“Phase Two”

DEAN: So, uh, after we finish here we move onto Phase Two of the anniversary evening.
RORY: Phase Two. Sounds very official, are there space suits involved?

I think Rory is referring to space missions, where each part of a particular mission is divided into phases. Each phase must be completed successfully and on schedule before the next phase can begin. Because of this, “Phase Two” reminds her of space suits.