I don't think cleaning them is "beyond" the engineers, but it may
be a case of diminishing returns (I was really hoping for someone with
direct knowledge to answer... Geoffery Landis?). Keep in mind a lot of
that "dust" is about the size of smoke particles, which you''ll have
trouble just "wiping off". Electrostatic solutions might be
troublesome on silicon cells.

From watching all NASA webcast lectures (tens of them), the message has
been (questions answered by the main scientists themselves) that there is
no way currently to prolong the solar panel longevity with any cleaning
methods. Of course you can clean your summer shack solar panels because
you do not have the absolute and strict limitations of distant space
rover. Simply dry wiping the panels you would prolly do more damage to
them than good.

There is lots of other things that lessen the lifespan of rover, one of
the absolutely unpassable (with solar panels that is) obstacle is the
Mars winter, no sun no power. The electronics will break up when they
cannot be kept in stable warmth with electricity.

But, from what ive seen in those lectures, they are now starting to
really develope rovers that utilize plutonium power. Seems like atomic
hysteria is somewhat over. But even those do not last for years, theyre
just too small and filled with super high tech components that cannot be
eventually protected by the temperature changes which will be very
dramatic on winter. You just can begin to compare Viking landers and
these things, its like saying that why does paper burn when rock doesent.

Or, it's ecomonics. Viking, which did a wonderful job (well beyond
design specs), also was a lot more expensive than a MER-class mission,

Plutonium power, i think, will be a lot cheaper than the high tech solar
panel arrays. Its because the Pu - electricity is very simple design (by
space tech standards).

Hardly. An RTG-powered rover is in the works for a future mission
with a life time of a year or so. But it will be a lot more expensive,
and will not use an airbag landing system (there are limits to that as
well).

I remember them saying something like 9 months of operation. One big
benefit, besides the lifespan is that such rover can move much much
faster (more amps available) and thus move farther, even hundreds of
kilometers.

It will be helluva bigger machine (size of small car), i think that
restricts the landing to rocket propelled lander. Which means lots of
additional fuel kg:s - lots of $$.

Sure. Good science would be to put hundreds of trained geologist on
the surface of Mars, with equipment to traverse the surface. But
economicly, there *might* be some constraints here.

I dont believe that Mars surface will ever be accessed by humans, robots
can stand the super harsh evinroment (solar winds etc.) better. In 2050
the robots will prolly be better geologists than humans.. If there is
anything worthwhile of sending more robots in the distant future.