Ask the sky to win the decisive battle
□ Our reporter Chen Liping and Lian Yingting
This is a decisive battle.
At 0:23 on October 16, the Long March 2 F Yao 13 carrier rocket (the "Chang 2 F Yao 13 rocket") carrying the Shenzhou 13 manned spacecraft was successfully launched at the Jiuquan Satellite Launch Center. Won the key battle for the construction of China's space station.
After that, three astronauts Zhai Zhigang, Wang Yaping, and Ye Guangfu successfully stationed in the core module of the space station.
The launch mission of the Shenzhou 13 spacecraft is the sixth mission in the key technology verification phase of the space station, and it is also the final battle and final battle of this phase.
One aiming room, one cloud-piercing arrow
At the Jiuquan Satellite Launch Center, next to the Changer F Yao 13 rocket tower developed by the China Academy of Launch Vehicle Technology affiliated to China Aerospace Science and Technology Corporation, there is a square house, about 150 meters away from the launch tower. This is the sighting room of the rocket.
It’s said that rocket launches are “a tiny bit missed, but a thousand miles away.” This is where the rocket’s correction is small and the power of a thousand miles is stored.
Before the rocket transitions to the launch zone, the work of the sighting personnel begins.
Wang Chao, a launch member of the Chang'er F Yao 13 Rocket Ground Support System, said: “Before the rocket transitions, the sighting personnel must complete the collimator self-check, verify the key parameters, and carry out the pre-targeting test.”
It is not easy for a collimator with a unit of "arc-seconds" to self-check accurately.
Wang Chao said that 1 degree is equal to 3,600 arc seconds, and the aiming instrument has an accuracy of 0.5 arc seconds. The completion of such a precision calibration is a severe test of technology and experience.
The rocket has undergone nearly 10 sightings before launching. Two sets of sighting equipment are used. In the small sighting room, the sighting staff of the Rocket Academy and the sighting staff of the launch site repeatedly calibrate, sometimes one school is a day.
Song Jing, the overall ground launcher of the Chang'er F and Yao 13 rocket, said that aiming is to let the rocket know the initial position. The accuracy is not only related to the rocket's take-off and rolling actions, but also related to whether the rocket debris can fall within the delineated landing zone and the spacecraft. Accuracy of orbiting and so on, so the aiming personnel will enter a state of high tension from the start of the equipment self-check.
Rocket aiming is divided into coarse aiming and fine aiming, which almost run through the entire process of the rocket in the launch area.
For a rocket that is close to 20 stories high and weighs tens of tons, any deviation may cause irreversible consequences.
The first rough sight was after the Rockets transitioned.
At this time, the rocket carried a load of several tons, walked nearly 1.5 kilometers, and just stood firm next to the launch tower.
The first task of rough aiming is to find the correct position and position for the rocket.
System-wide launch drills, emergency shutdown general inspections... After each key link, the rocket must be aimed, and the "instructors" responsible for the aiming will correct the rocket's stance deviation little by little until it enters the state of performing missions and becomes a real conqueror. "Warriors" in space.
The closer you are to launching, the more cautious the aiming will be. After the propellant is refilled, the rocket will have to undergo a series of rigorous precision aiming.
After the preliminary aiming, the rocket’s position and posture were quite upright, but the rocket with its empty stomach was filled with hundreds of tons of propellant, and its weight suddenly increased more than ten times. Under the combined action of multiple gravity, the rocket would appear to be certain. At this time, the aiming personnel will further approve the stance and other details for the rocket.
From -6 hours before the launch of the rocket, the precision aiming work is carried out in a high density, and the aiming personnel are highly concentrated, and the aiming parameters are corrected over and over again.
The aiming parameters of -5 hours before the launch will become the final aiming result. Together with the rocket trajectory and other data, they will be bound into the rocket control system computer to guide the rocket to perform the launch mission.
At this time, the aiming work is not over.
The aiming personnel must continue to monitor the aiming parameters and compare them with the aiming elements provided to the control system in -5 hours. If the deviation exceeds the specified value, the cause must be found and resolved.
15 minutes before the launch, the rocket entered the countdown to launch. Most of the team members in the launch area have already evacuated. At this time, the state of the rocket has stabilized.
At this time, it is often the time when Wang Chao's mood is the most complicated.
Sitting in the evacuated car, he couldn't help turning his head over and over again, looking at the rocket that had already stood still.
"If the aiming deviation is 0.1 degree, the orbit point will deviate by hundreds of kilometers. This is a mistake that the aiming personnel will never allow." Wang Chao said.
With more than 10 years of rocket aiming experience and nearly 10 long-term F rocket aiming missions, Wang Chao has never made such a mistake.
Why choose to launch on October 16
On October 15, the second manned spacecraft, Shenzhou XIII, in the construction phase of the China Space Station entered the final moments before launch.
