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

The folders with Russian numbers were placed in the center of the long table. When Jiang Ming entered the conference room, the security officer had just put the last seal into the registration bag.

The top-secret red stamp on the cover was pressed below the number, and the document was much thicker than the summary previously sent to 502, with several folded parameter tables tucked into the side.

Qian Xuesen sat in the main seat, the major general sat in the military seat, and the returned control experts, ballistics group members, and overall coordinators sat on either side of the long table.

Ren Xinmin sat near the corner of the table, with a grid notebook in front of him and the parameter package beside him already turned to the chapter on engine shutdown signal logic.

After all the attendees had arrived, Qian Xuesen lightly tapped the agenda with his pen and briefly explained the purpose of the symposium.

"Today we will go through the entire system. The Soviet parameters can be used as a basis, and the applicable conditions must be verified item by item. Any problems found will be marked at the meeting."

The ballistics team first opened the folder and placed the longitudinal guidance equations, lateral stability control, and atmospheric density correction model on the file table next to the projector stand in turn.

Subsequent chapters include the engine shutdown signal logic and gyroscope drift pre-compensation table, each with Soviet recommended values, error ranges, and usage conditions.

The engineer in charge of the presentation started with the longitudinal equations, connecting the velocity integral, attitude angle correction, and predetermined shutdown conditions to the same system block diagram.

Ren Xinmin kept flipping through the chapter on engine shutdown signals. When the introduction reached the thrust termination logic, he used his pen to tap the delay column in the table.

"What is the total delay in milliseconds for the shutdown signal, as specified by the Soviet side, which is the thrust chamber response time plus the relay action time?"

The ballistics engineer checked the Russian annotations, reported the values ​​in the table, and explained that these values ​​were used to calculate the distance difference between the actual thrust termination point and the command time.

Ren Xinmin wrote a line in his notebook, then pressed the parameter page under his elbow without commenting on the values.

After the introduction of longitudinal and lateral control, the agenda moved to the guidance group discussion, and the Major General turned to the page containing the atmospheric density correction model.

He first glanced at the standard atmospheric stratification on the parameter page, then placed the Earth rotation correction record left over from the preparatory meeting on the desktop.

"The 2% drift mentioned last time has been confirmed to need to be recalculated. What about the atmospheric model in this complete parameter package?"

The major general looked up at Jiang Ming, his finger still pressing on the eleven-kilometer stratification line given by the Soviet side.

Jiang Ming opened his canvas bag, took out the three-page analysis draft he had prepared overnight, got up from his seat, and walked straight to the whiteboard in the conference room.

He first drew a standard atmospheric temperature-elevation profile on the left side of the whiteboard, marking the altitude on the vertical axis and the temperature on the horizontal axis, and then marked the tropopause at eleven kilometers.

The right side then shows the actual sounding profile of Jiuquan, with the curve continuing upward along the tropospheric decay rate, and the turning point falling at 13.2 kilometers.

The two profiles are roughly the same from the ground up to 11 kilometers, and then gradually diverge after entering the 11 to 13 kilometer range.

"The Soviet parameter package uses standard atmospheric stratification, with the tropopause fixed at 11 kilometers, and the applicable latitude is listed in the appendix conditions."

Jiang Ming wrote down 45 to 50 degrees north latitude on the whiteboard and marked the latitude of Baikonur next to it.

The returnee control expert immediately turned to the appendix and checked the Russian condition table line by line, his pencil hovering over the latitude range.

"Did the Soviet model use the standard for this latitude zone?"

"The applicable area given in the parameter appendix falls in this region, and the temperature lapse rate corresponds to the same standard atmosphere as the 11-kilometer tropopause."

Jiang Ming clipped the second page of the radiosonde record to the edge of the whiteboard, pointing to the measured data from several summers in Jiuquan in 1955.

"Jiuquan is located at around 40 degrees north latitude. In summer, the tropopause often rises to 13 to 14 kilometers, with the average recorded value being 13.2 kilometers."

