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[MUSIC PLAYING]

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Our most powerful
window in the universe

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is nearing final assembly.

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A 21 foot diameter
segmented array of mirrors

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is the heart of NASA's
James Webb Space Telescope.

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This powerful successor to
the Hubble Space Telescope

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will allow humans to see
farther into the universe than

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ever before.

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This Herculean effort has pulled
together technical experts

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from across the nation.

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The mirror odyssey begins in a
mine where the precious metal

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beryllium is extracted.

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Beryllium is the choice
for mirror material

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because it is lightweight and
stable at the cold temperatures

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of space.

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The beryllium powder is
cast into four foot wide

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hexagonal mirror segments.

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They are precisely ground
and polished to a precision

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1,000 times smaller than the
thickness of a human hair.

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The mirrors are then tested to
simulate the cold of deep space

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at minus 400 degrees Fahrenheit.

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Mirrors are next coated with
a very thin layer of gold,

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which is needed to efficiently
reflect infrared light

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to the telescope's cameras.

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The mirrors are then
vibrated to see if they can

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survive the rigors of launch.

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At present, the mirrors
are nearly completed.

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They are ready to be positioned
on a giant skeletal frame.

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Cameras and other
instruments will be added

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to the rear of this back plane.

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The telescope will
then be rolled

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into the giant thermal vacuum
chamber used to test the Apollo

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Lunar spacecraft.

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After that, the two story high
optical telescope assembly

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will be attached to a tennis
court sized sunshade designed

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to deflect heat from the sun.

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The telescope's
gold mirrors will

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be used to seek our cosmic
origins by seeing earliest

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galaxies and perhaps detect
the first glimmer of life

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on an alien world.

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[MUSIC PLAYING]

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