What goes up must come down. And when the “what” is a weather balloon payload parachuting to the ground after a four-hour ride 98,000 feet into the stratosphere, you want to be able to find it.
That was the challenge faced by Scott Banister’s Engineering Design and Development class at Pittsford-Mendon High School in suburban Rochester, N.Y. For the last two years, Banister’s class has launched high-altitude weather balloons carrying payloads fashioned from small Styrofoam coolers. The launches were the culmination of a semester-long project to design and build the payload, then, using data and technology, track and retrieve the payloads and record the experience.
Using what they’d learned in class about the weather and wind patterns, the students tried to predict where the payloads would land. But since the balloons would rise nearly 20 miles high and could potentially travel hundreds of miles in any direction before expanding, bursting and dropping their payloads, the potential landing area could be almost anywhere in central New York State. The students needed an accurate way to track and find the payloads from their chase vehicles. They chose the Verizon 4G LTE network and smartphones emitting GPS signals as the solution.
“The first time we launched the balloons 18 months ago, the payloads came down more than 150 miles away near Binghamton,” says Banister. “But we were able to follow the GPS signals from the phones after they landed using the smartphones in our cars.”
This year, the class enlisted the help of local amateur radio operators to follow the balloons live in flight using radio transmitters and added GoPro cameras and environmental sensors to the payloads, along with Verizon’s 4G LTE smartphones. Also going along for the ride on the balloons were bobbleheads of the school’s principal and the district’s superintendent. A third balloon from Cazenovia High School near Syracuse launched with the two balloons from Banister’s class.
“We tracked the payload locations using an app called AccuTracking,” Banister said. “The app allows you to configure the phone to transmit its GPS coordinates at desired intervals which can be received and mapped on any device connected to the Internet.”
The phones lose their connection to cell towers as they rise in the air (that’s where the radio transmitters took over) and then regain the connection as they come back down and land.
“As long as the phones are in range of a cell tower when they come down, you can locate them on the ground,” said Banister. “Our ‘Mission Control’ at the school located the phones, sent us the GPS coordinates in a text message, then we proceeded to the location by car and finally on foot. Both phones were tracked to their final locations south of Ithaca.”
Banister says the project was a rewarding adventure for the students and they learned a great deal designing the project, building the payloads, and coordinating the different technologies they used along the way.
And since few people have had the opportunity to ride 98,000 feet into the stratosphere, the class posted a video of their balloon flight – from takeoff to landing.