At about 21 o'clock, the spacecraft began to power up, the countersignature process began to inject, and a "understand" was transmitted from the scene in Jiuquan to the lobby of the Beijing Aerospace Flight Control Center. On the screen was the Chang 2 F Yao 13 rocket in the dark night.
The launch was chosen in the early morning of the 16th.
The selection of this time period is determined according to factors such as the spacecraft's orbit, working conditions, the operating state of the core cabin assembly, and the tracking, measurement and control window.
In order to realize the radial rendezvous and docking of the in-line combination with the Tianhe core module, Tianzhou 2 and Tianzhou 3, the launch window has the characteristic of uniqueness.
"This mission has new challenges and differences. Shenzhou 13 will use the radial direct rendezvous and docking method for the first time. The radial docking state is new, the astronauts stay in orbit for a long time, the on-orbit test is difficult, and the ground provides normal support. The requirements for emergency control are high." said Li Jian, director of the Beijing Aerospace Flight Control Center.
At 22:13 on October 15th, three astronauts entered the spacecraft cabin, and they appeared on the screen wearing pressure suits in the cabin.
After entering the cabin, a series of operations proceeded in an orderly manner.
At 0:23 on October 16, the countdown to "Dididi" was endless.
"Take off!" From the commander of Dongfeng to the general dispatcher in Beijing, the announcement of the time of take-off sounded in the halls of the two places, and was broadcast to all the points participating in the mission through the sound reinforcement of the voice system.
After 582 seconds, the arrow separated and the spacecraft entered the predetermined orbit.
About 25 minutes after separation, under the control of Beijing Aerospace Flight Control Center, Shenzhou 13 entered the autonomous rapid rendezvous and docking mode.
"During the radial docking, the space station assembly occludes and the spacecraft's large attitude adjustments have a greater impact on the relay measurement and control and spacecraft energy. The measurement and control support mode and flight program arrangement adjustments have changed greatly. These have increased the ground state monitoring and judgment. The difficulty of emergency response." said Zhang Yuedong, deputy director of the Beijing Aerospace Flight Control Center.
In the lobby of Beijing Aerospace Flight Control Center, communication dispatcher Ma Zhongzheng has no time to appreciate the heroic posture of the arrow. His headset confers reports on various positions with image and voice. What he compares with his hand is the switching process, and what he sees in his eyes is The result of the image displayed on the actual screen, what is coming out of the microphone is his own decision-making password.
This is the normal state of every launch mission.
After 6 remote control and homing segment 4 pulse control, the spacecraft reached the mid-point of sight, then adjusted the pitch angle to 90 degrees, and parked at 200 meters and 19 meters in the radial direction, and finally at 6:56 on October 16 It is connected with the radial ports of the Tianhe core module to form a combination of Tianhe core module, Tianzhou-2, Tianzhou-3 and Shenzhou-13.
At 8:20, the docking channel leak detection and repressurization were completed. About 2 hours later, the astronauts successfully entered the Tianhe core module, the rendezvous and docking section was successfully completed, and the mission was transferred to the combined operation stage.
Many challenges were overcome in the on-site surveillance and judgment, and the sound of "unlocking and locking completed" testified to the kiss of space.
The world's integrated measurement and control network escorts the space journey
As the orbital calculation backup center and the land-based measurement and control network dispatch management center for this mission, the Xi’an Satellite Measurement and Control Center provides key measurement and control support for the entire process of the mission.
"Weinan, find the goal!"
"Qingdao, USB and radar tracking are normal!"
In the live broadcast of the launch mission, along with the loud scheduling password, the audience can clearly see the flight trajectory of the rocket and the spacecraft and the real-time pictures of the astronauts in the spacecraft. All this is due to the reasonable layout and complete function of the USB measurement and control network in China. .
Zhang Zhuo, engineer of Xi'an Satellite Measurement and Control Center, told reporters that China has built a USB measurement and control network covering land, sea and space, and its comprehensive performance has reached the international advanced level.
This measurement and control network is compatible with the world in terms of frequency bands and systems. It integrates orbit measurement, telemetry, remote control, voice, and television functions. It integrates measurement and control and space-to-earth communication functions. It is the only information line for the spacecraft to contact the ground after it lifts off.
"During the rapid autonomous rendezvous and docking process, the spacecraft relies entirely on autonomous operation, and the ground basically does not require intervention and control. During this period, the ground mainly relies on the sky-link relay satellite for tracking, measurement and control." Zhang Zhuo said, "The overall performance of the land-based USB measurement and control equipment It is relatively more stable, and when various conditions in space are unknown, we complement each other with relay satellites to form a world-earth integrated measurement and control network to jointly escort the astronauts' space journey."
After the rocket is ignited, on the newly upgraded display screen of the Xi'an Satellite Measurement and Control Center's Measurement and Control Command Hall, curves representing the flight status of the rocket are changing in real time as the rocket flies.
About ten minutes after the rocket flew, the large-screen real-time image and telemetry data simultaneously showed that the ship and the rocket were separated. The technicians in the orbital calculation post were immediately engaged in intense calculations as if they heard the firing of the starting gun.
