Ken Rentmeester, a regular reader of the blog, shared a news item from the IEEE (Institute of Electrical and Electronics Engineers) Spectrum. Calling Titan Aerospace’s Solara unmanned aircraft “atmospheric satellites,” the article gives a brief history of solar-powered craft, including the Boucher brothers’ Sunrise I, the first solar-powered airplane in 1974, Paul MacCready Jr.’s first piloted solar-powered flight in 1980, and the current world’s endurance record for unmanned, solar-powered flight by the QinetiQ Zephry in 2010. That airplane follows the look of the Boucher’s early effort, and Titan’s examples look a great deal like scaled-up versions of FAI F5-type models which rely on electric self-launching, rapid climbs and extreme flight capabilities to win contests. Despite great successes such as Zephyr’s, there so far has been no commercial market for this type of aircraft. Titan hopes to overcome shortcomings that prevented broader acceptance for its predecessors. These included limited photovoltaic capabilities, poor battery endurance, and fragile airframes, which were simply scaled-up …