In my last game my "Dark Curse" spent THREE consecutive turns on the same asteroid because a traffic jam of ships kept moving in front of him and prevented him from moving off said asteroid.
So, in that game, my opponent and I agreed that he didn't need to roll for damage each turn because the rules seem to indicate that you don't roll for asteroid damage for leaving the asteroid you are already on, which "Dark Curse" was trying to do.
However, does it say anywhere anything about staying on the same asteroid over multiple turns? Maybe this needs to be FAQed because with large ships I can see this happening more often.