1st February 1995
From
Michael Ashley.....
We continue to pump on
IRPS, which is being heated to +35C to accelerate the outgassing.
By noon we have the liquid nitrogen solenoid system working
nicely under computer control, and can cause LN2 to squirt
out of either of two nozzles with a simple keystroke. We point
the nozzles towards the entrance-way of the room that we are
in, and give some SPIREX people a shock when they come looking
for tools.
The LN2 control system has to be fairly
clever since we don't want it to accidently open a solenoid
and let out 50 litres of precious LN2 onto the floor. It has
to be able to cope with every imaginable error condition (e.g.,
the computer crashes after it gives the instruction to open
the solenoid). To do this, we are using a ``heartbeat'' circuit
in the control box that requires a special sequence of logic
pulses on five TTL lines (two highs, one low, one negative
going pulse, and a positive going pulse within 1 second of
the negative going pulse - hopefully this sequence can not
occur by accident!) from the computer before it enables control
of the solenoids (and if the pulses aren't re-issued within
100 seconds, it defaults to a safe state). This all seems
to work, which is pleasing.
Incidentally, the LN2 we are using
is shipped in from the States, but this winter CARA hopes
to have a liquid nitrogen manufacturing plant operating just
outside the Pomerantz Building. The plant works by liquefying
air, and then using some sort of membrane to separate the
liquid oxygen and nitrogen. LN2 is colder than liquid oxygen
so is better for our purposes - it is also much less dangerous.
By the afternoon we can read the ion
pump current with the computer, and can use this information
to calculate the vacuum pressure in IRPS. Our goal of a completely
automated instrument is getting closer.
After dinner we go outside to take
some publicity shots of us, with various items of UNSW memorabilia,
at the ceremonial South Pole. We would have taken a picture
with the UNSW official flag, except that the Vice-Chancellor
lost it the week before we left, so we had to make do with
a UNSW tea towel that John bought at the Logo Shop. The weather
was particularly cold (-38C, or -53C if you include windchill),
and after factorial-n combinations of flags, towels, pennants,
camera lenses, video gear, etc, my fingers were practically
frozen off. Luckily the batteries in both the camera and the
video recorder stopped working in the cold (which is the only
way to stop John from filming something - even ice on the
lens is no obstacle), and a hasty retreat to the warmth of
the galley in the dome restored sensation to my digits.
Jamie Lloyd left today for some ``R
& R'' at McMurdo. In a week he will be back at the Pole,
and will stay here all year. McMurdo is not the ideal site
for ``R & R'', but from experience the USAP has found
that if people go back to Christchurch, they tend not to come
back. McMurdo is sufficiently different from the Pole to be
a nice break (e.g., it's got dirt), but sufficiently unpleasant
to make you want to come back (e.g., the food is not as good
as that at Pole).
Before Jamie flew out, John took the
opportunity of interviewing him on camera, and getting Jamie
to do a guided tour of the station for the folks back home.
John used the radio microphone for this work - the wind was
so strong outside that Jamie had to shout to make himself
heard. When using the radio mike it is necessary to have the
camera outside its protective Sports Pack, so John had to
periodically warm it up inside his parka, giving him a becoming
pregnant appearance.
At 5:05pm, an LC-130 flies in, and
John is ready with his camera and shoots off 27 pictures of
the landing/taxing/unloading process. John is already planning
a series of slide nights when he gets back to Australia, and
hopes to have enough material to devote two nights to LC-130s.
Jean Vernin's balloon cargo finally
arrived (it was sent on Dec 1, and spent a few weeks here
and there in various customs halls). Jean excitedly opened
the boxes and began preparations for a balloon launch. (Aside:
I may not have mentioned that John and I are also involved
with a collaboration with Jean (and Rodney Marks) to measure
the microthermal variations in the atmosphere over Antarctica).
At the CARA meeting tonight, the usual
pre-meeting song was dispensed with. Jeff Peterson complained
that the haunting melody of the JACARA song had been going
around and around in his head for the last two days.
Every evening at about 8pm the satellite
peeps above the horizon for four hours, and we have Internet
access. It is fairly slow (perhaps 32K baud for the entire
station), but adequate for sending mail. Unfortunately, it
is hard to get access to a PC since many of them are used
by people playing mindlessly violent games. Having left much
of the ugliness of modern society behind us since arriving
in Antarctica, these games seem strangely out of place.
On a sombre note, a person was killed
today in McMurdo while climbing Castle Rock, a spectacular
outcrop about 5 km from the town. The flag at the South Pole
station was flying at half mast.
Michael Ashley (with contributions
from John Storey)
 
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