Solar Impulse 2 makes the first solar-powered Atlantic flight

Solar Impulse 2 has made history yet again. Earlier this month it finally completed the US leg of its "around the world" journey bourne on solar-powered wings. From New York, where it made a pit stop last June 11, it has now landed in Seville, Spain. This makes it the first solar-powered aircraft to cross the Atlantic ocean, in the tradition of the first voyages from Europe to the Americas and back. But as historic as the achievement is, the feat of the pilots themselves are equally impressive.

Solar Impulse 2 set on a course to travel around the globe on nothing but solar power, and, of course, batteries charged with solar power, in March last year, taking off from Abu Dhabi on an Eastward route. Along the way it had some difficulties but many notable victories as well, like cross the Pacific from Nagoya to Hawaii, recorded as the longest single solo flight which lasted 117 hours, nearly 5 days, over a near 9,000 km distance.

The plane's almost painfully slow speed is due to the nature of its power source. Although its wings span wider than a Boeing 747 in order to accommodate as many solar cells. During the day, it both powers the engines and charges four 41 kWh batteries which, in turn, power the plane at night. Top speeds reach 90 km/h during the day but dips to 60 km/h after sundown. Under those conditions, especially since the solar panels can't fully charge the batteries while in-flight, a non-stop flight isn't yet possible.

Not that any pilot would want that anyway. The Solar Impulse 2 actually has 2 pilots, Bertrand Piccard and André Borschberg, that take turns. Piccard made this transatlantic flight, making it his longest single flight journey. Borschberg, however, had the honor of making the Japan to Hawaii flight, a world record. And possibly an excruciatingly uncomfortable experience. To save energy, the plane can only accommodate one pilot and the cabin is unheated and unpressurized. The pilot can only take about 20 minute naps during the whole flight. One can only imagine the torture pilots had to undergo to make the journey.

So why do it at all? It's not like the Solar Impulse 2 will ever become a passenger plane. The goal, says Piccard, is not revolutionize aviation but to actually advertise and encourage the use of renewable energy and the extremes it can be used for. That fact that you can also rack up world records and feats is definitely a bonus.