Pilots aim for first solar-powered aircraft circumnavigation of globe

PUBLISHED : Friday, 20 June, 2014, 12:22pm
UPDATED : Friday, 20 June, 2014, 12:22pm

With a top speed of a mere 69km/h, it's not going to revolutionise the aviation industry at large, but the planned journey of Solar Impulse 2 is sure to make us all think twice about just how much energy it takes to fly.

Scheduled to traverse the globe over a period of about 20 days next year, the adventure by two Swiss pilots will cover a staggering 35,000km in a daring attempt to become the first to fly around the world without carrying fuel.

The only aircraft able to fly day and night without polluting, if Solar Impulse 2 does make it round the globe, it will become the first ever round-the-world solar flight.

It will be piloted by psychiatrist, balloonist and explorer Bertrand Piccard, and engineer and entrepreneur André Borschberg, who flew the first incarnation - Solar Impulse 1 - from California to New York City in 2012.

"It has taken 12 years of calculations, simulations, construction and testing to arrive at the launch of Solar Impulse 2 - the most revolutionary aircraft of our time," they say in a statement.

Not surprisingly, Solar Impulse 2 is little more than a huge solar panel. Its enormous 72-metre wings - longer even than those of a Boeing 747 - harvest energy from the sun using an incredible 17,000 solar cells. They provide four 17.5 CV electric motors with enough renewable energy to propel the Solar Impulse 2, which weighs about the same as an average car at 2,300kg.

During the flight, those solar cells recharge on-board lithium batteries that add a further 633kg. Thankfully, the Solar Impulse 2 is made from carbon fibre and is one of the most aerodynamic and energy efficient planes ever designed.

Test flights are already under way for next March's attempt, which will head east from Switzerland to the Arabian Sea then across India, Myanmar, China, the Pacific Ocean, the US, the Atlantic Ocean and then either Southern Europe or North Africa, before returning to Borschberg and Piccard's native Switzerland.

It won't be much fun. A 3.8 square metre cockpit is all Borschberg and Piccard will have for up to five days at a time, though they'll take turns to fly, so will be alone; Solar Impulse 2 is a single-seater aircraft.

Worse, the cabin is neither heated nor pressurised in order to conserve energy, so the journey's longest stretches - five days over both the Pacific and Atlantic Oceans - could get cold.

"Solar Impulse 2 will have virtually unlimited autonomy, and now we need to make sure the pilot is as sustainable as his aircraft," Borschberg says. "This is why the round-the-world flight will be as much a human as a technological feat."

But the pilots will get a break. Solar Impulse 2 will travel about 1,610km each day in its 20-day circumnavigation, but it's a feat that will be performed in stages over three months. In between flights Borschberg and Piccard will attend outreach events.

Even when it's flying, Solar Impulse 2 will be trying to inspire people. Search engine Google is Solar Impulse's official Internet Technology Partner, and during the solar circumnavigation the aircraft will have its Google+ URL google.com/+solarimpulse painted on the side.

"This partnership is a unique occasion to promote mutually shared values like pioneering spirit, innovation, engineering excellence and clean technologies allowing to protect natural resource," Piccard and Borschberg say.

"With Google on board, our reach with the public, younger generations, media and political and business decision makers will be significantly enhanced."

Expect some activity on YouTube, Google+, Google Glass and Google Earth, with Google Hangouts already confirmed to broadcast live during flights.