[aprssig] A strong argument for a cutdown device

[John Gorkos]

Our local club did a HAB launch today that went horribly wrong.  Check out
the track of AB0OO-11 to see what I mean.  After 12 hours aloft, we are
still getting good positional data from the balloon, but we have no control
over it.
We ran out of fill gas and only had about 3.5 pounds of lift on a 3 pound
payload.  Instead of just aborting, we launched anyway.  The balloon
averaged about 100 feet per minute of lift, and after 7 hours it had only
made it to 60k feet.  For the last 4 hours, it's been gradually drifting in
circles, getting lower and lower.  We're going to lose it somewhere over
south western North Carolina, and we'll probably never see it again.
This balloon was flying the new Byonics MT-400 tracker, which is still going
strong with a Sparkfun >60k GPS (it's been flight tested by us to 93k) on 6
Energizer Lithium Ultra batteries..  Unfortunately, I didn't include the
additional battery pack, relay, and wiring needed for a nichrome cutdown, so
instead of being able to abort the flight at the time of our choosing, it
continues to drift aimlessly over the Carolina's, along with 2 HD video
cameras.

If anyone happens across what will probably be a still-inflated balloon, I'd
really like the memory cards out of the camerasŠ

John Gorkos
AB0OO




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