William Pogue had made an interesting — if somewhat distasteful — personal discovery. The astronaut, who piloted the third and final manned mission to the Skylab space station in November 1973, experienced a phenomenon known as a wet burp. You may laugh (or wrinkle your nose in disgust), but in space, a wet burp is no joke.
As it turns out, an environment of near-weightlessness doesn’t allow the contents of your stomach to settle out by weight as they would on Earth. Gas, liquids and solids bump against the esophageal sphincter, the ring of muscular tissue that separates the esophagus from the stomach.
“The sphincter is gravity-assisted; it’s not a total closure,” says Vickie Kloeris, manager of the International Space Station’s food systems as well as NASA’s Space Food Systems Laboratory at Johnson Space Center in Houston. And if you belch in space, there could be some backflow.
