The world's most advanced sun-powered airplane began its first cross country journey this morning. Around dawn, the Solar Impulse lifted off from Moffett Field, North West of San Jose bound for New York. The single seated plane has the wing span of a 747, but the weight of a mid-sized car and is powered by 12-thousand photo cells covering the wings. The plane's creator says while the solar impulse is an example of the potential of solar power, it will never replace commercial flights.~The plane reaches a top speed of 43 mph and holds the altitude for solar-powered planes record at 30,300 feet. The Solar Impulse will first stop in Phoenix, and then head to Dallas, St. Louis, Washington, D.C., and New York. Each flight leg will take 20 to 25 hours, with 10-day stops planned in each city.