Can a solar airplane circle the globe?

In earlier days of aviation, flying around the world was the ultimate test of pilots and new aircraft and now in the days of alternative-fueled aviation, it seems that test remains the ultimate challenge.  Bertran Piccard, the pilot of the first nonstop, round-the-world balloon flight, hopes to achieve that goal in a solar-powered airplane called the Solar Impulse.

The Solar Impulse design was first unveiled in late 2007, but now a working prototype has been developed.  The plane will get a chance to take its first test flight at the end of the year.  The test flight will consist of flight sequences over two days and one night.  If successful, the team will start preparing for the round-the-world flight.

The Impulse is made of carbon fiber, has a wingspan of 63 meters and is covered in 12,000 solar PV cells.  The power generated by the solar cells is stored in over 400 kg of batteries, which allow for flying at night.  The plane is propelled by four ten-horsepower electric motors.  It can't reach great speeds, meaning circling the globe will take a long time, but if it accomplishes such a feat, we'll know that solar-powered air travel (as well as other types of transportation) could have a real future.

via Inhabitat