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

lu7abf lu7abf at amsat.org.ar
Tue Feb 20 08:10:13 PST 2007

```Hi Marc!,

Tks for time and comment!.

A .00005 Tesla is like .5 Gauss. Magnetorquers aboard sats can generate variable fields depending on current going above 1 Gauss if required.

Ncube at http://www.ncube.no/ and AAU at http://www.cubesat.auc.dk/ , the Norway & Denmark student satellites have analysis on magnetorquers, as usually satellites also include magnetometers attitude an magnetic south/north could be detected and compared to actual satellite attitude. Interesting information is on http://www.amsat.org.ar/cubesat/svartveit03.pdf or others at http://www.amsat.org.ar/cubesat

Looks like scenario could be known regarding bird attitude and earth poles aboard sat. Perhaps an experiment in actual sats could further shed light on this uncertain possibility of managing satellite attitude.

Best Regards and Tks !

73, lu7abf, Pedro Converso
lu7abf at amsat.org.ar
www.amsat.org.ar

============================================

Hi Pedro,

Interesting thought!! A few remarks around this:

- AFAIK magnetorque-ing is being used to change orientation but not for
changing orbit. I wonder what would happen in your scenario: I kind of
expect the satellite to change orientation because of the impossibility of
exactly opposing the poles.

- I assume that magnetorque-ing is achieved by sending a current through a
coil. The force on a conductor in a magnetic field is:
Force = current [A] x length [m] x magnetic field [Tesla]
The magnetic field of Mother Earth is about 0.00005 Tesla at the surface so
a fraction of that at satellite altitude. Generating usable force looks like
a challenge.

-----Original Message-----
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of lu7abf
Sent: Monday, February 19, 2007 4:48 AM
To: amsat-bb at amsat.org
Subject: [amsat-bb] Could we raise orbit thru magnetorque?

In thinking on a future satellite project, this question was made.

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 ?.

Tks for any answer or argument.

lu7abf, Pedro Converso
lu7abf at amsat.org.ar
www.amsat.org.ar
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