Flight #6
Launch Date: November 18, 1999, 12:30 AM Central Time
November 30, 1999
A few more of the design drawings are now online. Check out
the overall design, the
parachute deployment system,
and finally our flight logo.
Thanks to Blaise for providing these, and my appologies for not
getting them on the site sooner.
Here are the GPS tracks from the APRS program:
2D (overhead) view
3D view, looking north
November 27, 1999
Flight software now online.
The Hi-8 camcorder that made the flight on November 18 has
finally surrendered its tape. Unfortunately, the flight tape
didn't reveal any meteors. We were able to get a better idea
of how a balloon behaves in flight (at least, a flight to 23,000
feet), but other than city lights from some towns and the airbase,
two or three bright stars, and the moon, the tape revealed little
of interest. The two hour tape ran out just minutes before the
cutdown mechanism released the balloon, so we didn't even get to
see the gondolas rapid plumit to the ground. The only interesting
effect observed was the attenuation of the audio tracking beeper
as the balloon ascended into thinner air. Even so, the potential
for use of a camcorder on board the gondola has been demonstraited,
and a daylight mission to proper altitudes will be planned for
sometime next spring.
Even with the technical success of the flight (building, launching,
tracking, and recovering our first night mission), the near
complete lack of meteors that night made the results less than
satisfactory. Maybe we'll have better luck next time.
November 18, 1999
Well, last night was interesting. I got the last components
for the balloon flight that I was responsible for built by about
6:45 pm on wednesday. When I arrived at Space Sudies, tensions were
running a bit high. The payload had turned out to be about two pounds
heavier than it was supposed to, and would be the heaviest we had
ever launched. After some ruffled feathers were smoothed, we decided
to go with what we had (making a few provisions to dump weight if we
absolutly had to). Reports from the BBC about 1,000 meteor per hour
observations in Europe only goaded us on, and we headed out for the
launch site about 11:00 pm CST.
At the launch field just outside Northwood, ND, we pointed
all our vehicles at the assembly area and left the headlights (and
engines) running. I shot some video tape of the filling operations
as we continued to monitor the weather. The weather turned out to be
very nice the whole night, with mostly clear skies and almost no
wind. When all the helium we brought had been pumped into the balloon,
it didn't provide as much lift as we expected (possibly due to the cold
weather). The lift was just sufficient to loft the payload as designed,
so we decided to go for it.
The stack consisted of: a 1200g latex weather balloon, a drogue
parachute made from part of an old bed sheet, two chemical light sticks,
the cut-down mechanism, the main parachute made from another golf
umbrella, the dust collector (which formed the lid of the gondola),
the gondola, and the tail, from which hung the audio tracking speaker,
the radar reflector, and the marker strobe light.
For this mission, the flight computer was programmed to activate
the cut-down at two hours. This would release the balloon from the
gondola. The departing balloon lanyard was also attached to two trigger
lines: one to pull a retaining pin on the dust collector doors and
allow them to shut and seal. The other was attached to a nylon bag
containing the main parachute. This would pull the 'chute out of the
bag (paratrooper style) and deploy it. The drogue 'chute was to provide
some resistance in case the balloon burst before the cut-down was
triggered, since some tension on the lanyard was needed to deploy the
main 'chute.
Despite predictions, after release the balloon headed
southwest. This is actually a pretty set pattern for our flights.
It went far enough that way for the chasers to take off in hot pursuit.
The balloon then went north, then east, passing our location to the
north. Just like previous missions, we got to wave to the chasers as
they sped by again :).
We tracked the balloon visually from the launch site for over an
hour. The little Radio Shack personal safety strobe light was
visible for over 10 miles! The chemical light sticks, however,
were invisible just after launch. No surpise given their low
output (made lower by the cold).
At about 2 hours and 5 minutes mission elapsed time, the cutdown was
activated by the computer with the balloon at about 23,000 feet altitude
northeast of East Grand Forks. At this point the gondola started a
rather rapid descent. Even so, the GPS reacquired satellite
lock on the way down and relayed us one last position report at about
7,000 feet altitude. One chaser in the area heard a strong signal on
the ground, and other chasers equipped with mobile APRS terminals
raced to the scene. The GPS was still working, and allowed us to get
a precise position report of the package on the ground. We found the
gondola about a half-mile into a plowed field at about 5:00 am (which
would have been impossible in the dark without the GPS signal), and
returned to Space Studies with it.
