The Solar Impulse takes off from Moffett Field NASA Ames Research Center in Mountain View, Calif., Friday, as a team member rides an electric bike alongside the plane. AFP/AFP/Getty Images hide caption

itoggle caption AFP/AFP/Getty Images

The Solar Impulse, a solar-powered plane, flies over Switzerland. The makers will be journeying across the U.S. this spring, hoping the flight helps challenge assumptions about what solar technology can do. Courtesy of Solar Impulse hide caption

itoggle caption Courtesy of Solar Impulse