Andre Borschberg (left), Solar Impulse co-founder, CEO and pilot, greets pilot Bertrand Piccard at Sky Harbor International Airport in Phoenix early on Saturday, May 4, 2013, after Mr. Piccard completed the first leg of the Solar Impulse aircraft's coast-to-coast flight. (AP Photo/Scuteri)

Photo by: Rick Scuteri

Andre Borschberg (left), Solar Impulse co-founder, CEO and pilot, greets pilot Bertrand Piccard at Sky Harbor International Airport in Phoenix early on Saturday, May 4, 2013, after Mr. Piccard completed the first leg of the Solar Impulse aircraft's coast-to-coast flight. (AP Photo/Scuteri)