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James Webb's mirror is revealed James Webb's mirror is revealed
(35 minutes later)
Revealed for the first time in all its glory - the main mirror of the James Webb Space Telescope, which will be launched in 2018.Revealed for the first time in all its glory - the main mirror of the James Webb Space Telescope, which will be launched in 2018.
JWST is regarded as the successor to Hubble, and will carry technologies capable of detecting the light from the first stars to shine in the Universe.JWST is regarded as the successor to Hubble, and will carry technologies capable of detecting the light from the first stars to shine in the Universe.
Paramount in that quest will be a large primary reflecting surface.Paramount in that quest will be a large primary reflecting surface.
And with a width of 6.5m, JWST's will have roughly seven times the light-collecting area of Hubble's mirror.And with a width of 6.5m, JWST's will have roughly seven times the light-collecting area of Hubble's mirror.
It is so big in fact that it must be capable of folding. Only by turning the edges inwards will the beryllium segments fit inside the telescope's launch rocket.It is so big in fact that it must be capable of folding. Only by turning the edges inwards will the beryllium segments fit inside the telescope's launch rocket.
The observatory is currently under construction at the US space agency's Goddard Space Flight Center in Maryland.The observatory is currently under construction at the US space agency's Goddard Space Flight Center in Maryland.
When in recent months engineers stuck down the segments to their support structure, each hexagon had a cover on it.When in recent months engineers stuck down the segments to their support structure, each hexagon had a cover on it.
Only now, as the engineers prepare to move to the next stage of assembly, have those covers been removed to reveal the full surface.Only now, as the engineers prepare to move to the next stage of assembly, have those covers been removed to reveal the full surface.
Shortly, the secondary mirror, which is at the top of the black extension poles will be collapsed into a flat configuration.Shortly, the secondary mirror, which is at the top of the black extension poles will be collapsed into a flat configuration.
Then, the whole edifice will be flipped 180 degrees. This will permit the engineering team to attach JWST's instruments behind the main mirror. Then, the whole edifice will be flipped 180 degrees. This will permit the engineering team to attach JWST's instruments behind the main mirror.
These can be seen in a raised cage off to the left.These can be seen in a raised cage off to the left.
Once this integration is complete, the telescope will be sent for environmental testing. It will be shaken and blasted with sound to mimic the rough rocket ride to orbit.Once this integration is complete, the telescope will be sent for environmental testing. It will be shaken and blasted with sound to mimic the rough rocket ride to orbit.
Assuming that goes well, the whole train - mirror and instruments - will ship to Nasa's Johnson Space Center for some final deep-chill testing. Assuming that goes well, the whole train - mirror and instruments - will ship to Nasa's Johnson Space Center in Texas for some final deep-chill testing.
This will be conducted in the giant cryo-vacuum chamber built to accommodate the 1960s Apollo hardware.This will be conducted in the giant cryo-vacuum chamber built to accommodate the 1960s Apollo hardware.
Once that work is complete, engineers must attach the spacecraft bus, which incorporates elements such as the flight computers and communications system. Finally, James Webb will be given an immense deployable visor - the structure that will shield its delicate observations from the Sun's light and heat.Once that work is complete, engineers must attach the spacecraft bus, which incorporates elements such as the flight computers and communications system. Finally, James Webb will be given an immense deployable visor - the structure that will shield its delicate observations from the Sun's light and heat.
Only then will JWST be ready to go into space. Lift-off aboard Europe's Ariane rocket is scheduled for October 2018.
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmosJonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos