The spy drone lurking above our heads: British-built solar powered aircraft can quietly cruise through the stratosphere for months at a time

It looks like a cross between a toy airplane and a drone, but this British solar-powered aircraft could be the future of aerial surveillance. BAE Systems has completed new stratospheric test flights of the PHASA-35, a British-built solar powered drone with a 115ft wingspan that can operate in the air for 20 months It is powered by the sun during the day and by batteries overnight, allowing it to maintain flight for over a year operating in the stratosphere, lower than most satellites The 150kg aircraft, which has a wingspan lined with solar panels, is powered by the sun during the day and by batteries overnight. This allows it to maintain flight for over a year operating in the stratosphere, lower than most satellites BAE Systems said PHASA-35 completed two stratospheric test flights from Spaceport America in October, the first since its maiden flight in June 2023. It harnesses power from the sun to stay airborne, charging a bank of small batteries during the day to keep it flying overnight PHASA-35 builds speed on a runway just like more conventional aircraft but detaches its wheels shortly after takeoff and glides to a landing on its belly PHASA-35 maximum payload of 15kg could comprise cameras, sensors and communications equipment to allow troops to talk to each other or provide internet access to rural locations during a natural disaster or emergency PHASA-35: Key specs Wingspan: 115ft Weight: 150kg Payload limit: 15kg Max altitude: 70,000ft Power system: Solar powered Cost: Tens of millions of pounds Applications: Environmental surveillance Disaster relief Border protection Maritime and military surveillance Mobile internet communications These recent flights are part of a series of trials intended to confirm the performance of the aircraft before it can be bought by defence and commercial customers. BAE systems say PHASA-35 will be available by the middle of the decade and provide a 'persistent and affordable alternative to satellite technology', which is traditionally heavier PHASA-35's maximum payload of 15kg could comprise cameras, sensors and communications equipment to allow troops to talk to each other or provide internet access to rural locations during a natural disaster or emergency.