The Apostate discusses a post by Paul Campos about the fortieth anniversary of the first moon landing and the lack of women in the program. Here's Paul:
(2) Considered as an incredibly expensive and complex exercise in practical engineering, the Apollo program was indeed a stunning achievement. In many ways it was a paradigmatically American achievement, and specifically of American men, or rather boys as men (think of the most impressive neighborhood treehouse, times ten million). Aside from putting the Russians in their place, the most important motivation was probably the sheer desire to figure out how to actually make the thing work. And it was an intensely and peculiarly male project: I don't recall ever seeing a single woman in that huge Houston control center, where hundreds of guys in short-sleeved white shirts and crewcuts ran the show.
One measure of how much has changed in the last 40 years is that the very idea of a woman astronaut in the 1960s would have seemed outlandish to most Americans (that the Russians had a female cosmonaut was widely interpreted as a preposterous publicity stunt).
He later added an explanation to his post:
Update: In response to a couple of comments, I would have thought it obvious from my remarks about how much has changed in regard to things like gender roles and being an astronaut that I wasn't ascribing the intensely male atmosphere of the Apollo project to biology, as opposed to say sexist assumptions about men's and women's work.
But the absence of women astronauts in the program has a much more concrete reason: They were excluded from it. Books have been written about that: Margaret A. Weitekamp's Right Stuff, Wrong Sex and Stephanie Nolen's Promised The Moon.
And there were women involved with the project itself as described by Robyn C. Friend in The Women of Apollo. You can hear one of the original engineers, Ann Dixon, speak about her experiences here:
I'm not sure why women's history appears to evaporate the way it does.
Note that I'm not arguing here that women were common in the Apollo program. But there are all sorts of reasons for that.