Xinhua News Agency, Wenchang, Hainan, May 10 Title: Sending Tianzhou at Night -- The Flying Record of the Tianzhou No. 4 Cargo Spacecraft
Xinhua News Agency reporters Li Guoli, Sun Luming, Zhang Ruijie and Chen Kaizi
At 1:56 a.m. on May 10, the Tianzhou-4 cargo spacecraft flew into space from the Wenchang Cosmodrome on the shore of the sea, supported by the Long March 7 carrier rocket.
This is the fourth cargo spacecraft successfully launched by the mainland since April 2017, and the third express "package" sent to the space station's sky and core modules.
On a good night of the year, the Tianzhou set off again.
The curtain on the construction phase of The Chinese space station was officially opened, and a key battle was launched to achieve the "three-step" strategic goal of the mainland's manned spaceflight project.
At 1:56 a.m. on May 10, the Long March 7 carrier rocket lifted the Tianzhou-4 cargo spacecraft into the air, and about 10 minutes later, the spacecraft and the rocket successfully separated and entered the predetermined orbit. Photo by Xinhua News Agency reporter Yang Guanyu
Bid farewell to the sea and fly to the heavens
Qiongbei Guyi, the summer night is already deep.
The Wenchang Space Launch Site on the edge of the Coconut Grove Sea is brightly lit, and the Tianzhou-4 cargo spacecraft and the Long March 7 carrier rocket are ready to go and point to the sky.
"Attention to each number, 1 hour to prepare!"
At 0:56, the password of Wang Yuliang, commander of the launch mission 01, resounded throughout the launch site, and the launch tower slalom platform slowly opened.
Under the searchlight, the halo of the milky white ship and arrow combination flows, and the bright five-star red flag and the 6 large blue characters of "China's manned spaceflight" are particularly eye-catching.
This was the first launch of the construction phase of the continental space station and the fourth expedition of the station's cargo transport system.
Five years ago, as the finale of the second step of the "three-step" development strategy of the mainland manned spaceflight project, Tianzhou-1 flew from here and embarked on the journey of pursuing dreams of space.
"Attention, 30 minutes to prepare!" At 1:26, Wang Yuliang's password resounded again at the launch site, and the refueling personnel began to evacuate to the safe area.
This is the 17th space launch mission carried out after the completion of the Wenchang Space Launch Site, and the fifth time to release the Long March 7 carrier rocket.
"As the first mission in the construction stage of the space station, whether Tianzhou-4 can be successfully launched is directly related to whether the subsequent mission can be successfully completed." Zhong Wen'an, chief engineer of Xichang Satellite Launch Center, introduced.
At 1:56 a.m. on May 10, the Long March 7 carrier rocket lifted the Tianzhou-4 cargo spacecraft into the air, and about 10 minutes later, the spacecraft and the rocket successfully separated and entered the predetermined orbit. Photo by Xinhua News Agency reporter Guo Cheng
Over the past few days, the scientific and technological personnel of the launch site have meticulously and meticulously grasped the quality control, analyzed and identified them step by stage, project by project, and step by step, and continued to improve various program plans to ensure that the launch mission is foolproof.
"Attention, 15 minutes to prepare!" At 1:41, the 01 commander once again issued a countdown password.
A year ago, Tianzhou-2 was full of cargo, and from here it pierced the sky to pursue the space station Tiantian and core modules that had just taken off. Eight months ago, still in this old place, Tianzhou-3 rushed to the clouds and sent astronauts' daily necessities, propellants and other cargoes to the Tianhe core module.
On that day, two cargo ships flew together with the Tianhe core module, setting a new record in the history of China's manned spaceflight.
"Attention to each number, 1 minute to prepare!" At the sound of the password, the pendulum bar supporting the rocket is opened, and the system equipment connected to the rocket on the launch tower automatically falls off.
At this time, the space station's Tianhe core module and Tianzhou-3 combination were flying over Wenchang, Hainan Province, at a height of 400 kilometers.
At this moment, everyone at the scene held their breath, and the originally lively launch site was also quiet, only Wang Yuliang's password echoed between heaven and earth——
"5, 4, 3, 2, 1, ignition!"
At 1:56 a.m., the earth-shaking roar resounded through the sea and the sky, and the Long March 7 carrier rocket lifted the Tianzhou No. 4 into the air, drawing a brilliant trajectory in the night sky, bidding farewell to the sea and flying to tianhe.
The sea has once again witnessed the highlight moment of China's aerospace.
At 1:56 a.m. on May 10, the Long March 7 carrier rocket lifted the Tianzhou-4 cargo spacecraft into the air, and about 10 minutes later, the spacecraft and the rocket successfully separated and entered the predetermined orbit. Photo by Xinhua News Agency reporter Hu Zhixuan
"Courier" delivery, waiting for "signature"
Booster separation, fairing separation, successful separation of the ship's arrows... Tianzhou-4 successfully entered space.
