5 Types of Foods Astronauts Avoid Eating in Space — and Why

If you make the mistake of eating a gassy chickpea salad for lunch at the office, you may experience some stomach rumbling during your afternoon meetings. But if your work takes place in space, the consequences are a little more serious.

Astronauts have some choice when it comes to food, but the food is often packaged months in advance. Additionally, astronauts must figure out how to eat in microgravity, when their food and utensils can float above their plates.

But with all the advances in food technology, some foods are just plain terrible in space.

Why should we care about what astronauts eat in space? Vickie Kloeris, a food scientist and retired NASA space food systems manager, said, “If you look at the history of the space program, humanity in general has benefited from the technologies that came out of that program.” So figuring out how to keep astronauts healthy, happy, and well-nourished is critical to any space mission.

It turns out that space experts have five types of foods they advise against eating in space.

Those who have been unfortunate enough to get food poisoning have no desire to go through that experience again. “There’s nothing worse than throwing up or (worse) in orbit,” Kloeris said. Microgravity would make things very messy and smelly, all in confined spaces.

Many foods can cause food poisoning, including undercooked meat or seafood, unpasteurized dairy products, and unwashed fruits and vegetables. Since the International Space Station doesn’t have a dedicated refrigerator, everything has to be stable at room temperature, says Kloeris, who is also the author of Space Bites: Reflections of a NASA Food Scientist.

According to NASA, astronauts can eat eight major categories of foods. First, there are rehydratable foods, which have had their water removed and can be rehydrated before consumption, such as oatmeal, rice, ramen, and powdered drinks. Heat-stabilized foods are processed using heat and include foods like canned fish, fruits, and vegetables. There are intermediate-moisture foods, which are foods that have had some of their water removed and can include dried fruits and jams.

Next come irradiated foods, which have been exposed to ionizing radiation (this is often the case for meat products). Next come frozen foods, such as chicken pot pies, and natural foods sold in ready-to-eat packages, such as nuts and granola bars. The last two categories are fresh foods, which include unprocessed foods such as vegetables or fruits (which must be consumed quickly); and then refrigerated foods, such as dairy products.

Since everything must be stable at room temperature, NASA is careful with its microbiological requirements to prevent food poisoning, Kloeris says. Nothing is left to chance: All foods are tested for safety and taste by the astronauts themselves. A nutritionist reviews the astronauts’ favorite menus to make sure they’re getting a balanced meal.

In addition to NASA’s strict diet guidelines for astronauts, the agency requires astronauts to quarantine for seven days before launch to keep the crew healthy. That also means astronauts don’t eat out or at home, “because that increases their exposure to others and their risk of contracting foodborne illness,” Kloeris explains in his book.

Meals, ready to eat (MREs) are self-contained, shelf-stable rations used by the U.S. military. But unfortunately, they could wreak major havoc in space.

MREs are high in salt and fat, which is important to the military because it provides salt to replace electrolytes drained in the desert and plenty of calories in a compact space, Kloeris explained. But the high salt content would exacerbate one of the known side effects of microgravity: bone loss. Without the constant push of gravity, humans lose bone density during their time in space. NASA explains, “For every month spent in space, astronauts’ weight-bearing bones become about 1 percent less dense if they don’t take precautions to counteract this loss.”

Exercise contributes to reduced bone density and weakened muscles, but diet plays a role. Salt can worsen bone loss. The first thing your doctor will tell you if you have osteoporosis is to “stay away from a high-salt diet,” Kloeris says.

Nothing is more satisfying than the crunch of a potato chip. But chips, bread, and other foods that produce crumbs are risky in space.

It all comes down to microgravity. On Earth, crumbs simply fall to the ground. But in space, they float around and create a mess. Jordan Bimm, a space historian and professor of science communication at the University of Chicago, has noted that crumbs can get into air filters, onboard instruments, and even astronauts’ eyes. In 1965, Astronaut John Young He got in trouble for smuggling a corned beef sandwich into space aboard Gemini III, but he only ate a small amount for fear the crumbs would get everywhere.

While attempts have been made to introduce Pringles and other crunchy foods into space, the mess and anxiety have generally not been worth it. Instead, astronauts primarily use tortillas in place of bread. Other options are bite-sized crackers and cookies that can be eaten whole without much crumbs.

No one particularly likes bland food, but it’s a particular problem in space. Dr. Michael Harrison, Axiom Space’s chief medical officer, noted that “due to changes in bodily fluids in microgravity, astronauts often experience facial and sinus congestion. This impacts their sense of smell and taste.” Hot sauces, such as Tabasco or Sriracha, are particularly popular because they add a punch of flavor to their dishes.

But it’s not just about wanting to taste their food. Not only does food provide nutritional benefits, but eating tasty food also has psychological benefits.“What brings everyone together? It’s food,” he explains. Stephanie Wanstrategic partnerships advisor in support of the Deep Space Culinary Challenge from the Methuselah Foundation. Food brings the crew together and encourages social bonding and team spirit, Kloeris noted.

In the early days of the U.S. space program, NASA was fairly utilitarian when it came to food; the agency’s concern was to provide calories and reduce the weight of food for astronauts, he explained. Richard Fossculinary historian and author of “Air and Space: The Amazing Story of Food and Drink in the SkyThe agency wasn’t even sure humans could eat in space. The challenge was to make a compact object, easily usable by a person wearing gloves — since astronauts lived in their spacesuits at the beginning of the program — that someone could put in their mouth, bypassing their nose.

Plus, it was going to be cold since the capsules weren’t heated, Foss noted. And the first foods sent out were mashed potatoes or spaghetti noodles.

“If you imagine holding your nose and eating something straight out of the refrigerator, you’ll get a sense of the pleasure it gives you,” Foss said. As a result, astronauts hated eating and came back to Earth dehydrated, hungry and disoriented, a major problem in keeping them healthy and happy.

A glass of champagne might seem like an ideal drink for gazing at Earth. But NASA and the International Space Station have banned alcohol. Kloeris noted that the ban was initially driven by safety concerns: If we don’t want pilots and train drivers drinking on the job, we probably don’t want astronauts getting drunk or inebriated in something as complicated as a spaceship. Property damage in space would be a huge problem.

Over time, NASA learned that ethanol did not degrade when recycled through water and air. Kloeis noted that “when ethanol gets into the air, it becomes a pollutant in the air system and then in the water system.” But of course, while it does pose a risk, one or two unofficial bottles of alcohol have made it to space, as cognac with russian cosmonauts.

It’s not all doom and gloom when it comes to food. Astronauts have choices. Kloeris noted that astronauts have more than 200 different foods and beverages available to them through NASA’s program. With regular deliveries to the International Space Station, astronauts can get fresh fruits and vegetables, and sometimes even frozen treats. Wan said the first Korean astronautSoyeon Yi brought kimchi into space in 2008. Harrison noted that Axiom has brought a variety of foods into space, including “Bellota ham, dates, Arabic coffee, Alicante nougat, Swedish sweets and Turkish delight.”

But long-duration space travel to Mars and beyond will require innovative solutions to keep astronauts happy and healthy. Through the work of companies and competitions like the Deep Space Food Challenge, we’ll see incredible technologies emerge that could impact people on Earth and in space. And maybe one day astronauts will be able to safely enjoy a corned beef sandwich on thick bread.