Re: Could we raise orbit thru magnetorque?
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)
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)
"People don't like to be meddled with. We tell them what to do, what to think, don't run, don't walk. We're in their homes and in their heads and we haven't the right. We're meddlesome." -- River Tam, "Serenity"
I seem to remember back when they were testing tethered satellites from the Shuttle that one of the possible applications being discussed was that if you could deploy enough wire and put the right current through it that it was possible to change orbits. I dont see why it wouldnt work if a large loop of wire could be created say between three satellites in a triangle.
Jim Mankin n5x@psu.edu
Bruce Bostwick wrote:
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)"People don't like to be meddled with. We tell them what to do, what to think, don't run, don't walk. We're in their homes and in their heads and we haven't the right. We're meddlesome." -- River Tam, "Serenity"
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Bruce Bostwick wrote:
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.
It seems to me that the issue is that depending on where the magnet is and the relative strength of the field as controlled by other electromagnetic factors, trying to figure out how to put the magnetic field exactly parallel to the force you want to use for translation would be difficult, if not impossible. It would require extremely sensitive innertial detectors and then a dynamic coil control system that would be able to vary the field generated fast enough to keep the rotation from happening, or to react to the rotation dynamically so that inspite of the rotation there is still a desired vector for translation.
Gregg Wonderly W5GGW
participants (4)
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Bruce Bostwick -
Gregg Wonderly -
James C. Mankin -
John Mock KD6PAG