All of the statements in this article are based on reliable sources and are reproduced at the end of this article
In recent years, the mainland's manned space technology has developed rapidly, and the mainland has also made major breakthroughs in space research.
It is more than five months before the mission of Shenzhou 17 to fly into space, which means that the space travel of Shenzhou 7 will come to an end, and in late April 2024, the mainland's Shenzhou 17 will return to Earth with 3 astronauts.
At the same time, the launch of Shenzhou-18 was also put on the agenda.
A new space journey
In February 2024, China's manned space program has revealed that it will launch two manned spacecraft into space this year, and continue to promote the progress of the two major tasks of the mainland space station application and the manned space landing program.
Even though we already know that the two spacecraft will be launched one after another, the country has not specified the exact date, Shenzhou 18 is expected to be at the end of April, and Shenzhou 9 has been postponed to October, and the disclosure of this time period has made the people of the whole country full of expectations.
You must know that the launch of manned space rockets has always been an exciting existence, and every launch will usher in a round of applause from all over the country, and Shenzhou 8 is no exception.
In addition to the conventional manned spacecraft, there are two cargo launch missions this year, namely Tianzhou-7 and Tianzhou-8, their role is to provide food supplies to astronauts doing research in space, and in January 24, Tianzhou-7 has successfully docked with Shenzhou-7.
You must know that every time the mainland carries out a space mission, there are three astronauts fixed, and only three astronauts went to space last year, and according to the usual practice, six astronauts will go to space this year.
As early as February, when the country announced the launch news, the astronauts were already making final training preparations to face the crisis that could arise in space at any time. And in the trio, there must be an astronaut in space, that is, an experienced old man who will go to space with two newcomers.
Because in the process of astronautics, it is possible to encounter uncontrollable situations at any time, you must know that the training on the ground is meticulous, and when you actually board the rocket, the situation will be different, and you have to face the maintenance and replacement of some equipment, if you are just a newcomer, you may not be able to start, so this model has always been used by the mainland.
Of course, before each space mission, the name of the astronaut is kept secret, just like even if you already know who it is, you can't reveal his name, so no matter how much the people look forward to it, they can't know who will be the latest member of the space team.
When the Shenzhou-17 mission on the mainland was carried out, everyone knew very well that their mission was more about the maintenance of the "solar wing" of the space station that was hit by a meteorite.
And the ascent of Shenzhou 18 also carries a certain purpose and task, just like Shenzhou 7, which will land before this.
Shenzhou 7 returned
Shenzhou-7 is a manned spacecraft launched by the mainland in October 2023 and successfully docked with the Tiangong space station, followed by the three astronauts officially starting a months-long space trip.
At that time, the three space astronauts Tang Hongbo, Tang Shengjie and Jiang Xinlin were all space pilots, and the three of them formed the youngest space crew in history, among which Tang Hongbo participated in the Shenzhou 12 space mission in 2021, so he belonged to the "old man" with space experience among the three.
When the three astronauts entered the space station, they began the space mission, including but not limited to the inspection and maintenance of various facilities, the equipment inspection of Tianzhou-6, and the two out of the capsule during the period to overhaul the solar wing of the core module.
It is important to know that although astronauts carry a variety of scientific research tasks in spaceflight, it is the first time for the maintenance of solar wings, and this task is extremely challenging.
Because in space, there are many small meteorites, will also cause damage to the surface of the space station, the solar wing is in flight with the small meteorite in space friction collision caused by damage, of course, such a small damage will not affect the normal operation of the Chinese space station, but in order to show the Chinese's technology for out-of-cabin operations and ensure that the space station can operate more durably, or to carry out the maintenance of the solar wing.
Although it was the first time that the astronauts had carried out extravehicular repairs, the astronauts successfully completed the maintenance work with their excellent physical fitness and expertise.
Thrilling homecoming
After several months of scientific missions, the astronauts docked with the ground and began to prepare for their return to Earth. Like the Shenzhou spacecraft currently used on the mainland, it adopts a three-cabin configuration, consisting of three parts: the propulsion module, the return module and the orbital module.
They all have different roles, the propulsion module and the orbital module are both to prepare the return module for a safe landing, and when the return module successfully enters the atmosphere, the propulsion module and the orbital module will remain in space until they are burned to ashes by the atmosphere when they return to Earth on their own.
The orbital module is the place where astronauts live normally and carry out research work, which is mainly paired with food, food and other living equipment and research equipment, etc., and its functional equipment is the most complete among the three modules. As the name suggests, the propulsion module provides power for the return module, and when the astronauts decide to return to the ground, the propulsion system in the propulsion module begins to provide the spacecraft with the propulsion of orbit change and speed change.
The role they provide for the re-entry capsule is no longer effective when the re-entry capsule enters the atmosphere, and the re-entry capsule is where the astronauts control the spacecraft, because it is only the re-entry capsule that finally descends to the ground, so its role is significantly higher than that of the other two.
The life support system and environmental system configured in the return capsule provide a more suitable environment for astronauts, because its bottom layer and side are in contact with the atmosphere, so they are set up with heat-proof coatings, when the spacecraft passes through the atmosphere, the violent friction produces high heat, it is reported that the temperature of the surface can even reach 1000 °C, but the return capsule with the exothermic coating, even if the appearance is burned red, the spacecraft will still remain intact.
In addition to these, the re-entry capsule is also equipped with a parachute to control the landing speed. When the spacecraft is 140 kilometers above the ground, the propulsion module separates from the return module.
The spacecraft must also be cautious when entering the atmosphere alone, and the spacecraft must find a good flight angle when it begins to land before entering the atmosphere, which is also known as the "re-entry angle", which is an angle that can be measured to enable the spacecraft to enter the atmosphere smoothly.
His error cannot be greater than 3°, otherwise too large an angle will cause the spacecraft to increase its speed and increase friction, resulting in the heat shield being burned out and the spacecraft being burned out. But if the angle is too small, the spacecraft will not be able to cut into the atmosphere, but will be ejected by the atmosphere, so it will be difficult to have another chance to return to the earth.
When the spacecraft descends to about 10 kilometers, the parachute carried on the spacecraft will also be opened to control the landing speed of the spacecraft, although there is a parachute buffer, but when it is almost to the ground, it still descends at a speed of 10 meters per second. This air pressure will weigh heavily on the astronaut's body.
At the moment of landing, the thrust at the bottom of the spacecraft will produce an extremely strong reaction force, instantly reducing the speed of the spacecraft to a speed of less than 2 meters per second, so as to ensure the physical and mental health of the astronauts.
Finally, find the expected landing site and complete a smooth flight. But the astronauts who came off the spacecraft were still uncomfortable, and the gravity of the earth had to re-adapt them from the weightlessness to the ground, and the flight was a successful one.
Of course, soon Shenzhou 17 will return to Earth, and the next batch of astronauts welcomed by the Tiangong space station are also nervously preparing for the final training of space flight.
Since the successful launch of the mainland's first manned spacecraft in 2003, the mainland's manned spaceflight project has achieved a major process from scratch, and the frequency of the mainland's rocket launches has also increased from once a year to once every few months.
Shenzhou-18 is ready to go, and we are full of expectations for his success, and we have full confidence in him, because the mainland has strong aerospace technology.
Key Sources:
The original article was published on People's Daily Online on March 1, 2024 on "Shenzhou 18 and Shenzhou 19 will be launched this year".
This article was originally published in the Yangtze Evening News on October 28, 2023 on "Detailed Explanation of the Mystery of the Successful Launch of Shenzhou 17".
The original article was published on CCTV on June 29, 2012 on "How did the manned spacecraft return to the ground?".