YOU tumble through the air. You feel light as a feather! Free as a butterfly! On top of the world!. Ready to throw up. You're overcome with a seasick-y, sickening sort of dizziness. You grab a barf bag out of a dispenser as you read a sign stuck to a wall, explaining that two-thirds of first time space travelers vomit when they go into free fall. One of the astronauts' training vehicles is even nicknamed the Vomit Comet. The problem? Without the familiar anchor of gravity, your body gets confused. Tiny motion detectors in your inner ears, parts of something called the vestibular system, can't do their job, which is to tell your brain what's up and what's down. But your eyes still know what's ceiling and what's floor. This conflict between your eyes and vestibular system is a large part of what's making you feel sick. 
 
  
But you don't have time to worry about warring systems. Other weird stuff is happening, Without gravity pulling down, blood and fluids flow up to your head, making it feel like a balloon about to pop. As you float by a metal wall panel, you see a reflection you hardly recognize. The spacesuit and helmet have been somehow removed and a distorted version of your own face stares back. Puffy eyelids, swollen cheeks. Your floating image is taller than usual, too. Without gravity constantly yanking on your backbone, it's stretched out like an overused rubber band.