Navy's Solar Aircraft Aims for 90-Day Unmanned Flights
The U.S. Navy is pushing the boundaries of renewable aviation with a solar-powered, uncrewed aircraft designed to stay aloft for up to 90 days, a capability that would dramatically extend maritime surveillance operations. The aircraft, named Skydweller and developed by the U.S.-Spanish firm Skydweller Aero, could allow the Navy to maintain a persistent watch over ocean areas while accompanying ships for months, according to a report by New Scientist.
The Skydweller is a conversion of the Solar Impulse 2, a crewed solar aircraft that circumnavigated the globe in 2015 and 2016. By removing the pilot's seat, engineers freed up space and reduced weight, enabling longer flight durations and the ability to carry larger payloads, as detailed in Aviation Today.
The aircraft's wingspan stretches 236 feet, and its surface is covered with 2,900 square feet of photovoltaic cells, generating up to 2 kilowatts of power. It can carry up to 800 pounds of radar and camera equipment, making it a versatile platform for reconnaissance and surveillance missions.
Skydweller Aero CEO Robert Miller outlined the testing roadmap to New Scientist: “We are currently following our plan to test autonomous flight, then autonomous take-off, then autonomous landing and finally our first fully autonomous flight. Once all this has been proven, we will move into long-endurance testing with the goal of operating for 90-plus days.”
The Navy currently operates larger drones that can stay airborne for only about 30 hours during maritime patrols. The prospect of a 90-day endurance would represent a paradigm shift in operational planning. John Parkes, co-founder of Skydweller Aero, highlighted the efficiency gain to Aviation Today: “For us, if you’re flying 90 days with one aircraft, that’s two takeoffs and landings versus… hundreds.”
Why Longer Flights Matter
Extended endurance would reduce the logistical burden of frequent launches and recoveries, allowing for more continuous coverage of vast ocean areas. This could be particularly valuable for anti-submarine warfare, search-and-rescue, and environmental monitoring, though the Navy has not specified all potential missions.
Beyond solar power, Skydweller Aero is exploring hydrogen fuel cells as a supplementary power source or backup during adverse weather, which could further enhance reliability and performance.
The project is part of a broader trend in military aviation toward uncrewed systems and renewable energy. While the 90-day goal is ambitious, the company's stepwise testing approach suggests a methodical path toward operational capability. If successful, the Skydweller could become a cornerstone of long-endurance maritime surveillance, reducing both fuel costs and carbon footprint.
