Multiple sources describe astronaut careers as achievable through several different routes rather than a single formal training track. They note that there is no universal “astronaut school,” meaning aspiring astronauts typically build spaceflight credentials through broader education and professional experience. Common pathways include careers in fields such as engineering, science, medicine, piloting, or military aviation, alongside roles that demonstrate technical expertise and the ability to operate in high-stress or complex environments. Across outlets, the emphasis is on accumulating relevant qualifications, building a record of accomplishment in demanding jobs, and meeting the age, health, and education requirements set by specific space agencies. The sources also highlight that selection processes are competitive and vary by country and organisation, with candidates often applying through national astronaut selection programmes. While the exact routes differ, the overall message is consistent: becoming an astronaut generally comes from established career development and application to agency recruitment rather than from a dedicated astronaut academy.