B Earth Orbits of Geostationary Satellites

[John12343210]

Do geostationary satellites move with the Earth's orbit or do they not move at all?

 

[hutchphd]

Are you asking for the difference between geosynchronous and geostationary satellites?

 

[John12343210]

Are you asking for the difference between geosynchronous and geostationary satellites?

no

 

[Ibix]

What do you mean, then? All satellites move in some sense or other, including geostationary ones.

 

[russ_watters]

Do geostationary satellites move with the Earth's orbit or do they not move at all?

Geostationary satellites orbit the Earth once a day, remaining stationary in a rotating reference frame centered on Earth. Clearly they must also follow the Earth through its orbit around the sun, as all satellites do.

 

[Drakkith]

Do geostationary satellites move with the Earth's orbit or do they not move at all?

Both they and all other satellites, including the Moon, move with the Earth around the Sun.

 

[John12343210]

thanks guys, some of my textbooks were saying geostationary satellites don't move at all, so I was a bit confused

 

[Ophiolite]

thanks guys, some of my textbooks were saying geostationary satellites don't move at all, so I was a bit confused

What your textbooks are probably saying is that they do not move (significantly) relative to any "fixed" point on the Earth's surface. It sounds as if they weren't saying it very well.

 

[A.T.]

...some of my textbooks were saying geostationary satellites don't move at all...

Movement depends on the used reference frame. Make sure that you read precisely what the book says.

 

[hutchphd]

Movement depends on the used reference frame. Make sure that you read precisely what the book says.

For instance for a (center of mass) observer of the solar system all Earth satellites actually travel "open" spiral serpentine paths about the Earth's orbit!

 

[davenn]

thanks guys, some of my textbooks were saying geostationary satellites don't move at all, so I was a bit confused

They do oscillate a little north and south of a fixed point on the Earth's surface

Other than that, they rotate with the Earth. If they didn't, Satellite TV and other comms wouldn't be possible through themDave

 

[Ophiolite]

They do oscillate a little north and south of a fixed point on the Earth's surface
Other than that, they rotate with the Earth. If they didn't, Satellite TV and other comms wouldn't be possible through them

Let me be pedantic and amend your comment to, "If they didn't, Satellite TV and other comms would be much more difficult to implement continously through them".

Early transatlantic television transmissions were made on two Telstar satellites in the early 1960s. These satellites had an orbital period of a couple of hours, so that transmissions lasted for only twenty minutes at a time and required the transmitting and receiving antennas to be continuously redirected.
I especially recall the transmission of a portion of the funeral of President Kennedy. Today we are accustomed to HD transmissions, in colour on 48" screens. Viewing the shaking image of the funeral cortège in black and white, on an 18"screen, with only 405 lines, strengthened the pathos and impact of the event.

Also, @John12343210, in regard to your original question, gravitational forces are continually tending to move the satellites out of position so that thrusters must be used to counteract this tendency. I understand the fuel load is what generally determines the effective lifetime of such satellites. The process is known as station keeping.

 

[davenn]

"If they didn't, Satellite TV and other comms would be much more difficult to implement continously through them".

Impossibly difficult as you wouldn't be able to use the fixed dishes that are currently used, you would be chasing the sat's all over the sky with signals coming and going as you tried to watch your fav movie or sports channel etc

The only people that like chasing sat's around the sky are amateur radio operators like myselfD

 

[Ophiolite]

Impossibly difficult as you wouldn't be able to use the fixed dishes that are currently used, you would be chasing the sat's all over the sky with signals coming and going as you tried to watch your fav movie or sports channel etc

Surely, so expensive as to be impractical, would be the more accurate description? Or, if you prefer, the equivalent, but more potent, practically impossible.
That said - at the risk of moving off topic - would the circuitry to adjust a steerable antenna responsive to signal strength be especially challenging? Or, given that the track of a given satellite would be known within reasonable limits coarse tracking could follow that, supplemented by feedback in signal strength.