Evidently, a person becomes taller when spending a significant time in space, but returns to normal height after being back on earth for a while. Maybe, if astronauts hurry to a basketball court when the arrive back on earth, they'll be able to dunk a basketball prior to gravity setting in.
"I did read in the newspaper the other day... that 7 percent of my DNA had changed permanently," says Kelly in reaction to NASA's announcement. "And I'm reading that, I'm like, 'Huh, well that's weird."