Satellites geostationary are those that complete in orbit the rotation around the planet in a time of 24 hours. How does this time correspond to the Earth's rotation period, a possible ground observer will perceive the satellite as a fixed point in the sky.
Geostationary orbits were proposed in 1945 by Arthur Clarke and, therefore, they were named Clarke orbits. Generally, geostationary satellites are used for communication because their movement follows that of the planet and, therefore, they can offer this service uninterruptedly. In addition, they have a wide range of operations, reaching distant regions.
Features of geostationary satellites
Geostationary orbits are over the equator line and correspond to approximately 6.6 times the radius of the Earth. Thus, satellites of this type have an orbit around 36,000 km, provided from the Earth's surface.
The linear velocity of movement of a geostationary satellite should be approximately 11000 km/h.
Brazilian geostationary satellite
The International Union of
telecommunications (ITU) has divided the geostationary orbit, which is 36,000 km from the Earth's surface, into 180 possible positions, each of which is separated by a 2° angle. O Brazil is entitled to seven positions for launching geostationary satellites.In May 2017, the Defense and Communications Geostationary Satellite (SGDC), first brazilian geostationary satellite, was released. This equipment will be used to give autonomy to the Armed Forces communication and will serve as part of the National Broadband Plan (PNBL), which aims to provide high-speed internet access in the parents.
O SGDC it has a mass of approximately six tons and orbits at a speed of 10,000 km/h. This equipment cost BRL 2.7 billion and has a useful life of about 18 years.
By Joab Silas
Graduated in Physics
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/fisica/o-que-sao-satelites-geoestacionarios.htm
