While millions were watching the solar eclipse – in person or via video stream – St. Michael, Minnesota, native and North Dakota State University Electrical Engineering student Evan Gjesvold was doing a bit more.
Gjesvold was conducting an experiment to determine the impact of the eclipse on heat generation for solar balloons. He journeyed to Columbia, Missouri to conduct the experiment.
Solar balloons are an Earth-friendly form of high altitude ballooning, as they don’t require the use of the limited Helium supply, nor do they consume fossil fuels like most manned balloons used for heating. Instead, a balloon is constructed out of dark Mylar material which absorbs the sun’s energy. When the sun is eclipsed, much of that energy is blocked. Evan’s experiment sought to characterize the impact of this temporary reduction in solar flux on balloon altitude.
“The total eclipse created an unusual environment to test the impact of removing solar radiation from the solar balloon,” said NDSU Computer Science assistant professor Jeremy Straub, who mentored the experiment. “It presents a very different set of conditions than what happens when the sun is setting in the evening.”
Gjesvold flew to Columbia with all of the supplies needed for ballooning. Unlike with many solar balloon launches, everything had to be able to be done without AC power. A battery-powered leaf blower was converted for use to inflate the balloon. All of the computers and camera equipment also ran off battery power.
“It was a thrilling experience,” Gjesvold said. “It increased my awareness of our minute by minute dependency on the sun and vulnerability to celestial objects. I hope it also increases others awareness.”
On warm summer days, solar ballooning relies on a small difference between the temperature of the air in the balloon and the ambient air. The balloon is lifted due to the fact that the hotter air rises. Due to the limited solar energy, the balloon gained minimal lift. In fact, it did not reach the altitude that the team was expecting and had prepared for. Solar balloons can be deflated and reused and the balloon has been brought back to Fargo where it will eventually be used for another launch.
This experiment was the first time solar ballooning was conducted by NDSU, though Straub had previously conducted multiple launches, prior to joining the university. Additional solar balloon launches are planned for the near future.