Skydweller Aero, an adaptation of Solar Impulse technologies, is working with the U. S. Navy to provide ultra-persistent flight capabilities. It’s using Solar Impulse Two, for which Skydweller purchased the assets and intellectual property rights. Being flown in Spain at this time, the aircraft’s 2,900 square feet of solar cells provide two kilowatts of power, and may be augmented by hydrogen fuel cells in future. In Spain Skydweller founders John Parkes and Robert Miller have headquarters in Oklahoma City, Oklahoma, but are performing flight tests in Spain, coordinating efforts with the University of Castilla-La Mancha (UCLM). After successfully completing ground tests that checked the structure and control systems, Skydweller works toward crafting the software that will guide it on unpiloted missions, scheduled to last at least 30 to 60 days. Such persistence, long sought by the military for ISR (Intelligence, Surveillance and Reconnaissance) missions, is also essential for many future civilian applications. Co-founder John Parkes explained this to Aviation Today. …