ELI5: Explain Like I'm 5

Space medicine

Space medicine is the branch of medicine that deals with the health, safety and performance of people who are travelling in space. It's different from normal medicine because when you're in space, health problems can be caused in ways that don't exist on Earth, such as microgravity or radiation, and the medicines and treatments we use on Earth don't always work in space. That's where space medicine comes in to help make sure astronauts stay healthy and safe.