The sound of pages turning came from the conference table as several ballistics team members simultaneously unfolded the appendix, density table, and height-layered pages of the complete parameter package.

The major general's palm rested on the folder cover, and he did not continue to flip through it for the time being. His gaze moved back and forth between the forks of the two curves.

Ren Xinmin also looked up from the page about the engine shutdown signal, glanced at the two markers of 11 kilometers and 13.2 kilometers, and then closed his notebook.

He turned to a blank page, wrote the date at the top, and moved his pen to the second line, waiting for the subsequent calculations.

Jiang Ming returned to the left side of the whiteboard and wrote out the stratified density function under the standard atmospheric model, then elaborated on the relationship between temperature, air pressure and altitude item by item.

"Below 11 kilometers, the Soviet model was treated as a decreasing temperature in the troposphere; after 11 kilometers, the bottom of the stratosphere approximation was used."

He moved the chalk toward the measured curve in Jiuquan and marked the decreasing segment below 13.2 kilometers separately.

"According to Jiuquan's summer records, the density between 11 and 13.2 kilometers is still in the troposphere, and the density decrease pattern has diverged from the Soviet model."

The head of the ballistics team took the calculation sheet from his assistant and asked, "Which guidance calculation will the altitude difference be included in?"

"First, we enter the drag integral of the ascent phase, and then the speed loss affects the shutdown state and the subsequent free flight phase. The lateral force correction is also affected by the density term."

Jiang Ming wrote the drag expression in the center of the whiteboard, indicating the atmospheric density, the square of the velocity, the drag coefficient, and the reference area in sequence.

Instead of directly presenting the conclusions he had calculated overnight, he substituted the Soviet 11-kilometer model into the first integral equation based on the speed-altitude relationship given in the parameter package.

The integration interval is divided into two segments: from the ground to 11 kilometers and from 11 kilometers to the bottom of the stratosphere. Each segment uses the density function specified in the parameter package.

The second integral equation is replaced with Jiuquan radiosonde data. The measured tropospheric temperature profile is used from 11 to 13.2 km before entering the stratospheric approximation.

The returning control expert unfolded his slide rule and recalculated along the height nodes on the whiteboard, while another person from the ballistics group took out a logarithmic table to verify the density interpolation.

After writing the first paragraph about velocity loss, Jiang Ming turned around and retrieved the density data for winter and summer from the analysis draft, listing the two sets of extreme values ​​in the lower right corner of the whiteboard.

Qian Xuesen kept his eyes on the two integral equations, his pen occasionally falling to the edge of the agenda to jot down a few words: resistance term, seasonal model, and sounding correction.

The major general flipped to the accuracy index page of the complete parameter package. The circular probability deviation requirement on the page was only half a table away from the whiteboard.

After the integral reached over eleven kilometers, the results of the two sets began to diverge. The density estimation of the Soviet model shifted to a flat zone ahead of time, while the measured model continued to change along the temperature decrease.

Jiang Ming listed the velocity loss at each altitude level below, then weighted the sum by the ascent time, with the chalk writing extending from the center of the whiteboard all the way to the right edge.

Ren Xinmin had moved the calculation sheet that was originally on the shutdown delay page aside, and he copied the upper and lower limits of integration for the two models into a blank notebook.

As the last set of density values ​​for 13.2 kilometers was written into the formula, the sound of pages turning in the conference room gradually stopped.

Jiang Ming took out a red chalk and drew a range between the winter and summer results, then wrote the sensitivity coefficient of the ballistic equation on the next line.

The speed loss deviation still needs the final step of calculation. The major general's finger, which was pressing on the accuracy index page, has moved to the landing point dispersion requirement.

The red chalk continued to move to the right, and the first digit of the kilometer marker that would determine whether the Soviet atmospheric model could be directly adopted began to appear on the whiteboard.