After several weeks of delays, a solar plane took off from China Saturday for a historic crossing across the Pacific that organizers hope will end in Hawaii in five days.
Solar Impulse 2, with André Borschberg manning the controls, was supposed to fly May 4, but repeated bouts of poor weather have kept the experimental plane grounded in China. The flight is being broadcast live on the web.
The Pacific crossing is part of a bid by Borschberg and Bertrand Piccard to fly around the world in the plane that depends on solar power for energy - thus showcasing the potential of renewable energy.
The around-the-world trip, which should take five months in all, had until recently been going smoothly. The plane took off from Abu Dhabi in July, and on the second leg of its journey, from Oman to India, it set a new world record for a flight in a piloted solar-powered plane.
"This is the moment of truth," Borschberg said in an interview with CBS News a few weeks ago of the plane, which until now has not flown more than 20 straight hours on any one leg of the trip.
"If successful, this flight to Hawaii will demonstrate the credibility of the vision Bertrand had 16 years ago of an airplane flying for days without fuel to change our mindset regarding the enormous potential of clean technologies and renewable energies," Borschberg said. The two co-pilots are taking turns flying alternate legs of the flight since there's only room for one man at a time.
The weather will be the biggest challenge over the next few days.
Because the plane is powered entirely by the sun, it needs clear skies to allow its batteries to be powered up enough to get through the night. And because it's 10 times lighter than the best glider, with a wingspan matching a Boeing 747, the plane is more vulnerable to storms and turbulence than a typical airplane.