[MUSIC PLAYING]
Each layer of the sunshield on the Webb telescope
works a lot like your umbrella.
It's folded up during launch, but when
it comes time for the mission, each of the layers
unfolds to become the size of a tennis court.
But there are features on the layers
that make the sunshield look a lot like a big kite in space.
To find out more about how this is done,
we've come to Huntsville, Alabama.
It's known as Rocket City.
But it's also home to the sunshield manufacturer, ManTech
Corporation.
So Matt, I was told that you guys here at ManTech
put features on the sunshield that make
it look like a kite in space?
Yes, we do.
There are several things that we add to the sunshield.
The first thing we start with is a light line,
which gives the outside shape.
OK, this design here, it runs along
the edge of the sunshield?
Yes.
OK.
Once we go from there, we move into the catenaries.
What's a catenary?
It's a metal strip, basically--
Mhm.
--that gives the membrane its three dimensional shape.
OK.
Once we add the catenaries in, we come in
and we put the compliant border into the actual kapton
material itself.
Allows the membrane to move and still keep an inner shape
that is flat and mirror-like.
OK.
And you want that flat, mirror-like surface because--
We want it as flat as possible because we
reflect more heat that way.
This is a pretty cool display, but can we actually
see something in action?
Yes, we can.
So, what's going on here, Matt?
We're folding up the light line to allow
us to place it on the membrane.
So, this is made out of stainless steel?
Yes, this is a stainless steel.
It is very light and very thin.
How long a strip is this?
This is about 34 feet.
And once we put the light line on,
we move into place two metal catenaries
onto the inside of the membrane to give the membrane its shape.
So, why do you have three people working on the catenary?
We can't afford any kinks or wrinkles in the material,
because it does affect the shape of the membrane.
So, what do we have here?
They're going to place the material
on top of the compliant border tool,
so that we can form a vacuum.
So, it's actually suctioning it?
Yeah, it puts a vacuum onto the film
and pulls it down into the shape that we're trying to achieve.
This is one of the slowest processes we have.
I can imagine, but he's real precise about it.
It takes almost 12 days to do this
around the complete perimeter.
Oh my, for each layer?
Mhm.
Oh, my goodness.
If you have a couple of these, we
can show you what it actually does
to help the performance of the sunshield.
OK.
We'll place this tape down and simulate
the catenaries position.
OK.
Because basically, catenaries are stiffeners, if you will.
Exactly.
You get any little wrinkle out here--
Yes.
--will cause unflatness--
Performance is degraded.
--performance is down a lot.
Mhm.
And this is just a small surface.
I would imagine if you're actually looking
at the larger scale sunshield
Exactly.
--you're going to see much more of a degradation.
Yeah, it's so much more magnified--
Yeah.
--once you get into the larger scale.
You'll recognize a couple of features
that you've already seen installed
on the membrane, such as the light line, the catenaries,
and the compliant borders.
We use different shapes in different areas
of the membrane.
To absorb any kind of deformation
that might be happening at the edges?
Yes.
Or any part of this?
Any part of the sunshield.
OK.
Well, thanks so much, Matt, for showing us what
you guys do with the sunshield.
All right, thank you.
The positioning of these features
vary depending upon what layer they're working on.
Because the five layers differ in shape and size.
Thanks for joining us for this edition of Behind the Webb.
[MUSIC PLAYING]