You can apply for astronaut training with the European Astronaut Corps or with NASA.
You need to be between 27 and 37 years old and able to speak English fluently. It'll be helpful if you can also speak basic Russian because it's spoken with English on the International Space Station.
You'll have an advantage if you're a pilot with at least 1,000 hours of flying experience in a high performance aircraft like a fighter jet.
You'll also need a degree and a postgraduate qualification in a relevant subject like:
- biology, chemistry or physics
- engineering
- medicine
- aeronautics
- mathematics
You must hold US citizenship or US dual-citizenship to become an astronaut with NASA.