Stratosphere or bust
September 12, 2009
SARC Home Station
Alvin Buckwold School
715 East Drive
After seeing all the new balloons at GPSL 2009, we thought it
was time to fly something better than our current military surplus ones.
Although they have served us well., they rarely get above 80,000 feet.
After a phone call to Kaymont, Gus had two new balloons on their way to us.
Our payload this flight will be a bit heavy so we may not reach the 100,000 foot
level but we can hope. Bob has also arranged for industrial grade Helium
which will be much more reliable than the balloon grade that we had used until
Change for this flight are to add an up-looking video camera to capture the antics of the balloon in flight. We are also flying an Skytraq Venus 634LPx GPS with integrated data logger. It has never been flown on a balloon and we want to check its performance above 60,000 feet. If it works well, it will reduce our tracker complexity and power consumption and may allow us to use a lighter on future fights.
- This was always intended to be our backup tracker but it has been the most reliable so it has become our primary tracker.
- Garmin GPS18
- Byonics Micro-Trak 300
- 6 AA Energizer Lithium cells
- Home made 1/4 wave vertical antenna
- The VE5AA-11 tracker has been combined with the camera control module into a single module.
- Inventek ISM300 GPS with active antenna
- Custom tracker based on Opentracker OT1
- SRB-MX146 Transmitter
- Custom camera controller based on PIC 16F88
- Polaroid iZone 300 still camera customized to allow computer control
- Polaroid iZone 300 video camera customized to allow computer control
- eBay special 8GB "Spy pen video camera" customized to allow computer control, looking up
- Sparkfun Logomatic data logger
- 11.1v 1800 mAh Lithium polymer battery pack
- External siren for recovery (optional)
- PC Electronics
- Skytraq Venus 634FLPx with integrated data logger
- Passive patch antenna
- 7.4v 250 mAh Lithium polymer battery pack
- 220 MHz, 5 mW CW beacon
Soon after liftoff we realized that we were a bit stingy on the Helium and we wouldn't get the type of lift that we expected. With only a 400 fpm ascent rate, it was going to be a long day. Fortunately we had several new people join us for the launch and the slow ascent meant that they had lots of time to watch the balloon. The lower winds also caused the balloon to travel north then double back near the launch point at about 30,000 feet.
As the balloon headed south from Saskatoon, we started our chase. Bob, VE5RGM and his wife Lynn were already stationed 45 km south of Saskatoon and were reporting great video images from the ATV payload. Gus, VE5SPI with his wife Lori and Leigh, VE5LEE and I set out to meet up with Bob and Lynn. At around 40,000 feet, VE5AA-12 tracker quit reporting and changes. We weren't too worried because VE5AA-11 was still working fine. Once we rendezvoused, we decided to head south of the predicted landing zone and double back so as to take advantage of the paved roads. As we drove, we watched the ever increasing altitude, 80,000, 90,000, 100,000, 105,000. With each new report cheers from the other chasers were head over the radio. Just after our 105,560 foot report the data showed that it was dropping so we pulled over to plan the decent chase. To our amazement, the GPS began to report that the altitude was holding steady at around 105,000 feet. We had ourselves convinced that it had hit some sort of equilibrium at this float altitude. This was not the case.
As we pondered our next move, we watched the ATV signal from the balloon and it showed that it was swinging and spinning very rapidly. (Clue number 1) We also noted that the signal was getting a bit stronger and wasn't as high in the sky. (Clue number 2) Fortunately Bob had the presence of mind to turn the VCR on start recording. About 5 minutes later we lost the signals from all of our transmitters. This cold only mean one thing. It was on the ground. With knowing this, we set out to the last know position as reported by VE5AA-12. Gus, Lori, Bob and Lynn stopped in Hanley while Leigh and I went on to do a quick sweep of the river valley where the predicted landing point was. We found nothing and returned to Hanley to join the others. After reviewing Bob's video tape we noted that there were two very distinct features on the ground that looked like irrigation ditches. Unfortunately we had nothing to compare them to so we broke into search teams to begin searching around the predicted landing site. After several hours of futile searching we all returned to Saskatoon.
Once home we were able to use Google Earth to locate and identify the irrigation ditches from our video. It showed the payload only a few thousand feet above the ground and located within 8 km of where we had stopped after the burst. With a good estimated location, Gus and I returned to the Hanley area. Shortly after entering the search area we heard an APRS beacon with the characteristic sound of a TinyTracker. At almost the same time we heard the faintest pings of the micro beacon. We knew we were close. We drove a bit further and the beacon got stronger and stronger. As we neared it, we switched to the directional antenna and it told us to head down a side road. At the strongest point, we stopped and prepared to track it on foot. On one side was a freshly swathed field of Canola. On the other side, and 8 foot high stand of corn. As we swept the beam around, we knew it was going to be a walk in the corn. We donned out jackets and bug spray and headed in. The corn was so thick we could only see about 2 paces in front of us. Over the next half hour we homed in on the mini beacon. At the last leg, we knew it was 12 paces off an irrigation track. I walked in 12 paces but could see nothing, and hten I looked up. There it was, the payload line as tight as guitar sting strung across the top of the corn. I grabbed the line and began to follow it. Once I found it, Gus grabbed the line and followed it to the other end. With our payload in hand turned and headed for the car. By now it was dark and we were just able to make out the shadow of the car in the distance as we emerged from the corn.
We called back to Saskatoon to let everyone know that we had survived and we had the payload. As I drove back, Gus flipped through the camera images with amazement.
As with all of our flights, we learn something. This time it was to use a bit more commons sense and less blind reliance on the GPS and trackers. If we had paid closer attention to what we saw on ATV or we had bothered to watch for changes in external temperature or had noticed that the HDOP of the GPS was so high as to make the reading meaningless, we would have realized the the balloon had come down where it did and saved ourselves a great deal of frustration. Oh well, that half the fun of it.
Final Flight Path
Gus taking as bearing on the micro beacon.
We could only see about 10 feet ahead of us.
Post-burst up-looking video