A solar-powered aircraft with a wingspan as wide as that of a jumbo jet but weighing as little as a small car has completed a history-making cross-country flight, landing Saturday night at Kennedy Airport.
The Solar Impulse flew out of Dulles International Airport near Washington a little before 5 a.m. Saturday and landed shortly after 11 p.m.
A tear was found on the left wing of the revolutionary plane earlier Saturday, forcing the aircraft to land three hours ahead of schedule. Officials said neither the pilot nor aircraft appeared to be in danger.
The accelerated schedule forced flight officials to scrap a planned flyby past the Statue of Liberty.
The Solar Impulse left San Francisco in early May and has made stopovers in Phoenix, Dallas-Fort Worth, St. Louis, Cincinnati and Washington.
Although the Solar Impulse is promoted as solar-powered, what really pushes the envelope is its miserly energy efficiency, said Solar Impulse CEO Andre Borschberg, one of the plane's two pilots.
Parts of its wings are three times lighter than paper. Its one-person cockpit is beyond tiny.
The aircraft, powered by some 11,000 solar cells, soars to 30,000 feet while poking along at a top speed of 45 mph. Its wings were lit with 16 LED lights that used less power than two 100-watt household bulbs.
"We can use much less energy than we use today without the sacrifice," Borschberg said. "And that's really important."
People won't sacrifice to save energy or the planet, but if they are smart they don't have to, Borschberg said. That's why he and fellow pilot Bertrand Piccard pointedly talk about "clean technologies" not "green technologies."
The only sacrifice with the plane is staying up in the air alone for 20 hours in such a small space, Borschberg said.
Still, questions of practicality come up.
"It's clearly a stunt," said John Reilly, co-director of MIT's Joint Program on the Science and Policy of Global Change. "And it's clearly an attention-grabbing stunt. The idea that you could fly an airplane powered by the sun is kind of hard to believe. So doing it is an impressive stunt, I suppose."
It will pay off more than promoting solar and other renewable energy technologies as economic stimulus, which is what happened four years ago, said University of Colorado science policy professor Roger Pielke Jr. He compared it to giant prizes that encourage private companies to go into space or build robot-driven cars, which are proving successful.
"The idea is that you're pushing boundaries and you're putting on shows for people and achieving milestones," he said.