Webb’s mirror, made of 18 individual segments, will be folded up inside the rocket that carries the telescope into orbit. Engineers are constructing the frame at the back of the mirror that will adjust Webb’s segments to achieve a single perfect focus.
“Behind the Webb” is an ongoing series that follows the construction of the Webb Space Telescope, Hubble’s successor. Find more episodes at Hubblesite.org.
“Behind the Webb” archive: http://webbtelescope.org/webb_telescope/behind_the_webb/archive