Antarctica 1995/1996 diary part 5
Dec. 26, 1995: Camping in the snow
Dave didn't like it too much, but Ashok and I went to the 'Field
Safety Training' (the official name) alias 'Survival Camp' (to scare
you) or 'Happy Campers' (which most appropriately reflects the event).
All I knew about it was that I had to show up at 9am with my ECW
(Emergency Cold Weather) gear in the SAR building. Everything here
goes by a TLA (Three Letter Acronym) and SAR stands for Search and
Rescue. We were 16 people there, 4 scientists, about 5 Navy people,
and the rest ASA people. ASA people staying over winter are required
to take the course, and the Navy normally pushes all their people
through this course. We loaded some training survival bags etc. on a
Spryte (small track vehicle) and a large track vehicle with a PAX
(passenger) cabin and drove out to Scott Base and then a little
further on the Ross Ice Shelf. It was very foggy, the visibility was
rather limited, some snow falling, quite some wind, and not too warm.
After some hot beverages in a Jamesway we went for some training in
the snow to a place below Castle rock where a small glacier joins the
ice shelf. In a relatively steep snow slope we got some training on
using an ice axe and in self arrest, i.e. how to keep you from sliding
down in a steep snow field in case you should fall. The most
interesting part was going down head first at quite some speed and
getting to a halt within a few meters. The trick is to put the pick
of the ice axe into the snow while firmly holding the axe. This then
rotates you around so that you end up feet first (i.e. downhill). You
then pull up and put the tips of your feet into the snow. This works
pretty well, although I can still feel my right shoulder from this
exercise.
Lunch consisted of bagel, crackers, pepperoni etc. in a Jamesway.
After that we had some theory on low temperature injuries and how to
deal with them, altitude sickness (the polar plateau is at 11,000
feet), and how to operate the stoves found in the survival bags.
After getting sleeping bags (heavy down for real expeditions, i.e. the
good stuff), a fleece liner, and two full-size mats), we drove out
onto the Ross Ice shelf. We split into two groups and first set up a
Scott tent (which is based on Scott's tents from the beginning of that
century) that consists of four poles that converge at the top and that
has four corners and yellow canvas exterior. We learned how to put it
up under heavy wind load with the help of some ropes and how to anchor
it safely in soft snow with so-called dead-man anchors. This tent
looks really old-fashioned, but it seems to do very well out in the
field. Another trick is a plastic tube in the top. When a stove is
operated inside, there needs to be ventilation because of carbon
monoxide (some people died a few years ago in such a tent). The top
of the tent tends to be warmest and is therefore likely to melt snow
and ice that form. The wet opening at the top of the tent might
collapse and freeze, thereby closing the ventilation hole. Therefore
a plastic tube is inserted in the top to keep the ventilation going
under all circumstances. Winds can be very strong in Antarctica.
In the SAR building they have a bag of rocks (about 1 inch = 2.5 cm
in diameter) that were recently found in a Scott tent after passing
through the canvas.
We also built up a regular geodesic dome expedition tent for two
people behind a snow wall, e.g. we learned how to make snow blocks
with shovels and saws. These modern expedition tents (NorthFace VE-14
and similar products) do relatively well, but under heavy wind
conditions they do not as well as the Scott tents, to my surprise. A
recent story was told that two guys were blown across the ice inside
their geodesic dome tent. Their ECW gear was blown out of their tent.
Unfortunately they were sleeping almost naked in their sleeping bags
and had a hard time not to freeze to death after their tent came to a
stop. That's why you want to safely anchor even a geodesic dome tent,
build a snow wall around it, and do not sleep naked in the sleeping
bag.
Unfortunately, the snow was too soft to build a real iglu. We
therefore got all our bags together and covered them with a sheet.
Next, we shoveled snow on top until the whole thing was covered by
more than 2 feet (60 cm) of snow everywhere. The snow was then
compressed with the shovels. By digging an intermediate opening into
this snow building, we were able to remove all the bags. We extend
our future 'home' by digging downwards inside and we built an entrance
by digging downwards on the side, then horizontal, and then upwards
again (like robbing a bank). This keeps the cold air outside while
still providing some fresh air. Finally we closed the intermediate
entry. We ended up with a nice iglu that had space enough for 3
people. Tiffany (a Navy weather person) in the mean-time took care of
preparing hot water in the Scott tent. This provided us with tea,
coffee, soup etc. Water was produced by melting snow. The stoves
were MSR Whisper Light and other well known expedition stoves, again
the good stuff that was familiar to me. Dinner consisted of
freeze-dried packages that had to be filled with 2 cups of hot water
and let soak for 10 minutes. Although the temperature was always well
below freezing, the meal was still pretty warm after 10 minutes. So,
I had beef Stroganoff out on the Ross Ice shelf. Shoveling snow
always kept us warm. We improved our iglu entrance and built an
additional snow wall for operating the stoves outside in the morning.
