Solar Impulse round-the-world flight (2015–2016)
Swiss pilots Bertrand Piccard and André Borschberg flew a solar-powered airplane around the world in 17 legs, proving an aircraft could fly day and night on sun energy alone, with no fuel.
Broke 19 world records and demonstrated solar aviation was physically possible.
The aircraft was never commercialized; Solar Impulse became a platform for promoting clean technology rather than a production aircraft.
Like Stella Juva, Solar Impulse proved a technology could work under real conditions but faced the harder question of whether anyone would fund, build, and maintain a fleet.
