The Bodily Function Astronauts Can't Actually Do In Space

The life of an astronaut may look glamorous from afar, but those who have really been to space know that many aspects of space travel are flat-out gross. Astronauts aren't able to shower on their missions, and that's hardly the worst of it. Human bodies were meant for planet Earth, and when you separate the two, some pretty strange consequences arise, including the fact that, in space, astronauts are physically unable to burp.

To understand astronauts' predicament, we need to cover why humans burp in the first place, and how that mechanism works in the body. When food and drinks arrive in the stomach, they get broken down by a combination of stomach acid and digestive enzymes. This process helps extract the nutrients we need from our food, but it also produces a lot of gas as a byproduct. We add to that gas buildup with the air that we incidentally swallow along with our food. Burping is a way to release this excess gas and free space in the stomach.

Unfortunately for astronauts, one of the biggest factors in burping is gravity. Here on Earth, gravity sorts the contents of our stomachs, with heavier solids and liquids sinking to the bottom, and gas rising to the top. As more gas builds up, it continues to rise, putting pressure on the sphincter between the stomach and esophagus. This forces the sphincter open, allowing the gas to escape upwards and out of the mouth as a burp. In space, none of that can happen.

Astronauts orbiting the planet on the International Space Station are not actually weightless, as many people mistakenly believe. However, they experience far less gravity than we do on Earth's surface, and that means the contents of their stomachs don't get sorted out like they are supposed to be. All of the solids, liquids, and gases in an astronaut's stomach are unified into a digestive stew of sorts, and without the force of rising gas, the burping mechanism is never triggered.

So, what do astronauts do to relieve the gas buildup in their stomachs? If a person here on Earth needs to force a burp, they can try drinking carbonated beverages or purposefully swallowing more air, and those techniques will also work in space ... sort of. If you try using one of these methods to induce a burp in microgravity, you'll just end up vomiting, which is obviously not ideal. That leaves astronauts with only one viable option: wait for the gas to come out the other end. The ultimate result? Astronauts don't burp, but they fart a lot more.