Volkswacht Bodensee - Pioneer spirit drives Swiss solar-powered plane altitude attempt

The SolarStratos electric plane took off from Sion airport in the Rhone valley in southwestern Switzerland at 1:21pm, in the hope that conditions higher up would prove favourable for record-chasing.

But it soon became clear that the rising warm air thermals Domjan needed to boost the ascent were not there, and it was better to save energy and try again another day -- all in the pioneer spirit, according to the adventurer.

The wildfires in neighbouring France were likely among the reasons why the forecast conditions had changed.

Domjan touched down 38 minutes later, deciding to preserve the charge in the batteries with a view to another go on Sunday or Wednesday, when the baking hot conditions look more promising.

"The flight was good but we didn't find any thermals," he told AFP after opening the cockpit and taking off his helmet, sweat rolling down his cheeks.

"We really needed to find something to climb... the sun was there but not the thermal activities.

"It was clear that it would not work. We tried."

- 10,000-metre challenge -

Domjan is aiming to get to 10,000 metres or beyond -- flying at the same altitude as airliners. Such a flight would take at least five hours.

"It's more difficult than expected," said the 53-year-old, who describes himself as an "eco-explorer" committed to climate protection.

"That's why we are the first to go there," he said, adding: "We try because it's difficult."

A warm-up flight on July 31 got to 6,589 metres -- the highest-ever for SolarStratos.

The propeller plane, made of carbon fibre, is 9.6 metres (31 feet and six inches) long. It has a huge wingspan of 24.8 metres to accommodate the 22 square metres of high-spec solar panels topping the wings.

The current altitude record for a solar plane stands at 9,235 metres, set in 2010 by the Solar Impulse experimental aeroplane, flown by Swiss pilot Andre Borschberg.

"We'll try and try until we go to 10,000 metres, or it's the winter when there is no sun and we cannot try anymore," said Domjan.

On Friday, Domjan reached 1,769 metres but quickly decided there was no point draining the batteries looking for thermal currents that were not going to show.

The slow-charging plane will be parked back out in the sun to fill the batteries for next time.

- Hanging in the sky -

Domjan's mother was there to wave him off on his record attempt.

After getting strapped into his emergency parachute and making a few last-minute notes on paper, Domjan strode towards his plane.

"Right, see you later," he said before clambering into the cockpit.

The hubbub in the hangar went quiet as he tested his oxygen mask, donned his helmet, checked his instruments and gave a farewell fist-bump before closing the canopy.

The plane taxied on the runway to the gentle sound of a traditional Swiss alphorn, with Sion's Tourbillon Castle and Valere Basilica providing a striking backdrop.

Almost immediately, SolarStratos was airborne, its slow movement giving it the impression of hanging in the sky as it drifted down the valley.

The plane made several turns as it gradually climbed beyond the lower terraced vineyards, above the deep green pine trees, and then towards the snowless Alpine peaks piercing the clear blue sky.

But Domjan found no rising thermals as he searched around Mont Gord -- and it was better to turn back.

In 2012, Domjan became the first person to sail around the world in a fully solar-powered boat.

"If you want to be a pioneer, when you start you will never know if you will be a pioneer of success or a pioneer of failure," he said, once back in the hangar on Friday.

"To be a pioneer, an adventurer, it means trying something you are not sure will succeed.

"The pioneer spirit for me, the spirit of adventure is to try something that nobody has tried before, and maybe you will not be able to reach success."

F.Mueller--VB