Vincent D. DeSimone wrote:
You could do it - in fact, the current Fregat upper stage is based on
the landing stage of the Lunas that landed the Lunokhod rovers. But why
use batteries when the solar arrays the two rovers used let them work
for several months to a year?


Remember, nighttime on the lunar surface lasts 14 days. You're going to
need batteries to store keep-alive power from what the solar panels can
accumulate during daytime. Plus, it gets mighty cold at night. You'll need
those batteries to provide power for heaters, as well (perhaps supplemented
by radioactive decay heaters).


On Lunokhod, the batteries were used to run the temperature control
system fans and crank open the solar array lid when daylight came again.
Heat was supplied by a isotopic heater mounted on the back of the rover
during the lunar night; although this didn't generate electricity,
there's no reason such a dual capability RTG system couldn't be designed
nowadays.*
Total electrical power output wouldn't need to be much if it wasn't
being used to power the wheels on the rover (like the big one of MPL will)

While you were right about the lack of interest in the past, I think that
the current international consensus is that there is plenty to see and
learn. The Moon has the surface area of North and South America combined.
All of the lunar landers, manned and unmanned, have surveyed a surface area
only equal to a single mid-sized city. Today's rovers could conduct surveys
relatively cheaply with today's technology and techniques.


But you can see a lot more of the surface in very good detail from low
lunar orbit than from a rover on the surface, especially with no air
drag or distortion to deal with, like occurs in a Earth satellite in
it's far higher minimum orbital altitude.
If you are going to put rovers down, then they had be mighty small and
light if you want to do it on a budget.
Even sampling the surface composition might be able to be done from low
orbit via vaporizing a small amount of it with a laser, and studying the
spectra of the gases emitted.
This could be done over a lot of points on the surface rather than the
limited area a rover could cover during even a long lifetime.
A lot of the surface has already been studied as to composition from
orbit simply by studying the backscatter of the sunlight hitting it in
various frequencies via tight wavelength filters.

* You can see the isotope heater on the right in the side view of the
Lunokhod in this drawing:
http://airbase.ru/space/crafts/ams/a...hod%5B1%5D.jpg
It's the cylindrical thing with the circular plate attached to it on the
side facing the rover's body; the little wheel next to it is lowered
onto the surface to measure true distances as the rover moves around,
and to avoid false distances due to the drive wheels slipping as they
rotate.

Pat