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the james webb space telescope is

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primarily an infrared telescope which

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means it has to be kept as cold as

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possible the shape of the sun shield

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helps it achieve and maintain those low

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temperatures to find out just how

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engineers on the ground are making sure

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that each layer of the sun shield is

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built correctly we are here at mantec in

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huntsville alabama so jason this is the

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sun shield what's so unique about its

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shape

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this one tenth scale model the sunshield

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from afar looks like a flat piece of

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material but it actually has a doubly

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curved shape which means it's almost a

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funnel towards the center of the

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telescope what we're about to see is a

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full scale layer and show you how we

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measure that shape

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there are five layers is each layer the

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same no actually each layer is different

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the layers are designed so that we get

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maximum heat rejection between each

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layer all the way up to layer five on

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top so that way layer one will always be

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the hottest facing the sun and layer

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five will be the coldest allowing the

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telescope to achieve operating

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temperature so you mean the shape of

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each layer is different yes actually it

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is

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great so we can go check it out now yes

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we can all right great over here we

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actually have one layer deployed in a

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flight-like simulator

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and it's tension to the loads that it'll

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see on orbit so like you said it is not

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flat

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no it's not you see it makes a funnel

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type shape towards the center of the of

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the telescope where daryl is standing

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the telescope will be sitting right

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there in the center facing us so what is

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he about to do

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he's about to set up a laser scanner we

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use the scanning system to measure the

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overall shape of the membrane we

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actually do seven different scans in

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seven locations

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each scan one 360 degree scan

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creates about 407 million points we

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combine those seven scans together to

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get enough points to build a solid 3d

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shape of the membrane to compare to our

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analytical model thanks jason for

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showing us just what you guys do to make

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sure the sun shield is built correctly

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thanks mary for coming to see it

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after testing here is completed the

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layer will be prepared for integration

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with the rest of the sunshield thanks