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Re: Mystery effect



I didn't think that any conclusion had been made on the Mystery
Effect.

>From what I've read here, whatever is causing the ME has to be a
dynamic thing.  A simple, static, magnetization of/in the spacecraft
wouldn't produce the kind of force needed to reorient a spinning
body.   The magnetorquers work by generating a magnetic field in the
coils at the right instant as the bird spins.  That's why we see periodic 
pulsing of the beacon's frequency during magnetorquing, as
the system load changes suddenly with each pulse.

My favorite theory is still a ground loop somewhere in the solar
battery circuit, such that magnetic field is generated that moves
around the spacecraft as the spacecraft's solar panels become
illuminated by the Sun.  Maybe even a field generated by the panels
themselves.  But, I understand that this theory doesn't fit all of
the data either...

Greg  KO6TH



>From: "Michael Kingery" <mkingery@ala.net>
>To: <amsat-bb@AMSAT.Org>
>Subject: Re: [amsat-bb] Mystery effect
>Date: Thu, 20 Dec 2001 17:21:34 -0600
>
>I recall an explanation of the mystery effect as being the alignment of the
>magnets in the momentum wheels.  Causing the spacecraft attitude to change
>slightly each orbit due to the same magnetic effect used by the 
>magnetorquer
>system.
>
>KE4AZN
>Mike Kingery
>
>----- Original Message -----
>From: "ne1h" <ne1h@highrf.com>
>To: <amsat-bb@AMSAT.Org>
>Sent: Thursday, December 20, 2001 4:21 PM
>Subject: Re: [amsat-bb] Mystery effect
>
>
> > One thought about the crazy theory.
> >
> > I believe that all sides of the SC except the top and bottom have
> > solar panels on them and they indicated based upon current telemetry
> > that they are there and intact.  While your logic could be also
> > applied to the top or bottom (remember the omnis), I'm not sure it's
> > spinning with those axis being exposed, more likely it's
> > spinning "about" those axis.  It has to be or the pointing would be
> > pretty funky and the spin modulation would be incredible.
> >
> > But, interesting thought non the less.  My guess, it's a multiple
> > effect.  Aerodynamic drag at perigee, out of balance because of
> > the "event", etc.
> >
> > If we only had a "fly by" camera..... If, if if... :)
> >
> > Alan
> >
> > --- In amsat-arch@y..., "Greg Preston" <preston@t...> wrote:
> > > Greetings All,
> > >
> > > Just thinking about the ongoing "mystery effect"...how persistant
> > it is.  I
> > > have a theory about what it could be and how to test the theory
> > during the
> > > coming weeks of changing spacecraft orientation.
> > >
> > > Have you ever seen one of those little solar novelty toys
> > consisting of
> > > diamond shaped paddles on a pinwheel balanced on a needle, and all
> > contained
> > > inside a vacuum bottle the size of a 100 watt bulb??  When you
> > bring a
> > > strong light source near the device, the paddles (black on one side
> > and
> > > white on the other) begin to spin.  I'm not really sure how it
> > works...I
> > > suspect it has something to do with heat absorption.  My point is
> > that if
> > > one (or more) of the panels on the spacecraft were blown open and
> > as a
> > > result, positioned such that the flat-black paint on the interior
> > was
> > > catching full sun--it may be possible to experience the same
> > pinwheel
> > > effect.
> > >
> > > This could be tested by carefully measuring any changes in
> > the "mystery
> > > effect" force with the widely varying ALON/ALAT over the next
> > period.  And,
> > > if we know the position of the spacecraft relative to the sun, we
> > may even
> > > be able to tell where and predict the extent of damage to
> > the "skin" of the
> > > S/C.
> > >
> > > Just a crazy theory, but, what the hey?  Why not put it to the test?
> > >
> > > Cheers,
> > >
> > > Greg
> > > SM/KF4BWQ
> > >
> > > ----
> > > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@a...
> >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> > To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> >
>
>
>----
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