Ilaria Rosella Pagliaro Swiss pilot Raphaël Domjan set a world record by flying his solar-electric plane SolarStratos to 31,237 ft (9,521 m), marking a major leap for clean aviation.
©SolarStratos
A historic ascent into the sky
On August 12, 2025, Swiss pilot and explorer Raphaël Domjan achieved a milestone that could reshape the future of aviation. Flying aboard SolarStratos, a sleek solar-electric aircraft, he climbed to 31,237 feet (9,521 meters), setting a new world altitude record for this class of aircraft.
Above the sharp ridges of the Swiss Alps, Domjan soared beyond the cruising altitude of a commercial jetliner. The image was striking: on one side, a giant aircraft powered by tons of fossil fuel; on the other, a feather-light craft propelled only by sunlight and the invisible lift of warm air.
The journey began at Sion airport in the canton of Valais. After more than two hours of steady climbing, Domjan surpassed the 2010 record of 30,295 feet (9,235 meters) set by André Borschberg with the pioneering Solar Impulse. To withstand thin air and extreme cold, he wore a pressurized suit not unlike those astronauts rely on. When he touched down, visibly moved, he summed up the experience in a few simple words:
“Flying up there, powered only by the sun, was an indescribable emotion. A moment outside of time.”
A featherweight machine
The record-breaking aircraft, registered HB-SXA, was built by German company Elektra Solar and later modified by the SolarStratos team. At just 992 pounds (450 kilograms), it looks more like a glider than a traditional airplane. Its long, delicate wings stretch 82 feet (25 meters) tip to tip and are covered with 236 square feet (22 square meters) of solar panels, enough to power two electric motors for more than a day under favorable skies.
For backup, a 20 kWh lithium-ion battery provides stored energy, though on this record flight the sun and thermal updrafts did most of the work. A newly fitted variable-pitch propeller gave the plane better efficiency at altitude, a key factor in reaching the record.
The cockpit, crucially, is not pressurized, which makes every technical decision a matter of survival. Still, the flight unfolded smoothly. By late July, the prototype had already logged more than 100 hours of experimental flight, a testament to its growing reliability.
Chasing the stratosphere
The project’s ambitions extend far beyond this summer’s success. SolarStratos ultimately aims to reach 82,000 feet (25,000 meters)—the edge of the stratosphere. Those missions, described by the team as a kind of “stratospheric odyssey,” will collect atmospheric data valuable for climate science and for understanding the upper layers of Earth’s air.
Domjan is no stranger to such pioneering ventures. More than a decade ago, he led PlanetSolar, the first solar-powered vessel to circumnavigate the globe. His pursuit of clean mobility is driven by urgency: aviation accounts for about 2.5% of global CO₂ emissions, and that number continues to climb.
Regulators are beginning to prepare for change. In the United States, the FAA has updated its rules to include electric and hydrogen propulsion in the light sport category, while the White House has announced support for both electric aviation and even a return to supersonic flight. These signals suggest that while solar aircraft are not yet ready to carry passengers or cargo on a large scale, the age of electric aviation is drawing near.
The message of SolarStratos
The symbolism of this week’s flight is hard to miss. SolarStratos has shown that clean aviation is not a utopian dream but a tangible reality, capable of pushing higher with each attempt. Reaching the stratosphere will undoubtedly pose new technical and human challenges. Yet this record proves how far sunlight, ingenuity, and determination can carry us.
Source: SolarStratos
