Telescope Mirror Blanks Completed
8 February 2007
Construction of the mirror blanks of the James Webb Space Telescope (JWST) has been completed by Axsys Technologies Inc. in Cullman, Alabama, USA.The JWST telescope primary mirror is composed of 18 hexagonal segments that will be joined together to form the 25 m² light collecting area. Each of the 18 segments has a diameter of 1.3 m and is made of beryllium, one of the lightest known metals.
 |
 |
|
Engineers at Axsys Technologies work with one of the mirror segments. |
JWST spacecraft with the main mirror composed of 18 segments |
After the grinding and polishing, the mirror segments will be delivered to Ball Aerospace in small groups where they will be assembled. Once the mirrors are completed, they will go to NASA's Goddard Space Flight Center, Greenbelt, Maryland, for final assembly on the telescope.
When fully assembled, JWST's telescope will have a diameter of 6.6 m - compared to the 2.4m diameter of Hubble's primary mirror. The larger area means the telescope will be able to detect fainter objects and will also have a higher resolution. Both these characteristics help to achieve JWST's science goals that range from the study of the most distant objects in the early Universe to sensitive infrared observations of exoplanets and of enshrouded protostars in the earliest stages of stellar evolution.