Secure quantum communication apparently demands some mighty groovy dance floor decor. With its spherical array of 318 mirrors, the Japanese satellite "Ajisai" looks exactly like a humongous disco ball. ("Ajisai" means "hydrangea," which is a lovely spherical flower. Why it wasn't named "mira bo-ru," or "mirror ball," is unknown; perhaps its engineers had a more refined aesthetic sense than Yours Truly's.)
Ajisai's mirrors aid in mapping the precise locations of isolated archipelagos and other terrestrial features like crustal movement. They have the additional benefit of looking really cool, as you can see in this photo from Japan's space agency.
Wednesday's Ars Technica reports that the disco ball satellite is also proving useful in determining variations in our planet's gravitational field. But its most unexpected application turns out to be in the field of encrypted quantum communications, which requires a satellite to detect (and reflect) packets of single photons sent from Earth.
Read more about those photon packets at Ars Technica: "Mirror balls in space lead to quantum communications advance"