On Mar 4, 4:14*pm, Eric Greenwell wrote:
wrote:
Bottom line is I would not personally have any issue if such a balloon were
launched while I was in any sort of aircraft in the same area.

With the right size balloon you might be able to fit the Spot inside
the balloon envelope. I'm guessing that would reduce the chances of it
striking anything directly as the upwash ahead of any moving object
would tend to deflect it - plus you get a built-in airbag. Anyone
who's seen a balloon on a freeway can understand that.

As to the turbofan scenario - jet engines are designed to eat birds up
to 5 lbs (as Capt Sully found out to his dismay, geese are bigger). I
can't imagine a Spot is any tougher than a duck. You'd get some damage
I'd bet, but I doubt it'd be catastrophic.

With a little effort you could balance things so the balloon didn't
get into the Class A. For instance a small pinhole would allow helium
out at a rate to ensure that the balloon didn't get too high or go too
far - how long a chase do you want anyway? If you release it away from
and downwind of any significant terminal areas your odds of hitting
anything are infinitesimal.

Given all the time lags associated with Spot messages I doubt you'll
be able to track the thing close enough to actually see it until it's
already on the ground. Also, you'd have to worry about lakes and maybe
forests as possible unhappy endings. Without a good wide area wireless
connection you will have trouble tracking it in real time from the
road, so you'll have to wait for it to land, get a fix and go find it.

Assuming you mean "wireless" as used for computer communication, that
may not be a limitation: SPOT service can be set to send text messages
with the coordinates to your cell phone, which usually has a lot more
coverage. The truly determined could rent/borrow a satellite phone for
the day of the flight. SPOT floats - tow a boat with your retrieve vehicle!

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* "Transponders in Sailplanes"http://tinyurl.com/y739x4
* * * Sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation"

You are going to want to hang the spot under the balloon some
distance, maybe on a little platform so the thing can be oriented
pointing roughly up for best GPS reception (not really an issue) and
best GlobalStar coverage (more of an issue).

Eric's idea of SMS message to an Iridium phone sounds sexy if you are
really remote. However SPOTcast/tracking only works to the internet
and won't transmit position data to SMS or email. So you will have to
modify the SPOT to "press" the OK button. Very simple to hack for
somebody with electronics skill, but encouraging this might annoy
SPOT, Inc. You'd need to find out if SPOT supports SMS to Iridium
numbers. Many places do, people even twitter to them etc.

My perception is that many of the SPOT position delays that Andy
mentioned are associate with the SPOT web pages, SMS and email
messages may get thought faster. It would be great to know if anybody
has hard data on this.

The problem on landing is the SPOT is unlikely to land upright
oriented with sight of the satellites so the best you may get is a 10
minute old position fix which may or may not be enough to find the
unit.

The idea of launching some balloons with small cameras etc on them as
a project with kids is quite interesting.

Darryl