A solar-powered plane that had a successful -- but short -- test flight last week, took off Tuesday morning from Moffett Field in the Bay Area, in the hopes of soaring its longest route yet: 16 hours.
Considered the world's most advanced sun-powered plane, the Solar Impulse took off at 7 a.m. Tuesday from Moffett Field in Mountain View, Calif., with an expected return of 11 p.m.
On Friday, the plane took a successful two-hour practice run.
Its Swiss creator and pilot André Borschberg said the plane should be ready for the cross-country journey on May 1, depending on the weather.
"We're here to inspire," Borschberg told NBC on Tuesday, adding that he hoped this science and technology -- and imagination -- would trickle down to the "younger generation."
The aircraft, which consumes no fuel because its wings are decked with thousands of solar panels, will stop in Phoenix, Dallas, Washington and New York.
Each flight leg will take 20 to 25 hours, with 10-day stops planned in each city.
Between Dallas and D.C., the plane will also stop at one of three other cities: Atlanta, Nashville or St. Louis.
The Associated Press contributed to this report.