Back at the U, a post-mortem revealed that the trigger line
that closed the dust collector had worked, but the one that was supposed
to deploy the main 'chute had broken. The bag was still over the 'chute,
and the payload had apparently free-fallen from 23,000 feet. Luckily for
us, the terminal velocity of a 10 pound foam box is not very high, and
the only piece of electronics that suffered visible damage was the
cut-down device. Our enthusiasm took a blow when we discovered that
the camcorder would not eject the tape or even rewind it, however.
There were no rattles or obviously broken parts (other than a pivot
on the viewfinder), and the mechanism may only be jammed. Unlike the
other electronics, the camcorder (although nestled inside the foam
box), had a steel mounting bolt protruding from the tripod socket
through the bottom of the box. This hit the ground first,
transfering the shock of landing directly to the camcorder (ouch!).
One of our engineering-types is going to disassemble the camcorder
today to try to extract the tape.
If the tape shows the same thing we saw in the night sky,
there will not be much to see. Despite amazing shows in other parts
of the world, we saw bloody zip that night. From 12:30 am to 6:30 am
I counted about 6 meteors total. Even sporadic meteors should do better
than that.
Oh well, even without getting spectacular images, we did have
a rather successful flight. Our GPS gear has never worked better, and
the proper operation of the cut-down at least kept us from losing the
gondola. The problems with heavy payload and less lift that ususal
can be chalked up to lessons learned. Night operations were certainly
interesting, but I'm not in any hurry to repeat them (nor are many
others in the group. Sleep is, in our opinion, a Good Thing).
November 17, 1999
Weather looks possible. As of 4:20pm, we are 'go' for launch.
If the launch is called off at the last minute, I will try to
update this page to reflect that as soon as possible. Launch is
still scheduled for 12:30 am Nov. 18, central time. Launch location
is near Northwood, ND.
November 16, 1999
Current weather forecasts do not look encouraging. Best we can tell,
the sky will start to get cloudy wednesday (Nov 17) evening,
becoming overcast by nightfall. Surface winds are predicted to
be in the 15-25 mph range. Since FAA regulations prevent us from
launching into a sky with greater than 50% cloud cover, it looks like
the mission may not be possible. We have also decided that inflating
a balloon outdoors in winds over about 15 mph is not worth the
trouble (it takes many people to control the balloon and the
possibility of damage is too great). At this point we are
continuing with gondola construction and programming, and will
make the final decision on wednesday morning.
We only have a few days of peak activity of the meteor shower,
and weather forecasts for friday and saturday night don't look
any better.
November 15, 1999
Gondola construction is near completion. A new system will be
tested to keep the parachute in a bag during ascent. The cut-down
system will cause it to be deployed at the begining of the descent
phase. Cut-down will also cause spring-loaded doors over the
dust collectors to shut and magnetically latch. This will help
solve the contaimination problem we had on previous missions.
The Sony hi-8mm camcorder with low-light capability has been
purchased and tested. Its sensetivity is far superior to the
other camcorder candidates.
November 5, 1999
Our group has changed its mind and is going for one more launch
in 1999. We plan to fly our first night mission on November 18.
This is the night of the
Leonids meteor shower, which astronomers
believe may reach a once-in-33-years peak on this date. If the peak
occurs at this time, the display visible from high altitude will be
awesome. We will therefore fly a video camera instead of our usual
35mm film cameras. Rather than try to build and troubleshoot an
amateur TV transmitter, we will fly an 8mm camcorder that will record
the night sky. We still have not decided yet if we will fly our
GPS receiver and APRS encoder (they are rather heavy), since we have
to add a strobe light and other things to keep the FAA happy with us.
Since this all has to come together in less than two weeks, we're
trying to keep things simple and quick. We have come up with a
design for a new gondola for this mission, and are in the process
of obtaining a strobe light and a backup radio tracking transmitter.
Further updates as events unfold.
This will be our most ambitious mission yet, and should prove very
intereting if we can pull it off.
October 29
There is the possibility that we may launch some ozone measurement
sensors in cooperation with some NASA scientists during the winter,
but these sensors will not be chased nor recovered. Plans for these
launches are still in the tenative stages and may change at any time.
Gondola construction photos to follow (when they're scanned)
Return to the UND HABP webpage.