Astronauts’ missions aboard the International Space Station (ISS) typically last between five to seven months. However, mission durations can vary based on mission objectives, spacecraft availability, and technical issues.
For instance, NASA astronauts Sunita Williams and Barry “Butch” Wilmore launched aboard Boeing’s Starliner in June 2024 for a mission initially planned to last approximately 10 days.
Due to propulsion problems with their return capsule, their mission was extended, and they remained on the ISS for about nine months, returning to Earth in March 2025.