Photograph by J. Revillard/Solar Impulse

Solar-Powered Plane Soars Across the U.S.

  1. Test Flight
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    Test Flight

    The Solar Impulse began its American experience at NASA’s Moffett Federal Airfield in Mountain View, Calif. Before crossing the continent, the pilots of the Solar Impulse flew test flights over San Francisco, including this trip on April 23.

    Photograph by J. Revillard/Solar Impulse
  2. Focused Pilot
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    Focused Pilot

    Pilot Bertrand Piccard, a psychiatrist who was the first person to make a nonstop around-the-world balloon flight, concentrates in Hangar 2 at Moffett Airfield. He and project co-founder André Borschberg, an engineer and professional pilot, will share piloting responsibilities for the Solar Impulse.

    Photograph by N. Ackermann/Solar Impulse
  3. Night Flight
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    Night Flight

    On another test flight, the Solar Impulse flies over the Bay Area at night, allowing the pilots to test the battery, which is used to power night flights. There are more than 11,000 monocrystalline silicon solar cells fixed to the plane, which provide direct power to the four electric engines when the sun is shining. Any excess solar power is stored in the batteries for use at night.

    Photograph by J. Revillard/Solar Impulse
  4. Instrument Check
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    Instrument Check

    Piccard performs final checks before being closed into the cockpit for a test flight. Everything on the plane, including the flight instrumentation, has been designed to save energy.
    Photograph by N. Ackermann/Solar Impulse
  5. Ready for Take Off
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    Ready for Take Off

    The Solar Impulse just before takeoff at dawn on May 3 during its first leg—from San Francisco to Phoenix. Its takeoff speed is 27 miles per hour, with an average flying speed of 43 mph. The plane cruises at a maximum of 27,900 feet, compared with the average jet’s cruising height of 30,000 feet to 40,000 feet. As the Solar Impulse approached its landing in Phoenix, many locals mistook the plane for a UFO.

    Photograph by F. Merz/Solar Impulse
  6. Galvanizing Graduates
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    Galvanizing Graduates

    The stated purpose of the Solar Impulse team’s journey is not to make speed records—it’s to inspire others to lead in engineering discoveries and ideas to decrease our dependence on fossil fuels. The team of 90 included 30 engineers. Here, the pilots speak at the convocation at Arizona State University’s Fulton Schools of Engineering on May 9.

    Photograph by J. Revillard/Solar Impulse
  7. Ground Crew
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    Ground Crew

    After nearly three weeks in Arizona, the plane gets prepped for the second leg of its journey—from Phoenix to Dallas/Fort Worth.

    Photograph by J. Revillard/Solar Impulse
  8. Mission Control
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    Mission Control

    The idea of the Solar Impulse was born at the Mission Control Center in Payerne, Switzerland. The center reviews final details of the flight plan with the local air traffic controllers before the plane begins each leg of its journey.


    Photograph by N. Ackermann/Solar Impulse
  9. Plane Hanger
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    Plane Hanger

    The technicians and pilot get ready to roll the plane out of its hangar in Phoenix.

    Photograph by J. Revillard/Solar Impulse
  10. Pilots Blessed
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    Pilots Blessed

    An American Indian traditional healer blesses pilots Bertrand Piccard and André Borschberg before departure.

    Photograph by J. Revillard/Solar Impulse
  11. Dallas Landing
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    Dallas Landing

    The second leg of the plane’s journey ends with a safe landing in Dallas/Fort Worth on May 23. The Solar Impulse team tweeted: “The longest distance flight in the history of the project was a success!”

    Photograph by J. Revillard/Solar Impulse