The final primary mirror segment is installed on NASA’s James Webb Space Telescope. Once in space and fully deployed, the 18 hexagonal-shaped mirror segments will work together as one large 6.5-metre mirror. The crowning mirror installation marks an important milestone in the assembly of what will be the biggest and most powerful space telescope ever launched.
NASA has successfully installed the first of 18 flight mirrors onto the James Webb Space Telescope — the successor to Hubble — beginning a critical piece of the observatory’s construction. Targeted for launch in 2018, the telescope’s 18 primary mirror segments will work together as one large 21.3-foot (6.5-metre) mirror.