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

[Tony Langdon]

At 05:55 AM 2/22/2007, Marc Vermeersch wrote:
>All,
>
>So why is the maglev principle (magnetic levitation)
>http://www.google.be/search?hl=nl&q=maglev&meta=
>not applicable in space?
>
>Magnetic levitation applied to trains generates an upward force equal and
>opposite to the earth's gravitation.

Much larger (relative) difference in separation between the pole 
pairs that are repelling each other.  One pair (top of the track and 
bottom of the train) are almost touching, the other ends of the 
fields are much more widely separated.

In the case of a satellite around the Earth, the difference in 
separation is almost zero (width of the satellite, compared to the 
distance from the satellite to the Earth's magnetic poles).  The 
gradient of the Earth's magnetic field is quite small, even near the 
magnetic poles.  You could get a very small lift by orienting the 
satellite correctly and turning on the magnetic field as it passes 
over the poles, but the effect would be incredibly tiny, and holding 
the orientation would take another system, to prevent the system 
providing torque instead of thrust (if that uses fuel, then the 
exercise is pointless ;) ), and if it's magnetic, it could nullify 
the thrust from the magnetic thruster.

73 de VK3JED
http://vkradio.com