Sun-powered airplane flies at record altitude!
The Helios Prototype airplane weighs less than most cars and carries no people.
Flying at low altitudes, it is quite slow. You can ride your bicycle almost as fast!
And forget loop-de-loops! It takes a minute to climb the height of a 30 story building. (Most elevators climb faster!)
But the Helios Prototype airplane can do some very useful things no other airplane can do.
On August 13, 2001, remote-control pilots on the ground used a computer to fly the Helios Prototype to an altitude of 96,863 feet. That's over 18 miles straight up! Before the Helios Prototype, the highest recorded flight of any aircraft was about 85,000 feet. This was done in 1976 by the SR-71 spy plane, the fastest jet in the world. Only rockets and rocket-powered airplanes have gone higher.
The air we breathe on Earth's surface is almost 100 times thicker than the air up where the Helios Prototype flew. Earth's atmosphere at this altitude is about as thin as the atmosphere on Mars. This altitude above Earth is so close to space that the sky is almost black, stars shine in the daytime, and the horizon looks curved.
How did Helios do it? Airplane wings must have air under them to work. What is so special about Helios' wings that they can work with so little air?
First, Helios' wings—or rather wing, since it is really just one flying wing—is 247 feet long, about a classroom width longer than a Boeing 747. But Helios is very lightweight, so this huge wing doesn't have to lift very much. How can this plane be so light? Because it is made of very lightweight materials, doesn't carry any people or fuel.