That's been my understanding as well. Magnetorquing by itself can drive rotation but not translation. Its main benefit is that it saves propellant, weight, and complexity, as well as moving parts and the risk of a hypergolic plumbing assembly exploding and taking out half the spacecraft's systems, by allowing the spacecraft to handle rotation with more reliable torquing coils and get its energy for that from the PV panels. Changing orbits still requires firing a reaction thruster of some sort.
On Feb 20, 2007, at 9:47 AM, John Mock KD6PAG wrote:
Argument is: if when satellite is in the north, a north magnetic field is applied on z plane, will satellite raise orbit ? Same but opposite on south. Considering limited energy available could this raise be significant if applied on all orbits ?.
I believe magnetorquing can only change the orientation of a satellite and not its orbit. It is certainly used in the process of changing an orbit, in order to get a thrusting device pointing in a direction where it will do something useful. But by itself, it can't change an orbit. It can help point antennas in the proper direction, etc.
-- KD6PAG (Networking Old-Timer, Satellite QRPer)
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