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Charles Redmond
Goddard Space Flight Center
Greenbelt, Md.                        Dec. 30, 1992
(Phone:  301/286-8955)

DANTE ADVISORY #3

ROBOT POISED AND READY FOR DESCENT INTO VOLCANO

        The 8-legged rappelling robot Dante was being placed into 
position at the rim of the Antarctic volcano Mt. Erebus late 
on December 30 in preparation for its descent down the steep 
slopes on Thursday, Dec. 31.  Dave Lavery, the Erebus 
project manager, said from the Antarctic that the team 
expected the robot to be actively descending the 70 degree 
slopes of the inner rim of the volcano by early morning on 
Thursday.

        NASA will provide a live video feed of the Dante robot 
activities, including the first live transmission from the 
robot's onboard television camera system, beginning at 8:15 
am EST and continuing through 9:00 am.

        The live video will continue later Thursday with 
live feeds showing the robot's point of view as it navigates 
slowly down the steep slope of the volcano.  Thursday video 
feed times have been set for 12:35 through 1:25 pm EST, 
2:10 pm through 3:40 pm, 3:42 pm through 3:57 pm, 
4:20 pm through 5:25 pm, 5:50 pm through 6:10 pm, and 
7:25 pm through 8:25 pm.  All of this video will be available on 
the NASA Select satellite as it is received by the communications 
support team at the Goddard Space Flight Center.

        During the 8:15 am through 9:00 am EST video period, Dave 
Lavery and possibly other members of the combined NASA-
National Science Foundation-university team at the volcano 
will provide a live audio commentary of the activity.  The 
video feeds are being transmitted from a remote NASA 
Tracking and Data Relay Satellite portable station set up on 
the ice at the team's base hut, several thousand feet below 
the volcano rim.  The audio portion will be transmitted 
through a communications link through the INMARSAT 
satellite.

        NASA will also provide a commentary from participating 
robotic and geophysical science team members during the 
Antarctic video feeds beginning at 12:35 pm EST.  The audio 
commentary will originate from robotic specialists from 
Carnegie-Mellon University, who built the $2 million robot 
system for NASA, and from NASA Goddard scientists involved 
in the geochemical and geophysical science investigations 
which the robot will perform once it reaches the floor of 
the crater.

        A similar video support schedule at approximately the same 
Eastern Standard times is being developed for Friday and 
Saturday.  If all goes according to current plans, Dante is 
to spend Friday exploring the lava lake in the crater floor 
of Mt. Erebus to provide geophysical and atmospheric 
chemistry data about the volcano's outgassing and the 
composition of the lava lake.  The team expects to have 
Dante begin its climb back up to the rim on Saturday, but 
that could be delayed by science observations until Sunday.

PROJECT IS DEVELOPING FUTURE EXPLORATION CAPABILITIES

        NASA and the National Science Foundation are undertaking 
this demonstration project to develop technology and 
telecommunications capabilities which NASA could use in 
future explorations of the Moon or Mars and which the NSF 
might apply to its ongoing research activities in the 
Antarctic.  Part of the test involves transferring control 
of the robot from the Mt. Erebus team to team members 
located at a payload control center at Goddard.  This 
portion of the project will test the "telepresence" 
capabilities of such robots for future NASA exploration 
missions and could occur during Friday or Saturday's lava 
lake exploration phase.

        Carnegie-Mellon University and the New Mexico Institute of 
Mining and Technology are partners with NASA and the NSF as 
robotics and volcano experimenters for this project.

        The following paragraphs have been abstracted from the 
message stream which Dave Lavery has been providing to the 
Carnegie-Mellon staff and other associates of the project who are 
located in a temporary payload operations control room at 
the Goddard Space Flight Center.  These messages have been
sent via the TDRS satellite from computers in the Erebus project
tent on the slope of Mt. Erebus and received by the POCC computers
at Goddard.  It is from this POCC that Jim Osborn, CMU Erebus 
project manager and four other CMU 
robotics experts will perform the remote control test to 
simulate "telepresence" activities.  These messages are 
abstracted from the past two days and cover the period from 
December 29 through 30 (Eastern) and 31(Antarctic Time):

****The following message posted by Erebus project manager 
Dave Lavery on Dec. 29 (local Antarctic time, which is EST 
plus 17 hours) describes the crater of Mt. Erebus:

"At the rim, the outer crater is about 750 feet across.  
Approaching from the ascent path, the slope is about 45 
degrees which nearly levels off to a twenty-foot side shelf 
at the edge of the crater itself.  The crater slopes away at 
a 60-degree angle very quickly, with a very short transition 
area, for about 100 feet.

"From there on down to the lava lake is a combination of 60-
to 90-degree slopes strewn with boulders and ice towers 
ranging from one to four feet in size.  About 700 feet down 
inside the crater is a very large fumarole that has recently 
appeared which is pounding out gases like an old steam 
engine which is right in line with the descent route and may 
become a primary target for gas sampling.

"The crater itself was fairly clear of gases most of the 
time that I was at the rim, and I had direct visibility down 
into the inner crater. The gases and steam from the crater 
are coming from the lava lake itself and from the fumarole 
fields, most of which are on the far side of the crater wall 
from our worksite.

