Swiss pilot Raphael Domjan beat the altitude record for a solar-powered electric plane in a 2025 flight that took him soaring to 9,640 metres, the World Air Sports Federation (FAI) confirmed.
The FAI governing body, holding its 120th general conference in Lausanne from Wednesday to Friday, validated the record attempt after verifying the flight data.
The SolarStratos plane made the landmark flight from Sion airport in southwest Switzerland on August 12 last year, taking advantage of warm air thermals to beat a 15-year-old record.
The previous certified altitude record for a solar plane was 9,235 metres (30,298 feet).
Domjan's flight lasted five hours and nine minutes.
"After several months of verification and certification, FAI ratification now gives this achievement full international recognition," the SolarStratos team said a statement.
"SolarStratos officially becomes the highest-flying crewed electric and solar-powered aircraft in history."
On Wednesday, Domjan was given the FAI's Louis Bleriot Medal -- established in 1936 and named after the French aviation pioneer -- in recognition of his world record flight.
"This distinction crowns more than 10 years of research, testing and commitment to pushing the boundaries of electric and solar-powered flight," SolarStratos said.
"SolarStratos takes another step towards its ultimate goal: reaching the stratosphere aboard a crewed electric and solar-powered aircraft, without using a single drop of fossil fuel."
Domjan is aiming to make the first manned solar-powered flight into the stratosphere, which at Switzerland's latitude begins at around 10,000 to 12,000 metres, depending on climatic conditions.
The single propeller plane, registration HB-SXA, is made of carbon fibre to ensure lightness and strength.
SolarStratos is 9.6 metres long. Its 24.8 metre wingspan accommodates 22 square metres (237 square feet) of high-spec solar panels and allows for flying at low speeds.
The plane can take off at low speeds, from 50 kilometres (30 miles) per hour upwards. Its maximum speed is 140 kph, while its cruising speed is around 80 kph.