I really love the writing and theme on this one; the maps look good, and the cover art is really evocative. It goes a long way toward selling the premise.
I wish the text had more breathing room, like others have said it can be a bit wall-of-texty, but I can't imagine what you could have cut and kept the high level of worldbuilding and vibe-establishing that you've got here.
I also think the adventure would benefit from a list of premade characters, or some tips on making traditional Cairn characters into Spacefleet crew on theme--it was hard for me to imagine running this with Cairn when there is so much implied worldbuilding in the Cairn character creation.