Answer on @Quora by @Astro_Clay to Do astronauts get space sick? – Xochielt Sanchez
Answer by Clayton C. Anderson:
Many astronauts get "space sick." Using your words, to me it's very much like being car sick or sea sick. It is related to motion sickness, as the body's vestibular system adapts to weightlessness. In nearly all cases, if you have it, you're likely to throw up!
My alter ego, super hero PEPS (Personal Equipment Protection System) Man, made appearances on ISS whenever inspections of emergency equipment (extinguishers/gas masks, etc.) were required!
I don't know the exact, quotable percentage any more, but it used to be that about one-third to half of all astronauts flying in space, experience some form of "space sickness." NASA flight surgeons refer to it as space adaptation syndrome –of course we have to have some fancy term for it– and it ain't fun… not that I know through experience. Honestly, I NEVER got sick while in space. Never. But I did take appropriate medications on launch day to help me avoid the "syndrome." After all, your tax dollars were invested in NASA and America was counting on me to perform at the top of my game while in space. If meds would help me (and apparently they did!), I was takin' 'em!
My first launch, STS-117 was with a crew comprised of both veteran astronauts and rookies… just like me. A high percentage of our crew could be found with white bags tightly positioned around their mouths at various times during the first two days in orbit. Fortunately for most, our bodies adapt quickly and the third day often brings relief and a normal appetite to even the most space syndrome-haggard astronauts.
Astronauts have been known to "blow chunks" just from flipping upside down. In not maintaining a "normal" earth-like, heads-up attitude, our brain can flip out a bit, causing many of our steely-eyed heroes to give a "technicolor yawn" for their crew mates. My need for the white bag did not occur until landing day, after a serious session in the port-o-potty. You can catch all those details in my book: "The Ordinary Spaceman," in stores next weekend. The Chapter? "The Hard Thump of Reality!"
Keep lookin' up!