Comet Enthusiast

The Global Hawk is a robotic plane that can fly autonomously to altitudes above 60,000 feet -- twice as high as a commercial airliner -- and as far as 11,000 nautical miles -- half the circumference of Earth. Operators pre-program a flight path, and then the plane flies itself for as long as 30 hours, staying in contact through satellite and line-of-sight communications to the ground control station at NASA's Dryden Flight Research Center in California's Mojave Desert. Image Credit: NASA/Tony Landis