I wasn't there, but two friends were playing a pickup game set in the KF cluster (using my fold up counters and a black tablecloth). And they were asking for some environmental hazard rules. Here's what I could offer for some home rules. Didn't know what people here might think. But I see it as being really crowded up there.
Floating Debris
Space is dark, and detection gear aboard your standard IS ship is understandably crude (I mean, they have wireless sets for communication, but only searchights to pick things out).
So caution is the keyword used by ethership captains while navigating the KF Cluster. Most hulls -- even unarmored ones -- are strong enough to operate for several weeks in the asteroid field before needing a stint in a dockyard. But reckless crews find themselves in trouble.
Two main factors that go against you when trying NOT to run into a chunk of floating debris -- your momentum and your size. Obviously, the faster you're going, the less time you have to react. The bigger you are, the less likely you are to be able to steer out of the way.
So.....
Before the battle roll to decide how dense this stretch of the KF Cluster really is.
My really basic approach was that the threshold/safe momentum for IS ships in a standard stretch of the KF Cluster would be:
8 for FACs
7 for VS ships.
6 for S and M ships
4 for L ships
2 for VL ships
During each turn your ship's listed momentum is greater than the limit listed above, you are targeted by number of attacks dependent on your speed.
Exceed the safe momentum by 1= 1 attack
Exceed the safe momentum by 2 = 2 attacks
Exceed the safe momentum by 3 = 3 attacks
What dice do you roll? Just a D4, but like a torpedo it halves your armor and rolls a D12 for damage. It inflicts two points of damage.
So say a very large BB with Armor 4 is moving through a standard stretch of the Cluster. Its momentum is 4. During the End Phase, it is damaged by a chunk of rock on a 4 (2+ half its armor). It has two chances of being hit, and for any attack that penetrates it rolls two D12s against its damage track.
A small CL is safe as long as its momentum is 6 or less. But with a momentum of 7 and an armor rating of 1 it would have a chance of being hit by one bit o' rock, damaged on a 3+ rolling D4. With a momentum of 8, it could possibly suffer two collisions.
FACs really see their mobility advantage disappear -- an attack craft moving with a momentum of 10 would be targeted by two attacks, and any hit is going to kill it.