Among the mirror segments can be seen are one gold-coated flight-spare beryllium segment (just in front of the AOS), one uncoated beryllium engineering unit segment, and ten gold-coated aluminum thermal simulator segments.
The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, the European Space Agency and the Canadian Space Agency.
Image Credit: NASA/Chris Gunn