Photo: Carla Thomas/NASA/Reuters
Boeing’s Phantom Eye drone, pictured here during testing in February at Edwards Air Force Base, in California, runs on liquid hydrogen. The ultraefficient unmanned aircraft carries enough fuel to stay in the air and monitor large areas for four days at a time.











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Willie Jones
Willie Jones is an associate editor at IEEE Spectrum. In addition to editing and planning daily coverage, he manages several of Spectrum's newsletters and contributes regularly to the monthly Big Picture section that appears in the print edition.
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