Airborne for a year

The PHASA-35 jointly developed by BAE Systems and Prismatic is due to fly in 2019.
BAE Systems

BAE Systems is working on a solarpowered, unmanned, high-altitude, long-endurance system. The PHASA-35, under development in conjunction with Hampshire-based technology company Prismatic, is being prepared for flight tests in 2019 following a successful maiden flight in 2017 of a quarter-scale model of the aircraft named PHASE-8.

The PHASA-35 will have a 114ft (35m) wingspan and weigh 330lb (150kg). PHASA stands for Persistent High Altitude Solar Aircraft. BAE said the system “uses proven, longlife battery technology and ultralightweight solar cells to potentially maintain flight for up to 12 months”.

For the PHASA-35 project, BAE will invest in the system’s development and flight-testing, providing aerospace technology and project management expertise.

Solar-powered HALE aircraft, also known as HAPS (High Altitude Pseudo Satellites), are a focus in the aerospace industry currently.

In addition to the PHASA-35, Airbus has its Zephyr project, and in April the California-based developer UAVOS announced it has developed a control system for flexible-wing HALE UAVs.

HALE/HAPS systems are designed to operate at very high altitudes (above 60,000ft) for long periods to perform functions commonly undertaken by satellites in low Earth orbits. The developers of these systems promise the aircraft will offer a cheaper alternative to conventional technologies. For example, BAE said PHASA-35 would offer a “year-round, low-cost persistent service for a wide range of needs, including surveillance and vital communications to remote areas, using only the sun to power the aircraft during the day and recharge the batteries for overnight operation”. Prismatic Founder and Managing Director Paul Brooks said the system “has the ability to revolutionise the way we think about beyond line of sight communications”. Mark Broadbent