A new solar-electric unmanned aerial vehicle (UAV) — with the potential to fly for up to a year before needing maintenance — is a step closer to reality after a new agreement between BAE Systems (www.baesystems.com) and Prismatic (www.prismaticltd.co.uk.

Engineers from the two British companies will collaborate on the development of the new solar-powered High Altitude Long Endurance (HALE) UAV known as PHASA-35 (standing for Persistent High Altitude Solar Aircraft); work is already under way to prepare the first aircraft for flight tests in 2019.

This UAV technology would offer a year-round low-cost ‘persistent service’ for a wide range of needs — including surveillance and communications to remote areas — using only the sun to power the aircraft during the day and recharge the batteries for overnight operation.

Solar HALE vehicles are said to offer a cost-effective alternative to conventional satellite technology. PHASA-35 will have a 35m wingspan and weigh just 150kg.

A quarter-scale model — PHASE-8 — completed a successful maiden flight in 2017.

Paul Brooks, founder and managing director of Prismatic, said: “PHASA-35 has the ability to revolutionise the way we think about Beyond Line of Sight communications.

“It’s great to have the support of a world-leading technology company like BAE Systems.”