Captain Piccard's planet-orbiting solar aircraft in warped drive drama

An airplane powered by nothing more than the Sun's rays has completed its 42,000-km (26,098-mile) journey around the world after landing in Abu Dhabi on Tuesday.

The Solar Impulse 2, piloted by Bertrand Piccard for its final leg, made the trip in 17 legs, flying around the Northern hemisphere with stops in nine countries. Its total flying time was 509 hours 29 minutes to make the trip.

"This is not only a first in the history of aviation; it's before all a first in the history of energy," said Piccard [PDF].

"I'm sure that within 10 years we'll see electric airplanes transporting 50 passengers on short- to medium-haul flights. But it's not enough. The same clean technologies used on Solar Impulse could be implemented on the ground in our daily life to divide by two the CO₂ emissions in a profitable way."

Maybe, or more likely maybe not. The entire trip took 505 days to complete, with the delays mainly due to it having to wait for good weather before taking off and the entire mission had to be put on hold to allow for repair work to be carried out.

When Solar Impulse 2 flew from Japan to Hawaii it not only broke the record for the longest solar-powered flight (117 hours, 52 minutes) but also its batteries, which overheated and broke down while in the air. New ones had to be built and shipped out to the aircraft before it was allowed to proceed by the US Department of Transportation.

The aircraft has its upper body coated in solar panels and uses them to charge a bank of batteries that make up a large chunk of its payload. The aircraft uses four electric motors to reach cruising speed of 90km/h (56mph) and has a maximum ceiling of 12,000 metres (39,000 ft).

When nightfall comes and the sun's power is lost, the batteries are enough to keep the aircraft aloft, although it descends to lower altitudes as well to save on power. In this way the aircraft was able to stay aloft for days at a time.

The whole point of the 13-year project was to prove the point that solar power is viable, but it's not going to change the aviation industry much based on this particular aircraft. To save weight the aircraft was unpressurized, leaving the pilots needing supplementary oxygen canisters, and the cockpit was just 3.8 cubic meters in size.

"This is a historic day for Captain Piccard and the Solar Impulse team, but it is also a historic day for humanity," said the UN Secretary-General Ban Ki-moon.

"You may be ending your around the world flight today, but the journey to a more sustainable world is just beginning. The Solar Impulse team is helping to pilot us to that future." ®