Breaking Energy recently spoke with Solar Impulse co-founders Bertrand Piccard and André Borschberg about their ambitious goal to fly around the world in a solar-powered airplane that uses zero liquid fuel and can fly through the night.

A major milestone along the path to that goal will be reached in the coming weeks when Solar Impulse flies from San Francisco (Moffett Airfield) and stop in four US cities including Phoenix, Dallas Fort Worth and Washington D.C. before reaching New York’s JFK airport, its final destination in early July.

“We want to show that with clean technologies, a passionate team and a far-reaching pioneering vision one can achieve the impossible,” said Bertrand Piccard, Solar Impulse Initiator, Chairman and pilot in a statement.

“A flying laboratory for clean technologies, this prototype is the result of seven years of intense work in the fields of materials science, energy management and man-machine interface. Many of these technologies can also be applied to sectors beyond aviation,” André Borschberg, Solar Impulse co-founder, CEO and pilot said in the same statement announcing the flight path and schedule.

The extremely lightweight plane is susceptible to windy turbulent conditions so the flights must be attempted during optimal fair weather windows, thus the schedule is flexible.

The “Across America” mission at a glance:

• Early May 2013: First leg San Francisco/Moffett Airfield – Phoenix/Sky Harbor
• Mid May 2013: Second leg Phoenix/Sky Harbor – Dallas/Fort Worth
• End May – Early June 2013: Third leg Dallas/Fort Worth – stopover city TBD
• Mid June 2013: Fourth leg stopover city TBD – Washington DC/Dulles
• Early July 2013: Fifth and last leg Washington DC/Dulles – New York/JFK