Yesterday’s taxiing test was performed to test the plane’s handling under power on the tarmac. Because of the plane’s extraordinary size to weight ratio, every aspect of its performance characteristics need to be examined. An ultralight single-seater, the Solar Impulse has a wingspan equal to the Airbus 380 airliner but only weighs 1600 kg (3527 lbs).

The initial taxiing test was conducted using a security trolley device under the cockpit to protect the craft in case the landing gears broke, and groundspeed was limited to 5 knots (approx. 6 mph). But a follow-up test will be carried out without this device. The team will also try to double the taxiing speed to 10 knots.

The maiden flight, scheduled for February 2010, is expected to last 2 hours. But the Solar Impulse should actually take to the air for the first time in a few weeks during a ‘flea hop’ flight to test the plane’s take-off performance. Similar to the initial flight of the Kitty Hawk in 1903, next week’s flight test of Solar Impulse will hopefully see the plane take to the air only a few meters above the ground and fly only a short distance. If results from this test are satisfactory, the Solar Impulse will be dismantled and moved to another base in Switzerland for the February maiden flight.

The Solar Impulse is designed as a single-seat long-range solar plane capable of remaining airborne for days. Once the efficiency of the batteries makes it possible to reduce the weight, a two-seater is planned to make circumnavigation possible. Circumnavigation of the globe is anticipated to take 20-25 days.

Piloted by Swiss adventurer Bertrand Piccard, Solar Impulse is expected to make its first non-stop 36 hour flight through darkness in spring of 2010, and in 2012 it will make a five stage flight around the world. Developers hope that the success of the Solar Impulse will add a new chapter to the history of aviation, with the capability of solar-powered flight which requires no fuel and produces no pollution.