Satellite data

Sputnik: An unmanned spacecraft orbiting the earth in space. Satellites basically orbit the earth according to the laws of celestial mechanics, but the actual motion is very complicated due to the influence of the gravitational field, atmospheric drag, solar gravity, lunar gravity and light pressure of aspheric earth with different orbits.

Man-made satellite is the spacecraft with the largest number of launches, the widest use and the fastest development. Satellite launches account for more than 90% of the total number of spacecraft launches.

Satellites can be divided into three categories: scientific satellites, technical test satellites and application satellites. Scientific satellites are satellites used for scientific exploration and research, mainly including space physics exploration satellites and astronomical satellites. They are used to study the atmosphere, radiation belt, magnetosphere, cosmic rays and solar radiation of a planet, and also to observe other planets. At present, most of the artificial satellites in the world are artificial earth satellites, and there are also artificial Mars satellites.

Extended data:

The role of satellites

Speaking of functions, natural satellites are naturally formed in the universe, and it is hard to say what functions they have. Of course, the moon is the natural satellite of the earth. It can balance the earth's rotation, stabilize the earth's axis, control tides, observe time, and imagine many beautiful legends. Satellites are widely used, some of which are equipped with photographic equipment, which can be used to take photos of the ground, investigate resources and monitor the climate and pollution of the earth.

Some are equipped with astronomical observation equipment for astronomical observation; Some are equipped with communication relay equipment to relay communication signals such as broadcasting, television, data communication and telephone; Some are equipped with scientific research equipment, which can carry out scientific research and special production in weightless space.

In a word, satellites have different uses because of the different purposes of development, production and users.

Baidu encyclopedia-satellite