At this time, the space station Tianhe core module and the Tianzhou-3 combination have been waiting in space for more than 230 days. In order to welcome the first "earth visitor" of this year, "China Palace" has made various preparations -
On April 20, Tianzhou-3 separated from the rear port of Tianhe core cabin, flew around and automatically docked to the forward port, and "let Xian" for the backward docking of Tianzhou-4.
Earlier, on March 31, Tianzhou-2 was controlled to re-enter the atmosphere after successfully completing its scheduled mission. Again, this is to free up the interface of the exchange in advance.
The Tianhe core module is equipped with 5 pair interfaces, of which the backward pair interface and the forward pair interface are used to dock the cargo spacecraft.
The Tianzhou cargo spacecraft is a ground logistics supply spacecraft for China's space station, and is also a cargo spacecraft with the largest cargo transportation capacity and the most comprehensive on-orbit support capability in service.
In order to meet the needs of intensive launch during the construction phase of the space station, the Tianzhou cargo spacecraft implemented group production, and produced two, three, four and five at the same time, which are similar in appearance and function or similar.
"Tianzhou-4 is the first spacecraft on the mainland to enter the construction stage of the space station, and undertakes tasks such as providing material support for Shenzhou 14 astronauts, supporting space station operations in orbit, and space science experiments." Dang Rong, deputy chief designer of the cargo spacecraft system of the Fifth Academy of Aerospace Science and Technology Group, said.
This time, Tianzhou-4 loaded a total of more than 200 pieces (sets) of cargo, including cargo package cargo and direct installation cargo, which will provide material support for Shenzhou 14 astronauts to stay in orbit for 6 months, assemble and build space stations, carry out material science and other space applications.
"Tianzhou-4 carried about 750 kilograms of supplemental propellant, which is similar to that of Tianzhou-3, but the total weight of uplink materials is about 6,000 kilograms, which is 300 kilograms more than Tianzhou-3, and the transportation capacity has been further improved." Bai Mingsheng, chief designer of the cargo spacecraft system of the Fifth Academy of Aerospace Science and Technology Group, introduced, "This time there is no longer an extravehicular spacesuit, because there are already 3 sets on the top." ”
At 1:56 a.m. on May 10, the Long March 7 carrier rocket lifted the Tianzhou-4 cargo spacecraft into the air, and about 10 minutes later, the spacecraft and the rocket successfully separated and entered the predetermined orbit. Photo by Xinhua News Agency reporter Yang Guanyu
In addition, according to the opinions of astronauts on the use of astronauts in orbit, the researchers have continuously improved and optimized the design of Tianzhou-4 .
For example, the color logo of the cargo bag has been added, and the astronauts have made it more convenient and intuitive to find the cargo: the cargo bags of Tianzhou-2 are all one color, and the label font is the same, which is not easy to distinguish. The cargo bag of Tianzhou-3 was tied with ribbons of different colors. Tianzhou No. 4 makes a color distinction from the identification label.
Compared with Tianzhou-3, the cargo of Tianzhou-4 is also more convenient to use. The cargo compartment is a cargo compartment, there is a cover plate on the cargo compartment, the previous design was screwed up with screws, open, cover need to twist the screws back and forth, the operation in the sky is quite troublesome. This time, the scientific and technological personnel used the velcro in the cover plate and the box, only need to twist the screw once when opening the cargo grid for the first time, and the back can be opened at any time, which is very convenient. They also optimize the block miniaturization of the buffer foam in the bag, which can reduce the space occupation and facilitate storage.
Nowadays, the space "express" has been delivered, only waiting for Shenzhou to "sign the person".
The Chinese space station has entered the construction phase, and every six months, astronaut crew rotation and cargo replenishment are carried out. This means that after the successful lift-off of Tianzhou-4, the Shenzhou 14 manned flight mission has also entered the countdown.
Jiuquan Satellite Launch Center, this time is also a busy scene, scientific and technological personnel are making preparations for the mission. The Shenzhou 14 astronaut crew has also been selected, and it is planned to knock on the sky again next month.
On the banks of the Weak Water River, the 9th flight of the Chinese will be witnessed.
This is a schematic diagram of the autonomous rapid rendezvous and docking of the Tianzhou-4 cargo spacecraft and the space station assembly taken at the Beijing Aerospace Flight Control Center (taken on May 10). Photo by Xinhua News Agency reporter Guo Zhongzheng
"Courier Brother" has won consecutive victories
Tianzhou No. 4 successfully lifted off, and Long March No. 7 won consecutive battles and won consecutive victories, and its performance was still outstanding.
