[amsat-bb] Re: Could we raise orbit thru magnetorque?

[James C. Mankin]

Here is a link I found to using current carrying tethers for changing 
orbits.

<http://science.msfc.nasa.gov/newhome/headlines/ast08sep97_1.htm>http://science.msfc.nasa.gov/newhome/headlines/ast08sep97_1.htm

Jim  KB3KJ
n5x at psu.edu


Marc Vermeersch wrote:
> Hi Jim,
>
> Is this the same principle? I believe this has to do with the gravitational
> field not the magnetic field.
>
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
> Behalf Of James C. Mankin
> Sent: Wednesday, February 21, 2007 7:16 PM
> To: Bruce Bostwick
> Cc: amsat-bb at amsat.org
> Subject: [amsat-bb] Re: Could we raise orbit thru magnetorque?
>
> 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 at 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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>>   
>>     
>
>
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