Astronaut in 1957: Test pilots with a new job title

The rarest job on Earth is practiced off it: roughly 700 people have ever held it, from Gagarin's 108 minutes to year-long tours on the space station. "Astronaut" is built from Greek — astron and nautes, "star sailor" — and every spacefaring nation has renamed the job in its own image: Russia's kosmonavt sails the universe, China's hángtiānyuán navigates the heavens. Whatever the word, it names the rarest profession on Earth. Since Yuri Gagarin's single orbit on 12 April 1961, roughly 700 people have held it — fewer than have climbed K2, and spread across barely a dozen employers worldwide.

There is no direct door into the job. Every astronaut arrives as something else first — fighter pilot, engineer, physician, biochemist, geologist — and survives a selection that routinely rejects more than 99.9 percent of applicants: NASA chose 10 from over 12,000 in 2021, and ESA chose its 2022 class from 22,523. Those selected then train for years, learning spacewalking in a 12-metre-deep pool and Russian in a classroom, for a flight that may never come.

This page follows the profession from the Mercury Seven and Gagarin's Vostok through the Moon landings, the Shuttle's scientist-astronauts and a quarter century of continuous life aboard the International Space Station, into today's commercial crews. It covers how people actually get selected, what a day in orbit is scheduled down to five-minute blocks, who reached the top of the corps and how, and how much of the work robots already do.