The Long March 7 is a new generation of medium-sized carrier rockets on the mainland, which has carried out four Launch Missions of the Tianzhou Cargo Spacecraft since its first flight in 2016, delivering a large number of materials to the Chinese space station and space laboratory, and is known as the "courier brother" of space.
In order to meet the needs of future space station operations, this time, the development team optimized the process before the launch of the Long March 7, reducing the measurement and firing cycle by 4 days compared with the launch of Tianzhou 3.
This is the first time that the Long March 7 has been tested and launched within a month.
"Reducing the test and firing cycle by 4 days is a major process improvement task, which not only challenges the comprehensive performance of the Long Seven rocket, but also tests the resilience of the launch team members in the high-intensity working environment, and the various subsystems of the rocket must carry out process optimization work at the same time to achieve the final goal." Meng Gang, commander-in-chief of the Zhengqi carrier rocket, the first president of the Aerospace Science and Technology Group, said.
The restoration of ground equipment was the first task of the Long March 7 to enter the field and a prerequisite for rocket testing, which alone saved 2.5 days.
This is the Tianjing-4 cargo spacecraft and the space station assembly photographed at the Beijing Aerospace Flight Control Center to complete the autonomous rapid rendezvous and docking (photographed on May 10). Photo by Xinhua News Agency reporter Guo Zhongzheng
Fan Hong, deputy chief designer of the Zhengqi carrier rocket, the first president of the Aerospace Science and Technology Group, introduced: "Link the original task with the previous and the last one, let the process 'live', the more fully the preliminary work is done, the faster the test task will be carried out after entering the field, the better." ”
On the afternoon of April 10, the Long March 7 opened the product out of the box. In order to achieve the goal of optimizing the process, the booster self-test, the rocket core stage out of the box and the fairing out of the box were carried out in parallel in different work plants for the first time.
"The assembly team was fully engaged, and the craftsmen, dispatchers, inspectors and personnel responsible for quality and informatization all arrived at the scene, and all of them worked hard for the same goal." Cui Yun, head of the general assembly technology of the Zhengqi carrier rocket, the first president of the Aerospace Science and Technology Group, said that the workflow of rocket products out of the box has also been compressed from 3 days to 2 days.
When Tianzhou-3 was launched, kerosene was filled with liquid oxygen after filling, and the two were completely tandem processes. For this launch, the Long March 7 was filled with liquid oxygen and kerosene in parallel, thus reducing the 12-hour process on the launch day to 8 hours.
It's a challenging job. Shao Yetao, chief designer of the Zhengqi carrier rocket, the first president of the Aerospace Science and Technology Group, said: "The parallel filling of liquid oxygen and kerosene has compressed the original process, and at the same time, it has reduced the parking time and temperature rise of kerosene, further ensuring the quality of the propellant." ”
After the launch of Tianzhou-4, it is necessary to conduct a rapid rendezvous and docking with the Tianhe core module. This requires the rocket to fire and lift off in milliseconds, pushing it precisely to the space orbital surface where the sky and core module are located.
To this end, researchers use iterative guidance algorithms to expand the emission window. Shen Dan, deputy director of the Zhengqi Carrier Rocket Model Office, the first president of the Aerospace Science and Technology Group, said: "Even if the Long March 7 deviates from the standard take-off time, as long as it is within two minutes, it will find a suitable route in the air to catch up with the sky and the core module." ”
This is a schematic diagram of the autonomous rapid rendezvous and docking of the Tianzhou-4 cargo spacecraft and the space station assembly taken at the Beijing Aerospace Flight Control Center (taken on May 10). Photo by Xinhua News Agency reporter Guo Zhongzheng
It is worth mentioning that this time, the Long March 7 for the first time took the Beidou satellite navigation system as the first priority of navigation reception.
"That is to say, after the rocket takes off, the navigation is provided by the Beidou system first." Shen Dan said.
In fact, the overall technical status of the Long March 7 has stabilized, and the flight reliability assessment value has reached the international advanced level of 0.9838.
In the roar, a large amount of white mist rose in a flash, and the Long March 7 spewed out tail flames, and soon lifted the Tianzhou 4 along the predetermined track and disappeared into the vast night sky.
Standing at the Wenchang Cosmodrome Accusation Building, the Long March 7 launch tower still stands on the seashore. Not far away, there is another launch tower.
Before the end of the year, the Wentian and Dream experiment modules will fly from this tower to Tianyu and dock with the Tianhe core module to form the "T" shape of the Chinese space station. "If you add 2 manned spacecraft and 1 cargo spacecraft, a Chinese space station with a total mass of nearly 100 tons will be presented to the world." Zhou Jianping, chief designer of China's manned space project, said.
At that time, the "China Palace" will be the brightest "star" in the vast universe. (Contributors: Pan Chen, Wang Weitong, Huang Guochang)
Source: Xinhua Net