High physical fitness is a requirement and that helps with the jaw line

To be an astronaut, you also need solid steel balls... and whatever the female equivilant would be to that statement.

3 of them were in the army.

Well it all goes away with the fluid shifts that happen in microgravity. Could you imagine the flabby chins that would occur with someone with a weak jaw line. I think its a self evident requirement.

Damn woke devs!

If you're physically fit but have a weak jaw and/or chin, your jaw line would probably still be well defined.