Watch the Solar Impulse take off from Moffett Field in Mountain View just after 6:15 a.m. on May 3. The plane is bound for New York.
A solar-powered plane that spent more than a week in North Texas has departed on the third leg of its cross-country trip and will attempt to land in an inflatable hangar set up in the wake of last week's tornadoes.
The Solar Impulse took off early Monday from Dallas-Fort Worth International Airport bound for Lambert-St. Louis International Airport, where a tornado had damaged several of the airport's buildings including the hangar reserved for the Solar Impulse. But postponing the flight, said Swiss pioneers Bertrand Piccard and André Borschberg, is not an option. Therefore, the two said in a release that they must take off Monday for a 21-hour flight, the longest flight to date, and will use its own "inflatable hangar" to park when it lands.
WATCH LIVE: http://live.solarimpulse.com/
It's the first attempt by a solar plane capable of being airborne day and night without fuel to fly across the U.S.
The plane left Moffett Field in Mountain View on May 3 and landed the following day in Phoenix. The Solar Impulse departed Phoenix on May 22 and landed a day later in Texas.
The plane flies about 40 mph. The Texas to St. Louis leg is about 560 miles.
The end of the journey will be when the plane touches down at New York's John F. Kennedy International Airport.
Each flight leg normally takes 20 or so hours, with multiday stops in each city.
The Associated Press contributed to this report.