UK engineers enter PHASA-35 of High Altitude, Long Endurance UAV development

UK engineers have signed an agreement to further develop PHASA-35, a solar powered UAV that can stay airborne for a year to deliver services that include surveillance and communications.


Engineers from Prismatic and BAE Systems will collaborate on the development of PHASA-35, a High Altitude, Long Endurance (HALE) UAV, which can also be used for remote sensing or environmental science tasks at altitudes of between 55,000 and 70,000ft. Work is already underway to prepare the first aircraft for flight tests in 2019.

According to BAE Systems, Solar HALE vehicles offer a significantly cheaper alternative to conventional satellite technology, with PHASA-35 (Persistent High Altitude Solar Aircraft), being a concept solar electric UAV that uses Li-ion battery technology and ultra-lightweight GaAs (Gallium Arsenide) solar cells to potentially maintain flight for up to 12 months.

The PHASA-35 concept has a 35m wingspan and weighs 150kg. A quarter scale model (PHASE-8) completed a maiden flight in 2017, with Prismatic and BAE Systems now looking to take the technology a step further.


Michael Christie, Strategy Director within BAE Systems’ Air sector, said: “Prismatic is a fast paced and forward thinking company and PHASA-35 is a great example of what the team can achieve in a short space of time.

“We were keen to invest in the programme as part of our long term strategy to explore new technologies and solutions in air and space.”

BAE Systems will invest in the development and flight testing of the PHASA-35 system as part of its drive to develop new technologies to support future aircraft, working collaboratively with SMEs and academia.

Under the agreement with Farnborough, Hants-based Prismatic, BAE Systems will provide expertise in aerospace technology and project management to progress the PHASA-35 programme through to a commercial product.