Astronauts in space can grow up to 3 percent taller during the time spent living in microgravity, NASA scientists say. That means that a 6-foot-tall (1.8 meters) person could gain as many as 2 inches (5 centimeters) while in orbit.
While scientists have known for some time that astronauts experience a slight height boost during a months-long stay on the International Space Station, NASA is only now starting to use ultrasound technology to see exactly what happens to astronauts' spines in microgravity as it occurs.
"Today there is a new ultrasound device on the station that allows more precise musculoskeletal imaging required for assessment of the complex anatomy and the spine," the study's principal investigator Scott Dulchavsky said in a statement. "The crew will be able to perform these complex evaluations in the next year due to a newly developed Just-In-Time training guide for spinal ultrasound, combined with refinements in crew training and remote guidance procedures."
A better understanding of the spine's elongation in microgravity could help physicians develop more effective rehabilitation techniques to aid astronauts in their return to Earth's gravity following space station missions.