NASA Astronauts Return After 9-Month Space Mission: Health Effects Explored
Spending extended periods in space can significantly impact human health, both physically and mentally. NASA astronauts Barry "Butch" Wilmore and Sunita "Suni" Williams have returned to Earth after an unexpected nine-month stay in space. Originally, their mission aboard Boeing's Starliner capsule to the International Space Station (ISS) in June 2024 was intended to last just a week. However, technical issues with the Starliner extended their mission, delaying their return until early 2025.
Prolonged space missions can lead to various physiological and psychological changes. Microgravity, which allows astronauts to float, contributes to muscle atrophy and bone density loss, as muscles and bones are less stimulated without regular exercise. NASA reports that astronauts can lose 1% to 1.5% of bone mineral density each month in space. Additionally, without a balanced diet and exercise, muscle mass diminishes more rapidly in microgravity than on Earth.
In microgravity, bodily fluids like blood and cerebrospinal fluid tend to move upwards, potentially altering the structure of the eyes and brain. Astronauts also face the risk of kidney stones due to dehydration and calcium loss from bones. Upon returning to Earth, astronauts undergo medical evaluations to readjust to gravity and regain balance for everyday activities.
Space radiation poses another challenge, differing from Earth's radiation. It includes particles from Earth's magnetic field, solar flares, and cosmic rays. While Earth's magnetosphere offers some protection, astronauts at higher altitudes are exposed to more radiation, increasing their risk of radiation sickness, cancer, and other health issues. During a six-month ISS mission, astronauts receive between 80 mSv to 160 mSv of radiation, compared to the 2 mSv of background radiation people on Earth receive annually.
Dr. Rihana Bokhari from Baylor College of Medicine notes that while ISS astronauts are partially shielded by Earth's magnetosphere, they still face higher radiation exposure than those on Earth. This increased exposure, though not immediately harmful, could raise cancer risks over time.
Isolation and confinement in space also affect mental health. NASA carefully selects and trains crews for long missions, but such environments can lead to behavioral changes, stress, and sleep disturbances. To combat these effects, researchers are exploring solutions like virtual reality to create calming environments and activities such as language learning or gardening in space.
Dr. Jennifer Fogarty, also from Baylor College of Medicine, highlights that chronic stress during missions can alter the immune system, emphasizing the need for a supportive environment to maintain astronauts' health.