for National Geographic News
NASA scientists have programmed a model airplane to seek out rising columns of hot air called thermals and use them to soar like a bird.
The airplane could help monitor forest fires, guard borders, and collect weather data, according to the team.
In the future such planes could use similar updrafts to extend flight time on Mars, giving scientists a bird's-eye view of the planet.
"There have been large dust devils detected on Mars, which indicates a lot of convection [warm updrafts]," said Michael Allen, an aerospace engineer at NASA's Dryden Flight Research Center in Edwards, California.
Allen led the team that helped design the soaring airplane. The vehicle is nicknamed Cloud Swift after a bird known to eat insects found floating in thermals.
The airplane is an off-the-shelf model glider with a 14-foot (4-meter) wingspan. It's equipped with an autopilot device that's programmed to seek out and fly in thermals.
Allen was inspired to make the planeknown as an unmanned air vehicle (UAV)after watching birds and glider pilots seek out thermals to extend their time in the air.
Once inside the thermal, birds and gliders are able to stay aloft and gain altitude without using any energy.
Since the columns of rising hot air are invisible, glider pilots and birds look for places where they're likely to form, such as a plowed field baking under the sun, or signs that thermals are nearby, such as cumulus clouds.
"We programmed the UAV to fly in a search pattern, and when the aircraft starts to rise it would then decide whether the thermal was strong enough to stop and soar," Allen said.
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