Epic solar flight family's latest adventure

Bertrand Piccard, left, will share flying duties across the United States with Solar Impulse co-founder Andre Borschberg. Photo / AP

Some might say Bertrand Piccard has adventurer in his genes. His father, Jacques, was one of the first people to explore the Challenger Deep, the deepest part of the world's oceans. And his grandfather Auguste - the inspiration for Professor Calculus in Herge's Tintin comic books - set records for exploring the highest reaches of Earth's atmosphere in his pressurised gondola balloon.

Now, Bertrand Piccard is looking to add a new record to the family mantelpiece by flying a jumbo jet-sized plane powered solely with energy from the sun across America.

The attempt is part of the initial stages of Piccard's lifelong dream to see a solar-powered plane fly around the world by 2015.

Clear skies permitting, his Solar Impulse HB-SIA plane is due to take off any day from Nasa's Silicon Valley research airbase for a test flight, before undertaking a five-stop flight across the United States starting on May 1 and taking in Dallas, Phoenix, Atlanta or St Louis, Washington, DC, and finally New York.

"When I was a child I saw my father diving to the deepest point in the ocean with the US Navy," explained Piccard, a Swiss national and a psychiatrist by trade, in the latest promotion video on his website.

"That was my first inspiration. Today with scientific exploration I want to inspire others also to achieve the impossible thanks to pioneering spirit."

At first glance, Piccard's plane is a behemoth with a wingspan of 63m - 4m more than a Boeing 747. But unlike a jumbo jet, which comes in at more than 300 tonnes, the Solar Impulse weighs just 1600kg, about the same as a family car.

Engineers have had to shave every last gram of extraneous weight off the carbon-fibre frame because the entire aircraft is powered by four solar-powered motors putting out the equivalent horsepower of a scooter.

To keep weight down, the pilot has no heating and no pressurisation in the cockpit and the aircraft is acutely vulnerable in bad weather.

But the combination of huge wingspan and featherweight design has allowed Solar Impulse to do something no other sun-powered plane has yet managed to do - absorb enough energy in the day to carry on flying through the night.

As long as skies are clear, the only thing that can technically stop the Solar Impulse flying is the staying power of its solo pilot.

Piccard will share flying duties with a Swiss businessman and co-inventor Andre Borschberg, who flew into the record book two years ago with an earlier version of the plane after completing the first 24-hour solar-powered flight.

With a maximum speed of 80km/h, each leg of the five-stop journey across America is expected to take more than a full day and the team will rest for around 10 days in between stops to raise awareness about renewable energy.

Given the weight limits, solar powered aircraft are unlikely to replace traditional fuel-powered airliners any time soon, but Piccard and Borschberg's invention has already stoked interest among drone manufacturers who are looking for ways to increase flight times for the unmanned aerial observational vehicles.

In order to fly around the world successfully, the Solar Impulse team needs to create an aircraft that can operate in cloudy weather.

They are already working on a successor - the HB-SIB - to do just that.

If the flight across the United States is a success, the team hopes to fly around the world in this new plane in 2015.

Solar Impulse HB-SIA

5-stop flight across the US in May
80km/h speed
63m wingspan
1600kg weight

-Independent