The Shenzhou 12 manned spacecraft returned from space on September 17, carrying astronauts Nie Haisheng, Liu Boming and Tang Hongbo back to the embrace of the motherland, marking the complete success of the first manned mission in the Stage of the Chinese Space Station.
<h1 class="pgc-h-center-line" data-track="12" > Shenzhou returns to overcome the dangers</h1>
Return capsule landing moment / Source Xinhua News Agency
At 1:34 p.m. on September 17, the Shenzhou 12 manned spacecraft returned from space and landed safely at the Dongfeng landing field in Jiuquan, Gansu. The Shenzhou XII manned spacecraft, which guarantees astronauts to achieve round-trip between heaven and earth, is composed of an orbital module, a return capsule and a propulsion module. It set off from space more than 300 kilometers above the ground, overcame many difficulties to return to the ground, and mainly went through three stages: brake flight and free coasting, re-entry into the atmosphere and landing.
Li Meng, the overall designer in charge of the Shenzhou 12 manned spacecraft system of the Fifth Academy of china Aerospace Science and Technology Corporation, said that before returning to the earth, the various modules of the spacecraft must be separated step by step.
Li Meng: "The Shenzhou XII spacecraft is composed of three modules, and the real return to Earth is the return module. Of the other two modules, the first to separate is the orbital module. After that, we also have to adjust the posture, from forward flight to inverted flight, which is to prepare for braking, because our main orbital control engine is in the tail of the propulsion hatch, and then the propulsion cabin brakes, the orbital energy is reduced, and the height will naturally decay. After the end, the propulsion module is separated from the return module. ”
The return capsule crosses the "black barrier area" / source CCTV news
When the return capsule enters the atmosphere, at about 85 kilometers to 30 kilometers from the ground, it will violently rub against the atmosphere at a speed of thousands of meters per second, igniting a flame of more than 2,000 degrees Celsius, which is the most difficult "black barrier area". Astronauts are subjected to a huge overload, equivalent to the force pressure of many times more than their body weight. Li Meng said that in the process, the spacecraft's communications will also be completely interrupted.
Li Meng: "The temperature in the black barrier area is high, and after the air is ionized, the communication is blocked." Therefore, in the flight program, ground control will no longer be choreographed. The temperature outside the black barrier area can reach about 2000 degrees Celsius, and we have taken some measures, including the coating on the surface of the return cabin is heat-proof, ensuring that the cabin is still a more suitable temperature, about 24 degrees. ”
Orbital module separation / Provided by the Fifth Academy of Aerospace Science and Technology Group
Separation of propulsion module and return module / Provided by the Fifth Academy of Aerospace Science and Technology Group
The return module will soon return to Earth/Provided by the Fifth Academy of Aerospace Science and Technology Group
The shape of the Shenzhou XII manned spacecraft return capsule is like a narrow and wide "big clock", it will use its own equipped engine to adjust the attitude, return to the earth with the outsole facing forward, and the astronauts are also lying flat on the seat at an angle almost parallel to the outsole to alleviate the impact formed during the deceleration of the spacecraft. Li Meng introduced that the return capsule generates lift when crossing the atmosphere, which can have a certain correction effect on the flight trajectory.
Li Meng: "When it falls back, it will produce a lift, that is, the air has a force to lift up the return capsule. If our return capsule oscillates from side to side, it is equivalent to controlling its longitudinal range and lateral deviation and correcting it. This is a bit like we take a plane to turn left and right, to ensure that the landing point we finally return to is the desired point, and the error is as small as possible. ”
<h1 class="pgc-h-center-line" data-track="112" > airborne parachute landing buffer</h1>
The parachutes are pulled out one by one /from CCTV News
When the return capsule continues to decelerate until it is about 10 kilometers above the ground, the static pressure height controller on it measures the atmospheric pressure to determine the altitude, and opens the guide parachute, deceleration parachute and main parachute successively. Rong Wei, deputy chief designer of the Shenzhou spacecraft system of the Fifth Academy of China Aerospace Science and Technology Corporation, said that the umbrellas were opened one by one in order to achieve landing in a softer way.
Rong Wei: "The first ones that come out are the two smaller umbrellas, which play a guiding role, pull out the deceleration parachutes, and slow down the return capsule." After a certain period of working time, the speed of the return capsule can probably be reduced to 80 to 90 meters per second, which is equivalent to the speed of the high-speed rail of 350 kilometers per hour. At this time, we separate the deceleration umbrella, and it is used as a guide umbrella to pull out the main umbrella, and the area of the main umbrella is larger, about 1200 square meters. When it is opened, the speed of the return capsule can be reduced to about 7 meters per second. ”
The return capsule opens an umbrella in the air / source Xinhua News Agency
If the return capsule directly hits the ground at a speed of 7 meters per second, it will still not ensure the absolute safety of astronauts. The spacecraft development team also designed a set of "combination punches", which were decelerated again by the reverse thrust of the reverse thrust of the reverse thrust engine before about to land, and absorbed energy through systems such as vibration damping materials returning to the bottom of the cabin to achieve a "soft landing".
Safe landing in the return capsule / source from CCTV News
Rong Wei said that the final landing speed of the return capsule will be controlled at about 1 to 2 meters per second.
