I finally made it through an FTL game to sector 8 (on easy mode, of course), whereupon I found that everything changed.
Now I start at the right side, and there's a flagship on the left, and nodes are getting picked off one-by-one. I also was given some repair nodes, but apparently with no time to get to them before the flagship reached my base. (Later I discovered that the flagship doesn't move one node per turn, but only one node per two or three(?) turns.) Furthermore, I lost the game when the rebels reached my base even though the flagship was still a couple of nodes away.
How does sector 8 work? How fast does the flagship move? What conditions cause me to lose the game without getting blown up? (I realize this is more than one question, but I'm looking for an overall understanding of how sector 8 is supposed to work.)