The solar plane Impulse has landed after an over 26-hour flight in the skies over Switzerland. The Impulse, which has a 210-foot wingspan, was powered by a bank of 12,000 solar cells, which kept
batteries charged for electric power for the engine.
According to the New York Times:
"The propeller-driven Solar Impulse, made of carbon fiber, is powered by four small electric motors and weighs around 3,500 pounds. During its 26-hour flight, the plane reached a maximum speed of 68 knots, or 78 miles per hour, the organizers said."
The solar plane reached an altitude of 28,000 feet, with an average air speed of 23 knots. The technology to fly during the day on solar power and by night on stored electricity in batteries has been proved. How effective the solar cell/battery-powered engines would be during overcast or rainy weather is yet to be determined.
The Solar Impulse flew without consuming a drop of fuel, and without contributing one iota of pollution to the atmosphere. The single pilot was André Borschberg, a 57-year-old former Swiss Air Force fighter pilot. Borschberg endured buffeting on takeoff and sun-zero temperature during the 10 hours of night-flying in a cramped cockpit. His drinking water froze, and his iPod battery died as well. Aside from a sore back, Borschberg was in great spirits upon landing.
The technology that made the Solar Impulse possible is certainly not going to replace jumbo jets, which run on aviation fuel, any time soon. However, one can see the technology being incorporated into small, light sport aircraft, for example.
The ability to stay aloft for days or even weeks at a time could be used in pilot-less drones, monitoring everything from the weather to natural disasters, such as earthquakes and forest fires, to observing national borders and high-crime areas and performing reconnaissance missions over combat zones.
An all-electric system should also be quieter and easier to maintain than one using fossil fuels.
The solar plane Impulse is the brainchild of Bertran Piccard, who achieved the first nonstop circumnavigation of the globe in a balloon in 1999. The Solar Impulse project took seven years and tens of millions of dollars to progress to the first completed flight.
Next on the test regime for the Solar Impulse is a flight across the Atlantic, to be followed by a nonstop flight around the world.