Last few clean room jobs

We're still working through our checklist of jobs to do before the SAC can leave the clean room...  Next up: the installation of Blackbeard's Patch - a small baffle that needs to be suspended between M2 & M3.  While not an award-winning photograph, this flash pic does show how effectively the Nextel paint that we used absorbs light. 

The 3 attachment strings were ingeniously caught (fish-style) through the hole in M3 using a hook on a stick which was fed through the sides of the SAC cage.  The baffle was roughly centred  by eye with the 3 of us each tugging on our respective strings.  Then the fine alignment was done with the alignment telescope, by measuring the position of a tiny hole in the centre of the baffle (illuminated from below) & comparing that to the coordinates of the coat hanger reticle.

Removing the Faro labels around the outer edge of M4 had pulled some of the paint off so we opted for a bit of cosmetic touching-up.

With no scale bar in the image, one could be excused for assuming that the next item is one of the Space Shuttle's main engine nozzles...

But it's not.  While waiting for the paint on M4 to dry, we hauled out the very nifty new conical baffle for the central hole in M5 & carefully installed it.

Then took the coat hanger out from between M2 & M5 & put it back in its box for safe keeping.

After that, the paint on M4 was dry & the steering wheel could go back in...

& the repeatability of attaching the SAC reference mirror could be tested.

Lastly, it was time to blow the surfaces of M5 & M3 with compressed air to remove any dust before closing up shop for the weekend.

With all the new baffles in place, we took turns crawling in underneath the SAC & looking up through the hole in M3.  We leave it as an exercise for the enthusiastic reader to figure out what all one sees from this primary mirror type perspective!

Here's a similar view, but taken with a flash this time, & slightly off axis to provide more clues...

Watch this space as we hope to move the SAC out of the clean room on Monday to prepare for its return to the tracker later in the week!