A solar-powered plane is flying from Arizona to Texas on the second leg of a trip across the United States.
The Solar Impulse is making the first attempt by a solar airplane capable of flying day and night without fuel to fly across the U.S.
The plane took off from Phoenix's Sky Harbor International Airport at 4:47 a.m. MST Wednesday and is scheduled to arrive in Dallas early Thursday morning.
From the ground, it looks like any other aircraft, but moments later, you notice it's not moving very fast.
"It's about 21 hours of flight. It's going to be a difficult flight because there is fairly strong winds," said Betrand Piccard.
We have dense prep the last few days. Weather is not totally straightforward, especially the arrival in Dallas," said Pilot Andre Borschberg.
Borschberg is 1 of the plane's creators along with Piccard.
The solar plane is a one pilot machine and is powered by the suns rays and four 10 horsepower electric engines.
It only moves about 40 miles per hour at about 28 thousand feet in altitude, but the wing span is huge. It's the same as a Boeing 747 jet, with solar panels resting on the wings.
The goal is to inspire others to be pioneers in renewable energy.
"It's a big responsibility for us..also to stand to the level of the expectations and to really promote this message which is so important for the future," said Piccard.
The plane flew its first leg from California in early May. From Dallas, it will fly to Lambert-St. Louis airport, Dulles airport in near Washington and New York's John F. Kennedy airport.
Each flight leg takes 20 or so hours, with multiday stops in each city.
Copyright 2013 The Associated Press modified.