[Space] Balloons

[James Mulroy]

I almost forgot.  If you guys ever want we CAN fly longer flights (days
instead of hours) by picking up a small zero pressure balloon, but it will
cost you.  A zero pressure balloon is the same type that HASP flies (except
ours would be significantly smaller).  Unlike our latex "sounding balloons"
these don't pop.  They have valves which let out helium as they ascend and
they reach a zero pressure differential between the inside and outside of
the balloon.  So they just float there 120k-130k feet above the ground, and
they fluctuate in altitude depending on if it's day or night.  We can buy
these, I don't know what the smaller ones cost, but I believe they are
several hundred dollars.

-James

On Sun, Aug 7, 2011 at 4:29 PM, James Mulroy <james.d.mulroy at gmail.com>wrote:

> Hey guys, here are a couple sites you can buy balloons from that aren't 30
> years old...
>
> Scientific Sales
>
> http://www.scientificsales.com/Meteorological-Balloons-Weather-Balloons-Sounding-Balloon-s/25.htm
>
> Nova
> http://www.novalynx.com/400-balloons.html
>
> American Science & Surplus (you'd have to inquire about how many grams it
> is and fill capacity)
> http://www.sciplus.com/singleItem.cfm/terms/16947/cartLogFrom/froogle
>
> Scientific Sales is by far the best bet (my group often bought from them,
> then again, our budget wasn't exactly limited as we were government funded).
>  A bit pricey, but a 1200 gram balloon won't have a problem bringing a 6
> pound payload to 80K or 90K feet.
>
> To practice, testing communication equipment, we might try picking up a
> couple of the really cheap smaller balloons.
>
> On a side not: if you want to see a 'real' balloon check out
> http://laspace.lsu.edu/hasp/images/2005-2006/album/08-26-2006/index3.php
> HASP launches balloons that stay up for 20-30 hours.  This balloon
> fluctuates between 120K and 130K feet, carries about 6K pounds of payload
> and several hundred pounds of metal dust as ballast, and when it gets to
> altitude it is so big that you can theoretically rotate an entire football
> stadium inside of it 360 degrees all around and it won't touch the sides.
>  This is what NASA considers a "small" balloon compared to the other ones
> they launch....
>
> Also, if you don't already then you should use a burst calculator for
> determining how much helium to use.  You can also use it to determine where
> your balloon will land within 5 miles.
> http://www.srcf.ucam.org/~cuspaceflight/calc/
> http://www.qsl.net/wb9sbd/burst-calculator.html
> You should aim for an ascent of at least 7 m/s or else you risk that the
> balloon will reach altitude and not pop, in which case it will end up in
> Greenland in a couple months or something...
>
>
> -James
>
>


-- 
James Mulroy
Student Researcher
Freelance Writer <http://www.pcworld.com/author/James-Mulroy>
james.d.mulroy at gmail.com
(920) 470-3473
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