Shenzhou 12 manned spacecraft successfully landed on the landing site after separating from the space station’s sky and core module. It was corrected four times on the way. Basically, the landing point coincides with the return aiming point. This kind of control has to be said. That's awesome. Such precise control is not only the Beidou positioning system as simple as the infrared imaging device on the ground and the aerial search and rescue. The spacecraft has to land from space several hundred kilometers high, and must pass through the atmosphere again on the way. This is a severe test. The trajectory of movement cannot be predicted with complete accuracy. Therefore, the cooperation of space, air, and ground parties is required to ensure the final The completion of the action.
The spacecraft is different from the landing of ordinary aircraft in the atmosphere. From the time it enters the re-entry corridor, its accuracy is roughly fixed. A major factor affecting the landing point is the parachute landing after the black barrier. At this time, the impact of the landing point will be there, but it is not too big. The key factor is the deceleration in the re-entry corridor. Once it is not well controlled, it may land early. It is possible to land in the East China Sea or even in the Pacific. The former Soviet Union had a tragic experience, which was nearly 5,000 kilometers away from the landing point.
determines the approximate landing point of the spacecraft. The next step is trajectory tracking. This is a fine activity and requires real-time updates. For example, satellites, radars, ground infrared trajectories, and optical tracking equipment must all be activated. The range of the landing point can be further reduced, and finally the air trajectory tracking is required. At this time, the Air Force aircraft is required to be dispatched. Both the spacecraft's return device and the aircraft land on the ground from the air, but because the landing starting point, route, speed and altitude are different, the spacecraft needs more and more sophisticated equipment to assist in a safe landing.
I believe that Beidou navigation can be found in the ground control station, spacecraft and astronaut’s personal equipment.If you fall into the virgin forest or desert and the search and rescue team cannot arrive in time, then the Beidou positioning function will be quite important when you rescue yourself or walk to a place that is easy to be rescued. So this is a must-have in the personal emergency kit equipment. Like the previous my country's Chang'e 5 , it is planned to land at the Siziwangqi . When Chang'e Five was finally discovered, she was only 500 meters away from the expected landing error, which shows that my country's extraterrestrial celestial body return and control technology is quite mature.
The landing process of the return module is a test of the search and recovery capabilities of our country's ground search and rescue team. The Shenzhou 12 return module carries the Beidou navigation terminal, which continuously sends out precise positions and speeds to the ground control unit when it is in space to facilitate tracking by ground personnel. However, the return capsule cannot communicate with the outside world after the atmosphere enters the black barrier. At this time, ground radar is required to track and measure to predict the approximate location of the landing site. After the return capsule flies out of the black barrier, the Beidou navigation device on the return capsule will re-establish contact with the outside world. In addition, the staff will use helicopters to monitor the return cabin. When the return cabin is safely landed, Beidou Navigation will continue to transmit location information, guide helicopters, ground search and search and rescue teams.
The design of a spacecraft, orbit calculation, when to fire and change orbit, and what angle to enter are all accurately calculated. Generally, it is impossible to have too much error because of the guidance of the satellite navigation system. It can only be said that the landing location cannot be very accurate, and the actual landing point of Shenzhou 12 this time is only more than 600 meters away from the first predicted landing point. This is really a hundred steps through the Yangtze. This kind of accuracy is deservedly the world's first. If it is replaced by the ballistic missile , the accuracy can reach ten meters or even the meter level. The recovery of US spacecraft has always been carried out at sea. It is because he cannot accurately predict the landing point, so he has to choose a relatively wide and safe sea surface. (Text/Mountain)
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