You know this already, but it's ridiculously hard to get in. I know two people who have applied. One's a PhD cosmologist who does aerobatics on the side. One's a PhD geophysicist who's also an experienced pilot and a mission data scientist. They didn't get in.
OTOH, I know another person who's also qualified who doesn't want the job, because you have to live in Houston, do a lot of PR and outreach, and the chances of actually flying are not very good.
You didn't say if the cosmologist is theoretical or experimental. A scientist would need a solid experimental record to be very competitive as a mission specialist astronaut candidate. (And of course an applicant for pilot astronaut has basically zero chance without top performance as an experimental test pilot at Edwards Air Force Base on her resumé.)
All I'm saying is, they're both exceptional (among the class of serious-about-flying hard-science PhDs with extensive publication records and > 10 years mission experience) and they did not get in. Just calibration.
A woman I knew in college got in and flew on the Shuttle. She was a geology major and then a high school teacher. So there must be something beyond the science and pilot aspects in the evaluation.
When I was in college I made a laminated pocket-size printout of the Astronaut Candidate Basic Qualifications and carried it in my wallet every day, and it actually inspired me often to study harder and to go running.
I think it's hard to overestimate how much benefit the space program has had just in terms of how much it has inspired people to study math, science, and engineering -- or how much further that inspiration would go if we were sending astronauts to destinations beyond low-Earth orbit.
I liked to imagine astronauts as individuals who excelled so much in their given fields that they stood out and were actively recruited by NASA. Instead, I find out that NASA posts job postings and interviews people just like everyone else. This would be mildly concerning other than the fact that it appears to be working.
Edit: I wonder if they are asked silly interview questions such as "If you were stuck on the moon with only three items, what would you want them to be and why?"
I liked to imagine astronauts as individuals who excelled so much in their given fields that they stood out and were actively recruited by NASA. Instead, I find out that NASA posts job postings and interviews people just like everyone else
Possibly if your job is "test pilot" then you might still get recruited by NASA. For scientist-astronauts, though, I'm guessing that being spectacularly brilliant in your particular field is neither sufficient nor necessary to be a good astronaut; better to hire good but not necessarily field-leading science-trained types who also excel in the various other qualities which you need in order to strap yourself to a giant bomb and perform brilliantly in adverse circumstances for several days without enough sleep.
Early this year, the NY Times had an article about NASA losing astronauts to private companies (like SpaceX and Virgin Galactic) because NASA cancelled the Ares I and Constellation programs. Who wants to be an astronaut if you are unlikely to fly?
Actually, the base level GS-11 pay grade, with a location adjustment for Houston, apparently translates to about $65K. I really hope that, like military pay, gets boosted with all sorts of crazy allowances, because $65K just seems... unbecoming.
OTOH, I know another person who's also qualified who doesn't want the job, because you have to live in Houston, do a lot of PR and outreach, and the chances of actually flying are not very good.