"Michael Gallagher" wrote in message

Right now, we have Spirit on mars, and it seems to be doing ok, but as
I understand it, in three months it will go at most 125 feet from the
lander; there's no chance of it making to the mountains in the
distance. And it took a week just to check out the systems and get it
to roll off the lander to begin with.

The MERs *can* go a kilometer or two during their lifetime
(http://www.jpl.nasa.gov/news/fact_sh...rs03rovers.pdf) -- particularly
if it turns out to be an extended mission.

Jon