Today, being a NASA astronaut is kind of a dud job. There are about 50 active astronauts at the moment, and not very many flights for them. Peak was around 150, in the Shuttle era. With 135 Shuttle flights, with up to eight people aboard, most of them got a chance to go up, usually more than once. Not today.

Another astronaut comments on what the Crew-9 people can expect: "The returning astronauts will "struggle to walk, get dizzy easily, and have bad eyesight", because the "build-up of fluid changes the shape of their eyeballs, and weakens their vision". They may need glasses for the rest of their lives."

Living without gravity seems to be harder on some than others. Valery Polyakov spent 435 days in space, longer than anyone else. He apparently didn't suffer much in the way of after-effects, had a good post-flight career, and died at age 80.