The astronauts' diet is currently the most stringent food standard for human beings, and so far no astronauts have ever suffered from food-borne illnesses in space, which shows how strict the astronauts' dietary standards are.

Compared with the Earth's food, space food has the most stringent microbiological standards, and food testing frequency, testing more, as long as there is a kind of food does not meet the standards, then a batch of food will be eliminated. The food that goes into space must be safe and at the same time can provide sufficient nutrition.

Astronauts living on any space station can basically enjoy a week's worth of non-repeating optional food, and on the Chinese space station Tianhe, there are even a variety of classic dishes. But there are some Earth foods that astronauts can't take into space, no matter how much they like them.

Crackers, bread and other fragile food:

Crackers and bread are the most common snacks, and many people use these foods as a small snack. But in space, bread, crackers and other foods that produce crumbs are not allowed to enter the space station.

If there are crumbs inside the space station, they will not only affect the interior of the station, leading to system interference and damage, but also affect the astronauts' daily lives, and even drift into their noses and eyes.

So astronauts can't have this type of fragile food in their meals, and to make up for this, space meals have special tortillas, which aren't as fragile as crackers, but are more similar to eat.

Salt, pepper, pepper, and other seasonings:

Many restaurants on Earth provide salt, pepper, sugar, and other seasonings along with their catering, thus helping customers to mix their favorite flavors. But in space, these seasonings are not available, and if you shake a seasoning bottle on a space station, the particles don't land on the food, but are suspended in the air.

Floating particles have the same effect as food crumbs, but these condiments have a stronger flavor, and there is the potential for hygiene and allergy problems.

While these seasonings can't be taken into space, liquid seasonings have become a substitute in order to provide a richer mix of flavors.

In space, all seasonings are liquids, similar to various sauces. Salt, which is currently used by astronauts, is replaced using brine, while other seasonings, which are dissolved into oil or made into sauces.

Liquid seasonings don't produce suspended particles, and although there is a slight difference in flavor and regular seasonings, they can meet the astronauts' daily needs.

Carbonated beverages:

No experiments have been conducted on drinking carbonated beverages in space, but carbonated beverages have been ranked as the most dangerous space food. This is because carbonated drinks contain carbon dioxide, and in a low-gravity environment, carbon dioxide from carbonated drinks will not separate from water, and these gases cannot be absorbed by the human body, thus remaining in the astronauts' bodies and having adverse effects.

While the consequences of drinking carbonated drinks in space are only speculative, the experiment could not be conducted in a way that would ensure safety, and scientists believe that drinking carbonated drinks in space could cause vomiting, and is therefore classified as a prohibited liquid.

Alcohol:

The ban on drinking liquids containing alcohol in space is not for the health of astronauts, but rather the current space recovery system, which does not support the handling of alcohol, and in fact, if humans were to undertake long-duration space travel, alcohol might be offered to astronauts' drink menus.

Current space survival systems rely heavily on the recycling of liquids, and alcohol is a volatile liquid that, when it enters the circulatory system, produces chemical contaminants that can affect the functioning of the entire life system. But spaceflight history shows that many astronauts will secretly bring alcohol into space.

Summary:

The astronauts' dietary menu is extensive, but the vast majority of the food that astronauts eat is dehydrated food, as well as food that has been specially processed so that it can be stored for a longer period of time. After all, when you go into space, you may only get supplies once every few months, so all food needs to have a long shelf life.

In addition to the lack of flavor, astronauts' food will also be limited, fragile food, condiments, carbonated drinks, alcohol, can not be enjoyed in space, can not eat favorite foods, you still want to go to space?