Space Solar Wins £1.3m ARIA Contract to Help Power Enduring Stratospheric Flight Over Britain

Space Solar, the UK deep-tech company developing space-based solar power and wireless power beaming, has secured a £1.3m research contract from the Advanced Research + Invention Agency (ARIA) to develop RF power beaming technology for high altitude platforms.

Space Solar is one of 18 funded R&D Creators in ARIA’s Enduring Atmospheric Platforms programme, led by Programme Director Rico Chandra and backed by £70 million over 3.5 years. The programme is developing technologies to enable aircraft known as High Altitude Pseudo-Satellites (HAPS) to operate reliably and cost-effectively in the stratosphere, providing the physical backbone for next-generation advanced communications and a path to connectivity for underserved regions.

Solar-powered stratospheric aircraft can face significant energy constraints at UK latitudes in winter. Project HAWK will explore a different approach: separating the energy source from the aircraft, with a ground-based transmitter beaming power by radio frequency at 5.8 GHz to a lightweight conformal receiving antenna, or rectenna, built into the platform’s wing. This could enable the aircraft to draw power from the ground regardless of season, weather or time of day, with potential applications spanning communications, Earth observation and other persistent stratospheric services.

Project HAWK will advance the rectenna technology from Technology Readiness Level (TRL) 3 towards TRL 7 over a 36-month period. The wider Enduring Atmospheric Platforms programme is working towards a single galvanising demonstration: suspending and powering communications payloads in the stratosphere above the UK for a week. Within that ambition, the programme targets power beaming of a net 300 watts of continuous DC power delivered to a 20 kg payload at stratospheric altitude for at least a week, at an operational cost below £500 per hour by the end of the programme, with a route to below £100 per hour.

Space Solar brings demonstrated capability to the project, with its HARRIER prototype, the world’s first retrodirective phased array capable of 360-degree beam steering, having been tested at Queen’s University Belfast’s anechoic chamber. Those tests validated the company’s digital models and provided the technical foundation for scaling the technology to 5.8 GHz.

“Project HAWK applies our core power beaming technology to one of the most compelling near-term markets: persistent stratospheric flight,” said Martin Soltau, Co-CEO of Space Solar. “Energy is one of the central constraints for HAPS. With ARIA funding, we can take our rectenna technology from the laboratory towards an integrated flight demonstration, while building the UK capability needed to manufacture and scale the technology.”

Space Solar is working closely with two partner organisations on the project, coordinated through a joint Programme Steering Committee: Prismatic Ltd, the BAE Systems company developing the PHASA-35 high altitude platform, and MuWave Limited, which is developing the ground-based transmitter.

The three-stage project will end with an integrated flight demonstration aboard the Prismatic PHASA-35 HAPS aircraft.