Solar Impulse is a solar powered vehicle as never seen before. Aviation pioneers Bertrand Piccard and André Borschberg managed to create a solar plane so ingenious that it can stay in the air pretty much perpetually. It is the power of the sun that powers their amazing airplane and the Solar Impulse is capable of breaking all the aviation records out there. And that is exactly what they are doing…

Solar Impulse HB-SIA prototype airplane attends his first flight over Payerne

Solar Impulse flies across the USA

Solar Impulse has completed the historic crossing of the United States, west to east, over a 2-month period in the summer of 2013. On the footsteps of aviation pioneers like the Wright brothers and Charles Lindbergh, Bertrand Piccard and André Borschberg underwent the coast-to-coast challenge to spread a message. By flying from San Francisco to New York powered solely by the sun, the two pilots were on a mission to demonstrate what can be done with the spirit of innovation and with clean technologies.


The Across America transcontinental bid began in San Francisco in early May 2013 – at a top speed of 70km/h (45mph). It included stopovers in Phoenix, Arizona, Dallas-Fort Worth, Texas, and St Louis, Missouri.

The Solar Impulse HB-SIA has the same wingspan as an Airbus A340 but at a weight of just 1.6 tonnes. By comparison, a fully laden A340 weighs about 370 tonnes.


Solar impulse’s technical specs:

  • Wingspan – 63m (208ft)
  • Weight – 1,600kg (3,500lb)
  • Covered with 11,628 solar cells
  • Carries 400kg (900lb) of lithium-ion batteries
  • Maximum cruising altitude of 8,500m (28,000ft)

The plane’s wing and stabiliser are covered with nearly 12,000 solar cells, which drive its four propellers and charge the plane’s 400kg of lithium-ion batteries for night-time flying. The project has been billed as the first time that a solar-powered plane capable of flying day and night has attempted a journey across the US.


Andre Borschberg and his fellow pilot Bertrand Piccard have been alternating flying duties on the single-seat craft, with each leg of the trip designed to be under 24 hours in length.

The prior leg was complicated by high winds and air traffic, so it was re-routed via Cincinnati at the last minute in order to stay under this limit.
“It was difficult to find all these ‘weather windows’ in the States – especially this last one,” Mr Borschberg told BBC News prior to the flight. “We had so much to organise to make it feasible – to integrate an experimental airplane like Solar Impulse in the busiest air traffic in the world, flying from Washington to Kennedy (airport) was extremely hard.”


A Solar Impulse Round the World Trip?

The Across America project is the last outing for the HB-SIA prototype craft. Piccard and Borschberg’s intention is to finish a larger, two-seat plane, the HB-SIB, and fly it around the world in the spring of 2015. This would make it the second solar powered round the world (RTW) trip after the SOLARTAXI drove around the world on sun power only in 2008.

UPDATE 2016: the solar impulse round the world trip has become reality. Read all about it here.

“The unpredictable side of the project requires a lot of preparation.”
The HB-SIA craft carried out the first inter-continental flight in 2012 and holds the world record for the longest manned solar-powered flight at 26 hours. During the Across America bid, it set the record for the greatest distance of a manned solar-powered flight.


The project coincides with Piccard’s and Borschberg’s Clean Generation Initiative, an effort to encourage policy-makers and businesses to develop and adopt sustainable energy technologies.

This year’s mission was made possible thanks to the support of Solar Impulse  partners Solvay, Schindler, Bayer MaterialScience, Swiss Re Corporate Solutions, SunPower, and the Swiss Confederation all partners in the RTW fly attempt as well.

If you are looking for more details of this kickass flight here is the “Across America” mission at a glance: