Navy Completes 73-Hour Nonstop Flight of Solar-Powered UAS

August 6, 2025

The U.S. Navy, in partnership with Skydweller Aero, recently achieved continuous solar-powered uncrewed flight during a nonstop three-day test from Stennis, Mississippi.

The U.S. Navy, in partnership with Skydweller Aero, recently achieved continuous solar-powered unmanned flight during a nonstop three-day test from Stennis, Mississippi. Led by the Naval Air Warfare Center Aircraft Division (NAWCAD), the test of Skydweller UAS marks a significant advancement in both long-endurance solar-powered UAS technology and its potential to enhance maritime intelligence, surveillance, and reconnaissance (ISR). (Image: NAVAIR)

Led by the Naval Air Warfare Center Aircraft Division (NAWCAD), the test of Skydweller UAS marks a significant advancement in both long-endurance solar-powered UAS technology and its potential to enhance maritime intelligence, surveillance, and reconnaissance (ISR).

“This demonstration is a prime example of how NAWCAD partners with industry to deliver what the fleet needs,” said NAWCAD Commander Rear Adm. Todd Evans. “It also reflects the technical depth of our workforce and our ability to translate ideas into capability.”

The 73-hour flight proved Skydweller’s ability to maintain continuous solar-powered operation and demonstrated the feasibility of achieving a positive energy balance to power the aircraft during extended flights. It also validated the system’s communication links, autonomous real-time decision making and ability to adapt to turbulent weather.

“Integrating Skydweller into the Navy’s ISR architecture creates a layered and resilient network that maximizes the capabilities of all our assets,” says NAWCAD’s Special Purpose UAS lead Bill Macchione. “This collaborative approach ensures we have the right platform for the right mission, optimizing our resources and enhancing our overall maritime domain awareness.”

Skydweller Aero’s solar-powered UAS has a wingspan that is the same size as the wingspan of the Boeing 747. (Image: NAVAIR)

Skydweller’s strength lies in its ability to provide continuous, wide-area surveillance over extended periods, enabling more advanced systems to focus on missions that require such specialized capabilities as rapid response and advanced sensor packages.

The solar-powered aircraft used by the Navy for the test flight is the Solar Impulse 2, which the company describes as the "first solar-powered aircraft to circumnavigate the globe." The aircraft has a 72-meter wingspan (236 feet), — the size of a Boeing 747 — can carry up to 800 pounds of payload and is capable of staying aloft for "30-90 days or longer," according to Skydweller Aero.

The aircraft is powered by solar cells and a backup battery system that is leveraged in overnight operations. According to Skydweller, the aircraft also has a maximum operational altitude of 45,000 feet and a maximum speed of 100 knots (115 mph).

NAWCAD began experimentation with Skydweller’s solar-powered UAS capabilities in 2020 to address U.S. Southern Command (SOUTHCOM) operational challenges, including drug trafficking and border security. This technology provides continuous surveillance over vast areas, enabling the U.S. and its allies to enhance maritime security and disrupt illicit activities. NAWCAD will conduct further testing with Skydweller later this summer in the SOUTHCOM area of responsibility.

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