Unable to abandon a fascination with all things that fly, I call your attention to a Swiss airplane that is flying on a 24-hour hop as I type—and using zero fossil-based avgas. The airplane is an ultralight, single pilot aircraft with the wingspan of an airline passenger jet. The wings are covered in solar panels charging about 1,000 pounds of batteries spinning four propellers.
Ultimately, the aircraft may undertake a round-the-world powered only by the sun. Earlier today the pilot reported shutting down the solar recharging system because it was working too well. The airplane climbs as high as possible during daylight hours and glides at lower power settings and a slight rate of descent at night. It’s a proof of concept project that will not by commercially manufactured.
It would be interesting to someday see the Solar Impulse hanging in the Smithsonian Air&Space Museum next to Burt Rutan’s Voyager. Here is more information, photos, videos and regular updates about the flight.
They did it! The Solar Impulse landed safely this morning completing a 26-hour flight powered by solar energy.