Runways on the Moon?

Dear Space Futurists,
The Lunar Dragger is an interesting idea; thanks for the reference. I am
sorry I have not had the time to study it. But, I have questions. How does
it generate drag forces? And how much mass do the draggers require compared
to the satellite's mass?
The friction of a rope dragger would be only the dragger's mass on the
surface, times the Moon's surface gravity, times what ever coefficient of
friction is possible. To get 5 Earth g's of deceleration from friction of a
rope, I calculate the dragger would have to have about 30 (6 times 5,
assuming a coefficient of friction of 1.0) times the total mass of the
satellite and dragger. A plow could generate a drag force which could
exceed friction, sometimes. But a plow could hit snags, mentioned by
others. Maybe lots of little plows would help, but would they break off?
An advantage of the dragger is that it could (but how?) get to the surface
while the space craft was still above the Moon, but other than that it would
not be nearly as effective in braking as a skid, which could use the mass of
the entire craft to generate the normal force for frictional braking. So
that braking acceleration could (with a coefficient of friction of 1) only
be one-sixth Earth's g. So the runways need to be much longer (~ 30 times?)
than discussed.
Maybe 1200 km, which sounds really long, but the Maria are large and
relative flat. Mining could be part of the runway's preparation, extracting
iron and solar wind entrapped atoms, and helium-3, from the regolith as part
of the process, which some claim will be done anyway. Some plans include a
circum-lunar-equatorial railroad (CLER), so there are construction plans for
the Moon which are far larger than these runways. Maybe a circum-lunar
equatorial runway would make sense for the really big dreamers. Then with
possible scheduling it could be used as a road also, or maybe space craft
could land by settling on top of more slowly moving CLER trains, which could
use electromagnetic braking, and also turn the kinetic energy of the landing
craft into electricity to feed the lunar electrical system. Still, I am not
sure one could make wheels which would turn or otherwise make a craft or
lunar trains which could accomplish all that is needed for landings at such
speeds.
Thanks for the stimulation, Jay S. Huebner at jhuebn@...