What is Geosynchronous Orbit

On 22/07/2012, in How it works, by Norman Dean

As a WildBlue & Exede dealer-installer I regularly am asked how does the satellite stay in the same place way up in space?

When something is shot into space it tends to either fall, escape the pull of Earth’s gravity and continue out to space or neither. When the neither option happens its called orbit, the object is falling but has enough momentum to balance between escape and returning to the ground, this is called an orbit.

The amount of time that an object in orbit takes to make one revolution around the planet is called its duration. Objects in low orbit look like they are traveling very fast and don’t take long to make one revolution. Sometimes low orbit satellites can be seen traversing the night sky by the naked eye. These are not good at all for general communication because the are moving too fast and are only accessible for short periods throughout the day. To have constant contact with a satellite you don’t want it to move according to your spot on the surface of the earth, this is where geo-sync comes in.

As you add speed to an object going into orbit the object will want to move farther out away from earth, geosynchronous orbit satellites are traveling around the earth in a fast and very long orbit to make 1 revolution every 24 hours. To a person on the surface of the earth that also makes one revolution around the earth in 24 hours a geosynchronous satellite looks to be not moving in the sky. Most geo-sync satellites are parked over the equator so they are always in the same inclination above the horizon as well as the same azimuth, and are 22,000 miles out. Even though a person on the ground doesn’t see the satellite moving it is traveling a distance of 26199.6 miles every 24 hours, equating to 1091 Mph, while you on the ground are traveling at 165.13 Mph around the earth’s axis.

Now you know… and knowing is half the battle.

Here is a short youtube video that explains it as simply as can be.

 

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