UNLEASHING THE POWER OF THE SKIES: THE PHASA-35 SOLAR UAV

The PHASA-35 solar UAV is a high-altitude long-endurance unmanned aerial vehicle developed jointly by BAE Systems and Prismatic, designed to operate in the stratosphere for months at a time on nothing but sunlight. With a 35-meter wingspan, a total weight of around 150 kg, and a target operating altitude above 65,000 feet, the PHASA-35 sits in a category of its own: part satellite, part aircraft, capable of performing persistent surveillance, communications relay, and environmental monitoring missions that would otherwise require expensive orbital assets.

What Is the PHASA-35 and How Does It Work?

PHASA stands for Persistent High Altitude Solar Aircraft. The vehicle harvests solar energy through photovoltaic arrays during daylight hours and stores the surplus in rechargeable cells to sustain flight through the night, enabling theoretically indefinite endurance missions. Its lightweight composite structure, advanced aerodynamics, and solar-electric propulsion system allow it to climb above most weather systems and operate in the near-space environment known as the stratosphere. This altitude band sits above commercial aviation traffic and below orbital satellites, making PHASA-35 a high-value platform for applications that require persistent coverage of a fixed geographic area.

Key Capabilities: Surveillance, Communications, and Environmental Research

The PHASA-35's stratospheric station-keeping ability opens a wide range of operational use cases. In a surveillance role, it can monitor vast territories continuously without the logistical overhead of crewed aircraft or the cost of satellite deployment. As a communications relay node, it can extend network coverage to remote or disaster-affected regions that lack terrestrial infrastructure. For environmental researchers, the platform offers an unparalleled vantage point for tracking climate systems, wildlife migration, deforestation, and the evolution of natural disasters in near-real-time. The ability to carry a 15 kg payload adds flexibility in sensor and instrument configuration.

Milestones: First Flight and Stratospheric Test

PHASA-35 completed its maiden flight at the Woomera Test Range in Australia on 17 February 2020, supported by the UK's Defence Science and Technology Laboratory and Australia's Defence Science and Technology Group. The most significant milestone came during a subsequent test from Spaceport America in New Mexico, where the aircraft completed a 24-hour flight reaching 66,000 feet, its first successful stratospheric transit. BAE Systems has committed to making the platform available for operational activity as soon as 2026, representing a significant step toward commercially viable pseudo-satellite capability. The official PHASA-35 product page is on BAE Systems' website. The Royal Aeronautical Society published exclusive coverage of the stratospheric breakthrough with technical detail on the flight profile.

Discover Exceptional Aircraft and Flying Machines at TheArsenale

The PHASA-35 represents the cutting edge of unmanned aviation technology. For those who want to experience the world from the air in a more personal way, the Air collection at TheArsenale brings together the most remarkable flying vehicles available, from eVTOLs to ultralight aircraft. The XPENG X2 eVTOL Flying Car offers a vision of personal urban air mobility, while the ZOOZ Urban Ultralight Electric Bike delivers agile, lightweight performance for those who want to move through their environment on two wheels.

Photo: BAE Systems / Prismatic