What’s the best way to make a really powerful telescope? Build a big mirror! The James Webb Space Telescope has the largest mirror of its kind that NASA has ever built. So big that it can’t fit inside a rocket without folding up. In early March, testing teams deployed Webb’s 21 feet 4-inch (6.5 meter) primary mirror into the same configuration it will have when in space. Like the art of origami, Webb is a collection of movable parts that have been specifically designed to fold to a compact formation that is considerably smaller than when the observatory is fully deployed or extended. This allows it to just barely squeeze within a 16-foot (5-meter) payload fairing or cargo bay of a rocket, with little room to spare. Once in space, it will blossom and unfold into the world’s premier space science observatory. Image credit: Northrop Grumman