 0.01 millimeters, the guide rail straightness is 0.02 millimeters per meter. If I started from scratch, I wouldn't even be able to produce a blank in three months. Even if you brought in a god, it wouldn't work."

He emphasized the word "immortal," glanced at Qian Zhiyuan sitting opposite him, and made his meaning clear—whoever proposed the plan should figure out a solution themselves.

He Yuzhu turned his gaze to Qian Zhiyuan. Qian Zhiyuan hadn't spoken, a thick stack of blueprints spread out in front of him, the top one depicting a strangely shaped machine. His finger traced down the parts list, stopping halfway down. He glanced at Chief Engineer Liu, then at He Yuzhu, his lips moving as if he were carefully choosing his words.

"Chief Engineer Liu, what if we outsource the spindle and guide rails?" Qian Zhiyuan turned to the third page of the blueprints, pointing to the parts list. "Harbin Bearing Factory produces precision spindles, and Shanghai Machine Tool Factory has readily available high-precision guide rails. We don't need to build from scratch; we only need to purchase the key components and assemble and debug them ourselves."

Chief Engineer Liu picked up the blueprint and stared at it for a long time, his brow furrowing deeply. He slammed the blueprint back onto the table, tapping the numbers with his knuckles, making a loud thud. "Outsourcing? Do you know what the process is like for outsourcing precision components for military projects? Whether the Harbin Bearing Factory will even supply us is another matter. They need to check the approval documents, the intended use, and the end user. Going through all that takes two months. And you expect me to assemble a bunch of parts into a machine in just one month?"

The air in the conference room became stuffy and heavy. Lin Jianguo leaned over from the other end of the conference table, elbows resting on the table, fingers interlaced. "Chief Engineer Liu, I'll handle the electrical control system. The Automation Department of Chengshan Research Institute has done six-axis linkage servo drives for Xinghe-6, so we have a ready-made solution. Give me a month, and I'll equip the control cabinet and software completely. Mechanical and electrical work can be done in parallel, so it won't take up your time."

Chief Engineer Liu glanced at Lin Jianguo, then looked down at the blueprints again. His fingers stopped tapping the table and began to move slowly across the blueprints, as if measuring every dimension with his fingertips. The only sound in the conference room was the rustling of the pages turning. He Yuzhu leaned back in his chair, taking in everyone's expressions. Qian Zhiyuan's fingers tapped lightly on his knees under the table, the rhythm quick. Lin Jianguo's clasped hands clenched tighter and tighter, his knuckles turning white. Old Zhou sat silently in the corner, his eyes behind his glasses narrowed to slits.

Chief Engineer Liu finally raised his head. "Two months for mechanical work, one month for electrical work, working in parallel, we can produce the first prototype in two and a half months. But there's one thing—" He turned to Qian Zhiyuan, "Director Qian's carbon nanotube fiber production needs to keep up. If the machine is built but there's no material to bind it, it's all for nothing."

Qian Zhiyuan took a roll of black fiber from the file folder and placed it on the table. The fiber was as thin as spider silk, gleaming dimly under the fluorescent light. He pinched one end of the fiber and handed it to Chief Engineer Liu. "Chief Engineer Liu, please try pulling it."

Chief Engineer Liu took the fiber, gripped it with both hands, and pulled hard. The fiber didn't budge. He put in even more force, the veins on his arms bulging, but the fiber still didn't break, nor did it change length. He released his grip, looked at his palm, and saw a faint red mark left by the fiber. He held the fiber up to his eyes, examined it against the light for a few seconds, then put it down, his voice lower. "This stuff is stronger than steel cable."

"The tensile strength is ten times that of steel wire of the same diameter, while the weight is only one-fifth." Qian Zhiyuan carefully placed the roll of fiber back into the file bag. "My current pilot production line produces fifty meters of continuous fiber per day. In two and a half months, the capacity will increase to two hundred meters per day. Winding a three-meter loop requires about 1,200 meters, which is enough. But there's one thing—" He paused, lowering his voice, "I need to add a used drawing machine, costing 500,000 yuan. It can be modified and used. Without this machine, doubling the production capacity is impossible."

All eyes turned to He Yuzhu.

He Yuzhu stood up, walked to the blackboard, picked up the chalk, and wrote a few lines. The chalk made a slight scraping sound on the blackboard, and white powder fell down in a flurry.

Mechanical Systems – Chief Engineer Liu, two and a half months.

Control system – Lin Jianguo, one month.

Carbon nanotube fiber – Qian Zhiyuan, two and a half months, daily production capacity of 200 meters.

Superconducting ring repair – Lao Zhou, proceeding simultaneously.

Additional funding – 500,000.

He tossed the chalk into the blackboard tray and turned around. "Timeline aligned. By mid-October, all components will be in place. By the end of November, repeat the curvature perturbation experiment. Target magnetic field of 25 Tesla, continuous operation for one hour without structural damage. Chief Engineer Liu, your pledge wasn't written for me, it's for the National Defense Science and Technology Commission. The superconducting ring reinforcement project has been included in the Spark Program's key project list; they're watching it closely."

