James Webb Space Telescope mirror installation halfway complete
NASA recently announced that the ninth flight mirror of the James Webb Space Telescope (JWST) has been installed. This marks the halfway point of the segmented primary mirror’s completion. Engineers working in the massive clean room at NASA’s Goddard Space Flight Center used a robotic arm to place the mirror onto the telescope structure. The first of 18 mirror segments was installed in November.
“The years of planning and practicing is really paying dividends and the progress is really rewarding for everyone to see,” said NASA’s Optical Telescope Element Manager Lee Feinberg
Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). Once they are pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5 meter) mirror. Full installation of the mirror segments is expected to be completed early in 2016.
The mirror segments are made of ultra-lightweight beryllium which was chosen thermal and mechanical properties at extremely low temperatures. Each segment also has a thin gold coating chosen for its ability to reflect infrared light.
The mirrors where built by Ball Aerospace & Technologies Corp. in Boulder, Colorado. Ball is the principle subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is being performed by Harris corporation of Rochester, New York, which is leading integration and testing for the telescope.