Pressure!

I saw the attached pic in a Facebook group, and of course someone cried "sexism!" Someone always cries "sexism" at the sight of the female form, though sweaty images of Conan never elicit the same criticism. Apparently, it's only the sight of women that these people hate. Sexist, indeed. If you think it's sexist that women are shaped differently than men, you should take it up with God... or your psychiatrist.

Of course, they have convinced themselves that the "sexism" is that the women are depicted as having female shapes rather than being hidden under bulky suits. But does that criticism have legs?

FUN FACT: to be effective, a pressure suit does not have to provide air to the skin. It has to provide pressure. The pressure provided by an elastic, form-fitting garment will do. Don't take my word for it; believe NASA. Here's a link to the Bioastronautics Data Book, second edition. 200 mm Hg is barely tolerable; but look at page 5: a properly fitted elastic suit can protect you down to 15 mm Hg.

So, trope though it may be, those tight form-fitting reflective suits of the fiction of yesteryear have a certain plausibility. And of course, we don't know what they're made of, and whether they're constructed of some memory material that's more responsive to pressure changes than mere elastic. This would be a minor advance that is far more believable than, say, the magic gravity deck plating of Star Trek and damned near every other sci-fi darling. Granted, you still have to provide temperature regulation and protection from radiation, but that could be done with a relatively svelte oversuit; you don't really need a huge bulky space suit to do the job. Inside the ship, where the oversuit isn't needed, it would be entirely plausible that the skintight pressure suit alone would be used as safety equipment.

Indeed, it would be somewhat easier to provide said pressure to the female form than the male in certain areas due to the nature of the ... er... "baggage" inherent in the male form. And yes, it may very well have that "thong" to keep it tight. And men's suits would of necessity be constructed a little differently, being bulkier around the nethers. If you'd like to argue that point, I'll happily discuss your own sexism. Even in the future, some men will have balls. Nevertheless, concerning these "space catsuits", where in my youth I might have said, "That's ridiculous," I now know better.