Solar Impulse is basking in the success of the first international flight of its solar-powered aircraft, and aims to operate either a transatlantic or round-the-world flight with an upgraded version of the prototype in 2014.

The company's HB-SIA prototype took off from Payerne air base in Switzerland at 08:40 local time on 13 May, piloted by Solar Impulse CEO and co-founder André Borschberg. It landed nearly 13h later on Brussels Zaventem airport's Runway 02.

Solar Impulse
 © Solar Impulse

Borschberg described it as a "beautiful flight", following some "hectic times at the beginning" as he faced some fog on the ground and heavy air traffic due to a NATO military exercise. "The cruise flight was very smooth and I collected more energy than I needed," said Borschberg, adding that the flight to Brussels used the same amount of energy as "a small scooter".

The four-engined aircraft, which has a 64.3m (211ft) wingspan and weighs 1,600kg (3,525lb), is powered by 450kg of lithium ion batteries.

HB-SIA reached an altitude of flight level 120 during the flight and flew "more or less" a standard route to Brussels, said Borschberg. "The flight proved that despite the fact that it's a prototype, it can really fly to a destination and the technology works."

Solar Impulse's next project, after displaying the prototype at the Paris air show in June if weather conditions are favourable, is to develop a bigger aircraft to either fly across the Atlantic or circumnavigate the globe.

Test flights with HB-SIB are expected to begin in 2013, with the longer flight scheduled to take place the following year. To be able to fly over oceans, the second prototype will "need an autopilot and a different cockpit" to make the flight "more comfortable for the pilot", said Borschberg.

Source: Flight International