Students from Redmond High School’s astronomy club made a trek to Ellensburg last week as they chased down a weather balloon they launched from their school.

Keenan Ganz, a junior, started the club this year and said in an email they initially estimated the balloon would land near North Bend and Snoqualmie when they launched it on June 22.

The balloon itself was inflated to just under 6 feet in diameter. Ganz said they were unable to inflate it to 6 feet, and balloons with smaller diameters travel farther.

They astronomy club also ran into technical problems when they were creating a parachute to safely land the payload the balloon was carrying, which included a styrofoam container holding a GPS unit, a GoPro camera and insulation to keep the instruments warm as it reached heights possibly exceeding 50,000 feet.

Instead of purchasing a pre-folded parachute, the club hand-cut and sewed a parachute made of Tyvek, which is a type of covering used during building constructions.

Ganz said while it is strong, light and cheap, it doesn’t fold very well.

So instead of packing it, they wrapped it around the top of the balloon, so when the balloon was popped, the parachute would already be deployed, Ganz said.

The group also used travel simulators developed by the University of Cambridge and the University of Michigan to estimate where the balloon could land.

Ganz said these estimates can be inaccurate due to how many factors go into the projections. He gave the example of a balloon inflated to 5 feet will float nearly 10,000 feet higher than a balloon inflated to 6 feet.

The team would also be tracking the balloon from two different vehicles, one which would tail it and one which would head out in front of the balloon. They also had to wait for a day with little wind and clear skies.

Finally on the Thursday of the launch, Ganz said the conditions aligned and they launched the balloon. The club was nervous, Ganz said, because if the balloon landed on a large tree or on a mountain, it would be unrecoverable, and the equipment that had either been loaned or belonged personally by the club members would be lost.

The group tracked the flightpath of the balloon as it shot rapidly southeast from Redmond. At one point, it was moving at more than 90 mph as it moved over the Cascade Range toward Easton.

While Ganz said they can’t know the exact altitude the balloon reached, the onboard GPS unit stops working at 50,000 feet, and they lost contact with it for a brief period, possibly meaning the balloon exceeded that limit.

Chad Keddie was part of the astronomy club and a member of the team that tracked down the balloon when it finally landed near Ellensburg.

“We had no idea where it was going for around a half hour,” he said. “… We had to go to one to the local places, get Wi-Fi and basically kind of update the location.”

They continued to track the balloon after they confirmed it cleared the mountains and eventually sent a cluster of eight pings on a property owned by a Methodist church camp around 13 miles west of Ellensburg.

Ganz said they got permission to search for the balloon and after an hour of hiking around the property, they located it in a tree and eventually were able to recover it.

When they finally got it down, Ganz said the GPS was still working and the GoPro had shut off after recording around 30 minutes of the balloon hanging in the tree after its trip across the Cascades.

The camera also recorded around two hours of its journey across the Cascades, including shots of Puget Sound, Lake Washington, the Olympics and Lake Sammamish.

Keddie said being a part of the astronomy club during its first year was a good experience.

“It was awesome, a lot of fun from the very beginning,” he said.

This project in particular really caught the team’s attention, he said.

The club didn’t have much, if any, funding, so the members had to get resourceful and rely on either donations or make the items themselves.

“It’s just really cool to see when you have an idea and you have all these pieces moving and working together,” he said.

As next year is Keddie’s senior year, he said he hopes to inspire younger students to join the astronomy club to keep it going in future years.

“We’re looking for more people to expand and keep the club going,” he said.