Mirror Size: Webb’s large, segmented primary mirror gives it unprecedented light-gathering ability. Contributed by Shahbaz Aslam Khan. It is almost three times the size of Hubble’s mirror, boasting a light-collecting area seven times greater, but both mirrors weigh almost the same owing to the lighter materials used on the JWST’s mirror. Together they create a 6.5 meters (21.6 feet) surface.

6. In contrast, the Hubble Space Telescope’s primary mirror is a single, round, 2.4-meter mirror. It’s seven times more powerful than the Hubble Space Telescope. One of the James Webb Space Telescope's science goals is to look back through time to when galaxies were young. James Webb Space Telescope.
The giant mirror of the JWST is made of 18 individual hexagonal segments composed of lightweight beryllium. The James Webb Space Telescope Observatory - Mirrors. Webb will do this by observing galaxies that are very distant, at over 13 billion light years away from us. ... hexagonal mirror segments, each 1.3 meters (4.3 feet) in diameter • Each mirror segment weighs about 20 kg (46 lbs.) • The primary mirror’s total diameter is 6.5 m (21 feet 4 in.) To see such far-off and faint objects, Webb needs a large mirror.

Engineers at NASA’s Johnson Space Center in Houston used light waves to align the James Webb Space Telescope’s mirror segments to each other, so they act like a single, monolithic mirror in the cryogenic cold of the center’s iconic Chamber A. JAMES WEBB SPACE TELESCOPE GO BEYOND WITH BALL. Each of its 18 hexagonal-shaped mirror segments is 1.3 meters (4.3 feet) in diameter. The James Webb Space Telescope will launch on ESA's Ariane 5 rocket in 2018 2 / 4 The primary mirror of the James Webb Space Telescope is made up of 18 hexagonal segments coated in gold James Webb Space Telescope: Named after: Edwin Powell Hubble: James Edwin Webb: Launch date: April 24, 1990: March 30, 2021 (Planned) Launch site: Kennedy Space Center (LC-39B) Guiana Space Centre (Kourou ELA-3) Rocket: Space Shuttle Discovery (STS-31) Ariane 5 ECA: Launch mass: 10,886 kg (about 24,000 lb) 6,500 kg (14,300 lb) Dimensions: 13.2 m × 4.2 m (43.3 ft × 13.8 ft) 21.197 m x … The telescope will help piece together puzzles scientists have been trying to solve throughout the cosmos. The primary mirror of NASA's James Webb Space Telescope that consists of 18 hexagonal mirrors looks like a giant puzzle piece standing in the massive clean room of NASA's Goddard Space Flight Center in Greenbelt, Maryland.