After the Solar Impulse prototype broke 8 world records for solar-powered flight, creators Borschberg and Piccard knew it was time to tackle the next big challenge: a trip around the entire planet. In order to do so, they had to build a bigger, badder Solar Impulse to withstand the increased difficulties of a such an arduous trip.
Drawing upon years of design, complex simulations and test flights with the ﬁrst prototype, the Solar Impulse 2 features a range of impressive new technologies, many of which were designed specifically for the aircraft. “Solvay has invented electrolytes that allow the energy density of the batteries to be increased; Bayer MaterialScience is allowing the project to make use of its nanotechnologies; and Décision is using carbon fibers that are lighter in weight than any previously seen,” explains the Solar Impulse website.
The Solar Impulse 2 sports a massive 236 foot wide wingspan–wider than that of a Boeing 747 Jumbo Jet–yet it weighs about the same as a mid-sized car. The giant wings (as well as the fuselage and horizontal tailplane) are covered in 17,248 monocrystalline silicon solar cells that are each only 135 microns thick. Harvested solar energy will be stored in lithium polymer batteries which are insulated by high-density foam and mounted in the four engine nacelles, along with a system to control charging thresholds and temperature. Those batteries will serve to power the plane’s four 17.5hp engines, allowing for a minimum speed of 20 kts (about 22mph) at sea level and 31.5 kts (about 35 mph) at maximum altitude.
Needless to say, it’s not going to be a quick trip. That’s why Borschberg and Piccard will share the duties of pilot, taking turns at each stop. Even when not controlling the Solar Impulse 2, each will have to overcome the human challenge of sitting for several days in a row in a unpressurized and unheated cockpit. That’s a big reason why the plane features a multi-purpose seat built to function as both a reclining berth and toilet. A parachute and a life-raft are packed into the seat-back. When fully reclined, the special seat allows the pilot to perform physical exercises.
Despite the challenges–technical, physical, and mental–of making such a revolutionary trip, the team behind the Solar Impulse 2 is enthusiastic. “Just imagine your energy reserves increasing during flight! To make this dream a reality, we had to make maximum use of every single watt supplied by the sun, and store it in our batteries. We tracked down every possible source of energy efficiency. By tapping into each team member’s experience and using the combined potential of them all, we managed to find the solutions,” said Borschberg.
On Thursday April 10 at 6:45 PM CET, Co-Founders & Pilots of Solar Impulse Bertrand Piccard and André Borschberg will host a guided tour of the airplane while wearing Google Glasses. Join the Hangout On Air “Walk Around Solar Impulse 2″ to see even more of this incredible plane.
All images © Solar Impulse and Jean Revillard/Rezo.ch