WRAL WeatherCenter Blog

Triangle group launches homemade experiment into the stratosphere

Posted June 18, 2012 8:56 a.m. EDT
Updated June 18, 2012 8:57 a.m. EDT

NC Near Space Research launched an experimental weather balloon Saturday from the Kerr Scott building at the State Fairgrounds as a part of NC Maker Faire 2012.

Each launch costs the group about $150 to $200, including the balloon, helium, and lithium batteries needed to power the electronics in the cold of the stratosphere. The group has invested another $700 in cameras and other electronics that can be recovered and reused mission-to-mission.

These are the same weather balloons that NOAA's National Weather Service launches from over 100 sites throughout the U.S. and its territories each day.

Those balloons provide valuable data used to build the weather models that the WRAL Weather Center team uses. NOAA doesn't track where those payloads come down as closely NC Near Space Research does, though, and only gets about 20 percent of those payloads back as a result.

The 6-foot helium weather balloon lifted the NC Near Space Research's 1.5-pound payload up over 85,000 feet in altitude. A sealable plastic container, like one you might have in your kitchen right now, held a GPS, video and still cameras, and a transmitter which broadcast its position via ham radio throughout the two-hour flight to help ensure recovery. Ground stations as far away as Atlanta and Knoxville reported hearing the signal.

The group of space and weather enthusiasts also added some small experiments to the payload. A small bottle of water and a slightly inflated party balloon were monitored by an on-board camera with a Lego mini-figure overseeing it all. The water began showing signs of freezing 26 minutes into the flight as it approached 35,000 feet (higher than Mount Everest), and the party balloon expanded as the balloon rose through the increasingly thin air.

The balloon and its payload traveled south toward North Carolina's Sandhills immediately after launch. As it rose through 60,000 feet north of Fayetteville, winds pushed the balloon west where it sailed between Womack Army Medical Center and Pope Air Force Base at over 75,000 feet.

NC Near Space Research team member Rodney Radford noted, "This is the fist time we have had a flight go southwest. The six previous flights all went northeast."

"This is an unmanned balloon. Once released, we have no control over where it flew," Radford added.

Several minutes later the weather balloon, now 16 to 18 feet in size, burst over Fort Bragg. The payload quickly lost altitude as the parachute helped little in the thin stratosphere. As it descended into the troposphere around 50,000 feet, the parachute filled, and it all turned south where the experiment landed a few minutes later in a tree three miles southeast of Raeford, thankfully well out of Ft. Bragg.

In the end, the balloon traveled 16.5 miles up and along a path 86.5 miles long over about two hours. Team member Tanner Lovelace reported that when he retrieved the payload, the water in the experiment bottle was still frozen, and the party balloon was still intact. Only the first hour of the flight was available on the cameras, but team members plan to troubleshoot and try again during the next flight.