1. people who are trained to travel and work in outer space

Examples

• The astronauts conducted experiments on the International Space Station.
• NASA selected twelve new astronauts for the Mars mission program.
• The astronauts performed a spacewalk to repair the satellite.
• Three astronauts returned safely to Earth after six months in orbit.
• The astronauts trained for years before their first space mission.
• Young children often dream of becoming astronauts when they grow up.