In a groundbreaking achievement for sustainable aviation, the SolarStratos project has set a new altitude record for a manned solar-powered aircraft. On August 12, 2025, Swiss eco-explorer Raphaël Domjan piloted the HB-SXA aircraft to an impressive altitude of 9,521 meters (31,237 feet) above the Valais Alps in Switzerland .
A Leap Beyond the Solar Impulse Record
This remarkable feat surpasses the previous record held by the Solar Impulse aircraft, which reached 9,235 meters in 2010. The HB-SXA’s achievement marks a significant milestone in the pursuit of solar-powered aviation.
Aircraft Specifications
The HB-SXA is a lightweight aircraft, weighing only 450 kilograms (992 pounds), and features an expansive wingspan of 24.8 meters (81.4 feet). Its wings are equipped with 22 square meters of high-efficiency solar panels that power a 43-horsepower electric motor. A 20-kWh lithium-ion battery serves as a backup power source, providing an estimated endurance of up to 24 hours under optimal conditions .
Flight Details
The record-setting flight commenced from Sion Airport, with Domjan navigating the aircraft to its peak altitude over a five-hour and nine-minute journey. Utilizing solar energy and thermal currents, the HB-SXA ascended to the record height, crossing paths with a commercial airliner during the flight—a symbolic moment for the future of clean aviation .
Future Aspirations
The SolarStratos team aims to continue pushing the boundaries of solar aviation, with plans to reach the stratosphere at altitudes exceeding 25,000 meters. Achieving such heights would require the use of pressure suits due to the low atmospheric pressure, cold temperatures, and the need for supplemental oxygen.
