11/1/93: Weekly Report of the TROV Project

CRS (Carol Stoker) 11/1/93

This past week has been devoted primarily to training operators to
use the TROV system by local and remote control.

At the beginning of the week, the TROV was moved to a position in
Cape Armitage directly over a permanent study site originally put in
place by Paul Dayton of Scripts Institute of Oceanography.  The first
day after the move to Cape Armitage was spent setting up and
aligning the equipment that must be deployed out side the fish hut.
In order to get a clean video transmission of TROV video all the way
back to Ames Research Center, considerable care must be taken in
aligning the Laser video transmitter/receiver pair.  The transmitter
is set up on a tripod next to the Hypertat hut, and the receiver is
mounted on another tripod on the roof of the Firehouse building in
McMurdo nearly a1 km away.  Both the transmitter and receiver pair
must be precisely pointed at each other.  We found that the
alignment of the transmitter receiver pair  must be repositioned
daily, evidently because there is enough drift in the ice in the bay to
change the alignment.  When the pointing is not perfect, the video
signal reaching California becomes distorted periodically.

Once the equipment was in place and working, we attempted to find
the location of Dayton's original study site.  We sent the TROV down
with a dive team to show the way.  The TROV was first lowered into
the dive hole.  Then, 3 divers went down the same hole.  Their dive
plan was to swim over to the transect area, with the TROV following
them, and then to swim to a different hole and come out from their
dive in a different location.  Divers Dale Andersen, John Heine, and
Mark Slattery made the dive with the TROV.  After the divers came
down the hole, the TROV followed them easily.  Divers even reported
that the TROV swam so fast it kept bumping into them.  However,
towards the end of the dive it seemed that the TROV got stuck and
could not keep up with the divers.  They quickly swam away and were
out of sight.  Uncertain of the sudden cause of the lack of mobility,
we decided to tow the TROV back to the dive hole using its umbilical.
With thrusters off, it is an easy matter to tow the TROV back to the
hut.

Dale Andersen was still wearing his scuba dry suit from the previous
dive so he went back down the hole to help retrieve the TROV.  He
found that the retrieval rope had come loose and gotten tangled in
one of the thruster shafts.  That explained the fact that the TROV
would not drive properly.

Once the TROV was back in the hut, we were able to untangle the
rope that was wrapped around the thruster shaft.  The thruster
checked out OK and we expected to be back in operation the next
day, Oct 27.

That night we spent several hours getting everything set up and
aligned perfectly so we would have a full day of remote operation
from Ames.  We got down to the hut early and set up for
deployment.  Video and all systems looked perfect and we prepared
for launch of the TROV.  Suddenly, video went black.  Strangely, we
had not been touching anything when this happened.  We spent
approximately 2 hours diagnosing what had gone wrong, while our
California team stood by patiently waiting.  We finally traced the
problem to the fiber optic cable on the TROV.  Evidently, the fiber
optic cable had broken.  We can't be sure exactly when or how this
happened, but the incident the previous day where the thruster was
fouled had caused the TROV to spin in circles, possibly putting extra
stress on the cables.  It seems likely that the fiber had broken at this
time, but was not displaced enough to loose video transmission until
later.

Fortunately, we were prepared for this kind of equipment breakdown
and had brought a spare fiber optic cable to replace the broken one.
The fiber optic cable is taped to the TROV umbilical once per foot
for the 1100 foot length of the cable.  With all five members of the
team involved in doing the taping job, we installed the new cable
by the end of the next day, a day and a half from the discovery of
the broken fiber.

During this repair, on Friday October 29, the communications system
including computer network link, video transmission, and telephone
lines was being taken off line for 72 hours for an upgrade to a wider
bandwidth transmission system.  This was a planned upgrade which
we knew would improve the resolution and reduce the compression
ratio of our video transmission to Ames.  While the satellite
communications link was down on Saturday, we trained new drivers
Carol Stoker and Don Barch in local operation of the TROV.

