A solar-powered drone with a 236-foot wingspan equivalent to a Boeing 747 completed a record-breaking eight-day flight before crashing into the Caribbean Sea. Originally the Solar Impulse 2 aircraft that circled the globe between 2015-2016, the drone was modified by Skydweller Aero for military testing purposes.

The carbon-fiber aircraft featured more than 17,000 solar cells covering its massive wings, enabling it to fly solely on renewable energy and battery power while carrying up to 800 pounds of payload. During its final mission, the drone participated in US Navy Fleet Experimentation exercises near Key West, conducting maritime patrols and serving as a communications hub for naval operations.

Skydweller Aero reported that extreme weather conditions with unprecedented vertical air mass variability caused the crash on May 4, despite all aircraft systems remaining nominal throughout the flight. The drone ultimately performed a controlled water ditching but sank due to its non-buoyant composite structure.

Though the aircraft was lost, it achieved its goal of demonstrating persistent solar-powered flight for military applications. The crash ends the operational career of an aircraft that previously completed the world's first solar-powered transatlantic and transpacific crossings.