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 (4-Aug-94)
Message-ID: <1994Aug5.164626.23304@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: Fri, 5 Aug 1994 16:46:26 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 (4-Aug-94)

At the close of yesterday's activities, the Dante project team had
developed a probable diagnosis of the cause of the power failure which
halted the progress of the robot yesterday afternoon.  It was suspected
that a short in either the cable plant at the power station on the
crater rim or a fault in the power station breaker box had caused a
premature shutdown of power to the robot and the rim station equipment.
It was confirmed that the satellite connection was still active (carrier
signal was being received), indicating that the power generator was
still operating.

The decision was made to fly a small team out to the crater rim to
investigate and, if possible, repair the source of the problem.  The rim
team, comprised of Dave Wettergreen, Scott Boehmke and Ryan Miller, was
ready to fly to the rim yesterday evening but bad weather and poor
visibility on the crater forced a delay of the flight until late this
morning when they were finally able to depart at about 11:00am ADT.

By 1:30 the rim team had landed on the volcano and began to examine the
power station equipment.  Within twenty minutes the rim station
computers and the rim camera were powered up, with video from the rim
camera received about five minutes later.  The team then proceeded to
investigate the cause of the power loss to the robot.

Shortly thereafter, it was confirmed that the diagnosis had been
correct.  The cable which connects the 1000-volt power line encased in
the robot's tether to the power station had apparently collected
condensation inside the connector at the upper end of the cable.  This
had then shorted out the connector, causing it to melt and fail.  The
connector was removed by the rim team and replaced.

After replacing the connector and testing the power system, Dante was
powered up at 3:00pm, and a checkout of the robot computers and onboard
systems was started.  The checkout indicated no electrical damage to the
robot, and Dante resumed walking up the crater slope at 3:45.

Although no electrical system damage was detected during the system
check out, it was determined that the laser scanner system may not have
fared so well.  After being immersed in the steam and particulates
carried in the volcano plume for the past three days, a significant
amount of material has apparently built up on the mirror which targets
the laser beam.  This is now preventing the laser >From obtaining
terrain scans, and it is not likely that this capability will be
recovered during the ascent.  The robot does not needs these scans to
complete the ascent, as a nearly contiguous set of scans of the path was
gathered on the way in to the crater, and the onboard camera systems are
all still working and can provide sufficient information to allow the
operators to command the robot.

By the end of the day, Dante was 521 feet deep in the crater, having
climbed up 100 feet during the few hours of operation following the
restoration of power.  Dante has now emerged from the most difficult
terrain at the bottom of the crater, and it is expected that the
remainder of the ascent will progress at a relatively rapid rate.  If
all goes well, Dante should be back at the rim of the crater by late
Saturday night or early Sunday morning.

At the end of the day, the team also received word that Discovery
Magazine has selected Dante as one of the ten most significant
technological achievements of 1994.  Hooo-ah!

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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
