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

In the main conference room of the West City compound, the vacuum tube computer spat out the last piece of perforated paper tape. The edges of the tape were charred from baking, and the smell of ink mixed with the heat from inside the machine. The recorder reached out and caught the tape, his fingertips touching a layer of fine dust first. Everyone around the round table turned their attention to the string of numbers that had just been translated.

When Jiang Ming pushed open the door, Ren Xinmin was standing next to the computer with three verification sheets in his hand. Qian Xuesen was sitting on the inside of the long table. The major general and several experts from the overall group had already taken their seats. Vasily was standing at the other end with the original Soviet parameter file spread out in front of him. His translator held a pen, but did not turn the page for a long time.

"Jiang, the results just came out." The overall team leader pushed the analysis and decoding sheet to the center of the table. "The maximum wind shear in Jiuquan in August, according to the Soviet method of smoothing the lateral deviation coefficient integration, the final segment point laterally deviates to the right by 2.7 kilometers."

The numbers on the analysis sheet were circled twice in red. Below were three sets of sideslip angles, separation positions, and control response times. After entering the wind shear zone in the low Mach range, the lateral residuals began to increase continuously. Although the control surface correction had reached the calculation limit, the trajectory still deviated to the outside of the safe zone. The last column stated that the test zone boundary distance was insufficient and direct adoption was prohibited.

Ren Xinmin spread out another table, his voice dry: "If we change it to the measured wind field in Jiuquan and recalculate it according to the lateral deviation function after preserving the original undulations, the lateral deviation falls between 180 meters and 240 meters. The error still needs to be corrected. The result at 2.7 kilometers shows that the smoothing matrix has erased the changes in the dangerous section."

Vasily slammed his hand on the table, and Russian burst from his mouth. The translator followed to write it down, but the meaning was only one sentence on the table: there were problems with the way the Chinese wind speed model was collected; the measurement altitude, sampling interval, and wind direction conversion at the Jiuquan meteorological station did not meet the Soviet test standards.

He spoke faster and faster, his fingers tapping back and forth on the calculation table, trying to push the 2.7 kilometers back into the error range of the meteorological data. In the conference room, several experts were looking through the original radiosonde records. Ren Xinmin arranged the hourly wind direction, wind speed, and altitude data of Jiuquan Station, the edges of the pages were already soft from being turned over repeatedly.

After Jiang Ming sat down, he didn't say anything. He first took out the outline he had prepared the night before and placed three hand-drawn flow field diagrams in front of Vasily. The diagrams showed the crossflow on the leeward side of the projectile, the movement of the separation point, and the change of the lateral pressure center. The three sets of sideslip angles were marked with the positions of the residual symbols. The calculation formulas next to them were unfolded along the flow field diagrams, and each change in parameters had a corresponding physical location.

Vasily's finger stopped on the first diagram, his gaze shifting from the separation point to the lateral force curve. The translator leaned over to read the formula, pausing when he reached the part about the asymmetric shedding of the crossflow vortex. He turned to look at Vasily, waiting for the next instruction.

Jiang Ming pointed to the bend in the curve with a pencil: "After entering the sideslip state in the low Mach section, the boundary layer separation position on the leeward side will change with the sideslip angle. The shift of the pressure center will cause a jump in the lateral force slope. If the controller replaces this change with a smoothing function, the integral loop will treat the reverse yaw as a continuous offset. After the rudder effectiveness decreases, the error will accumulate along the final stage."

Vasily looked up and retorted, saying that the Chinese derivation lacked the original wind tunnel data from the Soviet side, and that the three hand-drawn diagrams could only represent theoretical speculation and could not refute the parameter package that had been verified at the test range.

Jiang Ming turned the third graph to Qian Xuesen and placed the measured data from Jiuquan and the original Soviet summary side by side: "The data does not lie. The original parameters are smooth because the high-risk frequency bands have been removed. The few residual fluctuations left in the Soviet summary happen to fall in the area where the separation position changes direction. All three sets of sideslip angle calculations show residual reversal in the same direction. This pattern is unrelated to measurement noise."

