Re: the final crewed mission of the Mercury programme
I'll say 'manned' because
a) it's politically incorrect
b) it's true (there WAS 'a man' aboard)
c) Proper grammar defaults to male pronouns, etc. when sex is indeterminate or unimportant. See 'a'
/me wonders why the 'pee' problem in Gordo's flight was never mentioned in "The Right Stuff".
(my 'mailman' is a woman)