The current aircraft HB-SIA is effectively the prototype for the craft that will eventually be used for transoceanic flights and the round-the-world trip.

BBC: Solar Impulse plane lands in Phoenix

Almost a decade later, those trains were a huge part of why I gave notice at my law firm to do a round-the-world trip, but over the years, my fantasy trip to Siberia had morphed into a trip to... everywhere.

BBC: How I quit my job to travel: The corporate lawyer