Swiss solar plane on course for history with night flight
A solar powered aircraft emerged from a night flight high over Switzerland on Thursday, on course to making history as the first plane to fly around the clock on solar energy.
More than 24 hours after it took off, Solar Impulse was still flying in spectacular early morning clear skies in northwestwern Switzerland after dawn.
Pilot Andre Borschberg was set to land at Payerne at about 8:30 am (0630 GMT), after being confined to the cockpit of the single seater experimental aircraft for about 26 hours, team chief Bertrand Piccard said.
Applause and cheers broke out at mission control as the sun rose over Payerne airbase at 5:43 am (0343 GMT) with Solar Impulse still in the air.
"It's the first time ever that a solar airplane has flown through the night," said Piccard, who himself headed the first round the world ballon flight in 1999.
"That was the moment that proved the mission was successful, we made it," he told journalists.
Flight director Claude Nicollier said that the flight had gone well overnight as Borschberg guided the experimental aircraft towards a landing after dawn.
"It went better than that," Nicollier said.
The plane's flight during the overnight hours of darkness was powered by the charge its batteries had stored during the 14 hours of daytime flight thanks to its array of 12,000 solar cells on wings the size of an airliner's.
"It's a super flight, better than nominal," added Nicollier, a former space shuttle astronaut.
Nicollier said 57-year-old Borschberg was "very positive" after more than 22 hours in the air in the single seater, having been forced to stay alert for the full period.
"He is in very good spirits physically and mentally," said Nicollier.
Borschberg's impassive expression broke into a broad smile as the crew announced that dawn had officially broken at Payerne, live images from a cockpit webcam showed.
The high-tech single-seater aircraft took off on the historic attempt in the early hours (0451 GMT) of Wednesday.
The controllers decided as darkness fell later to press on with the night flight, despite fears that a sudden burst of strong high altitude wings at dusk had deprived Solar Impulse of some of the stored energy to last the night.
However, Piccard revealed early Thursday that the aircraft had emerged from darkness with three hours of energy left in its batteries, a far bigger margin than expected.
The solar panels spread over the wing of the high tech craft were switched back on as the sun bathed the plane, fuelling the four electric motors and recharging batteries.
"Nothing can prevent us from another day and night... and the myth of perpetual flight," an elated Piccard told journalists, as his sights shifted towards the prospect of transatlantic and round the world flights in 2013-2014.
The first prototype, shaped like a giant dragonfly, is clad with solar panels across a wingspan of 63 metres (207 feet), the size of an Airbus A340 airliner.
The solar cells and nearly half a tonne of batteries provide enrgy for four small electric motors and propellors -- the "power of a scooter", as the crew put it -- and weigh little more than a saloon car.
Solar Impulse took off into clear summer skies at 6:51 am (0451 GMT) on Wednesday.
The team is also driven by a desire to demonstrate that clean energy is technically feasible and should be developed and used more widely for transport, in the household and at work.
"We didn't really have credibility until today," admitted Piccard. "What we have done today in the air is an example of what should be done on the ground."
© 2010 AFP