Thursday
14th January - Snow Storm
From
John Storey.....
Last
night lots of Hercules arrived when I was trying to get to
sleep, and then I started dreaming about Hercules only to
be woken up by another arriving. But the one I was dreaming
about was even louder so it put me back to sleep again (I
think).
When
I awoke the station was in the midst of a snow storm, with
a 36km/hr wind blowing at right angles to the runway and wind-blown
snow going everywhere. Visibility was down to about 50 metres.
They even closed the big doors at the front of the dome -
something I've never seen before and in fact I didn't even
know the doors existed. Bob Lowenstein was also surprised
by the doors, as he hurtled down the big slope to the dome
entrance on his skis...
Under
normal summer conditions here, when the wind is low and the
temperature above -30C, I'm quite comfortable walking around
in my Rockports and with my hands retracted into the sleeves
of my parka as a substitute for gloves. However today was
a stark reminder of how quickly the weather can get very nasty,
when nothing short of the full ECW gear will keep the elements
out.
It
was very pleasing to see *no* snow accumulation on the sodar
antenna. As hoped, the cover shakes like a drum-head in the
wind, and keeps itself completely free of snow. On the other
hand the sodar doesn't work at all when it's windy. Daniel
says it's because the noise of the flags flapping etc drowns
out the echo.
Daniel
and I made an insulated collar for the antenna so that its
little bottom can be kept as warm as possible by the AASTO
room heat.
Peter
has finished machining up parts for the tip-tilt secondary
and has reassembled it. He's also measured the weight of the
mirror and the spring constant of our phosphor-bronze diaphragm
spring, calculated the maximum acceleration of the mirror
and adjusted the tension accordingly (ie, to about one tenth
of what it was before). He has also beautifully documented
all the details, setting new standards for the project.
Abu
is sitting forlornly while we await the arrival of Al Harper
and the new cold head. At last count they still hadn't left
Christchurch.
I
tried to get the Toshiba to work but without success. The
power light doesn't come on and it makes no attempt to read
the floppy. Technically speaking, it's stuffed.
I'm
about to put the SBIG camera and X-Y stage and Vectra computer
business together, and see if it all works. Al Fowler has
zero confidence that I'll be able to figure it out - slightly
more than I have. Actually it looks pretty straightforward,
but I can't help wondering:
1.
Why the "Z" motor on the X-Y-Z stage is loose,
2. What the spare translation stage is for.
Today the AASTO had a visit from a reporter from the Washington
Post. He is writing a major article about Antarctic physics,
so we gave him the full tour. He especially liked the webcam
movie, and said he was very keen to see the new one that Melinda
is making.
Thomas
has contacted PI in Germany on our behalf and arranged for
them to specially make a replacement PZT. This can be flown
out to Christchurch in a couple of days, which is fantastically
good news.
The
latest addition to the upstairs lounge is - to my complete
astonishment - an automatic ice-maker. That's something that's
clearly going to be really useful here. I'm going to survey
other US stations around the world to see if the lounge in
Saudi Arabia has an automatic sand maker. Such a trend in
completely superfluous appliances could lead to a fog machine
for the London embassy and an aphrodisiac dispensing machine
for the White House.
Matt
has been initiated into the delicate art of dallas dangling,
and has rewired the sensors to the "big" supervisor
computer. The new wiring complies strictly with the definitive
dallas dogma of the dallas-danglin' big daddy himself (mcba):
ie a straight daisy chain with no branches, twisted shielded-pair
cabling and 0.1 mu capacitors at every point where voltages
might otherwise be tempted to get out of hand. It's also routed
mostly away from other digital cables - as long as you don't
count ethernet as digital. With luck it will work more reliably
than last year's wiring, which was basically a carefully uncontrolled
experiment to see
just how tolerant the dallas sensors really are. Here's
the detailed dallas designation dope:
1400000008D34910 Flag pole (Australian), 1 metre above AASTO
3B00000008F1A510 AASTO ceiling next to air intake baffle
E800000008D42B10 Sodar baseplate
Since
last summer the station has acquired a brand new Caterpillar
tractor for dragging the snow grader and other things around.
It's one of the modern curvy ones with rubber tracks and has
been named, appropriately enough, "The Drag Queen".
Caterpillar certainly seem to be the heavy machine of choice
around here. As the bumper sticker says: "If it ain't
a Cat, it's a dog."
John
 
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