Swiss solar-powered aircraft strives for height ascension, driven by pioneering spirit
On Tuesday, August 12, 2025, Swiss eco-explorer Raphaël Domjan and his SolarStratos plane soared to new heights, reaching an altitude of 9,521 meters. This achievement surpasses the previous record of 9,235 meters set by the Solar Impulse experimental aeroplane in 2010.
The flight lasted an impressive 5 hours and 9 minutes, with solar energy supplemented by thermal updrafts powering the plane. However, Domjan's previous attempt on August 8, 2025, fell short due to weak thermal lift.
The SolarStratos team is now aiming to surpass 10,000 meters, pending favourable weather and adequate battery power. The successful record flight is currently undergoing official validation by the Fédération Aéronautique Internationale (FAI), the world air sports governing body.
The SolarStratos plane, a propeller plane made of carbon fibre, is 9.6 metres long and has a wingspan of 24.8 metres to accommodate 22 square metres of high-spec solar panels. Before takeoff, the hangar went quiet as Domjan tested his oxygen mask, donned his helmet, checked his instruments, and bid farewell.
Domjan's mother was present to wave him off on his record attempt. He expressed that being a pioneer involves trying something that may not guarantee success. The first warm-up flight on July 31 reached 6,589 metres, the highest ever for SolarStratos.
As the plane took off from Sion airport in the Rhone valley in southwestern Switzerland at 1:21pm, it provided a striking contrast against the backdrop of Sion's Tourbillon Castle and Valere Basilica. During the flight, Domjan made several turns as he climbed beyond lower terraced vineyards, above deep green pine trees, and towards snowless Alpine peaks.
However, on Friday, August 8, 2025, the flight was cut short due to unfavourable conditions. Wildfires in neighbouring France may have contributed to the insufficient thermal conditions that forced an early termination of the flight. Despite this setback, Domjan plans to try again on Sunday or Wednesday when conditions are more promising.
Domjan, who became the first person to sail around the world in a fully solar-powered boat in 2012, described himself as an "eco-explorer" committed to climate protection. The SolarStratos plane taxied down the runway to the sound of a traditional Swiss alphorn before its historic flight on Tuesday.
The SolarStratos team is planning to use science and technology, particularly solar energy and thermal updrafts, to surpass 10,000 meters in altitude, as they did with the Solar Impulse experimental aeroplane in space-and-astronomy. This significant achievement, featuring the SolarStratos plane, will be subject to official validation by the Fédération Aéronautique Internationale (FAI).
