The US Navy is working on a uncrewed, solar-powered aircraft that can fly for up to 90 days. The Skydweller could be used to relay communications or as an escort surface ship's information.Solar Impulse 2, a piloted, solar-powered aircraft that flew around the globe in 2015-16, was upgraded with new software and hardware by the test aircraft. Skydweller Aero, a US-Spanish aerospace company, made the new plane. The aircraft's development contract was awarded to the company at $5 million.Robert Miller, CEO Skydweller Aero, notes that prior Solar Impulse flights were not able to.