Resolution Limit (Dawes Limit) = 116 / (aperture in mm)
Lets assume you can do way better than that in space and use
58 / aperture in mm
The HST has a main mirror diameter of 24000mm
So using the above figure the HST could resolve something .002
arcseconds across.

The moons perigee distance (from earth's centre) is 356000km, and the
HST orbits at 600km above the earths surface, or 13600km above the
earth's centre. So the closest it ever gets to the moon is 342400km.

The smallest thing it can see (in m) is tan(.002/3600) * 342400000
or 3.3m using our rediculously optimistic resolution capability.

Footprint? Flags? Landers? No.
Rover? Strongly doubt it, but might show as a blotch.

Also this would have to happen when the moon was at pergiee, and the
hubble directly between it and earth.

I'm sure if I've screwed up the math, I'll be corrected right smartly,
because this is Usenet, and everybody checks everybody's figures.

--V