Unmanned Systems Technology 022 | XOcean XO-450 l Radar systems l Space vehicles insight l Small Robot l BMPower FCPS l Prismatic HALE UAV l InterDrone 2018 show report l UpVision l Navigation systems

68 A lthough still relatively young, the high-altitude pseudo-satellite (HAPS, or HALE) unmanned aircraft sector has been prone to periods of cautious optimism punctuated by tectonic shifts in industry player activity. It was not long ago for example that Silicon Valley heavyweights Facebook and Google were poised to design and build their own huge, solar-powered systems that would dominate the industry. These aircraft, both tech giants claimed, would be their sustainable, autonomous tools for delivering high-speed internet to the most remote parts of the Earth. But 2017 saw Google give up on its Project Titan, and in June 2018 the Facebook Aquila suffered the same fate. In their wake, however, smaller companies are continuing to develop high-altitude unmanned electric aircraft that can fly for up to a year or more using just the Sun’s energy to recharge their batteries. One such company, Prismatic, based in Hampshire in England, is partnering with defence and aerospace contractor BAE Systems to pool their expertise to create a 35 m wingspan HALE platform. Called the PHASA-35, its engineers will aim to create a system that can carry 15 kg of payload for a full year, for missions such as surveillance, telecoms and environmental research. Development of the PHASA-35 did not start until September 2016, but even so a platform was soon required to test, demonstrate and evolve critical technological capabilities in aerodynamics and propulsion – capabilities that would be vital if the production version was to fly safely and successfully. The company therefore began to build the PHASE-8, in July 2017, with the intention of producing a tool capable of verifying and optimising HALE technologies but with greater cost- effectiveness than a 35 m testbed. And although it may originally have been a stepping stone towards the PHASA-35, discussions between Prismatic and interested third parties When – and how – does a test platform for a HALE craft become a UAV in its own right for other developers? Rory Jackson reports A true test October/November 2018 | Unmanned Systems Technology The PHASE-8 is designed to fly at sea level while accurately simulating the fluid dynamics of a much larger HALE aircraft at 55,000 ft (Photos courtesy of Prismatic)