High Altitude Balloon Launch (HABL)

Introduction:

As our last balloon launch, my class and I sent an eight foot diameter balloon along with a camera and rig up into the stratosphere to collect images. We have been leading up to this launch for quite some time as we developed the rigs months ago and have been testing out the balloons for our aerial imagery projects. We weren’t sure what to expect in terms of distance or the imagery we collected, but were very happy with the results. The balloon reached a height of about 100,000 feet above the Earth’s surface and travelled nearly 80 miles over the course of about an hour. The balloon eventually popped due to pressure in the atmosphere and fell near Marshfield, Wisconsin. We were then able to find and gather the balloon and view our imagery. We were able to collect some really fantastic imagery of the Eau Claire area and western Wisconsin.

Figure 1: This is the path that the balloon flew after it was released from the UW-Eau Claire campus. (Map credit to Joe Hupy.)

Methods:

The rig for this launch was created back in February along with the rigs for the aerial imagery balloon launches. We used a Styrofoam bait warmer to hold the camera with heating packs inside to keep the camera from freezing at such great heights. We also cut a hole in the bottom of the bait warmer to fit the size of the camera lens so that it could collect imagery of the Earth. Four strings about three feet long were tied to the warmer and taped along the sides connecting at the top with a carabiner at the top to suspend the rig from the bottom of the balloon. A GPS unit was also attached so we could track the balloon and collect it once it landed. A parachute was attached so the rig could land safely after the balloon popped up in the atmosphere as well. The camera we selected for the HABL was a digital flip camera, and we took video rather than a continuous shot mode as we had for the aerial mapping launch.



Figure 2: This is a photo of the rig that we created for the high altitude balloon launch. It was developed earlier on in the semester.

On the day of the launch, we filled the balloon using a large helium tank. We had to be sure to fill the balloon with enough helium that it would rise quickly, but also leave enough space for the helium to expand with the higher altitude without popping the balloon right away. Once the balloon was filled properly, we attached the rig, making sure the camera was set to the correct settings. Then we were ready to launch the balloon. We chose to release the balloon at 10a.m. on the 26^th of April because the weather conditions were most permissible at that time. The balloon was let go in the center of our campus mall.

 Figure 3: This is an image of the class walking the balloon to the center of campus for the launch after it had been filled.

At first, we weren’t receiving a signal from the GPS unit attached to the rig and weren’t sure if we would be able to recover the footage. Fortunately, after about an hour, the signal appeared near the city of Marshfield, Wisconsin—78 miles east of Eau Claire. Our professor and a couple students then set out to find the balloon and bring back the rig. They found that the balloon had landed on some private property and had to ask the land owner’s permission to retrieve the rig. They received permission and ended up having to climb up a 50 foot tree to get it down. Our professor had to saw off a limb of the tree to actually recover the rig.

 Figure 4: This is an image of our professor climbing  a 50 foot tall tree to retrieve the HABL rig. He ended up sawing off a large branch of the tree.

Results/Discussion:

The HABL was an overall success—we were able to recover some amazing images from the camera and have a video of most of the flight. There were several aspects of the rig and camera that did not go perfectly, however. Unfortunately, once the camera had reached a certain height, condensation began to cover the camera lens producing a hazy film for some of the imagery. The camera was only able to capture about an hour of footage before the battery died, as well. This wasn’t a huge issue as we were still able to see the launch up through the point where the balloon began its descent, but it would have been nice to see the entirety of the launch. We also decided that any future launches would also include a barometer, thermometer, and anemometer to collect more information about the flight.

Figure 5: This is a stillframe from the balloon as it left the UW-Eau Claire campus. This is one of the very first images that was collected during the flight.

Figure 6: This is an image of the Chippewa River to the east of Eau Claire. As can be seen, the balloon had reached much greater heights at this point than it had while it was near the campus.

Figure 7: This is one of the last images taken by the camera before the battery died at about 100,000 feet in the air.

Conclusion:

The high altitude balloon launch was an amazing experience for our class. Very few people have been lucky enough to send a balloon up into the stratosphere at 100,000 feet above the surface of the Earth and collect imagery themselves. Although there were a few issues with the HABL, our hard work and planning for the rig paid off. Below is a link to a video that our professor created to summarize the launch.

http://desi.uwec.edu/Geography/Hupyjp/Weather_Balloon_1024.asx