South Pole Diaries 1998/99



Tuesday 12th January - Mostly Bad

From John Storey.....

Most of today's news is not good.

Last night we had a meeting to discuss the PZT assembly behind the secondary mirror. Although we were initially quite proud of our design, Peter and Fred were able to point out some rather serious problems with it. First, the length of the aluminum rods on the end of the PZTs means that the weight of the mirror creates a bending moment on the PZT when the telescope is tipped. Secondly, the balls at the end of these rods are forced to slide across stainless steel grooves. Thirdly, because the backing plate is made of aluminium, rather than Invar (our original Invar one was the wrong shape), there will be a substantial sliding motion required. All this is in addition to the lateral load that we are placing on the PZTs through the weight of the mirror. In effect, the mounting almost *required* one PZT to break in order to accommodate the thermal contraction.

We decided the best thing was to machine grooves into the end of the aluminium rods, allowing the balls to roll rather than slide. (IRIS II at the AAT uses a similar system.) It was in disassembling one of the PZTs to do this machining that we broke it.

If we can't get a replacement we will instal the dummy PZT, and basically be back where we were 2 months ago.

The Abu cryo-cooler is still going ker-chug ker-chug, but to little effect. Al Harper is bringing in a new cold-head: it will take a week to instal and test. If it doesn't succeed in bringing the temperature down we will have little choice but to cancel the whole project.

A final piece of sad news: Walter Wild, an adaptive optics expert and astronomer from the University of Chicago, died yesterday of a heart attack, aged 44.

Last night the mail spooler (or name resolver or whatever) of magnolia got jammed, meaning that none of my mail went in or out. Victoria the unix she-guru fixed it this morning just before the satellite set, and there was a rash of messages transferred but not, I think, all.

Thanks to some very helpful messages from mcba, jfm, Mick, Andre and especially Thomas, we've solved most of the minor problems we were facing.

While I think of it, the last team here clearly made a big impression on the station. I'm often being asked (mainly by the women), "where's Mick, where's Andre, where's John?" (or, "where's that big hairy guy, where's that cute eskimo, and where's that Australian guy with the American accent?) and I have to confess they've scattered to the four corners of the earth.

Having got to bed late last night after picking up bits of broken PZT from the floor, I was awoken again at around six by a D7 bulldozer just outside my tent. Apparently they'd decided to rearrange the snow. Given that Antarctica is twice the size of Australia and is mostly snow, they had plenty to choose from and I cannot see why they couldn't have gone and rearranged some other bit. I guess I wasn't in a very good mood anyway.

Then they decided to fix the Rodriguez well that supplies water to the station, using waste heat from the diesel generators to melt snow. This meant we went into water conserving mode, which means paper plates and plastic cutlery in the dining room, just like being on a picnic.

The psychologists are continuing to watch my efforts to grow to love Windows 95. My attempts to actually print something today came to nought. Maybe I shouldn't have disconnected myself from the Microsoft Network by turning off the Microsoft Netware tool that was insisting I impersonate someone else so I could log into a Microsoft mail-server. As soon as I find the Windows 95 CD I'm back in business.

The good news is that, with jfm's help, I've found out what the other mouse buttons do! Namely, middle button: nothing; right-hand button: bring up a menu to change the screen colour. Hey, this is great, Bill! It's really useful having that on a mouse button! I like to change my screen colour every 5 minutes; much more often than I want to, say, print things. Oops, the shrinks are writing stuff down in their notebooks again...

The really funny thing is that *everyone* from PI AG (Deutschland) to Mick to various people's kids sent messages saying: "of course the bridge won't balance unless you include the extension lead, which has about 5 ohms resistance". Well yes of course I know that (now) and so I've taken the resistors out of the strain-gauge preamp while no-one was looking and it works perfectly and it's probably Ant's fault anyway.

The good news today was that Michael Burton, Daniel and Matt arrived this afternoon, along with the sodar. The sodar has been uncrated and looks good; the sodarmites also appear to be in good shape and ready for some hard work.

I've had no success with the Orbcomm. It's all wired up and claims to have spent the last 4 hours looking for a satellite. I've suggested to it that it try looking in the sky, rather than underneath buildings or hidden behind bulldozers but, even with this helpful advice, it's having no luck. I've now taken Andre's "short big" antenna and lashed it to a flag pole. This brings it 3 metres closer to any passing satellite than it was before, which might help.

Tonight there are a couple of talks by a team of French and a team of Dutch folk who are skiing their way across Antarctica. I've decided to give the talk a miss partly because I want to get on with doing stuff, and also I find it hard to fathom why anyone would want to ski across Antarctica when it's already been done. Particularly bizarre are those folk who choose to walk, when skiing is a lot easier and being towed behind a parafoil easier still. If you're going to be cold and miserable for 6 weeks why not just lock yourself in a meat freezer and listen to Spice Girls tapes. I look forward to meeting the first group to roller-blade across the continent dressed only in board shorts, T-shirts and back-to-front baseball caps.




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