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Re: AO40: status



On Sat, 6 Jan 2001, Phil Karn wrote:

> Nope, not quite. If the fuel had simply dribbled out from the outer
> edges of the spacecraft, the spin would have slowed down as the
> propellant moved outward.

Yep, in this case, I was taking your assumption of it leaking off near
the center.  Thus it does not take away any angular momentum and the
spaceframe must spin up to conserve the angular momentum... But even if it
moved outwards, it didn't stay there but just left the spinning
system without taking away any angular momentum.  Thus, in any case, it
must spin faster...

> > >How much was the mass of the propellant? > 
> The figures I have show 63.37 kg of N2O4 in each of two tanks, 34.35 kg
> of MMH in each of two tanks, plus 26.65 kg of NH3 in each of two tanks.
> I can't find a figure for the helium mass.

Wow, my 250 Kg wild a$$ guess was pretty close.  So that sould explain a
doubling of the spin of a 500 Kg spacecraft.  Its about 18 now, did I hear
someone say it was about 6 at the start of the burn?  That leaves the last
6 RPM to be accounted for by the reaction of uneaven tangential
venting? Seems plausible...

de WB4APR, BOb


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