U.S. Department of Energy

    Swiss Solar-Powered Plane Makes its Maiden Flight

    April 14, 2010

    Photo of a wide-winged aircraft, with a thin long fuselage, soaring in the sky with mountains in the background.

    The Swiss solar-powered aircraft Solar Impulse makes its maiden flight in Switzerland.
    Credit: ┬ęSolar Impulse/Reuters/Christian Hartmann/pool

    A solar-powered aircraft took its maiden flight on April 7 in Switzerland, achieving the latest milestone in a project that aims to launch a zero-emission flight around the world in 2012. Solar Impulse HB-SIA, a lightweight prototype with the 208-foot wingspan of a Boeing 747-400, climbed to just under 4,000 feet during its 87-minute flight. The aircraft has nearly 12,000 silicon mono-crystalline solar cells on its wings and on its horizontal stabilizer, and those solar cells provide power to the craft's four electric engines. A test pilot put the craft through a series of maneuvers before safely landing the Solar Impulse at an airstrip. Solar Impulse chairman and co-founder Bertrand Piccard noted that the project had taken an important step with the recent achievement, although the team still has far to go before it is able to fly a craft all night in preparation for the around-the-world flight.

    Piccard, who was the first to pilot a balloon non-stop around the globe, initiated the Solar Impulse Project in 2003. The co-founder has since been joined by a team that includes multi-disciplinary scientists and advisers from a number of countries. In December 2009, the Solar Impulse completed a short inaugural takeoff-and-landing at an airport in preparation for this initial extended flight. Solar Impulse backers plan further testing of this model, which relies on minimal instrumentation and an unpressurized cabin. The next major goal is to make a 36-hour flight, which would require the addition of lithium-polymer batteries for night flight. Following that, a second aircraft, Solar Impulse HB-SIB, will be developed to attempt several consecutive 24-hour flight cycles. Success in those trials would enable the Solar Impulse to attempt its first trans-Atlantic crossing, currently scheduled for 2012. Meeting that benchmark would clear the Solar Impulse for an around-the-world solar journey. See the Solar Impulse press release and the flight video.