Q: Is it correct to leave “post” as a separate word in the following sentence? “These activities must take place from prelaunch to post launch.”
A: In section 8.3.1 (“When Not to Use Hyphens”), you’ll see the following:
Note that when post is used as a combining adjectival form, as in postmortem examination, it is set closed up. When it is used as an adverb, as in post hoc testing, it is set as 2 separate words.
So in your example, you would not close up “post launch.” However, the meaning of this sentence is ambiguous to me. I would suggest rephrasing it to avoid an awkward construction and to clarify exactly what interval you are talking about. How about “These activities must take place both before and after launch.”?—Cheryl Iverson, MA