What’s inside the big white thing?

It’s our the test version (called the pathfinder) of JWST’s backplane. What’s the backplane you ask? The backplane is the structure that supports the primary mirror segments, as well as the structure behind the mirrors that holds the telescope’s instruments.

This special JWST transport is called STTARS – or Space Telescope Transporter for Air Road and Sea. Actually the big white container was shipped from Northop Grumman in southern California aboard a C-5 to Andrews Air Force Base – and then the truck brought it here at night, when it would interfere with traffic the least.

Credit: NASA/Chris Gunn

They unloaded the huge white shipping container and prepped it to go into our huge cleanroom at NASA Goddard:

Credit: Maggie Masetti

I missed them pushing it into the cleanroom – but I did see them prepping it, as shown above. They actually turn on this apparatus that seemingly makes this big container work like a puck on an air hockey table, allowing them to push it around relatively easily.

When I checked back later in the day, it was in the cleanroom:

Credit: Maggie Masetti

Before too long, they had undone all the latches on the cover to this container, hooked up the crane too it – and then finally lifted it off!

Credit: Maggie Masetti

Next they took the wrapper off the pathfinder backplane – and there it was! It looks just like the flight one will. And helps gives a sense of scale for just how big this telescope will be! You can see the sort of hexagonal shaped holes, which is where mirror segments will go – and the long struts are the booms that will fold outward and support the secondary mirror.

Credit: Maggie Masetti

The big reveal:

Credit: Maggie Masetti

Here’s a photo from above:

Credit: NASA/Chris Gunn

This all happened on a Friday afternoon – on Monday they moved the pathfinder backplane over to the assembly stand.

Credit: Maggie Masetti

Credit: Maggie Masetti

Credit: Maggie Masetti

Later on in the week, two of the secondary mirror booms were extended.

NASA/Chris Gunn

So what’s next?

Over the next few months, they’ll be using a robot arm to mount the spare second mirror at the end of that boom – and also install two spare primary mirror segments onto the pathfinder backplane. After that, the whole thing will be going to NASA Johnson for cryogenic testing in the enormous Chamber A. All a part of the dress rehearsal for the real thing!

Tags: JWST