Listen up folks, this is important. You know astronaut ice cream? That hard, crumbly freeze-dried mystery sweet in the guise of a Neapolitan? Astronauts don't actually eat it. I know, I was shocked too. In fact, it's only even been in space once—back in the 1960s, when an astronaut requested ice cream—and even then, it was a far cry from the stuff marketed in museums and magic shops.
So what are our space explorers actually eating? It's surprisingly quite tasty.
The Space Diet
It turns out that astronauts choose from a core menu of over 200 items, all before they even leave solid ground. It's called 'pantry-style' dining and the selection's remarkably broad. "We have all kinds of meats," explains Vickie Kloeris, one of NASA's food scientists. "We have chicken, we have beef, we have fish, we have ham. We have vegetables. We've got desserts, drinks, rice, potatoes. It covers everything."
Sure enough, on paper the menu looks pretty similar to what we're eating earthside. But the food does have to work in microgravity, which is where things get interesting. There's no refrigeration or freezers, so everything needs to be non-perishable. That means food and drinks are either freeze-dried (the crew member has to add water to rehydrate the food), thermostabilized (essentially canned products stored in pouches to save weight), or powdered (the astronaut has to add hot or cold water to all beverages).
In other words, packaging is essential. Most foods look pretty unrecognizable, encased in vacuum-sealed pouches. And then there are the things that just don't make sense for space—astronauts can't have peas floating around and clogging up instruments; crumby bread is replaced with tortillas; liquids have to be carefully contained and sipped through specially engineered straws, and so forth. That said, some products you wouldn't expect to find aboard a spacecraft are free to fly: things like cookies, candies, nuts, and dried fruit—any supermarket product that meets microbiological requirements and doesn't need to undergo a change of state.
In fact, all the powdered beverages are bought off the shelf—I'm talking everything from Tang to coffee to Kool-Aid—and repackaged by NASA for flight. But the majority of the food is developed from scratch in the lab, and a single recipe can take years to perfect.
These days, there are about 60 thermostabilized and 50 freeze-dried products that NASA has developed, and space station-bound crew members are allowed nine preference containers for every six months they spend on the space station. The boxes are specially filled with that person's selected items, whether it's more of the same from that menu of 200, or plucked from an array of commercial products that meet the shelf-life and microbiological requirements for sending food into space.
If you're envisioning a diet of shrink-wrapped TV dinners, think again. Or better yet, just watch Canadian astronaut Chris Hadfield assemble his very own peanut butter and honey tortilla "sandwich." That's right. They may not have stovetops and ovens, but even astronauts have the chance to do a little cooking. Just take a look at this "space cheeseburger" made by US astronaut Terry Virts. You could also call it what happens when beef patties, cheese, tomato paste, and Russian mustard collide on a single tortilla.
Of course, just like their earthbound counterparts, astronauts can't always get everything they want. When NASA first started the shuttle program, a Japanese crew member requested sushi. But with no way to keep it cold and fresh, it was denied—all the products have to be able to last a long time at ambient temperatures. Another time, some crew members were on their way to pick up another astronaut. He'd been in space for a while and was feeling homesick, so they wanted to bring him a hamburger to take the edge off.
"Yeah, okay, we're going to put a hamburger on the shuttle, and he's going to eat it three days later when you dock," Kloeris quipped. "No, that's not going to work. I don't think your buddy would like to get food poisoning in microgravity. That would not be very pleasant."
But other than orders that go unfilled, all the astronauts try the food they've requested before they fly, so they know exactly what to expect. And the team in the food lab tries everything as well, just to make sure it's palatable. Kloeris even lived off shuttle food for an entire month.
Her favorite dish? The shrimp cocktail...and it may not be what you expect. Space shrimp cocktail comes dehydrated in a pouch, kind of slimy once rehydrated but with a spicy, tangy tomato- and horseradish-based sauce that crew members adore. That's probably because "eating in space is like eating with a head cold," explains Hadfield. "You just can't taste very much." He even gives a shout-out to the aforementioned shrimp cocktail for delivering some actual heat.
"It's historically been one of the most popular items that we have," Kloeris adds. "We've had it all the way back through the shuttle program. It's not gourmet, obviously, but the food is good. For the most part we get really positive feedback."
From a Galaxy Far, Far Away
Of course, astronauts didn't always have such posh meal selections. Back in the '60s when the shuttle program was just starting, Mercury and Gemini mission astronauts enjoyed what Kloeris calls "cubes and tubes" food. Basically, solid food came in dried cubes—dried cereal cubes, dried sandwich cubes, dried cookie cubes. Food with some moisture to it came in tubes—more or less puréed baby food that the astronauts squeezed into their mouths. Over the years, though, more effort was made to incorporate new flavors and textures.
But it was the mid-'70s that saw the most sophisticated food system in NASA's history. The Skylab program actually had room for freezers, so the crew members could have a limited amount of relatively undoctored frozen food.
Come the 1980s, when NASA's shuttle program started to fly, it was back to an all-shelf-stable food system. The shuttles were designed to be work vehicles, Kloeris says, and had limited power—not enough to support refrigerators and freezers that could have improved the onboard dining experience.
To this day, the freezer system has yet to return. The original plans for the International Space Station included a "U.S. Habitation Module" with freezers and refrigerators. NASA even allotted part of its budget for a packaging system to fly fresh food into space. Alas, the module was never actually built.
"Partly it was a budgetary thing, but partly it was a power thing," Kloeris explains. "They realized as they were building the station that there was no way they were going to have enough power to be able to operate refrigerators and freezers for food. They already had to have refrigerators and freezers for science, for medical samples. So that got canceled and now we continue on with a shelf-stable food system."
But that doesn't mean astronauts never get fresh food; it just happens rarely enough to be a special treat. When a U.S. or Russian cargo vehicle docks at the space station, it usually carries a small amount of fresh fruit for the astronauts—and it's always eaten right away, because it's a special occasion.
Better yet, "the last commercial cargo flight that went to the station had a freezer on board to bring frozen medical samples back from orbit," Kloeris says. "It was empty on the uphill trip, so we were able to send some ice cream. When it docked, they had to hurry up and eat the ice cream so that they could then refill the freezer with medical samples."
So why no freeze-dried astronaut ice cream? "We don't fly it," Kloeris says. "If our crew members wanted to put it in their preference containers, they could; it certainly has a long enough shelf life. It meets all the requirements, but we don't have any requests. It's not like real ice cream, it's more like hard cotton candy. And it wouldn't be easy to eat in microgravity because it's very crumbly, so it would make a huge mess."
Have more burning astronaut questions? Hadfield's entire YouTube series is pretty crucial viewing for anyone curious about life in microgravity.