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ZL3AI > APRDIG 13.04.04 15:13l 85 Lines 4297 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Apr 10, 2/2
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: BalloonSat VI communications package test this morning
From: "Tim Cunningham" <tim_cunningham@mindspring.com>
Date: Sat, 10 Apr 2004 22:24:18 -0500
X-Message-Number: 11
BalloonSat VI launched this morning around 11:00am CDST. Since we were out
all day, I have not looked at the data to get the exact time.
I apologize in advance for the short notice. Since I was out of town all
week and returned home late Friday to help the students prepare part of the
communication package, there was little time to send out the announcement.
BalloonSat VI was sent a cut-down command when it reached about 75,000 feet
(rough guess). It was planned to be cut-down at 50,000 ft to control the
landing location. The ground team could not communicate with the payload,
so Dr. Corsetti (KG4UWE) and I send the proper command sequence to initiate
the separation of the payload from the balloon. This process takes about
15-30 seconds for the nicrom wire to burn through the rope after the
payload responds to the command. Shortly after the successful cut-down
uplink sequence was initiated, communications from the APRS beacon ceased
operation and no further APRS beacons were heard from the payload.
Bill Brown, WB8ELK, gave us some updated landing data based on the altitude
when the payload was commanded to be released and parachute back to Earth.
The secondary 30 mW CW beacon on 144.34 was used to radio locate the
package. We heard the signal as we drove up I-59 from Alabama route 40. Ken
(WB4FAY) joined the chase from Birmingham as we left Huntsville. John
(W4JXP) was in another chase vehicle with one of the students. We realized
things were going to be rough when nobody had a directional antenna or
attenuator. This was not going to be easy or it seemed that way.
As we neared the Georgia state line on I-59 from both directions we
detected the secondary CW beacon. Then, we split paths to search east and
west of I-59 near Rising Fawn, Georgia. This gave us the information that
the payload was east of Rising Fawn. Ken (WB4FAY) had the signal full scale
in his direction so we circled around to cover the area he was located near
Johnson Lake Dam off of SR189. Since this area is full of hills and valleys
we had to get several position fixes using signal meters on our mobiles and
getting out of the vehicle frequently with an HT held close to our bodies
to get a general direction of the signal. As we combed the roads and spoke
with a local, we found some new roads with the help of a passerby.
Now, we were hot on the trail. Within minutes we had very strong signals in
a very wooded and hilly terrain. Ken, WB4FAY, spotted the payload with the
attached parachute in a tree off a dirt road and radioed the information
back to the rest of the search team.
With the payload identified, the task was to remove it from a tree that
could not be climbed easily. Another team brought some rope and we finally
tied a hammer to the end of it and made several attempts to reach the
payload in the top of a tree at about 60-70 feet. Finally we pulled it down
from the tree and recovered the package. It was a long day on the balloon
chasing trail, but the team was successful in the recovery process.
So what happened to the APRS beacon you might ask. The answer is very
simple and obvious after looking at the package. The antenna separated from
the package during the separation process. This is usually a very violent
process and the package starts to drop. Early video footage from previous
balloon launches confirm this condition that happens when a balloon bursts.
I am sure the antenna problem will be corrected for the next payload
scheduled for next Saturday morning. Stay tuned...
Many thanks to Ken, WB4FAY, for his radio location skills in the recovery
process. He commented, "Real hams don't need any stinking directional
antennas". We certainly accomplished the task using some primitive
techniques. Basically, the challenge was met, when all the high tech tools
were left behind on this chase.
Thanks to all who sent reports via email. Until next week, happy balloon
chasing to all next weekend. Information will be posted as early as
possible in the week.
73's,
Tim - N8DEU
Huntsville, Alabama
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