A NASA team flying an uninhabited aerial vehicle to study thunderstorms
achieved a milestone Wednesday, Aug. 21, completing the study’s
longest-duration research flight – six hours and 32 minutes – and monitoring
four thunderstorms in succession.

Based at the Naval Air Station Key West, Fla., researchers with the Altus
Cumulus Electrification Study (ACES) used the Altus II remotely piloted
aircraft to study a thunderstorm in the Atlantic Ocean off Key West, two
storms at the western edge of the Everglades and a large storm over the
northwestern corner of the Everglades.

“We gathered an extensive amount of data and had the opportunity to observe
a variety of storm conditions, such as when the second and third storms
merged into one larger storm,” said the study’s principal investigator, Dr.
Richard Blakeslee, a NASA atmospheric scientist at the Global Hydrology and
Climate Center in Huntsville, Ala. “We were fortunate to have a front-row
seat to this meteorological event.”

One of the most exciting data sets gathered, he added, was gleaned during
the fourth and final thunderstorm of the day. “With cloud tops at 50,000
feet, it would have been nearly impossible to study this storm without the
technology we have today. But thanks to recent advances in aviation, we now
have remotely piloted aircraft that can reach these altitudes,” he said.

The ACES lightning study uses the Altus II twin turbo uninhabited aerial
vehicle, built by General Atomics Aeronautical Systems, Inc. of San Diego.
Capable of high-altitude flight of up to 65,000 feet, the remotely piloted
aircraft has the ability to fly near thunderstorms for long periods of time,
allowing investigations to be conducted over the entire life cycle of

“The aircraft was able to stay over and around the final storm for one hour
and 20 minutes, gathering a vast amount of scientific information,”
Blakeslee said. “For this one storm alone, we gathered data on more than
500 optical and electrical triggers produced by lightning flashes.”

With dual goals of gathering weather data safely and testing the
adaptability of the uninhabited aircraft, the ACES study is a collaboration
among NASA’s Marshall Space Flight Center in Huntsville, the University of
Alabama in Huntsville, NASA’s Goddard Space Flight Center in Greenbelt, Md.,
Pennsylvania State University in University Park and General Atomics
Aeronautical Systems, Inc.

The Global Hydrology and Climate Center is one of seven science research
centers at the National Space Science and Technology Center (NSSTC) in