At 13:34:19 on September 17, 2021, the Shenzhou 12 return capsule landed smoothly in the designated area of the Dongfeng landing field, and the 3 space heroes have returned triumphantly, drawing a successful end to the 3-month space mission.
After returning to the embrace of the motherland, it is still impossible to reunite with the family for the time being, because it is necessary to go through 14 days of medical isolation, which is not afraid that the three astronauts will bring us back an unknown virus, but that the astronauts will have a decline in resistance after returning home, but will be infected with common viruses, because the space station environment is completely different from the ground environment.
According to the convention, in order to quickly replenish physical strength, the first meal of astronauts home will eat foods that are rich in high-quality protein and easy to absorb, such as tender mutton soup, as well as eggs, etc. These foods help astronauts quickly recover their physical strength, supplement the lack of trace elements, and the first meal after the Shenjiu and Shenshi astronauts return home has mutton soup.
Tens of millions of Chinese people watched the live video of Shenzhou 12 returning home, I don't know if you have noticed, at 13:34 minutes and 19 seconds, when the Shenzhou 12 return capsule suddenly raised a large fireball at the moment before touching the ground, and then the ground was dusty, where did this fireball come from? Could it be that the return capsule burned when it hit the ground?
This is actually the last safety guarantee of the Shenzhou 12 return capsule to return to the ground, the reverse thrust engine group at the bottom of the return module at the "last meter" from the ground, the automatic ignition eruption, the purpose is to play a certain back thrust buffering role, reduce the return capsule of the fall speed, so that the return capsule landed more smoothly to ensure the safety of astronauts.
The return chamber thrust engine set is located at the bottom of the return capsule and consists of four solid thrust engines, which are installed in the bottom four directions, each engine weighs about 11 kg and looks like a hat, the upper part of the thrust engine is equipped with solid propellant, and the lower part is a number of small holes, which look like a honeycomb.
Shenzhou 12 return capsule weighs about 7 tons, at a speed of 3 meters per second back to the ground, do not underestimate the speed of three meters per second, it is equivalent to the speed of our usual trot, imagine, if you accidentally hit the wall when running, even if you will not break the head and bleed, it will also make you a piece of purple, the astronaut sits on a chair, easy to hurt the neck and spinal cord.
Therefore, it is very necessary to say that the return capsule reverse thrust engine exists, when the return capsule is only one meter high from the ground, the reverse thrust engine group will trigger the start, generating about 12 tons of thrust, which can completely dissolve the momentum of the return capsule, completely support the return capsule, and then gently lower it to reduce the impact load when it reaches the ground and ensure the safety of astronauts.
The biggest technical difficulty of the return cabin reverse thrust engine set is "precision" and "synchronization", precision is that when the return cabin must be automatically triggered when it is 1 meter from the ground, it is not good to be early, it is not good to be late, the response time is not more than 20 milliseconds, to know that the return cabin arrives at the ground from a height of 1 meter is only 300 milliseconds, and it is too late.
Synchronization means that the four reverse thrust engines must be started at the same time, the difference time is not more than 10 milliseconds, if one or two of the engines start in advance, then the return capsule may be directly overturned to the ground, which may be more harmful than the landing damage of 3 meters per second, which is counterproductive.
Therefore, the Shenzhou 12 return capsule suddenly raised a large fireball when it touched the ground, not that the return capsule caught fire, but that the reverse thrust engine group at the bottom of the return capsule was successfully started, but it showed that the engine put the astronauts back to the ground at the last hurdle and ensured the safety of the astronauts' way home.
The smooth return of the Shenzhou 12 astronauts means that the subsequent launch mission will proceed as planned, Tianzhou 3 will be launched at the end of September, Shenzhou 13 will be successfully launched on October 3, shenzhou 13 is the most concerned question, whether there are female astronauts, who are the female astronauts, although there is no official announcement, but it can basically be determined that Shenzhou 13 should have Wang Yaping. Interesting scientific exploration content, please pay attention to the only WeChat public number: Interesting Exploration #Shenzhou ## Space Trip Trio Home ##Shenzhou XII Astronauts Home ##神舟十二号返回克服了哪些难点 #