Solar Impulse Airplane Leaves Phoenix, Heads East on Around-the-World Voyage

A solar-powered airplane designed to bring attention to renewable energy departed from the Phoenix area early this morning to continue its attempt at an around-the-world flight.

The Solar Impulse 2 spent 10 days in the Valley after pilot André Borschberg landed to the cheers of a small crowd on May 2 at the Goodyear Phoenix Airport, following a flight from San Francisco.

Just after 3 a.m. today, Bertrand Piccard, the Swiss adventurer who in 1999 flew around the world in a helium balloon, took off for an expected 17-hour flight to Tulsa, Oklahoma. He's expected to land at the Tulsa International Airport at 11 p.m. local time.

Internet users can watch the flight live in the "virtual cockpit" and listen to Piccard talk to the media and ground control.

The airplane, whose wings and upper fuselage are blanketed with photovoltaic panels, requires roughly the wingspan of a Boeing 747 in order to lift the weight of an automobile. The solar setup allows the electric airplane to run strictly on solar power for about two-thirds of the time. Batteries power the nighttime takeoff and landings, as well as other times when the sun's rays aren't available.

The goal is to reach and cross the Atlantic Ocean in the next few weeks, with a planned July touchdown in Abu Dhabi, the United Arab Emirates capital where the journey began in March 2015.

Piccard said this morning from the cockpit that the airplane uses "no fuel" and remarked how far renewable energies have come.

The airplane has been dogged by problems and delays, though. And it's not quite accurate to state, as the project's website does, that the airplane is "powered only by the sun, with no fuel or polluting emissions." Besides its batteries, the airplane is aloft because of a $170 million, decade-long effort involving hundreds of people.

Despite the obstacles, the high-tech airplane and risk-taking pilots have inspired millions around the world.