State of the job.

The people I work with directly in the lab are: Tom and Iliya, the techs; Ken, the cognizant engineer; and Todd, the non-cognizant engineer. Ha ha, just kidding, Todd. Actually, Todd invented and patented the optic assembly procedure.

This post is a more complete description of what I actually do every day.

When I arrive at the lab in the wee hours, the optics look like this:

The metal pieces with tubing attached are called load bars. They slide into slots in the disks at each end of the optic. Air pressure in the tubing forces a plunger down to press the next layer, strong backs, against the optic. Here is a photo after I've removed a few load bars:

(I realize that it's hard to make things out in this picture, and the program I used to post this entry doesn't allow clicking on the photo to get the full-sized version. If you're interested, click here.)

The optic is visible in the area where both the load bars and strong backs have been removed. Strong backs are visible above that area. I remove the load bars followed by the strong backs, until only the guide wheels remain:

Then I remove the guide wheels. All of this hardware removal is kind of scary, since metal has very little trouble smashing the thin optic glass into smithereens, given the opportunity. With the guide wheels removed:

At this point I make a few adjustments, check settings on the computer, and start the grinds.

As you might recall, the optics are made of layers of specially formed and coated glass that are separated with great precision by graphite spacers. The purpose of the very large tool on which the optic is mounted is to grind the spacers to the correct height. There are three grinds, each of which takes slightly over an hour. The first removes much of the spacers, the next a bit less, and the final grind ensures that the spacers are within micrometers of the specification. While the grinds are running, I listen carefully for any sound that might indicate that something is not quite correct, and also monitor the room's temperature and humidity. While I'm doing that, I prepare the strong backs for the next layer. This is a naked single strong back:

It's a bit hard to see, thanks to my lack of photography skills. It is a metal bar with protrusions on the ends so that it can slide into grooves on the guide wheels. The top of a strong back is slotted, and O-ring material is inserted into the slot. The picture is of a single-slotted strong back; there are also double strong backs, which are used at the glass segment junctions.

The next thing I do is apply Teflon tape to the tops of the strong backs. The tape helps to hold the spacers in the grooves, and also protects the strong backs in case some epoxy drips. Here is the strong back with the tape applied:

When that's done, I insert the graphite spacers into the slots:

If all of that sounds simple, it is. However, everything has to be done precisely. Last week I made an error, and Todd had to send a non-compliance report to NASA. Since then a black car has been parked across from our apartment. There are two guys in there with sandwiches and binoculars. I don't know if they have anything to do with NASA, but it's suspicious, as is the notice I just received that my tax returns for the last 15 years will be audited. Oh, well.

When the grinds are finished, Tom and Iliya magically appear. They clean the optics, scan the spacers, and then epoxy the glass segments to the spacers that were just ground. They then put epoxy on the spacers in the strong backs and slide them down on top of the glass. They put load bars on top of the strong backs and turn on air pressure to press everything together while the epoxy sets. And so it goes.

I used to get up at 04:00 so the grinds would be done before Tom and Iliya arrive at the lab. But about a week ago, Mother Nature went off before my alarm clock. It was 03:55, and I quickly calculated that it made sense for me to get up then, although pee-and-go-back-to-bed had a definite appeal. Even though that 5 minutes didn't seem like much, it made a big difference on my commute home. There are a couple of schools in one place on the commute, and the traffic really gets backed up when parents are dropping their brats off. (Whatever happened to walking to school?) So now I get up at 03:50 and hope it doesn't get earlier when the optics expand.

My workday at the moment is 4 hours, because of the time it takes to do the grinds. Soon FM1 will switch from sextants to dodecants, which means there will be 120 sets of load bars and strong backs instead of 60. And about 15 assembly days after that the other optic will expand, so everyone will be much busier. The big thing for me will be safely removing all the hardware and starting the grinds early enough.

I'm using a new program to write and post this entry, so if you see something extremely weird, that's why. I'll be working on it!