Solar-powered plane takes to skies
A solar-powered plane whose inventors hope will make a round the world trip has taken to the skies for its first proper flight.
Swiss adventurer Bertrand Piccard said the two-hour test was to see if the plane, with the wingspan of a Boeing 747 and the weight of a small car, can keep a straight trajectory.
"To fly without fuel, we have to make it fly in line," said Piccard, who in 1999 copiloted the first non-stop round-the-globe balloon flight. "There might be things that go wrong - maybe a technical problem, engine failure or a part breakdown."
At a military airport in the Swiss countryside, the "Solar Impulse" plane lifted off after only a short acceleration on the runway, reaching a speed no faster than 28 mph. It slowly gained altitude above the green and beige fields, and disappeared eventually into the horizon.
The £70 million project has been conducting flea-hop tests since December, taking the plane no higher than two feet and 1,000ft in distance. A night flight is planned later this year, and then a new plane will be built based on the results of those tests. The big takeoff is planned for 2012, and it will use not an ounce of fuel.
Using almost 12,000 solar cells, rechargeable lithium batteries and four electric motors, Piccard and co-pilot Andre Borschberg plan to take the plane around the world with stops to allow them to switch over and stretch after long periods in the cramped cockpit.
The circumnavigation will take time. With the engines providing only 40 horsepower, the plane will fly almost like a scooter in the sky, at an average speed of 44mph. The trip will be split up into five stages - keeping the plane in the air for up to five days at a time - with the stopovers also allowing the team to show off their creation.
Solar flight is not new but Piccard's project is the most ambitious.
In 1980, the fragile Gossamer Penguin ultra-lightweight experimental solar plane flew short demonstration flights with one pilot on board. A more robust project called the Solar Challenger flew one pilot from France to England in a five-hour-plus trip in 1981.
Solar plane technology recalls the early days of manned flight, and the slow ascent of the Solar Impulse was somewhat reminiscent of the Wright brothers pioneering experiments over a century ago.