NASA astronauts are highly trained individuals selected to participate in space missions for the National Aeronautics and Space Administration. They undergo rigorous training in various fields, including science, engineering, and physical fitness, to prepare for the challenges of living and working in space. These astronauts operate spacecraft, conduct experiments, and perform spacewalks. They play a crucial role in advancing our understanding of space and Earth, contributing to missions aboard the International Space Station and beyond. Their work helps to develop new technologies and gather valuable data for future exploration.