He turned to the last page of the calculation sheet and pointed to the result of 2.7 kilometers: "If we continue to use this set of parameters, the missile will mix spin instability and lateral correction on the same smooth curve after entering the wind shear. The control system will continue to correct the wrong direction. Once the test missile crosses the safety boundary, the responsibility will fall on the launch and overall process. No one can replace the real physical boundary with the progress of cooperation."

The only sound in the conference room was the sound of paper tape sliding off the machine's exit. Ren Xinmin placed his hand on the initial draft of the lateral stability correction. He was originally worried about the local distortion of the lateral slip coefficient. The 2.7-kilometer verification result pushed the risk outside the test safety zone. If they continued to wait for the Soviet side to provide supplementary explanations, the Fifth Academy would arrange subsequent aircraft time on the incorrect chassis.

Qian Xuesen took the three hand-drawn flow field diagrams, looking at the first one and the third one. He then picked up the Jiuquan sounding record to check the altitude layer, leaving a few short marks on the record paper with the tip of his pen. He looked up at Vasily's dossier and pushed the stack of documents to the side of the table.

"This original file will not be used as the basis for the design at this time."

The major general then turned to the recorder: "The revised parameter package submitted by the Soviet side shall be sealed, numbered, and registered. No department may use it without a re-examination by the overall group."

Vasily's expression darkened. He reached out and gathered the files. The translator pressed him, asking if sealing them meant the end of cooperation. The major general looked at him, his tone restrained: "It means that China is taking responsibility for its own testing, and it also means that the parameters must first meet the physical conditions of the test site."

Vasily closed the folder, the chair leg scraping against the floor with a screeching sound. He left the conference room with the translator. After the door closed, Ren Xinmin stood up first and pressed Jiang Ming's hand-drawn sketch onto the overall calculation drawing.

"Immediately reconstruct the crossflow correction module at the Jiuquan test range," Ren Xinmin said. "Separation point reversal, sideslip angle sensitivity, and final shutdown delay should all be incorporated into the same simulation table. Engineer Jiang will be responsible for the underlying equations, and I will arrange the overall interface."

Jiang Ming wrote the three sets of sideslip angle conditions into the task sheet, and listed the recalculation cycles for low-latitude atmospheric correction, lateral stability and shutdown delay. Fang Xudong and the overall team calculators gathered around the table and checked the input format item by item. The underlying formulas that had been suppressed by the Soviet dossier began to re-enter the main process.

The afternoon meeting continued until dusk. The outer parameter freeze table was renumbered, the measured wind field in Jiuquan was listed as the main input, and the data from the Soviet side was reduced to the reference material. The three sets of sensitivity verification were scheduled to be completed before the first round of recalculation. Ren Xinmin pushed the signature column in front of Jiang Ming, and Jiang Ming wrote his name. The calculation path on the paper was thus changed.

After the meeting, Qian Xuesen stayed by the door until everyone else left. He then took out a confidential internal document from his briefcase, the cover of which was stamped with a security seal, and handed it to Jiang Ming: "The pulse records from Aksai Station No. 3 have been sent to the higher authorities. The instructions regarding strengthening the interception capabilities of the Northwest Air Defense Early Warning Network have been issued."

Jiang Ming opened the internal reference document and saw several lines about the arrangements for direction finding stations, receiving front-ends, and data aggregation. The eleven sets of pulses that appeared repeatedly in Lu Qinghe's letter began to be included in the construction list of the system-level air defense early warning network. Component specifications, communication decisions, and front-line deployments were placed on the same page.

Qian Xuesen watched him flip to the end and added, "Stabilize the guidance parameters first, and connect the Aksai line as soon as possible. Time won't wait for the two systems to be prepared separately."

Jiang Ming resealed the internal reference and walked out of the Fifth Academy's gate. A layer of dark clouds pressed down on the western sky, and the low vibrations of passing vehicles could be heard in the distance. He stood on the steps and looked back at the city lights. The red circle of 2.7 kilometers was still in his mind, as was the short frame in the waveform diagram that had not yet been translated.

Jiang Ming tightened the file bag, turned and walked towards the jeep parked outside the door. The new calculations had modified the chassis of the guidance system, but the new signal was still hidden in the northwestern night sky, waiting for them to use the newly made silicon tube to separate it from the noise.