The Solar Impulse project team has announced the launch of Solar Impulse 2, a new single-seater solar aircraft designed to take up the challenge of the first round-the-world solar flight in 2015.

Solar Impulse initiator and chairman Bertrand Piccard, and Solar Impulse CEO and co-founder Andre Borschberg has launched the Solar Impulse 2. Piccard sourced partners to finance the Solar Impulse project and Borschberg brought together and led a technical team of 80.

For launching the Solar Impulse 2, it took 12 years of calculations, simulations, construction and testing. The solar aircraft has a wingspan of 236ft and weighs 5,000lbs. It has a cockpit measuring 3.8m³.

Solar Impulse 2 will have to fly without fuel, with only one pilot, for five consecutive days and nights over oceans from one continent to another to complete the round-the-world flight.

Test flights are due to take place in May 2014, followed by training flights over Switzerland. Solar Impulse 2 will be used to fly around the globe in March 2015 from the Gulf area.

"This is why the round-the-world flight will be as much a human as a technological feat."

Solar Impulse 2 will fly, in order, over the Arabian Sea, India, Burma, China, the Pacific Ocean, the US, the Atlantic Ocean and Southern Europe or North Africa before closing the loop by returning to the departure point.

Piccard said: "A vision counts for nothing unless it is backed up by action. With eight world records for Solar Impulse 1, the first solar aircraft capable of flying during the night, crossing two continents and flying over the US, we have shown that clean technologies and renewable energies can accomplish the impossible."

Borschberg said: "Solar Impulse 2 will have virtually unlimited autonomy, and now we need to make sure the pilot is as sustainable as his aircraft. This is why the round-the-world flight will be as much a human as a technological feat."