WEBVTT

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[MUSIC PLAYING]

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Because the James
Webb Space Telescope

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will be searching
for the heat coming

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from faraway objects
in the universe,

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the observatory needs
to be kept cold.

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The layers of its sun shield
will separate from each other,

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much like this
fan does, in order

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to keep the Webb
telescope from heating up.

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To find out more about how
this is all going to work,

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we've come to Northrop Grumman
in Redondo Beach, California.

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Jud, I see that a test
is about to happen here.

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What's going on?

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Yes, we're about to deploy the
second half of the sun shield

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membrane assembly to see how
the whole system works together.

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We're trying to verify that
the behaviors of the sun shield

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pan out like we expect them to.

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If there are problems
with the deployment,

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then we know how to fix
the problems before we

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get into our flight production.

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How representative is it
of the flight sun shield?

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These are about 90%
representative of the flight

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membrane articles.

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They have similar coatings.

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And for the most part,
the overall construction

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of the membranes are identical.

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As we deploy the sun shield,
it unfolds in a controlled,

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organized manner.

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And that's allowing us to
keep the membrane assembly,

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or the sun shield,
safe during deployment.

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After the membranes
deploy all the way out,

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we are then going to
tension the membranes.

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And that's going to actually
cause the five layers

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of the membrane to separate.

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Our main concern right now is
to test the membrane interaction

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with the subsystems
of the sun shield

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to make sure everything's
functioning as intended.

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So when this test
is done, will it

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look like the pictures
we've seen of Webb?

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Actually, it won't look
exactly like the images.

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The overall shape and size of
the memory should be close.

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There are some differences that
we won't be able to replicate.

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Because we are deploying
in 1g of gravity on Earth.

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We won't be able to
realize the real shape

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until we get up into
space, where it's 0g,

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or weightless environment.

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Well, thanks, Jud, for
showing us what you guys

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do to test out the sun shield.

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Sure.

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You're very welcome, Mary.

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The observatory needs to
be protected from heat

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sources like our own sun.

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The suntan lotions you and I use
have a maximum sun protection

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factor of about 100 or so.

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The Webb telescope sun
shield has an estimated SPF

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of 1 million.

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Thanks for joining us for this
edition of Behind the Webb.

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[MUSIC PLAYING]

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