Paper that flew

Koryo Miura designed a fold for large panels in space: a zig-zag in both directions, at a slight slant. Pull two opposite corners and the whole sheet opens in one motion; push them and it closes along its own creases.

A Miura-folded panel was tested on Japan’s Space Flyer Unit, launched in 1995, and Miura maps are sold today. Other ideas from the same family — folding sunshades for telescopes, folding stents for blood vessels — have been built and tested, but not all of them have flown.

When you read about folding engineering, ask which it is: flown, in everyday use, tested in a laboratory, or still a design. The headline often doesn’t say.