A solar-powered airplane that developers hope to eventually pilot around the world took off early on Friday from San Francisco Bay on the first leg of an attempt to fly across the United States with no fuel but the sun's energy.
The plane, dubbed the Solar Impulse, departed shortly after 6 a.m. local time from Moffett Field, a joint civil-military airport near the south end of San Francisco, heading first to Phoenix on a slow-speed flight expected to take 15 to 20 hours.
The spindly looking plane barely hummed as it took flight in the still northern California morning as the sun was just beginning to peek out over the Santa Cruz Mountains to the east.
After additional stops in Dallas, St. Louis and Washington, D.C., with pauses at each destination to wait for favorable weather, the flight team hopes to conclude the plane's cross-country voyage in about two months at John F. Kennedy International Airport in New York.
The project began in 2003 with a 10-year budget of 90 million euros ($112 million) and has involved engineers from Swiss escalator maker Schindler and research aid from Belgian chemicals group Solvay - backers who want to test new materials and technologies while also gaining brand recognition.
Project organizers say the journey is also intended to boost worldwide support for the adoption of clean-energy technologies.
/Reuters/