Newsgroups: comp.robotics
Path: brunix!cat.cis.Brown.EDU!agate!ames!kronos.arc.nasa.gov!doctor
From: doctor@kronos.arc.nasa.gov (Terry Fong)
Subject: Dante II - Mt. Spurr Expedition Status (1-Aug-94)
Message-ID: <1994Aug2.162205.21815@ptolemy-ethernet.arc.nasa.gov>
Summary: status information on CMU/NASA volcano robot explorer
Keywords: Dante, teleoperations, volcano, Alaska
Sender: usenet@ptolemy-ethernet.arc.nasa.gov (usenet@ptolemy.arc.nasa.gov)
Nntp-Posting-Host: tardis.arc.nasa.gov
Organization: NASA Ames Intelligent Mechanisms Group
Date: Tue, 2 Aug 1994 16:22:05 GMT
Lines: 95

The following is a status update on the Dante II project. Dante II is
an eight-legged robot (developed by the CMU Robotics Institute with
sponsorship from NASA) which is currently descending into the active
crater of Mt. Spurr, an Alaskan volcano 80 miles west of Anchorage,
Alaska. The primary objective of the Dante II project is to develop and
evaluate new techniques and technologies which can be applied to space
and planetary exploration. 

Throughout the Mt. Spurr expedition, Dante II is being remotely
operated from a base station in Anchorage using control station
software developed at CMU and NASA Ames. Live video coverage is
periodically available via NASA Select. Full mission details including
current status, real-time images/video, and technical data is available
via a WorldWideWeb server provided by the NASA Ames Intelligent
Mechanisms Group. This site can be accessed on the Internet using
information browsers such as NCSA Mosaic and the URL:

	http://maas-neotek.arc.nasa.gov/dante

Questions regarding the Dante II project may be addressed to me via email 
(terry@ptolemy.arc.nasa.gov). Reponse time may be slow.

Terry Fong
NASA Ames Research Center

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Status Report (1-Aug-94)

At the conclusion of operations today, Dante had walked at total of 650
feet from the initial traverse deployment point.  The current position
of the robot puts it at the top edge of the fumerole field, just even
with the bottom of the large rock bulge which has been just to the south
of the descent course for most the day.  Dante is standing at the edge
of a 5-foot diameter vent opening which is encrusted with a variety of
deposited materials (based on observations by the Alaska Volcano
Observatory, the material is likely to be calcium sulfate or iron
sulfate) and which is emitting gases which are curling around the robot.
The robot will spend the night at this location, prepared for additional
walking to the central regions of the crater floor in the morning.

During the day, Dante descended approximately 100 feet from the position
attained last evening.  The traverse followed a route down a snow-filled
gully, up and over a berm at the lower end of the gully, and down a
boulder strewn path which lead to the top of the fumerole field.  Along
the way several decisions regarding the descent path had to be made as
the robot explored what was fundamentally unknown territory, which had
been completely snow covered and unobservable until just the past few
days.

Also, during the day the robot was subjected to the hazards of the
environment inside the volcano crater, including bombardment by rock
fall.  At about midday, two three-foot diameter boulders were seen
rolling down toward Dante from the rim camera viewpoint.  These boulders
were tumbling fast enough down the thirty- degree angle slope to become
airborne during most of their descent.  The boulders passed within a few
meters of Dante, one in front and one behind the robot.  The members of
the project team watching this event from the control station in
Anchorage breathed a collective sigh of relief at the near miss.
However, that was not to last too long.  Shortly before 9:00pm, a
one-foot diameter boulder came tumbling down the slope from the
north-east wall of the crater and struck the robot on the #5 leg (this
is the inner rear left leg). 

At the time, Dante was using the leg to provide primary support in
conjunction with the other leg of the inner frame, and was placing
approximately 450 pounds of downward force on the leg.  The force of the
impact was strong enough that it was knocked out of the support position
and away from the existing foothold and the other three legs of the
inner frame had to instantly provide additional support.  While the
robot operators quickly lowered the outer frame of legs to provide more
stability for the robot, the team looked around the inside of the crater
to identify any additional rock fall which may be following the boulder
which struck the machine.  The impact of the rock did not appear to do
any physical damage to the structure of the robot, however it is
becoming obvious that we are entering an area subjected to additional
rock fall incidents due to the funneling action of the inner crater
which steers falling objects into the region of the descent path.

At this point, the plan is to spend the majority of tomorrow's
operations moving the robot from it's current position adjacent to the
upper fumeroles to a location closer to the center of the crater floor.
The intent is to gather additional science information beyond the first
fumerole, and attempt to provide additional imagery of the crater floor.
The region has been continually covered by the plume of the volcano
since the 1992 eruption, and no-one is sure exactly what lies within the
region.

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-- 
_______________________________________________________________________________
 "Every once in a while declare        Terry Fong <terry@ptolemy.arc.nasa.gov>
  peace. It confuses the hell out      NASA Ames, M/S 269-3, Moffett Field, CA
  of your enemies" -- Rule of Acq. #76      (415) 604-6063, (415) 604-6081 lab
