Drone with Boeing 747-sized wingspan flies for 74 hours on solar power

US aerospace startup Skydweller Aero has achieved a major milestone by flying its solar-powered drone, with a wingspan larger than a Boeing 747, continuously for up to 74 hours using only sunlight and battery power. The drone’s carbon fiber airframe supports 17,000 solar cells generating up to 100 kW, which power four propellers and onboard systems during the day while charging a 1,400-pound battery that sustains flight overnight. Across four recent flights, the aircraft accumulated 222 hours in the air, demonstrating endurance and resilience. The US Navy’s Naval Air Warfare Center Aircraft Division is evaluating the drone for long-duration intelligence, surveillance, and reconnaissance (ISR) missions. Skydweller Aero aims for “perpetual” uncrewed flight lasting 30 to 90 days or more, requiring landings only for maintenance rather than refueling. The drone can carry payloads up to 881 pounds (400 kg), a significant improvement over previous solar UAV