Cities in space - Singles or clusters?

On Aug 26, 2006, at 11:20 AM, Darren wrote:

> I can see a lot of reaction mass being used for
> station keeping, getting the reaction mass would be easy enough but
> a cost
> you could do without.

Does there come a point where the reaction mass becomes a pollution
or collision problem? When you have all this spent propellant being
used by thousands of stations to maintain their orbits in a
relatively close area, would the smaller vessels be constantly
jostled by all the wakes left by the other craft? Would the Solar
Winds push the spent propellant to the starward side of the cluster,
making your time in orbit on that side more perilous?

just curious.

doug