From 28 hours to 8 hours, why is the speed of "returning home from space" getting faster and faster? How many launches will there be for the construction of the space station in 2022?

On April 16, the return capsule of the Shenzhou 13 manned spacecraft landed safely in the designated area of ​​the Dongfeng landing site!

There are camels near the landing area Source: Weibo/News Photo

After landing, the astronauts Zhai Zhigang, Wang Yaping and Ye Guangfu who carried out the flight mission exited the cabin safely and smoothly and were in good physical condition. The Shenzhou 13 manned flight mission was a complete success.

Three astronauts successfully exited the spacecraft Source: CCTV News Entering the Tiangong, spacewalking, giving classes in the Tiangong, celebrating the Chinese New Year in space... During the more than 180 days in orbit, the Shenzhou 13 flight crew created many "firsts": the first New Year's Eve in space, the first Spring Festival in space, the first female astronaut to conduct an extravehicular activity, the first time to complete the docking of a cargo spacecraft with a space station through manual remote control in orbit, the first time to stay in orbit for 6 months... Now that they have successfully returned home, what challenges did the astronauts experience on the way? Let's take a look.

How is the astronauts’ return date chosen?

In order to return to the ground during the day, the Shenzhou 13 flight crew began preparations for the return on the evening of the 15th. First, they had to ensure that the flight trajectory passed through the landing site, otherwise they would definitely not be able to return that day.

Return capsule landing Source: CCTV News

After the spacecraft enters independent flight, it will wait for the spacecraft to pass the landing site. The Shenzhou spacecraft has the ability to maneuver laterally, but too much maneuverability requires a lot of propellant, so researchers choose to trade time for space and wait until the spacecraft passes over the landing site before starting the return procedure.

In selecting the return date, trajectory is the most important factor. In addition, weather factors are also important. However, the weather requirements for the spacecraft's return process are not as high as those during launch.

How to achieve “get home within 8 hours”?

The return of the Shenzhou XIII spacecraft took only about 8 or 9 hours, while the return of the Shenzhou XII spacecraft took about 28 hours. The reason why the time was greatly shortened is that the Shenzhou XIII adopted the rapid return technology. By rationally cutting and adjusting the flight mission events and compressing the operation time, the time required for return was reduced from more than ten flight circles in the past to five.

After entering the return orbit, the spacecraft's braking and re-entry processes are the same as before. It takes more than 40 minutes to complete the four stages of braking and deceleration, free gliding, re-entering the atmosphere, and recovery landing before returning home safely.

Which part of the spacecraft returned?

The Shenzhou XIII spacecraft has a three-cabin structure, consisting of the orbital module, the return module and the propulsion module.

Schematic diagram of Shenzhou spacecraft Source: Wikipedia

The three astronauts are inside the manned return capsule. And only the return capsule will eventually return to the ground, while the orbital module and the propulsion module will eventually fall into the earth's atmosphere and be destroyed.

Building a space station, what are your future plans?

From 2021 to 2022, my country plans to carry out 11 launches to build a space station. Five launches have been carried out so far, and six more will be carried out in the future. Each cabin of the space station and the cargo spacecraft will be launched into space.

The cargo spacecraft will be launched by the Long March 7 rocket, the Shenzhou manned spacecraft will be launched by the Long March 2F rocket, and the various cabins of the space station will be launched by the Long March 5B rocket. The Long March 5B and Long March 7 will be launched from the Wenchang Launch Center, and the Shenzhou manned spacecraft will be launched from the Jiuquan Satellite Launch Center.

Since 2021, my country's manned space program has successfully carried out five flight missions in the key technology verification phase of the space station. The Shenzhou XIII mission is the sixth and the last of this phase. So far, the key technology verification phase of China's space station has been completed and it is about to enter the on-orbit assembly and construction phase.

Congratulations on the successful completion of the Shen-13 mission!

Source: China National Radio

The content of this article is compiled from: China National Radio, CCTV News, Beijing Daily, China News Service, the website of the Central Commission for Discipline Inspection and the National Supervisory Commission, etc.