Pilot unveils solar plane

It has the wingspan of a Boeing 747 but weighs less than a small car. And it is powered entirely by the sun.

Adventurer Bertrand Piccard on Friday unveiled the Solar Impulse, which with its sleek white wings and pink trimming, aims to make history as the prototype for a solar-powered flight around the world.

“Yesterday it was a dream, today it is an airplane, tomorrow it will be an ambassador of renewable energies,” said Piccard, who in 1999 copiloted the first round-the-globe nonstop balloon flight.

The plane will take part in a series of test flights over the next two years, and based on those results, a new plane will be constructed for the big takeoff in 2012.

In a swank ceremony at a military airfield near Zurich, Switzerland, Piccard and co-pilot Andre Borschberg hugged as the curtain was pulled across to give the public its first glimpse of the plane. Numerous dignitaries were in attendance, including Prince Albert of Monaco and major sponsors.

The budget for the project is $98 million, Piccard said.

He and Borschberg said the plane will fly day and night using almost 12,000 solar cells, rechargeable lithium batteries and four electric motors. It will not use an ounce of fuel.

But the maiden flight will take time. With the engines providing only 40 horsepower, the plane will fly almost like a scooter in the sky. It will take off at the pedestrian pace of 22 mph, accelerating at altitude to an average speed of 44 mph.

For that reason, Piccard’s circumnavigation will be split into five stages. Borschberg said the stages are five days long because of the cockpit, which was made non-pressurized to keep the weight down.

The first test flights will be later this year, with a complete night voyage planned for 2010.

“It will be like the Wright brothers,” said Piccard, 51, who comes from a long line of adventurers. His late father, Jacques, plunged deeper beneath the ocean than any other man, and grandfather Auguste was the first man to take a balloon into the stratosphere.

One thing a solar plane cannot handle is bad weather. Because the solar panels are needed for day flying and for charging the 882-pound lithium batteries that power the plane by night, it relies on sunshine.