The weather improved in the evening and we were able to see a little
further. We also had some cross-country skis with binding for the
large bunny boots, with which I skied around for some time.
The two instructors, Bill and Forrest, were both former mountain
guides. They did a
very good job. They slept in the Jamesway that was about half a mile
away from our camp. I slept in the iglu along with Bob (former ski
instructor with a BS in science education, works here as a general
assistant for ASA, i.e. does everything) and Keith (Navy communication
experts). The sleeping bag and the mats were really great and I never
felt cold.
Dec. 27, 1995: Getting out of the iglu and into the crevasse
I did not sleep too well because the ground was rather hard and not
very flat, and I felt my back. I got up around 8 and had a cup of hot
tea. At 9am the instructors picked us up with the track vehicles
after we had cleared all our stuff out of the iglu and the tents and
had packed up the tents. Bob and I walked back but had our gear
transported in the track vehicles. Back at the Jamesway we got some
hot water for tea or chocolate. Then we set out for the glacier that
extends into the ice shelf close by. We learned how to walk on a
rope, how to mount a harnasse, and hiked up onto the glacier. There
we got close to a crevasse and each of us got lowered into it to a
depth of about 30 feet. The instructors let us done, while the other
guys pulled us back out on a second rope. This was done in a very
safe manner and I never felt anxious. The view inside the crevasse
was great, and I was able to take some picture with my small camera.
We got a sandwich and some drinks in the large track vehicle on our
way back to McTown. The weather today was great with only a few
clouds and I got quite some sunshine. I hope that the sun blocker did
its job. Back at the Safety and Rescue house in McTown around 3:30pm,
we had to give back your cups and spoons we received the other day and
received a patch on the other hand. In summary, I enjoyed the course
very much.
After having a shower (a little longer than 2 minutes), I went to
Willy Field to help out with the optics. Dave had decided to exchange
a camera lens and remount some mirrors. The image quality, however,
was not improved. By moving the Barlow lens from its supposed
position further away, it was possible to get a reasonable focus
through the main telescope. The change of the lens enabled us to get
a collimated beam in the Fabry Perot. However, the beam is now much
smaller and the spectral band-pass is probably severely affected.
Again, we are struck by the cheaper and faster approach (anybody can
make it cheaper and faster, the trick is not to do it worse). By the
end of the day and after having dinner at Willy, I do have some hopes
that we can at least get some reasonable images up in the
stratosphere.
I can still feel my arms from the snow shoveling and pulling the rope
with up to 250 pound people on it. I enjoyed a good night's sleep on
a regular bed.
Dec. 28, Fiddling around with the optics
I still felt a little tired from the survival camp and therefore only
made it on the 9am shuttle out to Willy. The weather was not too good
and we therefore put the solar panels on the gondola and weighed the
whole thing for the NSBF people. Flare Genesis weighs 3150 pounds.
With the ballast and the SIP (Science Instrument Package that provides
us with satellite communication and controls the balloon), it will be
more than 4000 pounds (about 2 metric tons). The weather improved and
we started working on the optics. The image of the aperture is still
too small on the Fabry-Perot and I still need to figure out why.
Anyway, in the evening we ended up with a reasonable beam on the
Fabry-Perot and we hope to get some good images soon.
It seems that some of the small mirrors on the optical bench have
internal cracks. We also discovered that one of the lenses was
mounted in the reverse way, things that just should not happen. Dave
seems to be rather careless. The cracks are probably produced by
differential expansion of the mounts and the mirrors, which were glued
together at APL (Applied Physics Lab of the Johns Hopkins University)
with probably inappropriate glue. It might well be that the mirrors
are sometimes in bad optical shape now. But we have no reasonable way
to assess the quality of the mirror surfaces here in the wooden silo.
Dave tried to do a dry run with Phil on some aspects of the control
software. Kim was able to convince
NSBF that we need another two sunny days before launch, which is now
expected for Jan. 2. This has the advantage that the NSBF and Navy
guys do not need to be on duty over Dec. 31./Jan. 1. JACEE, the
payload that is currently going around the pole, is doing fine so far.
