Astronauts grow up to 3 percent taller during long missions on the International Space Station, NASA says, then shrink back to normal once they return to Earth.

Crew members grow up to three percent taller during long-duration missions on the International Space Station, NASA says, and return to their normal height back on Earth.

Medical researchers have observed the change in astronauts aboard the station, where weightlessness takes the everyday compression off the spine. NASA studied it with a Spinal Ultrasound investigation, imaging the spine in orbit.