SolarStratos reaches 8,224 m height

The SolarStratos, a Swiss stratospheric solar aircraft, reached a personal record altitude of 8,224 meters but fell short of the current world record for a solar-powered flight.

The Swiss project team had scheduled an official attempt to exceed 10,000 meters for Aug. 8, 2025, with the aircraft it has been developing since 2014. The milestone was part of its plan to reach an announced target altitude of 25,000 meters.

While overall weather conditions were favorable, the absence of warm air updrafts, crucial in the final ascent phase, forced pilot Raphaël Domjan to postpone the attempt to conserve battery power for better conditions.

This week, Domjan reached 8,224 meters during a flight lasting about four and a half hours. The altitude remains below both the 10,000-meter target and the current world record of 9,235 meters, set by Solar Impulse pilot André Borschberg.

The SolarStratos two-seater will attempt the climb again in the coming days, the team announced on social media. The aircraft remains exposed to sunlight to recharge its batteries, a process conducted exclusively with solar energy and under official notarial supervision.

The aircraft measures 8.5 meters in length, has a wingspan of 24.8 meters, and weighs 450 kilograms. It is covered with 22 square meters of solar panels with 25% efficiency and about 5 kWp output, which power an electric motor connected to lithium-ion batteries.

“Being a pioneer, an adventurer, is trying something you’re not sure will succeed,” Domjan told Agence France-Presse (AFP) last week. “We’re going to try again and again until we reach 10,000 meters. It’s important to demonstrate what we can achieve with solar energy, what we can do with electricity.”