During their presentation, Piccard and Borschberg also chatted a bit about their next big challenge, a solar-powered flight around the world in 2015. You see, the current Solar Impulse aircraft is merely a test mule, that has allowed the pair to learn much about solar powered flight. However, there have been advances in materials science, battery technology, electric motors and production processes since the plane first flew over three years ago. So, the new plane will have a larger cockpit that's "at least as comfortable as business class," according to Borschberg, to make the longer journey easier on the pilots. You see, because the current plane is so uncomfortable, it's only suited for being piloted for 24 hours or so continuously. By comparison, the aircraft destined to circumnavigate the globe will be flown for five full days at a time.

Of course, that begs the question: exactly how will Piccard and Borschberg be able to pilot a plane for a full workweek without sleeping? Well, Piccard fights fatigue through auto hypnosis, while Borschberg utilizes meditation to rest his mind and body. In preparation for the grueling global journey, they are also spending time in flight simulators to test out resting strategies (i.e. short naps) as the limits of the human body to do without sleep tops out around 36 hours. And, folks leery of having an unmanned solar plane flying overhead needn't worry -- the pilots will only be micro-napping while flying over oceans, not over land.