Solar Plane Preps for Historic Flight to Hawaii

Hawaii is the next stop on a globe-spanning attempt to make history and to prove what's possible without relying on fossil fuels. The "Solar Impulse" team is halfway through it's plan to achieve the first around-the-world flight using only solar power.

The "Solar Impulse" solar plane -- actually, the second one built for the mission -- is currently in Nanjing, China, the sixth of the twelve planned legs of their route. But the next segment, crossing the Pacific to Hawaii, will be the longest, estimated to take nearly a week.

Mission managers are still looking for the next take-off window, which will be no earlier than May 11. The team includes over 70 people, including 30 engineers, 25 technicians and 22 mission controllers.

In development for 12 years, the "Solar Impulse" flight is being led by Bertrand Piccard, who made the first ever non-stop around the world balloon flight. The aircraft will also be piloted by Andre Borschberg, CEO, trained fighter pilot and MIT graduate.

"By attempting the first Round the World Solar Flight, they want to demonstrate that clean technologies and renewable energies can achieve the impossible," explains the official site. "For the Solar Impulse team, pioneering spirit and innovation can change the world."

As impressive as their achievement may ultimately be, the larger mission is to drive action. Specifically, building the largest movement ever created to push world governments to heed the UN Conference on Climate Change, which will define the new Kyoto Protocol in Paris this December. Like all modern movements, there's an official hashtag: #futureisclean.

The meticulously designed solar plane has a 72-meter wingspan, larger than a Boeing 747, but weighs only about as much as an average car. More than a quarter of that weight, 633Kg of 2,300, is batteries, which are charged by 17,000 solar cells built into the wing.

Because the aircraft is relatively delicate, a lot of planning depends on the weather. It took three weeks to get to Nanjing, and that leg of the trip was less than two hours long. At one point, winds were so strong that the plane was effectively flying backwards.

This next leg is described as "an ultimate test of endurance," with each of the two pilots at the controls for five days and nights straight, with only 20 minutes of rest every few hours.

Borschberg has been posting updates on Twitter, talking about outreach events in China and cockpit survival training for the ocean crossing. On Tuesday, he described the Nanjing to Hawaii leg as "the flight of my life."

"Solar Impulse" kicked off on March 9 in the United Arab Emirates. When it finally departs China, it will land at Kalaeloa Airport. The full trip around the world will add up to more than 500 flight hours over five months.

Fortunately, it's easy to get the latest updates on the flight, including live webcasts at milestone events. Just visit SolarImpulse.com. The team is also very active on social media:

• Twitter: @solarimpulse

• Facebook: solarimpulse

• Instagram: solarimpulse

• YouTube: SolarImpulseChannel