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 (5-Aug-94)
Message-ID: <1994Aug10.070809.22230@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: Wed, 10 Aug 1994 07:08:09 GMT
Lines: 77

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 (5-Aug-94)

After completing the project objectives on Tuesday evening, Dante
continued to climb up from the bottom of the crater of Mt. Spurr today.
The majority of the activity focused on emerging from the rugged terrain
at the bottom of the crater wall.

Although Dante is ascending along the same path used for the descent,
this terrain is considerably more rugged than that experienced on the
way down.  During the descent, approximately half of the descent path
was covered by snow fields which masked the boulder fields underneath.
While walking on the snow- covered areas came with its own hazards, it
allowed the robot to quickly walk over the boulder fields and minimized
many of the steep cross-slope areas (by filling in and leveling some of
the larger gullies).  Due to the relatively high temperatures seen in
the crater during the mission (35-51 degrees F), a significant amount of
snow melt occurred during the excursion of the robot.  By the time Dante
began ascending up the crater walls, at least half of the snow fields
had melted, exposing more of the rugged terrain underneath and slowing
progress.

At 6:45pm ADT, Dante had climbed to about 200 feet above the crater
floor.  While ascending on a steep cross-slope the terrain under the
left legs of the robot collapsed, causing the robot to slide across the
slope and roll onto it's left side.  It appeared that the terrain,
having been saturated with water from the ongoing snow melt, was not
able to support the weight of the 1700-pound robot and simply gave way
when weight was applied to the legs of the robot as it walked.  Neither
the onboard behaviors of the robot nor the human operators were able to
react fast enough to prevent the system from toppling.

After careful testing, it appeared that all the onboard cameras,
actuators and electronics were still functional.  However, self-recovery
by the robot from this position is not possible.  At this time, the team
is examining options for assisted recovery of Dante.  The most likely
option will be to complete the extraction of the robot from the crater
via helicopter sling-lift early next week.

It should be noted that though the self-propelled ascent out of the
crater by Dante is concluded at this point, the primary objectives for
the project have already been successfully completed.  The technical and
scientific data gathered during the traverse of the crater floor will
not be adversely impacted by the conclusion of the robotic ascent.

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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
