By the 1960s, NASA achieved an extraordinary technological feat by sending men into space. Yet one deceptively simple aspect of space travel took several more years to perfect: the food. Today most space food looks a lot like food here on the ground. What started out as tasteless paste squeezed out of a toothpastelike tube has come a long way from space exploration's early days. Astronauts are even getting treated to gourmet meals designed by celebrity chefs.
But what is space food? A typical space menu is made up of a lot of the same items found in homes and restaurants here on Earth. It might include foods such as:
The biggest differences between space food and regular food are in the packaging and design. Space food must be carefully contained so it doesn't float around in the low-gravity (microgravity) environment. Even something as simple as a few crumbs can become deadly in low gravity. Loose pieces of food can become lodged in shuttle vents or can waft into an astronaut's nose or mouth and pose a choking or breathing hazard. Liquids can float away as well, so drinks like coffee, orange juice, apple cider and tea are packaged as powders. Astronauts add water to the contained drinks to rehydrate them.
So how has space food transformed over the years? What are the challenges of transporting, cooking and disposing of food beyond the Earth's surface? Find out on the next page.
Because the first space flights lasted just a few minutes, there wasn't much need to carry food onboard. But by the early 1960s, John Glenn and the astronauts of Project Mercury were staying out for longer durations and had to eat. The first space foods were unappetizing, to say the least. Most were semi-liquids that were squeezed from tubes and sucked up through straws. There were also bite-sized cubes of compressed and dehydrated foods that were rehydrated by the saliva in the astronauts' mouths.
By the time the Gemini mission launched in 1965, the food had gotten a bit more palatable. The astronauts were able to choose from a wider variety of foods, including shrimp cocktails, turkey bites, cream of chicken soup and butterscotch pudding. The food was freeze-dried, meaning that it was cooked, quickly frozen and then put in a vacuum chamber to remove the water. Freeze-drying preserved the food for the flight without compromising the flavor. To rehydrate the food, the astronauts simply injected water into the package with a water gun.
For the Apollo program -- the first to land men on the moon -- NASA provided its astronauts with hot water, which made rehydrating foods easier. The Apollo astronauts were also the first to have utensils and no longer had to squeeze food into their mouths. The mission introduced the spoon bowl, a plastic container with dehydrated food inside. After the astronauts injected water into the bowl to rehydrate the food, they opened a zipper and ate the food with a spoon. The wetness of the food made it cling to the spoon instead of floating away.
The Apollo mission also introduced thermostabilized pouches called wetpacks. These flexible plastic or aluminum foil pouches kept food moist enough so that it didn't have to be rehydrated. The Apollo crew was able to dine on bacon squares, cornflakes, beef sandwiches, chocolate pudding and tuna salad. As Apollo 8 circled the moon on Christmas Eve 1968, the crew even feasted on fruitcake.
The Skylab mission, which launched in 1973, had even more of the comforts of home. The large dining room and table actually allowed astronauts sit down and eat. Skylab had the luxury of onboard refrigeration (which even the modern space shuttle doesn't have), so it could carry a wider variety of foods -- 72 different types of menu items in all. Food warmer trays allowed astronauts to heat their food in-flight.
By the early 1980s and the launch of the first space shuttle, meals looked almost identical to what astronauts ate on Earth. Astronauts designed their own seven day menus selected from 74 different foods and 20 drinks. They prepared their meals in a galley with a water dispenser and an oven. When the Space Shuttle Discovery launched in 2006, it was clear space food had entered a new realm. Restaurateur and celebrity chef, Emeril Lagasse, designed a menu that included selections like "kicked-up" mashed potatoes, jambalaya and bread pudding (with rum extract since alcohol is not allowed in space).
But who determines which foods make the mission menus? What kinds of food make it into space? Go to the next page to find out more.
Today astronauts have dozens of different foods to choose from. They also play a big part in the selection process. About five months before a mission launches, crewmembers get to visit the Space Food Systems Laboratory at the Johnson Space Center in Houston, Texas. At the lab, astronauts act as food critics. They sample 20 to 30 items and rank them on a scale of 1 to 9 in appearance, color, smell, taste and texture. Any food that scores a 6 or higher can make it onto the menu.