Soon, the initial orbit and separation point parameters of the spacecraft were calculated, and the relevant data was synchronously transmitted to the Beijing Aerospace Flight Control Center for comparison, providing key data support for judging the successful launch of the mission.
"In response to the new situation and new characteristics of this mission, our Xi'an Center has improved the central computer system and optimized the orbit calculation mode to achieve rapid calculation of the initial orbit and separation point parameters of the manned spacecraft, ensuring timeliness as much as possible. "Yang Yongan, a senior engineer at the Xi'an Satellite Measurement and Control Center, said.
In the manned space mission, the Xi’an Satellite Measurement and Control Center serves as the orbital calculation backup center and is jointly responsible for the precise tracking, monitoring and calculation analysis of the spacecraft during launch into orbit, on-orbit operation, and return and reentry phases.
After the calculation is completed, the two centers need to compare the data to ensure that the calculation results of the two are within the allowable range of error, in order to judge the spacecraft's orbital data, operating status, and return cabin landing point in real time.
"'Backup' is a common international practice in the world's aerospace industry. It is specially set up to ensure that major space missions are safe, reliable, and foolproof. As early as the start of the manned space project, China was building a new mission control and command center at the same time. , To transform and utilize the Xi’an Satellite Measurement and Control Center, make full use of the rich satellite measurement and control experience of the Xi’an Center, and set up a solid “dual insurance” for the measurement and control of manned space missions.” said Yang Kaizhong, chief engineer of the Xi’an Satellite Measurement and Control Center.
In the calculation of the return point of the spacecraft, the point of impact forecast provided by the center can always control the deviation between the actual point of impact and the theoretical point of impact within the "ten rings" range of one kilometer, thus gaining valuable time for ground search and rescue.
During the return measurement and control mission of the Shenzhou 12 manned spacecraft, the difference between the theoretical landing point and the actual landing point of the return capsule calculated by the center was only less than 100 meters, setting a new record for the accuracy of the manned spacecraft return capsule landing point prediction.
Create a comfortable space home for astronauts
In space, astronauts can eat delicious Chinese flavors, enjoy space massages, and can monitor their health in real time, all of which are attributed to the technology and products of China Aerospace Science and Industry Corporation.
The food heating device, gas flow regulating valve, liquid circuit stop valve, physiological signal test box, and ECG recording device that accompanied the Shenzhou 13 spacecraft this time are mainly used for the Shenzhou spacecraft’s environmental control life insurance system and medical supervision and medical insurance equipment analysis. Systems, they are a part of "space kitchen", "space air conditioner" and "space hospital". These products provide astronauts with all-round care and create a comfortable space home for astronauts.
The food heating device in the "space kitchen" is installed in the spacecraft, which can quantitatively heat space food and beverages, and the heating time can be adjusted.
It is a white square box with a length of less than 30 cm, a weight of only 4.4 kg, and three layers of heating space. Press the power switch gently, and only need to wait a little while patiently, the astronauts can enjoy it in space Warm meals.
The locking device of the food heater in the "space kitchen" adopts a mechanical structure to ensure that the astronauts can freely open the "pot". This small and exquisite lock is composed of 7 parts.
Li Gang, winner of the National May 1st Labor Medal, is the designated assembly expert for space products.
In order to ensure that the astronauts can freely open the "pot", Li Gang repeatedly explored the disassembly and assembly to find the most suitable torque control index, which is easy to open and can safely resist the powerful impact during launch flight.
When the astronauts set out on the expedition, the physiological signal test box and the ECG recording device worn on the outer thighs are products of the "space hospital", which are carried by the astronauts, only the size of a cigarette case, and can monitor the astronauts' ECG and breathing during the flight in real time. The three physiological indicators of body temperature and body temperature are transmitted to the ground command center for diagnosis by ground medical personnel.
The ECG recording device mainly samples and stores the received ECG signals of the astronauts. It can record for more than 1000 hours. These data will be further analyzed after returning to the ground.
These two products are used in the process of astronaut lift-off, in-orbit flight, return, etc., and accompany the astronaut to complete the entire flight mission.
Different from other fixed-position equipment, these two "space hospital" products are placed outside the pocket of the space suit. As the astronauts are in the active state, this has a higher profile, volume, connector connection, electrical performance, etc. Require.
The final formed wall thickness of the physiological signal test box is only 1.5 mm, and the processing of thin-walled parts trembles under force and is extremely easy to deform.
Skilled masters such as Zhao Lianhai, Wang Donghua, Jiang Shuangjian researched and designed new tooling to enhance the rigidity of the parts, select reasonable processing parameters, and successfully avoid the resonance point of the part and the rotating tool to prevent chattering, and the flatness of the processed parts meets the requirements.
Other structural parts of the "Space Hospital" also use this processing method, and the product qualification rate has been greatly improved.