The next step was to create the payload box. The professor had done this before so he gave us tips on using foam core poster board, hot glue and HVAC tape. We chose to cover ours in mylar by applying a spray adhesive to the surface, then laying a sheet of mylar on it, and using credit cards to squeegee it flat as best as possible. The mylar was applied to the insides of the box before gluing, and the outside afterward.
The inside was filled with a medium density foam from a second hand art store (the scrap Exchange in Durham is AMAZING!). The GPS was velcroed to the top of the box. A hole was cut on both the inside and outside of the box in the mylar just where the GPS was so it could receive signal.
The launch was Saturday May 22nd at 12:40pm. There were scattered showers and a thunderstorm. Just before the launch, 5 “hot hands” packs were thrown in the center of the box, foam was added, and the box was taped up for launch.
The Carolina Edge of Space guys had their GPS/HAM radio setup sending APRS tracking data. All the payloads got a HOBO Data logger with internal and external temperature readings. There were 3 cameras in total.
We launched at 12:40pm, just as the rain turned to drizzle.
Since we launched in the drizzle, and just before a thunderhead hit, all of our cameras got wet and subsequently froze upon entering the lower temperatures of the stratosphere. All the cameras eventually stopped working, The one in our box stopped just inside the cloud. The other two stopped just after passing the cloud top, looking face first at the thunderhead. You can just see the beginning of the blackness of space behind the cloud. View the entire Flickr set here!
The arduino payload didn’t record data either. Just before launch I tested to make sure it was recording data, and it was. however, a last minute addition of a second parallel battery pack may have overloaded the already hot 5V voltage regulator. It seems that just as I connected the last battery, the entire circuit shut off and on due to an internal thermal overload switch in the voltage regulator. I didn’t notice this because as it was toggling, I saw the “reset” light flashing on the arduino. This LED is also connected to the SD card data line, so it looked exactly as if the SD card was being written to.
The only data that was recovered was of the data logger in our payload. The internal temperature stayed a toasty 130 degrees F (which added to the problem of why we got no data.) The external temp showed a very good profile of the balloon punching through the tropopause before plumeting back to earth.
Overall, the balloon went 74,642ft. before the balloon popped. It flew across two counties and the state line before landing. I exported the APRS data to a Google Earth KMZ File.
Google Earth export of the APRS data
It happened to land in the yard of a man who worked in the photo lab at NASA during the 60s and 70s. He told us some of the stories from their lab, and showed us large prints of iconic photos he had developed. One in particular was of a lunar earth rise!
A second launch was planned for Fall of 2010. Luckily it faired better than this launch. I’ll post the vids and pics of that adventure soon.