The first is a major demonstration of engineering capabilities, the rapid rendezvous and docking pair launch window, and the rocket’s orbit accuracy is extremely high (the two missions of Tianzhou 2 and Shenzhou 12 have achieved “horrible” orbit accuracy); and After the spacecraft enters orbit, it must quickly complete the status confirmation, and enter the orbit change and rendezvous and docking procedures. The previous mainstream two-day rendezvous program at home and abroad firstly has a greater tolerance for orbit deviation, and secondly, it has two days to confirm various states for the spacecraft and gradually change its orbit, with a large task margin and a high fault tolerance rate. Russia, a veteran manned spaceflight player, has been engaged in rapid rendezvous and docking for so many years, and it was only after 2010 that it began to engage in rapid rendezvous and docking, and it has been tested many times on the Progress cargo spacecraft, and it was transplanted to the alliance manned spacecraft when it matured. China has used the fast docking model from the beginning of the space station mission, which also shows that our technology is highly mature and we are confident in our technology. The role of rapid rendezvous and docking is easy to say. For manned spacecraft, astronauts can enter the space station in a few hours without having to squeeze in a small spacecraft for too long. It is also easier for a cargo spacecraft to transport some time-sensitive payloads. From ground packaging to receipt by the astronauts, the time can be compressed to about 12 hours. Quick docking also helps to release measurement and control resources, especially now that China adopts all-phase autonomous rendezvous and docking technology. It only needs to inject space station orbit parameters into the spacecraft, and the spacecraft can design its own orbital change plan until the docking is completed, without too much intervention on the ground. .