Flying in the dark on solar energy

Crew of QNX-equipped Solar Impulse plane gears up for historic flight.

The Solar Impulse 2, aka SI2
Source: Solar Impulse

The countdown has begun. On Monday, March 9, the Solar Impulse 2, a one-of-a-kind airplane that runs exclusively on solar power, will take off from an airport in Abu Dhabi. The destination? Abu Dhabi!

That’s right, this is a round trip — but not just any round trip. It is, in fact, the first attempt to fly around the world using only the power of the sun. On board will be André Borschberg, the former jet pilot who, together with Bertrand Piccard, cofounded the Solar Impulse project 12 years ago. (Piccard’s name may ring a bell — as well it should. In 1999, he became the first person to complete a non-stop balloon circumnavigation of the earth.)

The Solar Impulse can fly at night, using energy stored in its lithium-ion batteries. But it’s no fly-by-night operation. Borschberg and Piccard have spent the last 12 years on this project and have set 8 world records in the process, including longest uninterrupted flight (26 hours, 10 minutes) and highest altitude (9235 meters) for a solar-powered plane. That’s pretty impressive, but then, everything about this plane is remarkable, from the wingspan (72 meters) to the number of voltaic cells (17250) that power its electric motors.

Solar Impulse bootup screen. Screen-grab from video.

The human element is equally impressive. To cross the Pacific or Atlantic ocean, the plane, which has a cruise speed of 90  km/h, will need to stay airborne for about 5 days, nonstop. And that means the pilot also needs to stay airborne for 5 days, in an unheated, unpressurized cabin with temperatures ranging from -40°C to +40°C. Yes, the pilot is allowed to take naps, but only 6 a day, each lasting 20 minutes. Not surprisingly, both pilots (Borschberg and Piccard will each take turns flying the plane), have learned self-hypnosis and meditation techniques to help them enter and exit deep sleep as quickly as possible. The plane can accommodate only one pilot at a time, and the team plans a total of five stops to allow changes of pilots.

As mentioned in previous posts, QNX Software Systems is the official realtime OS partner for the Solar Impulse team, and the plane uses the QNX Neutrino OS for several control and data communication functions. So, as you can imagine, come next Monday, my browser will be tuned to the Solar Impulse website. I hope yours will, too.

Until then, here's a “making of” video of the Solar Impulse 2. Enjoy.