The mirror is so large that NASA cannot fit inside any rocket, so to launch it into space we must fold it and eventually deploy it into orbit to become part of the James Webb Space Telescope.
The James Webb Space Telescope will be able to image the Universe in the deepest and most powerful way possible. This mirror has seven times more light-gathering power than Hubble’s . It is the sophisticated that has been built to date.
The mirror that will undress the universe
James Webb Space Telescope (in English James Webb Space Telescope (JWST)), a space observatory will be developed by the collaboration between about 17 countries. But its golden mirror is particularly prodigious .
The sensitivity of a telescope is directly related to the size of its mirror , which determines how much light the telescope can collect from the objects it observes. So the Northrop Grumman engineers behind the James Webb Space Telescope had to go to great lengths to build such a structure.
They had to design a mirror with a diameter of 6.5 meters that can survive a rocket launch into space, orbit the Earth for 5 to 10 years and maintain its shape at temperatures close to 220 ° C. And, as has been said, it is not a single piece, but a series of 18 segments made of beryllium, a rare metal that is strong and light. Engineers coated them with a microscopically thin layer of pure gold for maximum reflectivity .
Each of these hexagonal shaped mirrors has a diameter of 1.32 meters and has a mass of around 20 kg. Small motors control each segment and can move up and down, left to right, and back to front. This is necessary to unfold and focus the mirror. The curvature of each segment is also adjustable .
When placed together in a honeycomb pattern, these segments form an effective surface that will be 6.5 meters in diameter.
Planning for the Webb began in 1989, a year before NASA put the Hubble telescope into orbit around Earth. Development began in 1996. NASA moved up an initial launch date from 2007 to 2011, then 2014, then 2018, and now, more than 30 years later, the telescope is expected to launch in 2021 .
First, the mirror segments are made of beryllium.
Each mirror segment is cryogenically tested at the X-ray and cryogenic facility at the Marshall Space Flight Center.
Mirror segment after being coated with gold