[Space] Minutes 3/9/09

Christie Dudley longobord at gmail.com
Wed Mar 10 23:50:48 PST 2010


I think the idea was to have an air vent in the bottom so we lose our
coolest air first going up.  If we got a one way valve in there, it'll cause
the mylar to get sucked up against stuff on the way down, which I consider
not so much of a bad thing either.  Vacuum packed!  At the very least it'll
prevent condensation.  It should also keep quite a lot of heat in still,
although it would circulate considerably less.

What would be the best method to seal it?  Can we do a melted heat seam?
 Sew it a mylar sweater!

Christie
_______
"We also briefly discussed having officers replaced by very small shell
scripts." -- Noisebridge meeting notes 2008-06-17

The outer bounds is only the beginning.
http://www.flickr.com/photos/genriel/sets/72157623376093724/


On Wed, Mar 10, 2010 at 11:29 PM, Mikolaj Habryn <dichro at rcpt.to> wrote:

> Will mylar hold much of a pressure differential? Or is the plan to
> line a foam cavity with mylar? I'm not sure we need to worry too much
> about heat loss through the foam, so I assume you're thinking of using
> the mylar to prevent convective heat loss through the cracks? Is there
> an easy way to prevent overheating as well?
>
> Tapping the radio battery triggers my recovery paranoia; if we have
> the weight budget to spare, I'd feel safer if we avoided tampering
> with the position reporting dependencies. For all the SMS stuff worked
> flawlessly last time, we'll be flying new software and if something
> goes wrong with it, the radio beacon will be the only way to find the
> payload.
>
> m.
>
> On Wed, Mar 10, 2010 at 8:07 PM, Christie Dudley <longobord at gmail.com>
> wrote:
> > While antifreeze sounds like a neat idea, vaporization is not the problem
> so
> > much as pressure/thinned atmosphere.  Think pv=nrt sort of deal, keeping
> in
> > mind those phase charts from chemistry.
> > Christie
> > _______
> > "We also briefly discussed having officers replaced by very small shell
> > scripts." -- Noisebridge meeting notes 2008-06-17
> >
> > The outer bounds is only the beginning.
> > http://www.flickr.com/photos/genriel/sets/72157623376093724/
> >
> >
> > On Wed, Mar 10, 2010 at 7:57 PM, Albert Alexander
> > <albert.alexander at gmail.com> wrote:
> >>
> >> Dear mod(s): Please disregard prev. email, accidentally sent as
> >> non-member.
> >>
> >> Here's what we did and thought about on Tuesday.
> >>
> >>
> >> THE FIGHT AGAINST CONDENSATION
> >>
> >> The internals of the payload will be contained in a mylar envelope. This
> >> will provide a continuous thermal space that retains a LOT of heat
> (space
> >> blankets claim something like 90%). I'm still investigating the energy
> >> required to keep this space above dew point. That would prevent
> condensation
> >> (hopefully).
> >>
> >> Still working on whether we should add a battery dedicated to warming.
> I'd
> >> much rather tap a camera or radio battery to avoid the extra mass. On
> first
> >> glance the radio battery looks like a prime candidate (low drain long
> life)
> >> and is least likely to automatically shut off if it gets hot.
> >>
> >> Indium Tin Oxide film (ITO) is enroute courtesy of Bayview Optics. This
> >> will heat the lenses with a thermistor circuit. There is a cup in my
> freezer
> >> with antifreeze on it to test evaporation rate; this could be an
> acceptable
> >> passive substitute for lens heaters depending on the distortion (its
> kinda
> >> viscous).
> >>
> >> Camera circuits will be sealed with a conformal coating. Silicone looks
> >> ideal. Hopefully will have some by Sunday for further testing.
> >>
> >>
> >> THE PAYLOAD
> >>
> >> Styrofoam was cut and beveled with the classy new wire cutter. A camera
> >> port has been added. The payload looks fairly anthropomorphic now. It
> needs
> >> a name.
> >>
> >>
> >> COMLINK
> >>
> >> Antenna was bound to carbon rods with thread.
> >> _______________________________________________
> >> Space mailing list
> >> Space at lists.noisebridge.net
> >> https://www.noisebridge.net/mailman/listinfo/space
> >>
> >
> >
> > _______________________________________________
> > Space mailing list
> > Space at lists.noisebridge.net
> > https://www.noisebridge.net/mailman/listinfo/space
> >
> >
>
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