Up in the air somewhere above your head, there's an astronaut aboard the International Space Station who's taller than when he or she first launched into orbit. They're not just standing a bit straighter. They are actually taller, up to 3% of their height in fact, as described in a NASA study summary “Risk of Spaceflight-Induced Bone Changes,” which attributes the change to the spine straightening out and elongating in microgravity, not to any actual growth of bone. If that astronaut is six feet tall, that means they've gained almost two inches in height without having to do anything about it. That sounds like a total glow-up. Except it isn't.
