Overnight first solar plane flight takes off from Switzerland

An experimental solar-powered plane took off from western Switzerland on Wednesday for a 24-hour test flight–a key step in a historic effort to one day circle the globe using only energy collected from the sun.

The plane has 12,000 solar cells on its 80-metre wingspan and looks like something out of a science-fiction movie.

Clear blue skies on Wednesday allowed the prototype aircraft to soak up plenty of solar energy as it flew over the Jura mountains west of the Swiss Alps. The big question, however, was whether the plane’s 12,000 solar cells could fill up its batteries with enough energy so the plane could fly through the night.

The flight is going “extremely well,” said team co-founder Bertrand Piccard, a record-breaking balloonist whose father and grandfather also accomplished pioneering airborne and submarine feats.

“The goal of the project is to have a solar-powered plane flying day and night without fuel,” Piccard said. “This flight is crucial for the credibility of the project.”

It took off at 7am from the Payerne airfield in Switzerland, with pilot Andre Borschberg planning to take it up to an altitude of 8,500 metres throughout the evening.

If all goes well he will continue to fly the plane through the pitch of night with just the power stored in the rechargeable solar-powered batteries.

By early afternoon, pilot Andre Borschberg had his oxygen mask on and was cruising at 19,680 feet (6,000 meters), after trying to dodge the low-level turbulence and thermal winds that are frequent in the mountains.

“Andre now reached 6000m in a cloudless sky … this situation will last the entire afternoon,” the control panel tweeted, adding later “batteries are nearly fully loaded. Sun rays now for climbing only.”

Piccard told The Associated Press he was confident the plane will collect enough solar energy to theoretically fly through the night but was not exactly sure how energy efficient the plane was.

“We will most probably take the decision to go through the night,” he said. “We’ll have to be very careful, because then we have to see if the energy that we have in the batteries will be enough.”

The plane is flying in loops in Swiss airspace and within gliding range of Payerne airport so it could land if it runs out of energy, he said. The solar plane needs a wide, concrete runway because of its wingspan.

Every aspect of the aircraft is monitored by engineers on the ground, with much of it fed onto the team’s website and Twitter page.

The 57-year old Swiss, a former fighter jet pilot, is wearing a parachute.