Dec. 29, 1995: Some more guessing about an optical problem
The weather was rather cloudy in the morning, and I spent time at the
Crary lab reading and writing e-mail. I took the 10am shuttle to
Willy field and arrived just in time for the sun to appear. We went
back to the original optical set-up and tried to figure out the
influence of shifting a field lens. However, it did not help and I
realized that it is not really a field lens but a negative meniscus
lens that should improve the image quality and adjust the focal length
of another lens. We put in the lenses according to the numbers
provided by the optical designer, but we could never achieve a
reflected beam from the Fabry-Perot filter that is the same as the
incoming beam, i.e. the beam was not well collimated. Weather got
worse and I spent the rest of the day trying to figure out what is
wrong. Two lenses are custom lenses which might not be what they are
supposed to be. I measured the focal lengths of these two lenses and
compared them with theoretical values I calculated in the Crary lab in
the evening (since the optical designer only provided the radii of
curvature and the materials but not the focal lengths of these
lenses). The measurements agree with the theoretical values to within
a reasonable accuracy. It is still unclear to me what is wrong.
Dec. 30, 1995: Even more fiddling around with the optics
I caught the 8:30am shuttle to Willy Field, thought some more about
the optics and did some more calculations, which helped me to
understand the design better. After quite some thinking and
back-of-the-envelope calculations, I concluded that the design does
not provide a well-collimated beam on the Fabry-Perot. And the image
of the pupil does not seem to be on the Fabry-Perot either since all
the lenses give measured focal lengths that agree with the theoretical
calculations. We therefore put back the lenses as specified in the
design. The weather was partly to mostly cloudy and we did not have
enough light to finish the job. Furthermore, it turned out that we
had to mover the stage holding the Barlow lens as well as the camera
stage (which can move the CCD camera for accurate focusing in flight).
This required some time of Harry and Kim. In the afternoon I tried to
download a optical design program to analyze the design, but there is
nothing suitable around. After driving back with a van, we wanted to
watch a movie on a VCR, but no TV and VCR were available. This was a
rather frustrating day.
Dec. 31, 1995: Waiting for some sunlight
There is no shuttle service operating on Dec. 31, and we drove the van
to Willy Field ourselves at 8:30 in the morning. Graham, Kim, Ashok,
and Harry had the day off because they were not really needed for the
work on the optics and there was not much left for them to work on.
Graham, Kim, and Harry set out to get onto Castle Rock, a mountain that
can be reached from McMurdo by foot within about 2 hours. Graham early
on decided that his newly arrived boots were not comfortable enough
and he went back to McMurdo. Harry and Kim, however, made it there
and back, although Harry has terrible blisters on his feet now and both
Harry and Kim feel very tired.
As far as the optics is concerned, Dave and I got some help from Terry
Harris at APL, who checked the optical design. Indeed, the beam on
the Fabry-Perot is not collimated, but the deviation from a collimated
beam is not too bad. So, we did not bother anymore about the
collimation and just put an image of the entrance aperture onto the
Fabry-Perot. During some moments of sunlight and with the help of
Steve guiding the telescope manually, we managed to get a reasonably
good image onto the camera. However, the sun light was not long
enough to really get the camera well focussed. Furthermore, the
camera stopped from moving and we didn't know why.
I didn't feel like going for any of the parties, and since I didn't
get much sleep in the last few days, I decided to go to bed early.
Unfortunately, shortly before midnight somebody called who was looking
for my roommate Dave.
Jan. 1, 1996: No sunlight at Willy Field
The weather looked pretty bad today, nevertheless we drove out to
Willy after 8:30 am. Kim was driving and went over one of the little
McMurdo lakes on the road to Scott Base a little too fast. The water
made a big splash. However, the water was obviously under-cooled and
froze immediately on the windshield. It took quite some work to get
the ice off the wind shield. Ashok and Graham stayed in town while
Kim and Harry (who is still walking very slowly) joined us. They
could not reproduce our problem with moving the camera. We suspect
that it was too cold yesterday when we had the gondola outside around
freezing temperatures(today the gondola was inside because we never
got any sun light). Harry mounted some of the oven controllers that
keep certain filters at a constant temperature onto the optical bench.
When he did that he shorted the 28 Volts which fried a microprocessor
and could have damaged all the electronics. We were lucky since only
a single chip was gone and got replaced within a short time. I spent
most of the time writing post cards (about 12 today) and correcting a
proposal for a near-sun fly-by mission.
When we arrived in McTown around 6pm, the Icestock open-air concert
was going on. Various rock bands played on a truck in a piece of
a Jamesway and people were dancing. Imagine people in all kinds of
dresses like parkas and heavy boots, almost everybody bearing hats
or balaclavas and gloves. It was fun to see this open-air concert
at temperatures below freezing, although it was not really my style
of music.