Swiss solar aviation pioneer SolarStratos said it has achieved a new altitude record for an all-electric aircraft, reaching 9,521 metres over the Valais Alps, surpassing the previous mark of 9,235 metres set by Solar Impulse in 2016.
The flight, carried out on Aug. 12, was piloted by Raphaël Domjan in a SolarStratos HB-SXA plane departing from Sion Airport, the company said in a statement. Powered by a double electric motor delivering 50 kilowatts of continuous output and a peak of 70 kW, the aircraft relied on lithium-ion batteries and 22 square metres of solar cells to sustain the climb.
“This flight is a powerful symbol of what the decarbonised aviation of tomorrow might look like,” SolarStratos said, after Domjan crossed paths with a commercial airliner at cruising altitude.
The record attempt, which is still under review by the Fédération Aéronautique Internationale (FAI), lasted 5 hours and 9 minutes. According to the company, the aircraft used warm air thermals to gain lift, reaching a propeller speed of up to 2,200 rpm through a three-blade, 1.9-metre propeller.
Designed by Calin Gologan and Germany’s Elektra Solar GmbH, the two-seat HB-SXA aircraft spans 24.8 metres, measures 8.5 metres in length, and carries solar cells with an efficiency of 22% to 24%. These provide a total capacity of 11 to 28 kilowatt-hours to recharge the onboard lithium-ion batteries.
SolarStratos has been preparing for this flight for months, with earlier tests including a July 31 sortie that lasted two and a half hours and reached 6,589 metres. The company said its next target is to climb above 10,000 metres, matching the typical cruising altitude of commercial airliners.
