Solar Impulse Breaks Record for Distance by Solar Powered Flight

Completing the second leg of its record-breaking transcontinental journey, the Solar Impulse airplane landed safely in Dallas, Texas Thursday, setting a new distance record for solar-powered flight.

The safe landing completes the second phase of the "Across America" campaign to promote the possibilities of flight with renewable energy sources. Solar Impulse takes to the air using only energy derived from its solar panels.

While it's breaking records in the realm of solar flight, Solar Impulse is not winning any awards for airspeed; it can only fly at an average of 43 mph. After 18 hours, 21 minutes and 958 miles (1,541km), Solar Impulse landed in Dallas amid challenging windy conditions.

Project co-founders and pilots, Bertrand Piccard and Andre Borschberg, alternate turns flying the plane; the second leg was flown by Borschberg, who told the BBC that latest journey was the longest distance flight ever flown by a solar airplane. He said the lack of autopilot makes the long-haul flight quite taxing on the body.

Of Swiss design, the single-seater airplane weighs about as much as a car and has the wingspan of a Boeing 747, plenty of room to house the aircraft's 12,000 solar cells.

By day, the solar cells power plane's electric motors while also charging batteries, meaning Solar Impulse - unlike other solar-powered aircraft - can fly at night.

Solar Impulse first took off May 3 from an airfield outside San Francisco for a journey to Phoenix, Ariz.. After a two week layover, the aircraft took the sky again for an 18-hour flight from Phoenix to Dallas. The journey will continue as Solar Impulse next flies to St. Louis, then to Washington, D.C. and finishing the journey in New York City.