> The problem occurs when someone thinks they can determine “best” from traits that probably don’t actually matter in space, like being shorter than average

You got me curious so I looked it up. NASA requires that astronauts be at least 62 inches (5'2", aka 1.57 meters.) So they already permit astronauts to be substantially shorter than average. They wouldn't take people with dwarfism I guess, or people without legs.

If I had to guess, these requirements exist because they need people who are compatible with existing equipment. For instance, astronauts on the ISS do not get personalized EVA suits; they pick one that fits from those which are already up there. Perhaps somebody without legs could fit in a suit with legs just fine (stuff the legs with some towels maybe, if the legs flopping around is a problem?) But for somebody with dwarfism or a related disorder, I can see this being a legitimate problem.

Incidentally, NASA also discriminates against the tall. For the Mercury program they wouldn't take anybody over 71 inches (5'11") and today they won't take anybody over 75 inches (6'3"). This doubtlessly is due to equipment that isn't sized for taller people.

A large part of non-personalized EVA suits is, when an emergency vacuum release occurs you wouldn't want astronauts (cosmonauts, if you prefer) looking for their personalized EVA suit. Seconds matter. I have a disability and would love to go into space, but understand the necessity for uniformity in EVA suits. I'm not trying to be the bad guy, but many of the well articulated amputation prosthesis might risk a suit puncture, the stresses on the body could cause high/low blood sugars when a person is unable to get to medicine or food to regulate their blood sugars, epilepsy is a non-starter, eye sight might be a pass with surgery (though I saw a pilot talking about that above), I saw someone arguing for paralyzed astronauts which was an argument that was beyond me (sorry) - I just don't think we're there yet. If we were at the level of a space elevator, then I think this would be a fantastic plan, and I would be the first in line! But as a disabled person, this seems to put inclusion and politic in front of safety protocol. They aren't just choosing astronauts based on physical performance, these are also startling smart individuals who have worked hard and I don't think that should be forgotten. The vast majority of them are science nerds, not jocks.

You mean Gattaca. The spelling was chosen to only contain the 4 chemical DNA bases. :)

(And I completely agree with your comment)