On Sunday October 31, the team had planned to take an excursion
out to Cape Evans to look over the site which we are considering for a
possible TROV survey.  Cape Evans is approximately 15 miles North
of McMurdo Sound and is reached by traversing the sea ice along the
shoreline of Ross Island.  The trip to Cape Evans in a "Sprite" tracked
vehicle took about 2 hours, with a number of stops to photograph the
views of Mount Erebus.  For the trip, we arranged to take a
"passenger Sprite" which in addition to having nice seats and
windows for all the team, also was equipped with a heater.  The
Beast 666, our workhorse Sprite, was lacking all these comforts.  The
traverse follows the shoreline and allows spectacular views of Mount
Erebus.  The traverse also passes between Erebus and several small
islands just off the coast including big and little Razorback islands.

Razorback Island is aptly named; it is a jet black and nearly
trapezoidal chunk of rock roughly 1000 feet long, and 300 feet high
jutting up out of the sea ice.  It's two sides form a knife blade ridge.
The ice pushes up against it's steep sides and forms a permanent
crack which provides surface access to a colony of Wedell Seals, their
huge forms lying out on the sea ice ring the island on the seaward
side.

The route also passes just in front of the Erebus Ice Tongue, the point
at which the glacier comes down from Erebus to meet the sea ice.
The glacier edge forms an ice cliff face 50 feet high, in which there
are overhanging spaces that form ice caves.  We passed a group of
New Zealanders who were practicing Search and Rescue techniques in
the ice cave area.

Cape Evans is the location of a spacious hut which was used by Capt.
Scott and his party to winter over prior to his final and fatal South
pole expedition.  Dwight Fisher, the senior National Science
Foundation representative in McMurdo, was kind enough to provide
us with a key to allow us to visit inside this hut.

The Scott hut is an incredible museum of polar history.  The hut is
exactly as Scott and his team left it.  Inside the kitchen there are pots
on the stove, and a pantry full of canned food.  Just outside the
kitchen are slabs of seal blubber which were used as fuel for the
stove.  Near by, the sleeping quarters have bunk beds with
mattresses and sleeping bags made of reindeer hide.  Clothes hang
from the posts on the beds, a man's suit coat hangs on a peg.  On the
floor are boots stuffed with Finesque, the dry grass that was used as
insulation in the shoes.  Books line the shelves next to the bunks.

Further on from the sleeping bunks is a laboratory area with flasks,
chemical vials, bunsen burner and a darkroom for developing
photographs.  Stretched out on the table in the laboratory is the
frozen body of an Emperor Penguin.  A box of penguin eggs lies
nearby.  We debated whether the Penguin had been stuffed or was
just frozen, but there was no way to tell.

In back of the hut, but inside protected from the weather are the
stables where the Siberian ponies were kept for the winter over.
The choice of ponies instead of dogs for transportation was the
decision that cost Scott the first to the pole.  In spite of their best
effort to care for and feed the ponies, most died during the winter
over.  Unlike dogs, they could not be fed using the most reliable local
resource, the Wedell seal.

After an hour or so exploring the hut, we emerged to find that the
beautiful clear weather we had driven out in was now a solid cloud
cover.  A storm had covered Erebus and the wind was picking up.
We decided to head back to try to beat the storm home.  Getting out
to the Sprite, we had a tense moment when we could not get it
started.  We had checked out with an estimate return time of 8:00
pm, and it was now 4:00 pm.  If the sprite didn't start, we would
have a cold 4 hour wait before anyone would start to look for us.

Fortunately, Roxanne has a way with cold engines and was able with
some coaxing to get the Sprite started.  The drive home was sort of a
race with the weather and all the views were obscured by the storm.
However, we arrived home safely by 6:00 pm.

Editor's Note (Butler Hine):  The communications line came back up
as scheduled on Sunday, Oct. 31st (california time).  We had a full
day of operations from Ames Sunday with the new high bandwidth line,
and the video resolution is very much improved.
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  Via FTL BBS (404-292-8761) and NASA Spacelink (205-895-0028)
