Andre Borschberg

Solar Impulse 2, a solar powered plane piloted by Swiss aviator Andre Borschberg, is seen as it prepares to land while the ground crew follow on bicycles at Cairo Airport

Amr Abdallah Dalsh/Reuters

Solar Impulse 2, a solar powered plane piloted by Swiss aviator Andre Borschberg, is seen as it prepares to land while the ground crew follow on bicycles at Cairo Airport, Egypt on Wednesday.

Solar Impulse, piloted by AndrĂˆ Borschberg, takes flight during the second leg of the 2013 Across America mission, at dawn, Wednesday, May 22, 2013, from Sky Harbor International Airport in Phoenix. The solar powered aircraft is scheduled to land at Dallas/Fort Worth International Airport on Thursday May 23. The plane's creators, Bertrand Piccard and Borschberg, said the trip is the first attempt by a solar airplane capable of flying day and night without fuel to fly across America. (AP Photo/Matt York)

Matt York/AP

Solar Impulse, piloted by AndrĂ© Borschberg, takes flight during the second leg of the 2013 Across America mission at dawn on Wednesday from Sky Harbor International Airport in Phoenix, Arizona.