Published: July 21, 2025 | By: Rungreung Huanraluek
The Concept of Communication Satellites
When we throw an object into the air, it moves upward until it reaches the highest pointwhere its vertical velocity becomes zero. At that point, the Earth's gravitational force pulls it back down. This behavior follows the laws of physics regarding projectile motion and gravitational acceleration acting on the object after its vertical speed reaches zero.
However, in 1945, the concept of communication satellites was first sparked by the famous scientist and science fiction writer Sir Arthur C. Clarke. He published an article in the magazine Wireless World, proposing that if an object were placed at an altitude of about 35,786 kilometers, it could float in space and orbit the Earth. This idea became known as the Clarke Orbit or Clarke Belt and marked the beginning of satellite technology as we know it today.
We refer to this altitude of around 35,786 km as the geostationary orbit (Geostationary Orbit - GEO) or Geosynchronous Orbit (GSO). These orbits are widely used for communication satellites, television satellites, and weather satellites. The key characteristic is that the orbit lies directly above the equator, and the satellites angular velocity matches the Earth's rotation (24 hours), making it appear stationary over a fixed point on Earth. This allows continuous communication with the same ground station and provides reliable signal coverage over large areas for radio, television, and telecommunications services.
This was the birth of the communication satellite conceptan idea that has become reality today.
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