Chief Engineer Liu didn't speak, but nodded.

"Lin Jianguo, the control system cannot have software failures. The data acquisition accuracy requirements for curvature disturbance experiments are extremely high, and the jitter of the control system will be directly reflected in the experimental results."

Lin Jianguo loosened his crossed fingers and tapped them lightly on the table. "I'll keep a close watch on the scene."

"Director Qian, your fibers must not be broken, must not have air bubbles, and must not contain impurities. If even one fiber breaks, the entire winding layer will have a weak point."

Qian Zhiyuan took a pen out of his pocket and wrote a line on the back of the drawing, the three "cannot" statements He Yuzhu had just made. He looked up after writing. "Understood."

The conference room door opened, and a young staff officer peeked in, holding a telegram. "Dean He, this is from Yang Xiaobing in Manila."

He Yuzhu took the telegram and glanced at it. Li Guodong had been arrested and was being held in the immigration detention center, awaiting extradition, expected in two weeks. He folded the telegram and put it in his pocket, not mentioning it at the meeting. He then scanned the people present. "Any more questions?"

No one speaks.

Meeting adjourned.

Everyone stood up one after another. Chief Engineer Liu tucked the wrench back into his belt, picked up the stack of blueprints, walked to the door, and glanced back at Qian Zhiyuan. "Director Qian, make sure the fiber doesn't fail you in those two and a half months."

Qian Zhiyuan hugged the file folder to his chest. "Once you build the machine, I can get on it."

Chief Engineer Liu snorted, pushed open the door, and left. Old Zhou followed him out, whispering something to Lin Jianguo as they walked. Only He Yuzhu and Qian Zhiyuan remained in the conference room.

Qian Zhiyuan didn't leave. He stood in front of the table, slowly gathering the scattered drawings one by one and stacking them neatly. He Yuzhu leaned against the blackboard, waiting for him to speak.

Sure enough, Qian Zhiyuan stacked the blueprints, hugged them to his chest, and turned around. His lips moved twice, but no sound came out; then they moved twice more.

"Dean He, I have a personal matter I'd like to ask you for a favor."

"explain."

"My son, Qian Yuhang, is taking the college entrance exam this year." Qian Zhiyuan's voice was muffled, as if squeezed from deep in his throat. He switched the file folder to his left hand, wiping his right hand on his trouser leg. "He wants to apply to Beijing University of Aeronautics and Astronautics to study aerospace engineering. His grades are good, but he's unsure of himself. I wanted to ask you... if you could write him a letter of recommendation?"

After uttering the last word, he let out a long breath, as if he had lifted a stone that had been pressing down on him for a long time. His eyes were not on He Yuzhu, but on the file folder in his hand, his Adam's apple bobbing up and down.

He Yuzhu paused for a moment, then smiled. "What's your son's name?"

Qian Yuhang.

"His name alone is destined for aerospace." He Yuzhu tore a page from his notebook and picked up a pen. The pen paused on the paper for two seconds before he began to write. He wrote slowly, each word carefully. "Qian Yuhang is an excellent student with a strong interest in aerospace. I respectfully request that Beihang University consider his application." He signed his name, wrote the date, folded the paper, and handed it to Qian Zhiyuan.

Qian Zhiyuan took the letter but didn't open it. He carefully folded it, tucked it into his inner pocket, and pressed his fingers against it, as if to make sure it wouldn't fall out. His hands were trembling slightly.

"Thank you, Dean He."

"You're welcome. If he gets accepted, the Shiroyama Research Institute will reserve a place for him after he graduates."

Qian Zhiyuan nodded vigorously, turned and left. He paused at the door, his shoulders trembling slightly as if he were taking a deep breath. Then he pushed open the door, his footsteps disappearing into the corridor.

He Yuzhu stood in the empty conference room, sunlight streaming in through the window and illuminating the few lines of chalk writing on the blackboard. The white chalk shimmered in the light. He erased the writing, chalk dust scattering across the floor. He tidied the folders on the table, preparing to leave.

The phone on the table rang.

He picked up the microphone. "Feed?"

The voice on the other end was urgent, trembling. "Dean He, something's happened at the Fifth Academy's ecological laboratory. Large-scale algae death, a sudden drop in oxygen levels, and the lab mice are suffocating. Dean Lin wants you to come over immediately."

He Yuzhu tightened his grip on the microphone. "I'll be there in twenty minutes."

He hung up the phone, stuffed the file bag into his briefcase, and strode out of the meeting room. The motion-activated lights in the corridor turned on as he passed, then went out one by one behind him. His footsteps echoed in the empty corridor, growing faster and faster until they became a jog.

Just when things were starting to get going with the superconducting ring issue, another problem arose.

He pushed open the building door, and the sun beat down on him. The old Jeep was parked in the yard, its hood scorching hot. He opened the door, got in, turned the key, and the engine roared to life. The car sped out of the gate, turned onto the road, and the tires left a black rubber trail in the asphalt.

The Fifth Academy of Aerospace Science and Technology is a 40-minute drive away. He needs to get there within 20 minutes.