It’s up, up and away with a big balloon as the Pitt Shadow Bandits practice for eclipse
A University of Pittsburgh team launched a weather balloon 10 feet in diameter from Allegheny Observatory on the North Side to practice its part in the big show that is the Aug. 21 solar eclipse.
The big balloon almost got away from the white-gloved hands of some of the staff and students after they filled it with helium from a tall, hissing tank shortly before 11 a.m. Friday out on the damp grass of Riverview Park.
Inside Pitt’s century-old observatory, where they’d been working since 7 a.m., one of three faculty leaders — physics and astronomy professor Russell Clark — warned reporters and photographers not to interrupt students Janvi Madhani and Grace Chu as they finished building the five payloads of microcomputers, cameras and other sensitive electronics that would hang on a 35-foot length of cord, as these details were “mission critical.”
They wanted to launch the rig while the sun was at the same angle in the sky that it will be during the eclipse next month just north of Springfield, Tenn., where they will send up a balloon as part of a NASA project to document and study this astronomical
phenomenon.
Around midday on that Monday, within a 70-milewide swath from Oregon to South Carolina, the moon will be positioned so that it will appear to completely cover the disc of the sun. It will cast a shadow, or umbra, that, as it rushes from west to east, will put places on that path into twilight for up to 2 minutes and 40 seconds. If skies are clear, people will be able to see planets and bright stars as well as the sun’s corona or aura. The rest of the country will be able to view, with proper solar glasses, a partial eclipse of varying degrees. Here in Pittsburgh, the passing moon will block up to 81 percent of the sun.
But a total eclipse rarely is so accessible to so many people, so some eclipse chasers made their plans years ago to see it from front-row seats. Helping to hype what it’s billing as the “Eclipse Across America” is NASA, which sees this as a chance to add some science to the public diet and also to do some collaboration and research.
So NASA sponsored the Eclipse Ballooning Project. Some 60 teams from high schools, colleges and universities across the country will be conducting high-altitude balloon flights from about 25 points along the total eclipse path, sending images from near space to a NASA website where people around the world can watch in real time. Such views of an eclipse have been collected only once, in Australia in 2012, and they have never been broadcast live.
NASA also will be broadcasting images from a dozen spacecraft, including the International Space Station, and several NASA aircraft. They’ll also share the footage with the citizen-science Eclipse Mega Movie Project.
David Turnshek, a Pitt physics and astronomy professor and the Allegheny Observatory director, is delighted that Pitt is part of the balloon project. There are two other teams from Pennsylvania — from Gannon University in Erie and Temple University in Philadelphia, both of which are launching their balloons from points in Kentucky.
The last total solar eclipse visible in the mainland U.S. was before all this internet wizardry, in 1979, and the last one to be visible from coast to coast was in 1918.
So after the idea to view this via balloons was floated, so to speak, by the Montana Space Grant Consortium at Montana State University in 2014, NASA was all in to fund it, for a cost of about $3,500 per team for a groundbased dish system and payload.
Just like the other heliumfilled balloons, Pitt’s will lift a tracking system (for the team as well as air traffic controllers), cameras and a modem. The balloon’s launch will be timed so that it can rise to an altitude of about 100,000 feet — the very edge of space — and capture images of sun, sky and Earth. Before the balloon bursts, the payload will cut away and a parachute will deploy to let the payload drift back to the ground, where the team will find and retrieve it.
Friday’s worry was flooding in the area where the payload was predicted to land.
Mr. Clark: “So, go or no-go at 11?”
Mr. Turnshek: “I say, let’s try.”
After the actual eclipse is over the and live stream ends, the science will continue. Some high-resolution images will be analyzed and shared later. Some of the balloons also will carry bacteria so they can be studied for effects of high-altitude flight. And each team will be doing its own experiment.
Pitt’s team, calling itself the “Shadow Bandits,” will document shadow bands, ripples of light that have been observed just before and after past total eclipses. The prevailing theory is that these are just atmospheric turbulence. But Pitt aims to test that by having light sensors “look” for them on the ground and at the atmosphere’s outer edges; if they’re detected there, then it will indicate that shadow bands aren’t just atmospheric turbulence.
Friday’s test flight was the eighth and probably last in a series of practice runs that has included some mishaps. As Mr. Turnshek acknowledges, “We’re not a very experienced ballooning team.” One payload strayed to Somerset County and became caught in a tree so tall the team was ready to try the old arrow-on-a-string trick to retrieve it. The wind blew it down by the next day.
On previous test flights, the balloons popped prematurely, causing some damage to the payload.
For each launch, they’ve made modifications, including, Friday, adding what looked like a foam swimming “noodle” to the payload cord toreduce spinning.
“Science is messy,” quipped team member Marshall Hartman of Whitehall, who graduated this spring and who already likes having this project on his resume. “People are really interested in it.”
Ms. Chu said she, too, got excited when she heard about the total eclipse, in part because the sophomore wasn’t alive for the last one in the U.S.
About 11:15 a.m., Mr. Hartman was manning the laptop set up on a table beside the NASA dish out on the lawn. Observatory technician Lou Coban used his cell phone to call air traffic control at Pittsburgh International Airport and said, “We are due east of your approach path and we are about to launch a weather balloon.” (As long as the payload is under 12 pounds, they don’t have to alert authorities, but they still do.)
With a passing aircraft adding to the drama, Mr. Clark alone held the bucking balloon by its tether as the team tried to get the live feed to work (it did not; science is messy). On Mr. Turnshek’s “Ready?” Mr. Clark said “Yep!” and let go, and the balloon smoothly and quickly climbed until it disappeared in the clouds, and they started following it via computer.
Just before 2 p.m., some of the team tracked it to the yard of a farm near Saltsburg and texted the Post-Gazette: “Payload recovered, some damage but mostly intact.”
A few minutes later: “Headed to Saltsburg for late lunch.”
As the eclipse date gets closer, the team doesn’t want to risk damaging its equipment, so rather than do flights, it will practice assembling the rig and test the electronics at the observatory.
Although all this practice increases their likelihood for success, they need to be ready for whatever on eclipse day.
“We’re going to have to be pretty lucky to have stable images, I think,” said Mr. Turnshek. “But we’ll see what happens. The great thing about it is, this is an incredible learning experience for these undergraduates.”