- We're here at the
Goddard Space Flight Center
in the Integration and Testing area.
Now you see these small things behind me,
these are smaller versions
of the space environment simulator,
and inside is the beating heart
of the James Webb Space Telescope.
It's the Integrated
Science Instrument Module,
otherwise known as ISIM.
(pulsating electronic music)
In just a few years, the
James Webb Space Telescope
will fundamentally
change our understanding
of the universe.
With a massive 18-section mirror,
measuring 6.5 meters in diameter,
the James Webb will allow our species
to gaze through time to the formation
of some of the first stars and galaxies.
That's pretty cool stuff, right?
But, how does it work?
It all depends on what's often called,
the heart of the James Webb, the ISIM.
The ISIM houses all the
light detecting instruments
on the satellite.
This includes an array of instruments
such as a specialized infrared camera,
spectrographs, and more.
We spoke with Instrument Systems Engineer,
Begona Vila, to get the scoop
on what these instruments sense,
and what sort of science
we expect to conduct
once the James Webb is in orbit.
- So we have four main instruments
which are the ones that are
going to be taking the science
into space, and when those instruments
are put together, we call that the ISIM.
So the instruments, each of
them, has a special capability.
So they compliment each other very well.
We have one of them called NIRCam.
It's a camera.
It will take images of
different parts of the sky.
We have another called NIRSpec
which will take a spectra.
I think everybody knows you can put
this lid to take a spectra.
NIRSpec has the capability of
doing up to a 100 at one time.
So you can take lots of x-spectra
in one part of the sky together.
Then we have MIRI which is the only one
that will go to the far infrared.
The other three instruments operate
between 0.6 to five
microns in the infrared.
MIRI is able to go to 25, and that MIRI
is so special because they
cool it down even further.
They go to six Kelvin
with a special cooler
to able to extend to that range.
And then the fourth instrument,
it has two components, one
of them is called NIRISS,
and it can take images and also spectra.
And the other one is the
Fine Guidance Sensor.
So the Fine Guidance Sensor is one
of the critical components
of the telescope,
because it allows you to
find a spot in the sky,
whatever the other
instruments want to observe,
and it's the one that will
help to keep the pointing
of the telescope really steady
so all the other instruments
can do their science.
- [Voiceover] And there's
an important point here.
We're talking about shooting
some tremendously sensitive
instruments into space,.
So, we need to be sure they
can withstand the rigors
of the journey.
This includes stuff like the
intense vibration of launch
and the immense heat of the sun.
So, before ISIM ever leaves the ground,
scientists put it through a
battery of extensive tests
to simulate the conditions of space.
Temperature testing is one
of the most crucial aspects
of this program.
Since these instruments detect heat,
they need to be as cold as possible,
but they still need to work
while in these incredibly cold conditions.
This is where the sunshield and
temperature testing come in.
We spoke with Aerospace Engineer Detailee,
Jody Davis, to get more information
about the testing process.
So, there are four main instruments,
and they have a near-infrared
and mid-infrared
capabilities, and those instruments
love to be nice and cold.
So, we're talking 40 Kelvin,
which is minus 387 degrees Fahrenheit,
and, then one, the
mid-infrared instrument,
loves to be at a balmy seven-K,
minus 447 degrees Fahrenheit.
So, because these instruments are so close
to absolute zero, they
need to remain cold.
And electronics, for instance,
love room temperature.
So, we need to dissipate all of that heat
before we get to the science instruments.
So, we have what's called
a harness radiator.
So, all of that we test here at Goddard,
and we go through a very
large, extensive test sequence
as we build up ISIM and then
the rest of the telescope.
So, right now actually
we're standing in front of
a cryogenic vacuum chamber,
and that actually has
ISIM in there right now.
And it is testing and verifying that all
of the science instruments
and the other functions
of the other components are working well
at those very, very low, low temperatures.
Just earlier this year, we went
through a successful vibration test.
And it also goes through an acoustic test,
basically, an environment
that we see during launch,
as we launch on an Ariane 5.
So that vibration testing was successful.
That's complete, and so
we're getting very close.
- So there you have it.
ISIM, the Integrated
Science Instrument Module,
from stem to stern.
This thing's gonna fly a
million miles into space
and if you'd like to learn
more about what it finds,
then stay tuned and check us out
at now.howstuffworks.com.
