Webb Telescope Actuators Move with Microscopic Accuracy

The James Webb Space Telescope will be the most powerful space telescope ever built. With a 21-foot diameter, the telescope’s primary mirror is six times larger than the one used by the Hubble Space Telescope. In order for such a large mirror to travel into space, it has to be broken up into multiple segments; in this case, 18 of them. But for the 18 to act as one primary mirror, they have to be adjusted while in orbit.