Why does NASA say no? From bread to fruit: 10 common foods banned from space travel

Space environments pose unique challenges to food safety. While on Earth, food is stored, cooked, and consumed in stable conditions, in microgravity, microbes can float freely and spread through the cabin air. Hence, NASA processes and tests all food on Earth for astronauts before launch to ensure it is safe to eat in space.

Bread is one of the most familiar items on Earth but it is extremely unsuitable for space. Crumbs are very likely to float away in microgravity, getting into instruments or being inhaled by the astronauts. Hence, NASA substitutes bread with crumb-free options like tortillas, as they are less messy and can be easily stored.

Granular seasonings like salt and pepper are usually banned in their regular shaker form from space. The reason behind this ban is their nature. In microgravity, the particles can scatter and contaminate the equipment they can even enter the eyes, irritate them and can even affect lunges if inhaled, hence causing serious consequences. In contrast, NASA offers these condiments in liquid form, suspended in either oil or water, to ensure their controlled and safe use during meals.

Next in the list are carbonated beverages. These are banned during space missions as without gravity, the bubbles in carbonated drinks don’t rise, thus the gas stays mixed with the liquid. When they are consumed, they cause discomfort and digestive issues called 'wet burp'. This makes carbonated drinks like soda impractical and unsafe for astronauts.

Despite occasional use during earlier space missions, alcohol is banned aboard the ISS and other missions. The reason is how it reacts, when consumed in microgravity. Alcoholic beverages can impair cognitive function, may seriously affect coordination, and even disrupt the closed-loop environmental control systems. To top it all, alcohol can influence how medicines are metabolised, which poses a health risk for astronauts in space.

The use of perishable items like fresh fruit, vegetables, and dairy is limited. This is due to the fact that these have short shelf lives and require refrigeration, which is something that’s extremely limited in space. Since space mission can be prolonged due to circumstances, NASA focuses more on foods with a long shelf life that can withstand long-term storage without spoiling or losing their nutritional value.