What happens to the human body during a year in orbit?

Space · Published 8 October 2026 Swipe more like this →

In short: As Expedition 45 enters its ninth month, Commander Scott Kelly and Mikhail Kornienko are providing more than just orbital observations. They are serving as human test subjects, gathering critical biomedical data to understand how long-duration spaceflight affects the body before we attempt the long journey to Mars.

Living aboard the International Space Station (ISS) is a rigorous biological experiment. For Scott Kelly of NASA and Mikhail Kornienko of the Russian Federal Space Agency (Roscosmos), the mission involves a year-long commitment to studying the physiological impacts of microgravity. Currently in their ninth month of flight, these crew members are collecting essential biomedical data that will inform the design of future human missions to Mars.

The ISS serves as a vital orbital laboratory where the effects of weightlessness are monitored in real-time. This research is fundamental for deep-space exploration, as the biological toll of prolonged exposure to space environments remains a significant hurdle for interplanetary travel. By studying how the human body adapts over a full year, scientists can better prepare for the extreme durations required for a Mars transit.

While Kelly and Kornienko focus on long-term biological changes, the station itself remains a bustling hub of activity and crew rotations. For instance, the arrival of NASA’s SpaceX Crew-13 on October 1 brought four new members—Jessica Watkins, Luke Delaney, Joshua Kutryk, and Sergey Teteryatnikov—to the station. After a record-breaking 7-hour, 55-minute Dragon spacecraft journey, this landing raised the station's total population to 11.

These rotations ensure the station remains operational while scientists continue to parse the data collected from long-duration crews. As one mission prepares for departure, such as the Crew-12 team, another is just beginning to acclimatize to life in weightlessness and familiarize themselves with the complex station systems.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• What happens to the human body during a year in orbit?
• What happens to the human body during a year in orbit?
• What happens to the human body during a year in orbit?
• What happens to the human body during a year in orbit?
• How does the human body survive a year in orbit?
• A critical leak threatens the International Space Station's ability to regulate temperature
• From Iowa and Texas to the Edge of Orbit
• The final journey of an automated orbital supply ship
• How do astronauts manage media interviews while orbiting the Earth?
• How Astronauts Communicate Their Mission Progress While Living Aboard The International Space Station
• How astronauts bridge the gap between orbital research and the public back on Earth
• How Astronauts Communicate Their Scientific Missions From The International Space Station To Earth

More in Space stations · More in Space · Latest · A–Z · All topics