First mirror installed on NASA's James Webb Telescope

NASA has successfully installed the first of 18 flight mirrors onto the James Webb Space Telescope, beginning a critical piece of the observatory's construction to replace the Hubble Space Telescope in 2018.
At NASA's Goddard Space Flight Centre in Greenbelt, Maryland this week, the engineering team used a robot arm to lift and lower the hexagonal-shaped segment that measures just over 1.3 meters across and weighs approximately 40 kilogrammes.
After being pieced together, the 18 primary mirror segments will work together as one large 6.5-metre mirror. The full installation is expected to be complete early next year.
"The James Webb Space Telescope will be the premier astronomical observatory of the next decade," said John Grunsfeld, astronaut and associate administrator of the Science Mission Directorate at NASA.

"This first-mirror installation milestone symbolises all the new and specialised technology that was developed to enable the observatory to study the first stars and galaxies, examine the formation stellar systems and planetary formation, provide answers to the evolution of our own solar system, and make the next big steps in the search for life beyond Earth on exoplanets," said Grunsfeld.
Several innovative technologies have been developed for the Webb Telescope, which is targeted for launch in 2018, and is the successor to NASA's Hubble Space Telescope.

Webb will study every phase in the history of our universe, including the cosmos' first luminous glows, the formation of solar systems capable of supporting life on planets like Earth, and the evolution of our own solar system.

The 18 separate segments unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium chosen for its thermal and mechanical properties at cryogenic temperatures. Each segment also has a thin gold coating chosen for its ability to reflect infrared light.
The telescope's biggest feature is a tennis court sized five-layer sunshield that attenuates heat from the Sun more than a million times.
"After a tremendous amount of work by an incredibly dedicated team across the country, it is very exciting to start the primary mirror segment installation process," said Lee Feinberg, James Webb Space Telescope optical telescope element manager at Goddard.

"This starts the final assembly phase of the telescope," said Feinberg.