Newsgroups: comp.robotics
Path: brunix!uunet!zaphod.mps.ohio-state.edu!news.acns.nwu.edu!news.ils.nwu.edu!mccoy
From: mccoy@ils.nwu.edu (Jim Mccoy)
Subject: Re: How to Explore Mars
Message-ID: <1993Jan8.222437.10042@ils.nwu.edu>
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Organization: The Institute for the Learning Sciences
References: <HAGERMAN.93Jan7224103@rx7.ece.cmu.edu>
Distribution: comp
Date: Fri, 8 Jan 1993 22:24:37 GMT
Lines: 44

In article <HAGERMAN.93Jan7224103@rx7.ece.cmu.edu> hagerman@ece.cmu.edu (John Hagerman) writes:
>
>There has been some discussion about the tradeoffs between using one
>large robot and many small robots for planetary exploration.  Has the
>Erebus experiment changed the opinion of anyone here?  I don't want to
>restrict attention to the specific results; for example, I don't think
>we learned anything new about fault tolerance.  Rather, I'm hoping for
>new thoughts engendered by considering the experiment in general.  In
>my mind, for example, the experiment supports large robots for such
>use since a fairly standard large robot design could be fairly easily
>modified to conceivably navigate the volcano, and it seems less likely
>that the same would hold for small robots.  Any other thoughts?

Actually, I came up with a completely different opinion based upon the
failure in Antarctica.  If anything, I believe this adventure has shown the
key weakness in the single robot proposals: if something goes wrong you are
completely screwed.  The scenario in Antarctica was similar to a Mars
exploration in that it is remote and a hostile environment, but one big
difference is that there will be no one around to crawl to the rim of a
canyon to reset the computers or perform other maintenance on Mars.  There
will be no modification of robot design once the mission to explore Mars
begins, you only get to use what you take with you.  Please remember that
the people paying for the exploration are not going to appreciate it if we
end up sending Mars it's biggest paperweight...

If anything, the failure of Erebus seems to point to the disadvantages of
using a single large robot to explore hostile, unknown environments.  With
a single robot you have a single point of failure for the entire mission,
if your robot ends up with machanical difficulties or other problems you
have just wasted millions.  With multiple smaller robots you still have
other robots to continue exploration and you have the option of making the
smaller robots capable of some specialization to explore unique
environments.

The Erebus experiment seemed to provide nothing to support the single robot
proposals, I am really curious as to how anyone could find support for them
under the circumstances of this situation...

jim
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