Solar Impulse 2 | An Idea Born In Switzerland

 Solar Impulse 2


Solar Impulse 2

Two Swiss men determined to explore the capabilities of solar power, André Borschberg, and Bertrand Piccard, share a vision. Today, on 3rd July 2015, they have demonstrated that you can fly an airplane longer with no fuel than you can with fuel. They wanted to achieve this historic first not so that they will appear in the record books, but for the sake of future expansion in the use of renewable energies. Today’s success has a history: Borschberg and Piccard’s prototype Solar Impulse 1 made the first manned solar-powered flight of 26 hours in 2010. Borschberg’s landing of Solar Impulse 2 in Hawaii today five years later, after five days and nights alone in the cockpit, is a new landmark in aviation history. 


Solar Impulse 2, or Si2, runs on solar power alone. Made of carbon fiber, it weighs around 2300 kilograms, about the same weight as a pick-up truck. Its 72-meter wingspan is equivalent to that of six albatross, birds with the widest wingspans on earth, wider than that of a jumbo jet and only slightly less wide as compared to the world's biggest traveler plane, the Airbus A380. 17,000 solar cells are charged by the Sun and power the plane’s electric motors during daylight hours and charge the lithium-ion batteries which sustain the plane during hours of darkness. Borschberg was alone in the cockpit where he could rest for only twenty minutes at a time. He was in constant communication with his team; oxygen levels in his blood were monitored throughout, and an armband vibrated to wake him from his rest periods. Despite all this, he still managed to maintain his mental stamina by yoga exercises, something he usually practices in his garden on the shores of Lake Geneva.


Hawaii marks the end of the eighth leg of 13 planned to circumnavigate the globe, but this was by far the riskiest. It was a ‘no-fail zone’: failure would have meant the death of the pilot as well as the dream. If the plane had run into trouble, there was no possible landing place for Borschberg to head for. Besides, at 7200 kilometers, this leg was by far the longest. None of the previous seven had exceeded 44 hours 9 minutes; this one across the Pacific Ocean from Nagoya in Japan to Kalaeloa in Hawaii took 117 hours and S2 minutes, just under five continuous days and nights, far longer and far further than any solo fuelled flight. The previous record set by the American adventurer Steve Fossett of 76 hours 45 minutes for a fuelled non-stop flight has held since 2006. What Borschberg calls his ‘interior journey’ has made new world records. ‘I feel exhilarated,’ he said after his safe landing. ‘I’ve climbed the equivalent altitude of Mount Everest five times with very little rest. I’m astonished that I don’t feel particularly tired. The Support I had during the flight from those on the ground gave me so much energy-but I’d sure enjoy a shower and a steak!’ 


The si2 website live-streamed the event throughout. On the night before he landed Borschberg’s upbeat log played down the real danger, ‘Beautiful. I am watching the full moon and the Sun from one place! Si2 is entering its most critical night so far; it is flying further South than in the past days, nights are longer ... Too bad the shining moon can’t charge the batteries!’ The support team knew that just as Borschberg must be tiring at the end of the flight, his vigilance and concentration were needed more than ever. They logged, ‘By the end of the night we expect the batteries to run down to 10% of charge, the lowest we’ve ever experienced. He can't allow the batteries to run down before the Sun begins to charge the sun based generators! We’re pushing the plane and pilot to their limits.’ But this morning at 5.55 a.m. Hawaii local time, like some gigantic mythical bird, Si2 made a gentle descent, and 62-year-old Borschberg tweeted ‘Just landed in Hawaii with Solar Impulse! For Bertrand Piccard and me, it’s a dream coming true.’ 


The next leg from Hawaii to Phoenix, Arizona will be piloted by Borschberg’s partner Piccard. Although at 4700 kilometers it is not as long as the previous flight it will still take four days and nights. From Phoenix, Si2 will head for New York, cross the Atlantic, fly over either Southern Europe or North Africa, and return to Abu Dhabi where it all started, thus completing the first zero-fuelled circumnavigation of the globe. When this next leg will begin depends on the mechanical team completing their tricky task of finding a suitable flight window. The plane’s slow speed, lightweight, and massive wingspan restrict the type of weather it can handle. Before he could continue to Hawaii, Borschberg had been held up for a month in Nagoya, where bad weather had forced an unscheduled stop. Even then he had to risk crossing two weather fronts and suffered some violent turbulence. 


The landing furthers Si2’s larger mission: to make zero-fuel airplanes a future reality. Although their art no plans to bring a solar-powered airplane to the passenger industry anytime soon, Si2 presents a possible alternative to our current fuel-guzzlers. Environmentalists have long criticized aircraft manufacturers for their products’ heavy use of fuel and have called on agencies around the world to seek new ways to power aircraft. Si2’s successful flight is a very real beginning.