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We are here at the
Marshall Space Flight

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Center in Huntsville, Alabama,
known for its long history

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in propulsion research.

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But this NASA site is
still a big player,

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this time for the James
Webb Space Telescope.

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We're right outside
the vacuum chamber

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where the mirrors for
the Webb Space Telescope

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are being tested.

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Back in the '90s,
this facility was

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used to test out one of
NASA's great observatories,

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the Chandra X-ray Observatory.

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We have here the project
scientist for Chandra,

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Martin Weisskopf.

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Can you tell us a little
bit about the differences

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between Hubble, and
Chandra, and James Webb?

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These are
observatories that look

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at different parts
of what we call

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the electromagnetic spectrum.

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That is light at various
different energies, from x-rays

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where it takes a lot of
energy to produce them,

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to visible light
where the Hubble Space

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Telescope operates, and the near
infrared where the James Webb

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Telescope will operate.

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In this way, by studying
objects in the universe,

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we can learn a lot
about them that we

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can't learn by just simply
looking at one wavelength.

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What kind of information
can we glean from x-rays?

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X-ray astronomy
is the system that

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brought the first discoveries
of black holes in the universe.

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So we look at very interesting
astronomical objects

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at very great distances.

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In conjunction with
Hubble, Webb will

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be looking to identify
many Chandra sources that

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are not seen with Hubble.

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Now we're outside the
facility where the mirror

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testing is being done.

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And you can't help
but see this long tube

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that is connected to
the building itself.

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I'm told it's almost six
football fields long.

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Martin, what was
this tube used for?

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This tube is very important for
separating the telescope that

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was on the Chandra
X-ray Observatory

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from x-ray sources located at
the other end of the building.

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It has to be this
length in order

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to make those x-ray sources
appear like tiny stars

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so that we could determine
whether our x-ray telescope

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could distinguish small
objects in the sky.

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Why is it still here?

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Chandra was tested
in the mid-'90s.

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It's still here because
it's very, very useful

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for many programs.

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The vacuum chamber is being
used to test the Webb optics.

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And we hope to be testing x-ray
telescopes in future programs.

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Well, thanks for
your time, Martin.

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You're quite welcome.

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The testing here for
the Chandra Observatory

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ran about six months,
from 1996 to 1997.

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Then the telescope
was sent off to be

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integrated with the
rest of the observatory.

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Chandra was launched
on July 23, 1999.

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Thanks for joining us
for another edition

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of Behind the Web.

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