How Astronauts Are Selected

The application requirements are dull and strict. At NASA, that means a relevant degree - engineering, natural sciences, mathematics, or medicine - plus several years of work in your field or extensive jet flight time as a pilot in command. Then come the body measurements: in the Soyuz, the seat liner is made for a specific body, and the spacesuit is tailored to your measurements. That is why open Russian calls for applications listed clear limits: height of about 150 to 190 centimeters, weight of 50 to 90 kilograms.

Applications far outnumber openings. In its 2017 selection round, NASA reviewed a record 18,300 applications and chose twelve people. The first round is reading: real people, including active astronauts, review the applications, and most candidates are screened out before anyone even meets you face to face.

After that, the funnel narrows quickly. Those who pass the paperwork are invited for several days of tests and medical exams, then for an interview, and then invited back again as finalists, by which point about 50 remain.

And even being accepted does not make you an astronaut. First comes about 2 years of basic training: spacecraft systems, working in a spacesuit underwater, and the language of your station partners. Only then do you earn astronaut status and join the flight queue, which can also stretch on for years.

For a long time, the psychological part was about screening people out: they looked not for strengths, but for red flags - a short temper, an inability to sleep through noise or live by someone else's schedule. As flights grew longer, a second question was added: not "Does this person have problems?" but "Could you live with this person for six months?" On the station, you cannot slam the door and go home, and a conflict that would have blown over in an evening on Earth can go in circles there for weeks.

That is why the interview is almost entirely made up of questions about your past, not your dreams. You are asked to recall a specific failure and say what you did next. They listen less to the facts than to your wording: whether you say "we" when it should be "I," and how many hours passed before you told the people affected by the problem.

There is no single formula: agencies change their criteria to fit their tasks, and some medical restrictions have eased over time - corrected vision, for example, has not meant automatic rejection for a long time. The funnel principle remains unchanged: at every stage, they look for a reason to say "no," and one is enough.