A Bird? A Plane? Nope. It’s A Balloon Practicing For Next Month's Solar Eclipse

Jul 14, 2017

A giant white balloon floated across Pittsburgh’s Riverview Park Friday morning as part of a test launch of a University of Pittsburgh and NASA research project. A few dozen people watched as the balloon and a few colorful containers attached by a rope were released into the cloudy skies just before noon.

Physics and astronomy students, calling themselves the Pitt Shadow Bandits, convened near the Allegheny Observatory to make sure everything was ready for the official launch during next month’s solar eclipse.

Part of the balloon's payload, which will hang with several other tubes about three stories when floating.
Credit Katie Blackley / 90.5 WESA

“The goal is to live stream the eclipse from a higher altitude, from the balloon,” said sophomore Grace Chu. “And our team is also incorporating some equipment that can try to detect something can ‘shadow bands.’”

Shadow bands, according to Chu, are light and dark streaks of light that appear in the minutes before and after a solar eclipse. Some scientists theorize that the bands are always around, but usually they’re outshone by the sun. Not a lot is known about the phenomenon, but Pitt’s Shadow Bandits, along with 54 other teams across the U.S., hope to gather data about them.

“Most people think that this is caused by atmospheric turbulence,” Chu said. “So by sending up sensors in the balloon where there’s less atmosphere, we want to see if we can detect other bands up there.”

It’ll take the balloon about 1.5 hours to reach the edge of the Earth’s atmosphere, which is between 85,000 and 105,000 ft. Inside the balloon’s payload is 12 pounds of gear, including Raspberry Pi computers, cameras, light sensors, modems and a cut-away system.

Pitt researchers tried to replicate the position of the sun, where it might be during the eclipse, for their test run, waiting until a little after 11 a.m. to launch the balloon.
Credit Katie Blackley / 90.5 WESA

David Turnshek, Pitt professor of physics and astronomy and director of the Allegheny Observatory, said the balloon will be tracked by a highly-accurate satellite, so the researchers will never lose sight of its location.

“That will tell us where the payload is going to land, probably to within plus or minus 20 feet,” Turnshek said. “So when we get there, the hope is that it didn’t land in a lake, it didn’t land up in a tree and it didn’t land on someone’s roof.”

For the test run, Turnshek predicted the payload would end up in Indiana, Pa. It actually landed near a farm in Saltsburg, Pa. When they do the official launch on Aug. 21, they’ll be starting in Springfield, Tenn.

Shadow Bandit crew members were assembling parts of the payload prior to Friday’s launch inside the Allegheny Observatory. Turnshek said this is the eighth test run for the balloon. In the past, they’ve had trouble with some of the technology, including the tubes meant to hold the items and the device to cut the balloon away.

The aptly named Shadow Bandits team from Pitt consists mostly of physics and astronomy students. Most of the members have been preparing for over a year for the eclipse.
Credit Katie Blackley / 90.5 WESA

“Originally, the payload containers we were advised to use were kind of like picture board stuff, so they break very easily. So the first couple of launches we actually broke that stuff,” Turnshek said. “(Now) they’re actually 8-inch diameter things called sonotubes, which are actually used for pouring cement.”

To solve the cut-away problem, Turnshek said they included two different systems: one that is controlled by a computer and another that is tripped by altitude.

On the August launch day, live video stream of Pitt’s team and other teams across the country can be viewed on NASA’s official eclipse site.