Magnetic field at satellite altitudes ?

[Externet]

Hi.

The earth magnetic field extends quite a bit in altitude, but do not know if is reasonably/equally strong at the altitude the satellites orbit. Can you confirm that?

 

Being the earth as a giant magnet, I believe that if onboard a satellite, a magnetic field is generated with energy from its solar panels; a repulsion or attraction effect relative to the earth could be managed by orientation of such.

 

Orbiting satellites lose altitude with time, some deplete their supply of propellant to stay put. Could repulsion management in a satellite sustain/gain orbital altitude to avoid falling eventually ?

If the main reason of satellite falling is loss of its speed, could such onboard magnetism management sustain/gain speed ?

 

Even a faint electromagnet action would produce a reaction up there, right ?

[Enthalpy]

In low-Earth orbit, where satellites decay, the geomagnetic field is as strong as on the ground, for your application. As it decreases as R^-3, 300km or 800km added to 6380km change moderately its intensity.

 

It suffices to control the orientation of satellites by current in loops. This is done routinely by amateur satellites.

 

It doesn't suffice, by far, to counter the orbital decay. I checked some years ago, despite it was known for long, and there isn't the slightest chance. Even with a magnetic core, or superconductors, and so on. The interaction with Earth's field (0.3e-4T) is too faint, and you benefit this energy only twice in a 90min period.

 

At geosychronous altitude, Eaerth's field gets quite weak and is often overriden erratically by Sun's field (trapped in Sun's plasma), so it's not quite useable and isn't used.

[Externet]

Thanks. Clear answer, as always, Marc.