Webb's 18 separate mirror segments will be held in place by a graphite structure called a backplane. This one-of-a-kind piece needs to be thermally stable to -400 degrees Fahrenheit (204 degrees Celsius), and hold Webb's mirror segments steady to within one-ten thousandth the diameter of a human hair. Engineers at ATK in Magna, Utah, take us through the process of designing and creating the backplane.
About the Backplane
James Webb Space Telescope's Actual 'Spine' Now Being Built (2009)