Flight isn’t easy at the edge of space. But tiny “microfliers” could soar high in Earth’s atmosphere fueled only by sunlight, experiments suggest.

At heights between about 50 and 80 kilometers above Earth’s surface, in what’s known as the mesosphere, the atmosphere is so thin that airplanes and balloons can’t stay aloft. But mechanical engineer Mohsen Azadi and colleagues at the University of Pennsylvania saw promise in a technique that uses light to levitate objects. The researchers cut disks of transparent Mylar 6 millimeters in diameter and coated the bottom sides with carbon nanotubes. When heated by light, the tiny aircraft floated inside a vacuum chamber with a pressure that mimicked the mesosphere, the researchers report February 12 in Science Advances.

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