Space system: also known as aerospace engineering system. An engineering system composed of spacecraft, aerospace transportation systems, spacecraft launch sites, aerospace measurement and control networks, and application systems to complete specific aerospace tasks is a typical modern complex large-scale system. The specific tasks performed by the aerospace system and the way it obtains information determine its working principle, composition, and structure. There are two ways to obtain information from space: one is to transmit it to ground receiving stations through wireless channels, and the other is to collect information through dedicated return modules. The manned space system of a spacecraft is called a manned space system; A space system that does not carry humans on a spacecraft is called an unmanned space system. The aerospace system that performs military aerospace missions is called a military aerospace system; The aerospace system that performs civil aerospace missions is called a civil aerospace system. Civil aerospace systems include those used for scientific research and those directly serving the national economy. Military aerospace systems and aerospace systems that directly serve the national economy belong to applied aerospace systems. There are various types of applied aerospace systems, such as satellite communication systems, satellite navigation and positioning systems, satellite meteorological observation systems, satellite reconnaissance systems, etc