This July 11, 2015 photograph captures one of the final, if not the final, James Webb Space Telescope flight primary mirror segments to be processed through NASA Goddard Space Flight Center's Calibration, Integration and Alignment Facility (CIAF).
The mirror is seen here on the Configuration Measurement Machine (CMM), which is used for precision measurements of the backs of the mirrors. These precision measurements must be accurate to 0.1 microns or 1/400th the thickness of a human hair.
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
Last Updated: July 28, 2015
Editor: Sarah Loff