 Jan 19,
2007
(an archived page, this may contain outdated or
broken links) 
The
University of Alabama Huntsville Space Hardware Club prepares a balloon
for launch.
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| How
did I get here ?
 I
have recently taken interest again in the sport of Ballooning. Not with
party balloons or huge hot air balloons, but the ones decked out with
student/hobby payloads that use GPS and Amateur Radio to
provide flight telemetry and tracking information. I was involved in
the startup of the well known EOSS
group in Denver in 1990, but moved back to Tennessee before they got
famous. None the less, the bug had bitten, and the "poor-mans
satellite" always found a way into my diet of radioactivity.
Periodically one of Bill
(WB8ELK) Brown's balloons
would come floating by and some of us would help provide tracking
feedback, or on a lucky day - be close enough to a landing site to help
with recovery. I guess I hadn't been paying attention, then all of a
sudden Bill lives just around the corner about a mile away ! Then I
find myself approaching New Years Eve listening on 20meters for a PSK31
beacon from an Arizona balloon launched by ANSR, and talking with
Jack (WA7JLC) via IRLP... I hadn't talked with Jack since I left Denver.
So much for my trip down
memory lane... Turns out that the UAH Space Hardware Club
has been launching some balloons recently and has one coming up
(scheduled for this coming Sat, Jan 20 @ 0900). I've been messing with APRS recently and wanted to participate in the tracking. Of
course it is so much easier nowadays, what with APRS-IS and findU.com.
The mapping is much better as well and I wanted some practice first, so
I dug up a TNC log file of a previous UAH balloon flight. From what I
can tell this was launched in November 2005 - and was called "HALO". I
sliced and diced the data and came up with a few interesting graphics.
 Doesn't this look like
fun ? |
Post-flight
Review - HALO
First, just a peek at
the raw data log - not going into that just now...
I
took data points about 5 min apart, to see how high it went.
The
same data points show how fast it went up and came down. It appears to
fall really fast before the atmosphere gets thick enough for the
parachute to have enough to grab onto.
So,
put these on a map, and show where it went.
- a little
closer view of the burst at ~86,678 feet
Well,
that was fun - but turned out to be a fair amount of work.
Thanks
to tiger.census.gov
for the map generation.
| So
this next flight was postponed last week, expecting poor weather -
hopefully this week will not be too windy. It must be tricky trying to
figure out how much gas, how much weight you can handle, how high it
will go before burst, which way and how hard the wind will blow at
different elevations, etc... One website has rolled a bunch of this
together to help 'Balloonatics' predict various possible flight plans
Visit www.nearspaceventures.com
and try it yourself. The primary flight calculations are by way of Bill
Brown's early programs originally written in Basic. The Google Map
output is just icing on the cake. This painlessly integrates the
forecasted wind profiles from NOAA. The estimate I got via
email
today from Bill was based upon a 1000 fpm ascent and a 1300 fpm
descent, so I ran a few passes with slightly slower rates to see how
much that would affect the touchdown. I also ran an earlier and a later
launch time to see how different the wind conditions might be. I'm sure
that there are a lot of factors I'm not considering, but it sure gives
me a better idea of what goes into this. I'll just drop these graphics
in here for comparison. Hopefully I'll have more about all this (with
external links) in a future page. If you can't wait, and need more
links, check
my Blog for January's research links. Come back after the
flight, and find out what happened.
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- again, but
with a slower descent
 - again, but with a
slower ascent and slower descent
* So, for a closer
landing we need less wind,
will that be earlier or later in
the day ?
Hummm,
kinda like rocket-science . . .
It's almost beyond
comprehension, to imagine the
balloons that NASA uses for their high altitude research.
Those can carry hundreds of pounds of payload...
73 for now
/;^)
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