What is a Communications Satellite?

The communication satellite acts like an international messenger and acts as a radio communication relay station. Collect "letters" from the ground and "deliver" them to users in another place. Because it is a "station" at an altitude of 36,000 kilometers, its "delivery" coverage is particularly large, and a satellite can be responsible for 1/3 of the earth's surface communications. If three communication satellites are placed evenly in the geostationary orbit, global communications can be achieved except for the north and south poles.

Communication satellite

Chinese name: Communication Satellite

English name: communication satellite

Definition: Artificial for communication

1 By track

Can be divided into different tracks

A geostationary orbit communication satellite can cover about 40% of the earth's surface, allowing any ground, sea, and air communication stations in the coverage area to communicate with each other at the same time. Three geostationary orbit communication satellites distributed at equal intervals over the equator can achieve global communications except for some regions of the poles. Communication satellite is one of the earliest and most widely used satellites in the world. Many countries such as the United States, the former Soviet Union / Russia and China have launched communication satellites.

When the satellite receives a weak radio signal from a ground station, it will automatically turn it into a high-power signal, and then send it to another ground station, or transmit it to another communication satellite, and then send it to the earth. On the ground station on one side, we received signals from far away.

Communication satellites generally use the geostationary orbit, which is located 35,786 kilometers above the Earth's equator. The satellite orbits the earth from west to east at a speed of 3075 meters per second in this orbit. The time around the earth is 23 hours, 56 minutes and 4 seconds, which is equal to the time that the earth makes one revolution. Therefore, from the ground, satellites are hung in the sky, which makes the work of ground receiving stations much easier. The receiving station's antenna can be fixed at the satellite and communicate day and night without having to "sway" like tracking those moving satellites, making the communication time intermittent. Communications satellites have undertaken all intercontinental communications and television transmissions.

Communication satellite is one of the earliest and most widely used satellites in the world. Many countries have launched communication satellites.

On December 18, 1958, the United States successfully launched the world's first communications satellite, the Skoll. On April 6, 1965, the United States successfully launched the world's first practical stationary orbit communication satellite: International Communication Satellite 1. So far, this type of satellite has developed to the eighth generation, and each generation has improved in terms of size, weight, technology, communication capabilities, and satellite life.

The communications satellites of the former Soviet Union were named "Lightning". Including Lightning 1, 2, 3 and so on. Due to the vast territory of the former Soviet Union, most of the "Lightning" satellites are not in a stationary orbit, but in an elliptical orbit with a large eccentricity.

China's first geostationary communication satellite was launched on April 8, 1984, and was named "Dongfanghong-2". Five satellites have been successfully launched so far. These satellites have successively undertaken radio, television signal transmission, long-distance communication and other tasks, which have played a huge role in the construction of the national economy.