Satellite Orbit Adjustments?

The Earth's tilt is a constant. It does not periodically change the tilt as you suggest.

If the Earth did tilt, which it doesn't, on its axis satellites would be able to make MINOR adjustments. Until their fuel runs out.

Repositioning geostationary satellites

The Earth's tilt is natural and does not change. (with very, very minor exceptions)

Spy satellites are an exception and can be moved around, some.

To all that you must also consider the Earth's axial precession movement. Although it's not very big (only 1 degree every 72 years) it adds up in time and it also changes the equatorial plane's positions, which makes the adjustment more complex (and fuel consuming).

Agreed..It does add up in time, but considering that the present life expectancy of a satellite is just 10 - 15 years, that 1° in 72yrs becomes just 0.2° in the 15 years life of the sat. By contrast, perturbation can affect satellites by as much as a couple of degrees per day. It will affect their right ascension by varying amounts and directions dependent on their orbital height and grade of motion around the planet.

Not all precession effects are fully corrected - often satellite orbits are designed so that precession carries their orbits where they are required.

For instance - a synchronous (not geo sync) orbitting sat will pass over the same ground point once every sidereal day, this means that at some stage, as the seasons change, that point it will be in darkness when the sat. passes overhead - a bit of a problem for a photographic mission.

As precession causes the orbital axis to revolve around the poles, it can then be controlled to make that axis sun-synchronous and thus in daylight at the required times for the entire year.

The fact that the earth's rotational axis is tilted at 23 degrees with respect to the earth's orbital plane axis is irrelevant as far as a geosynchronous satellite is concerned. These satellites are just launched over the equator at an altitude that takes 24 hours to complete an orbit, so they "park" over a fixed point on earth.

Note that there is nothing to keep them exactly in place, so small periodic adjustments are necessary, requiring the satellite to have a reserve of fuel. When the fuel is exhausted, the satellite can no longer maintain it's position.

The orbit is relative to the earth so the tilt does not factor in with exception to the forces of gravity coming from the moon and sun.

You can model it as if the earth were in deep space far away from any other gravity forces because the forces from the moon and sun are small. They do eventually add up and things need adjustment.

Drew K

Yes there is a traffic control center....The Space Command constantly monitors all traffic, the're the ones that give the launch windows and positioning info....at least they used to....I think there are private sector and military strategic components now...

http://spacenews.com/strategic-command-envisions-civil-space-traffic-management/

Thank you Einstein.

Obviously the number of good answers and the very interesting discussion prove that this was a good question. Thank you, IQ for posting!