NASA Goddard Space Flight Center, Greenbelt, Md., announces that one dozen beryllium mirrors have been installed on NASA’s James Webb Space Telescope, out of the eighteen mirror segments that make up the primary mirror. Each hexagonal-shaped segment measures just over 4.2 feet across and weighs approximately 88 pounds.
After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are placed on the telescope’s backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months.
“This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the three mirrors on each wing are left,” said Lee Feinberg, NASA’s Optical Telescope Element Manager at NASA Goddard.
The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The mirrors are being installed by Harris Corporation of Rochester, New York. Harris leads integration and testing for the telescope.
While the mirror assembly is a very significant milestone, many more steps are involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, four smaller components are less visible, yet critical. The instruments that will fly aboard Webb —- cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module, which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year.
Over the next two years in preparation for launch, various components of the Webb telescope will endure rigorous environmental and optical testing. The sunshield will be joined with the spacecraft bus (main structure) followed by more testing. The Webb telescope is planned for launch in 2018.
