Here is the track of the ballon as recorded by the GPS-enabled cellphone (red), GPS datalogger (Pink) and as projected by model (violet).
For the Earth Science Near Space Mission, ES110 class (winter 2010-11) constructed a device (SEE design) that would reach an altitude in near space, record its surroundings, and track its own position for us to find when it reached the ground. We purchased a latex balloon that would be filled with helium. Attached to it, we had a string holding our payload. Within the payload, we attached a video camera, a GPS, and our contact information (in case it was found by someone else.) We made sure that the payload remained at legal weight, and would travel into near space without breaking apart or collapsing.
For lift off, we had one person holding each connection to ensure that it would not tangle before going up in the air. The helium filled the balloon until it could carry our payload into space, and then we prepared to launch the balloon.
After it took off, the balloon traveled according to the jet stream of that day, January 25. The jet stream (charted in knots) carried the balloon eastward, with winds at a high of approximately 70 knots. The trajectory had a different outcome than we had initially predicted, due to the jet stream. Because the jet stream followed a pattern that traveled east, generally, it carried the balloon to its destination in New Jersey.
Our trajectory was inaccurate because we had overfilled the balloon with helium. This factor caused the balloon to travel unexpectedly. Our predicted trajectory was out of sync with the jet stream.
During the elevation of the balloon, it slowed down unexpectedly near its greatest altitude. With further investigation, we discovered that the reason for its decrease in speed was because at one point the pressure in the balloon was equal to the pressure outside of the balloon. This change in pressure began the slowing progression of the balloon until eventually it exploded. The balloon descended earlier than we had predicted because of this change in pressure. The balloon landed in a tree in New Jersey about three hours after launching. We retrieved it easily, all of its devices still in tact. We still have not seen any video footage, but the other data was recorded and we were able to analyze it in the graphs seen further in my report. This lab was a very useful learning experience for our class. We researched the construction of payload devices and the legislative requirements for launching. After setting up our mission, we drove westward in Pennsylvania and carried out the launch. It was informing and fun, which made the whole experience lively and memorable.
Written by Rachel Lindsay
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