FW: [MLB-WIRELESS] helium balloons anyone?

[paul van den bergen]

Bah-Bawghnnnn! 

does not solve the problem, likely only makes it worse.

lift capacity for a given material increases with something less than the 
square of the diameter of the balloon, while reduction in lift capacity for a 
given tether decreases with height (to all intents, it has the same stress on 
the wire.)

if you use a tubular tether, sure you increase the displacemetn volume, but 
you make a much more complicated shape that has to survive shear and 
extensional forces (i.e. it is trying to perform 2 roles: containment and 
shape (volume) retention and load carrying)

much better off investing in a bigger balloon and a lighter stronger tether... 
there are light weight sailing ropes not that can take several tons dead load 
over a few (3-8)mm diam.  (oriented Liquid Crystal Polymers if you must know)




>
> I had a theory on this, which was to connect the balloons to the ground
> via small tubes rather than ropes and then to pump the helium up these
> tubes. so long as the tubes were of a light enough material then the
> helium contained in the tubes would make them virtually weightless.
> Meaning you would only need to provide balloons big enough to hold the
> AP and associated equipment up.
> My other thought was that if you had this sort of setup, you could setup
> like a hot air balloon affect where you pipe gas up and ignite a flam at
> the end into a balloon in order to keep it up.  that way if you ran out
> of gas you could exchange the cylinders from the ground without having
> to bring the whole system down so to speak.
>
> Shane
>
> -----Original Message-----
> From: Rowan Crowe [mailto:rowan at sensation.net.au]
> Sent: Thursday, December 12, 2002 3:36 PM
> To: melbwireless at wireless.org.au
> Subject: Re: [MLB-WIRELESS] helium balloons anyone?
>
> On Thu, 12 Dec 2002, evilbunny wrote:
> > Hello melbwireless,
> >
> >   I think people have kidded about launching helium balloons before,
> >   but apparently someone took notice :)
> >
> >   http://www.sydneywireless.com/article.php?sid=537
>
> This one is definitely better than a business plan I saw a while ago - a
> company who were going to fly (standard) aircraft in circles 24/7 to
> provide wireless connectivity. ;)
>
> I wonder if an AP attached to several helium balloons (and tethered to
> the
> ground) would work for temporary setups, eg field days. I guess the
> weight
> of the cable to the ground would be significant...
>
> Cheers.

-- 
Dr Paul van den Bergen
Centre for Advanced Internet Architectures
caia.swin.edu.au
pvandenbergen at swin.edu.au
would somebody get this big walking carpet out of my way?

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