Quick facts
"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.
The profile
- Resists AI74
- Pay55
- Barrier to entry99
- Autonomy35
- Demand30
- Impact88
How exposed is it to AI?
Low
Task by task, a meaningful slice of the job is already automated: ascent, docking and re-entry are machine-flown with humans as monitors, and robotic probes do planetary science at a fraction of crewed cost. What cannot be automated is the mission's actual product — human presence, human physiology as the experiment, and improvised repair — so the profession shrinks or grows with political ambition, not with algorithmic capability.
AI & The Future →Seven ways into this profession
Frequently asked questions
How do you become an astronaut?
How much do astronauts get paid?
How long does astronaut training take?
Do you have to be a military pilot?
What are the physical requirements?
How many astronauts are there?
How dangerous is spaceflight?
Will robots replace astronauts?
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