Re: [amsat-bb] AO-40: Momentum Wheels tested!!!

[Peter Guelzow <peter.guelzow@xxxxxxxxxxxx>]

The absolute weight of the spacecraft before launch, i.e. with
full fuel tanks, is known *very* precisely..
There is no evidence that "pieces" of the S/C are missing since
the evidence. All the solar panels are in place and functional.
The other parts like Omni antennas or bottom plates are light
weight material, which would only add a little uncertainty...

73s Peter



Bernie Basel wrote:
> 
> Ok... Either I missed making my point or I missed the point, Hi.
> 
> I understand that the current mass of the s/c can be calculated, that was
> not what I was questioning.   My question was how do we determine how much
> fuel is left if we do not what the s/c mass is sans fuel.  In other words if
> pieces of the s/c are missing because of the post launch incident the mass
> is an unknown.  You can't subtract the an unknown value from the total mass
> to calculate the amount of fuel left.
> 
> 73's,
> Bernie, K3BAZ
> 
> ----- Original Message -----
> From: "Peter Guelzow" <peter.guelzow@arcormail.de>
> To: "Bernie Basel" <bbasel@yahoo.com>
> Cc: <amsat-bb@AMSAT.Org>
> Sent: Wednesday, August 15, 2001 5:09 PM
> Subject: Re: [amsat-bb] AO-40: Momentum Wheels tested!!!
> 
> > Bernie,
> >
> > you have the answer already below...
> >
> > We know the mass and thus the Moment of Inertia (MOI)
> > of the wheels..  from the change in spin rate we
> > can determine the s/c mass...
> >
> > 73s Peter
> >
> >
> > Bernie Basel wrote:
> > >
> > > I was under the impression that the mass of the s/c
> > > was an unknown due to the post launch mishap.  If we
> > > do not know the mass of the s/c how do we calculate
> > > the amount of fuel left?
> > >
> > > Bernie, K3BAZ
> > >
> > > --- Peter Guelzow <peter.guelzow@arcormail.de> wrote:
> > > > In fact, since the wheel MOIs are exactly known,
> > > > this means that we would be able to determine s/c
> > > > MOI to about 5% - from this we could possibly infer
> > > > how much fuel is left in the N2O4/MMH tanks.
> > >
> > ----
> > Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
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