Mouse Space Study Reveals Gravity Thresholds for Astronaut Muscle Health

In March 2023, NASA researchers sent 24 mice to the International Space Station to study how different gravity levels affect muscle function. The rodents spent approximately 28 days in chambers simulating microgravity, Earth gravity (1g), and reduced gravity levels similar to Mars (0.33g and 0.67g). Analysis published in Science Advances on March 13, 2024, showed that mice exposed to microgravity or Mars-like gravity experienced muscle deterioration, while those at 0.67g maintained full muscle function. The study, led by physiologist Marie Mortreux and skeletal researcher Mary Bouxsein, provides crucial data for NASA's plans for long-duration missions to Mars and the Moon through the Artemis program. Scientists identified 11 biological markers that could help monitor astronaut muscle health during spaceflight.