FW: [MLB-WIRELESS] helium balloons anyone?

[Donovan Baarda]

On Thu, Dec 12, 2002 at 04:23:28PM +1100, paul van den bergen wrote:
> 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)
> 

Actually, I think the plan as presented is the best choice... very high, no
tether, solar powered, self-navigating.

Tethers are OK if you need it very low, but you will always have problems
with strong winds tangling it up. If you go very high, the winds are less
intense and more predictable. Tethers are impractical for very high baloons.
Solar can power them indefinitely (no clouds that high), and with GPS
naviation you can remotely tell them to go wherever you want.... they become
relocatable floating wireless exchanges...

-- 
----------------------------------------------------------------------
ABO: finger abo at minkirri.apana.org.au for more info, including pgp key
----------------------------------------------------------------------

To unsubscribe: send mail to majordomo at wireless.org.au
with "unsubscribe melbwireless" in the body of the message