Workers inside the cleanroom at the NASA Goddard Spaceflight Center in Beltsville, Maryland, uncover the primary mirrors on the James Webb Space Telescope on the afternoon of April 25, 2016, in preparation for instrument installation. The covers were put in place to protect the mirrors while they are face up. JWST team members will then rotate the telescope so the mirrors are face-down to install the instruments behind the primary mirror. The telescope is scheduled to launch in October 2018.