In the aerospace field, every time a rocket takes off, every spaceship successfully docks and every satellite runs stably, it is inseparable from a seemingly ordinary but vital technology-aerospace sealing technology. Like an "invisible guardian" in space, it plays a decisive role in every key node, although it is not obvious.

The space environment is extremely harsh, and vacuum, alternating high and low temperatures, strong radiation and the impact of meteoroids all put forward extremely high requirements for the sealing performance of spacecraft. Once the seal fails, the air inside the spacecraft will leak quickly, the electronic equipment may not work normally due to the vacuum environment, and the life safety of astronauts will also be seriously threatened. Therefore, aerospace sealing technology has become a difficult problem that must be overcome in aerospace engineering.

In the design of spacecraft, the application of sealing technology is almost everywhere. From the combustion chamber of rocket engine to the fuel tank of satellite, from the sealing gloves of spacesuit to the sealing door of spacecraft docking module, every link needs accurate and reliable sealing. Taking the rocket engine as an example, the high-temperature and high-pressure gas in the combustion chamber needs to be strictly sealed to ensure that the fuel can burn efficiently and generate enough thrust. This requires not only high-strength materials to withstand great pressure, but also advanced sealing technology to prevent gas leakage. Engineers design complex sealing structures, such as labyrinth seals and bellows seals, to ensure that the sealing performance can still be maintained under extreme conditions.

The sealing of spacesuit is the pinnacle of aerospace sealing technology. Spacesuit should not only provide astronauts with a living space similar to the earth's environment, but also resist various threats in space. It needs to keep the internal pressure and temperature stable in a vacuum environment, and at the same time prevent the invasion of cosmic rays and micro-meteoroids. The sealing layer of spacesuit adopts multi-layer composite materials, including breathable layer, heat insulation layer and protective layer, and each layer has been carefully designed and strictly tested. These materials not only need good sealing, but also have enough flexibility so that astronauts can move freely. In addition, the sealing gloves and helmets of spacesuits are more difficult in sealing technology, because they need to ensure sealing while allowing astronauts to operate flexibly and observe clearly.

In the process of spacecraft docking, sealing technology is also very important. When two spaceships or spaceships dock with the space station, the sealed doors need to be reliably sealed in an instant to ensure that astronauts can safely enter each other's cabins in the joint flight after docking. Butt sealing technology needs to consider many factors, including the elasticity of sealing material, the reliability of sealing structure and the mechanical impact during butt joint. Engineers ensure that the butt seal can work perfectly in a complex space environment through precise design and rigorous testing.

With the continuous development of aerospace technology, sealing technology is also constantly innovating. New sealing materials, such as self-repairing sealing materials and intelligent sealing materials, are gradually being applied in the aerospace field. The self-repairing sealing material can be automatically repaired when it is slightly damaged, thus prolonging the service life of the sealing system; Intelligent sealing materials can automatically adjust the sealing performance according to environmental changes, and improve the reliability and adaptability of the sealing system.

Although aerospace sealing technology does not often appear in public view, it is an indispensable key technology in aerospace engineering. Like a silent "invisible guardian", it escorts the safety of spacecraft and astronauts in every detail. From rocket launch to satellite operation, from astronaut's spacewalk to spacecraft docking, sealing technology provides a solid guarantee for human space exploration with its precise technology and reliable performance.

（Writer：Laurro）