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Re: NASA's Tethered Generator
Subject: Re: NASA's Tethered Generator
Date: Thu, 08 May 1997 16:59:00 -0500
From: rickh-at-ghg-dot-net (Rick Holland)
To: Tesla List <tesla-at-pupman-dot-com>
References:
1
> >
> >Tesla List wrote:
> >
> >>
> >> Robert, Mark -
> >>
> >> You could both be wrong. Tesla invented the so called "Tesla Coil" to
> >> create ultra high voltages with maximum power. We should be trying to
> >> optimize this apparatus (to help NASA with its tether generator). Sparks
> >> of
> >> any kind are losses and prevent the production of the high voltages at
> >> maximum power.
> >
> >All right! I saw that. I'll have you know that we NASA weenies are a bit
> >miffed about the whole tethered satellite thing (not to mention the
> >Itialians). OK, so the thing generated in the thousands of volts and
> >made AMPs instead of milliamps, but how were we to know? Who else has
> >done anything like this? SO, we were moving a conductor through a
> >changing magnetic field. Who could guess that the magnetic field would
> >have areas of such intensity? I mean it's *just* a planetary magnetic
> >field; and just in case you forgot, we *do* have rocket scientists
> >working for us.
> >
> >Of course, all of the above is said tongue-in-cheek :>). There are some
> >rather sheepish-looking rocket scientists wandering around here
> >muttering to themselves. I, being a lowly technician, was not consulted
> >prior to the launch of this experiment, but I have had some ideas on
> >power generation using a conductor and changing magnetic fields, and I
> >could have told them that I thought they should use a really heavy
> >conductor (just on instinct, not knowledge base).
> >
> >I'm afraid I've gotten 'way off the topic, so I guess I'd better shut up
> >now. Just couldn't pass up the chance to poke a little fun.
> >
> >
> > Rick Holland
> >
> > The Answer is 42.
>
> Hi,
>
> Forgive me if this is off topic or if I missed an earlier discussion of
> this, but how did NASA plan to draw power from the tethered cable? I
> understand it was just a conductor fixed at one end to the satellite,
> and
> moving relative to the earths magnetic field. This seems like an open
> circuit to me, and I am wondering how current would flow since it is an
> incomplete path. Am I missing the big picture here? Thanks for your
> help.
>
> Dave
Dave,
In order to understand the phenomenon, you have to go back to the most
basic definition of electricity. The object was to create a difference
of electrical potential between the satellite and the Space Shuttle.
Anyone familiar with ground loops knows that even though a wire is
grounded at both ends, it can develop a voltage potential that will
influence the ground point reference at one end or both.
Since the Shuttle was riding at a higher orbit than the satellite, they
experienced differing magnetic potentials, effectively making one end
more negatively charged than the other. This has been demonstrated many
times on Earth without a tether by fast-moving (normally) aircraft
causing an ionized cloud to form around them. Anything that connected
the craft to the atmosphere outside the ionized cloud would conduct a
heavy current. By "dipping" the satellite into the outermost fringes of
the Earth's atmosphere, a conductive path was formed with the Shuttle
effectively acting as a "counter-poise"; something often used in Tesla
Coiling when a suitable ground path is not available.
>
> PS. I am new to this list and my posts have been taking a day, sometimes
> longer to show up. Am I doing something wrong here?
No, you're not doing something wrong. I am experiencing the same
difficulty as is Fr. Tom, and I think some others. Questions have been
asked and investigation promised, but results could be slippery. Chip is
very conciencious and will attack this when he gets back from vacation.
In the mean time, I consider it a minor price to pay for the wealth of
information I get from this list, and if it can't be fixed, I'll live
with it.
--
Rick Holland
The Answer is 42.