Path: utzoo!attcan!uunet!cs.utexas.edu!asuvax!noao!arizona!tucson!bill
From: bill@tucson.sie.arizona.edu (Bill Ganoe)
Newsgroups: comp.robotics
Subject: Re: CM Ambler Rover
Summary: Small is beautiful -- maybe
Message-ID: <72@tucson.sie.arizona.edu>
Date: 26 Jun 90 21:43:57 GMT
References: <3708@jato.Jpl.Nasa.Gov> <95816@philabs.Philips.Com> <8485@jpl-devvax.JPL.NASA.GOV>
Distribution: na
Organization: U of Arizona SIE Dept., Tucson
Lines: 40

In article <8485@jpl-devvax.JPL.NASA.GOV>, kandt@ai-jupiter.JPL.NASA.GOV (Kirk Kandt) writes:
>        .
>        .
>        .
> "exploration".  BTW, why are the "moon stompers" less useful than small
> machines?


   I don't think the issue is "moon stompers" vs. small machines.
I think it is more a matter that NASA seems to lean toward big, single-shot
missions with no consideration of the potential advantages of missions
involving multiple copies of small machines.
   Certainly there are tasks that little machines can't handle, but they
still might prove very valuable for reconnoitering the area around
a landing site.  Each mini-rover could carry one, or a few, sensor(s),
and a swarm of "insects" can certainly provide mission robustness that
we just couldn't afford with a big "stomper" that tried to be all
things to all people.  Conceivably, they could even be used to collect
material for sample return missions, although individual samples would
be smaller than a stomper might be able to handle. 
   The small machine approach also allows for the possibility of
multiple launches for a single "mission".  While our space program
has a better reliability record than the Soviets', the FOBOS mission
should serve as a reminder of what can happen.  (Even the doubly redundant
FOBOS ended in almost complete mission failure.)
    If you can afford to lose some of your mission's components without
endangering the entire mission (obviously more of a problem with rovers
than with the static landers of past missions) you don't have to spend
many years and mega(giga?)-bucks designing, building, and testing the most
failure-resistant system possible.  You can devote more of your time to
getting and analysing interesting data.
   Granted, the micro-rover approach wasn't even feasible until we could
miniaturize the sensors, control and communications hardware sufficiently
(and people started work on mini-rovers themselves), but it would be
encouraging to hear about more serious consideration of mini-rover
approach to lunar and planetary exploration.
-- 
What?  Me speak for my  | William H. Ganoe      bill@tucson.sie.arizona.edu
employer?               |  Systems & Industrial Engr. Dept, Univ. of Arizona
                        |  Tucson, AZ 85721; USA