"The consistency of the outer cone material is fairly poor.  
It is made up of a combination of desiccated lava bombs and 
rock crystals which are all very loosely bound together by 
crushed lava and ice.  Most of the exposed surfaces are then 
covered with a thin layer of sulfur deposited from the 
crater (which gives everything this weird green fuzzy 
appearance!)."

****The following message posted by Erebus project manager 
Dave Lavery on Dec. 30 (local Antarctic time, which is EST 
plus 17 hours) describes the finishing activities of placing 
the robot Dante and its carrier Geryon in place at the 
crater rim:

"Geryon, with Dante aboard, had been pulled to within 600 
meters of the Erebus
crater rim when work was stopped this morning at 1:00 am 
local time.  We anticipate that it will require four more 
winch pulls by Geryon to attain the crater rim.  Each winch 
pull involves driving two or three anchors into the ice with 
sledgehammers (each anchor is a five-foot length of  2-1/2 
inch diameter steel pipe), running out up to 200 meters of 
winch cable from the winch on Geryon to the anchors, slowly 
winching in to the anchor point, then repeating the process.

"The only problem we have really had so far is that we are 
running short of sledgehammers.  The handles become 
relatively brittle in the cold, and they keep breaking.

"We have received a question about the composition of the 
group currently at the Lower Erebus Hut (located about 1500 
feet below and 1-1/2 miles from the crater rim).

"Currently at the camp are: Red Whittaker (Carnegie-Mellon 
University, director of the CMU Field Robotics Center and 
chief project scientist); Eric Hoffman (CMU/K2T, designer of 
the Dante mechanism); Dan Christian (CMU, software 
specialist); Dave Wettergreen (CMU, software specialist); 
Dave Lavery (NASA, Telerobotics Program Manager, 
communications and videography); Phil Kyle (New Mexico 
Institute of Mining and Technology, principal research 
scientist and Mt. Erebus expert);  Sara Krall (Antarctic 
Support Associates, camp director and cook); Ken Sims 
(Antarctic Support Associates, mountaineer); and Steve 
Thompson (NASA/GSFC, TDRSS communications specialist).

"Also helping out  are Nelia Dunbar (NMIMT, volcanology 
researcher) and Bill Macintosh (NMIMT, volcanology 
researcher).  Bill and Nelia are here working under a 
separate grant doing their own research, but have been 
assisting the project quite a bit when manpower and Erebus 
expertise are needed.;

****The following message posted by Erebus project manager 
Dave Lavery on Dec. 31 (local Antarctic time, which is EST
plus 17 hours) describes their accomplishment of the outer 
rim ascent and preparations for the robot descent:

"As of 1800 hours, Geryon and Dante have completed the 
ascent of the outer cone of Mt. Erebus.  Once Geryon was 
aligned with the "launch point" for Dante's descent into the 
volcano crater, it was anchored in place.  Fittings and 
equipment for the final outfitting of the robot were then 
moved up to the launch point and stored for the evening.

"The final activity for the day was running the fiber optic 
cable from Geryon's position down the mountain to the Lower 
Erebus Hut to the operator control station.  This involved 
spooling out the fiber optic cable approximately 2 
kilometers to the hut, and then verifying the communications 
over the fiber.  As of 2300, the video and audio signals 
from Dante on the rim were being received at the control 
stations, and the communications to the robot appears to be 
fully operational.

"The plans for Dante's closeout tomorrow morning include 
assembling and installing the sensor mast (including the 
trinocular video system, the laser scanner and the 
teleoperated camera), completing the installation of the 
science package, validating the fiber optic communications, 
and final sealing of all enclosures.  After that, Dante will 
stand up off Geryon, Geryon will be removed, and Dante will 
squat down on the ground in preparation for "launching."  
When ready, Dante will be manually positioned at the 
transition point into the crater and slid over the lip of 
the crater rim.  The onboard and remote control systems will 
then take over and the robot will stand and begin the 
descent into the crater.

"This afternoon's ascent included my second trip up to the 
rim of the crater. The crater interior was much calmer today 
than during my last trip a few days ago.  The cyclonic winds 
emanating from the crater were more sedate, with what seemed 
like about half of the velocity of the previous visit.

"The plume from the lava lake itself was much milder, with 
clear visibility down to the inner crater.  Occasional puffs 
of steam reached as high as the outer crater rim, but rarely 
went above that.  Without the intense plume activity of the 
other day, and the milder winds, we were able to spend about 
three hours at the rim without too much trouble.  The rim of 
the crater is covered with a combination of crystallized 
lava and lava bombs.  The lava bombs are ejected 
periodically by the lava lake during eruptions, and vary in 
size from a few inches to several feet across.  They are 
primarily composed of lava glass, and weather away fairly 
quickly.  Within a year or two, they are almost completely 
disintegrated.  When they are completely decomposed by 
weathering, they leave behind lava crystals which were 
embedded in the bomb.  The crystals are anywhere up to three 
inches or so in length, and are all over the place.  They 
are pretty neat, but actually make for fairly precarious 
footing as they tend to slide over each other when stepped 
upon."

****End of this set of messages****
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