As far as I can tell, you're supposed to cut out the red areas on the ends of the supply pods/tanks (the thin red strips on the sides and the thicker bit across), then fold the remaining flap out abit. The 9a and 11a parts, that look like open fairings fill in the cut out red bits to make the sides and end stick out walls to make the protruding prism shape. I'm also guessing that the flaps for these fairing parts are valley folds, and they are glued to the back side of the pods ends (interior). Hope this helps.
Mine's printed and started, but because of the curse of North American paper sizes, I had top print it at 89%. Before I go any further, I've decided to double the size and build a really BIG one (200%). Any one else decided to go big on this baby!? I'm in the process of reprinting it now, and sorting out how I'll have to piece together all the parts.