Astronaut in 1961: Gagarin orbits the Earth

How long does astronaut training take? About two years of basic training covers spacecraft systems, spacewalking in a giant pool, robotics, jet flying, wilderness survival and the Russian language. Graduation only makes you eligible: a specific mission then adds 18–30 months of dedicated training across Houston, Star City, Cologne and Tsukuba. Counting the prior degrees and career, most astronauts fly 15–20 years after leaving school.

Less superhuman than people assume. Modern limits mostly ensure you fit the suits and seats — Soyuz-era seats accepted heights of roughly 150–190 cm — with vision correctable to 20/20 (NASA has accepted laser eye surgery since 2007), controlled blood pressure and no disqualifying conditions on a long-duration flight physical. ESA went further in 2022, selecting parastronaut John McFall, a leg amputee.

Vanishingly few. Roughly 700 people have reached space since 1961, and the active professional corps is far smaller: NASA lists around 40–50 active astronauts, ESA fewer than a dozen career astronauts, with comparably small groups in Russia, China, Japan and Canada. For comparison, a single large hospital employs more surgeons than there are trained astronauts alive.