Human: How do people become astronauts? Assistant: 
People become astronauts by completing a rigorous application process, which includes physical and academic requirements. Generally, they must have a college degree in a STEM field, and undergo extensive medical screenings, fitness tests, and many interviews. They also must have several years of related work or research experience, and may even need to train in special skills like spacewalking. After passing all these hurdles, they can be selected to join the corps of space explorers.