Rong Wei: "When the altitude is about 1 meter above the ground, the return capsule is decelerated again, relying on several engines to ensure the final landing speed of the return capsule, which is 1 to 2 meters per second when touching the ground, to ensure the safety of astronauts." ”
<h1 class="pgc-h-center-line" data-track="115" > hero triumphant return to the motherland</h1>
The Shenzhou XII return mission is the first time an astronaut has returned to Earth from the Chinese space station. For the first time, the mission used a number of new and verified measurement and control methods, including the spacecraft's dynamic adaptation return mode, predictive guidance and guidance measurement and control scheme, etc., to pave a smooth and safe way home for the three astronauts.
Dongfeng landing field / from CCTV news
Different from the previous China's manned spacecraft returning to land at the Siziwangqi landing site in Inner Mongolia, this mission chose to land at the Dongfeng landing field in Jiuquan, Gansu for the first time. Wang Yanan, a member of the Science Popularization Working Committee of the Chinese Society of Aeronautics and Astronautics, analyzed that the terrain of the Dongfeng landing field will be more complicated, but it will be conducive to the multiple trips of the spacecraft during the construction and operation of the Chinese space station.
Wang Yanan: "The current Dongfeng landing field is more suitable for the return of Chinese spacecraft in the construction of the space station, and in order to use the Dongfeng landing field, we have actually further optimized the trajectory design of the spacecraft and done a certain amount of excess mediation." However, the Dongfeng landing field has its own characteristics, its topography is relatively more complex than the Four Sons King Banner, and there are certain Gobi and desert. ”
Before landing, the Shenzhou XII return capsule made four landing predictions. In addition, the spacecraft designers also installed autonomous calibration equipment on the return capsule, telling search and rescue personnel "I am here" by sending radio signals, etc. Pang Zhihao, chief scientific communication expert of national space exploration technology, said that search and rescue is roughly divided into three stages.
Pang Zhihao: "After the return module leaves the black barrier area, the helicopter can approach the return module according to the predicted landing point. Generally, it is divided into three levels, one is long-distance search, which is based on radar; the other is medium-distance search, mainly by helicopter; the third, is close-range search, that is, centered on this landing site to find the target. The disposal of the return module was handed over to the troops on the ground. ”
Astronauts are about to leave the capsule / Source Xinhua News Agency
Astronaut in good condition / From Xinhua News Agency
After the successful landing of the Shenzhou XII manned spacecraft, search and rescue personnel immediately ran to the return module and planted a flagpole outside the cabin. Immediately after, a bright five-star red flag was unfurled in the wind.
At about 2:15 p.m., astronauts Nie Haisheng, Liu Boming, and Tang Hongbo who were on the mission were released from the capsule, marking the complete success of the first manned mission in the Chinese space station phase. Nie Haisheng said excitedly in an interview with the media that China's aerospace science and technology workers will continue to make unremitting efforts.
Nie Haisheng: "I think that with the continuous improvement of China's comprehensive strength and national scientific and technological level, there will be more astronauts to break the record and create China's height." China's aerospace science and technology workers will also live up to their mission, live up to their heavy trust, make new contributions, and make unremitting efforts for the motherland's aerospace industry. ”
After being assisted by the staff, the three astronauts sat in their seats, in good physical and mental condition, and then left the scene by helicopter. Pang Zhihao said that at this stage, medical staff will conduct preliminary health examinations for them.
Pang Zhihao: "After opening the hatch, medical supervision and medical support personnel will conduct a preliminary inspection and confirmation of the astronauts' health status, assist the astronauts to initially adapt to ground gravity, and supplement some drinking water and nutrient solution." Carry them in a chair, why? Because they have been weightless in space for a long time and have poor standing endurance, they are generally assisted to get out of the cabin. ”
<h1 class="pgc-h-center-line" data-track="121" > Shenzhou travels to explore the stars</h1>
The Shenzhou XII manned spacecraft was launched on June 17 and subsequently docked with the Tianhe core module to form a combination. After the three astronauts were stationed in the core module, they worked and lived in the space station complex for 90 days, setting a new record for the space stay time of Chinese astronauts on a single mission. During the orbital flight, the astronauts carried out two outgoing activities and also carried out a series of space science experiments and technical experiments.
Shenzhou XII launch / from the aerospace science and technology group public number
The spacecraft and the core module rendezvous and docking / from the aerospace science and technology group public number
Wang Yanan, a member of the Science Popularization Working Committee of the Chinese Society of Aeronautics and Astronautics, said that the complete success of the mission laid a solid foundation for the subsequent construction and operation of the Chinese space station.
Wang Yanan: "The special significance of this mission is that a flight crew that has been working on the space station for 3 consecutive months has returned to the ship and completed the important technologies of space orbit convergence and docking and extravehicular activities, marking the continuous progress of China's manned spaceflight project." Then, we began to achieve a more ambitious goal, which is to build a long-term inhabited Chinese space station with certain technical complexities. Not only for China, but also for the world's aerospace science and technology community to provide a valuable stage for exploring space technology. ”
According to the china space station construction mission plan, this year and next year, China will implement a total of 11 flight missions, and it is expected to complete the construction of the space station in orbit next year, build the national space laboratory, and enter the application and development stage. At that time, one "Shenzhou" will travel back and forth between space and the earth, carrying heroic astronauts to explore the vast universe.
Reporter | Sun Yuan
Edited | Zhao Mingcong
Editor-in-chief | Cheng Yan