Astronauts don't get the final say, however. A dietitian checks the menu to make sure that it contains enough nutrients. Astronauts need 100 percent of their daily requirements of vitamins and minerals.
But because the environment in space is different than that of Earth, they need to adjust their intake of certain nutrients. For example, astronauts need less iron than they do on Earth. Iron is mainly used to make new red blood cells but astronauts have fewer red blood cells in space. If they eat too much iron, it can build up and cause health problems. Astronauts also need extra calcium and vitamin D, because bones don't get the exercise they need to stay strong in the weightless environment.
But how does food stay fresh in space? And where do necessities like water come from? Learn how food gets into space in the next section.
About a month before a mission launches, all food that will be taken aboard is packaged and stored in refrigerated lockers at the Johnson Space Center. Three weeks before launch, the food is transported to Kennedy Space Center in Florida. It's loaded onboard the shuttle two to three days before launch.
The space shuttle carries about 3.8 pounds of food, including 1 pound of packaging, per astronaut for each day of the mission. The astronauts get three meals a day, plus snacks. A back-up Safe Haven food system provides an extra 2,000 calories per day, per astronaut. It's designed to sustain the crew for an extra three weeks in case of emergency.
The meals are stored in locker trays, arranged in the order that the astronauts will eat them. Considering that a space mission can last months, foods in space need to be designed and packaged to prevent spoilage. Because the space shuttle doesn't have a refrigerator, foods must stay fresh at ambient temperatures. There are several ways space food can be prepared:
- Rehydratable (or freeze-dried) foods: Water is removed from the food during packaging. Soups, casseroles, scrambled eggs and breakfast cereals are all packaged this way.
- Intermediate moisture foods: Some water is removed from the food, but not all. Dried peaches, pears and apricots are examples of intermediate moisture foods.
- Thermostabilized foods: These foods are heat processed to destroy bacteria and other organisms so they can be stored at ambient temperature. Fruits and tuna fish are sometimes preserved by this method.
- Irradiated foods: Meats are cooked, packaged in foil pouches and briefly exposed to radiation from gamma rays or electron beams so they won't grow bacteria. The World Health Organization and American Medical Association say that irradiated foods are safe to eat.
- Natural form foods: Granola bars, nuts and cookies are examples of food with a naturally long shelf-life. Natural form foods are kept in ready-to-eat pouches.
- Fresh foods: Fruits and vegetables are usually packaged in plastic bags and sanitized in chlorine to preserve their freshness. But with no refrigeration onboard the shuttle, these foods must be eaten within the first two to three days of the mission or they'll spoil.
Food packaging is designed to be easy to use, small enough to dispose of in the onboard trash compactor and sturdy enough to keep food fresh for up to a year. Rehydratable foods are packaged in flexible bowls with lids. A fabric fastener locks the bottom of the bowl to the meal tray. Foods can also be kept in cans with pull-off lids, plastic cups or flexible pouches. Astronauts add water to rehydratable food bowls and drink pouches through a small opening called a septum adapter.
Condiments like ketchup, mustard and mayonnaise have their own packaging. Salt and pepper are stored in liquid form so that the crystals or granules don't float away. Salt is dissolved in water while pepper is suspended in oil.
The space shuttle gets its water supply from fuel cells, which produce electricity by combining hydrogen and oxygen -- the main components of water. At the International Space Station, water is recycled from the cabin air. Because there is little water to spare, most foods on the Space Station are thermostabilized rather than dehydrated.
But how do astronauts actually prepare a meal in microgravity? And what will astronauts be eating on future missions? Find out in the next section.
The space shuttle's kitchen doesn't need to be too extravagant because most of the foods are practically ready to eat. A small galley in the shuttle's middeck houses a rehydration station that dispenses hot and cold water for rehydrated foods and drinks. Astronauts use the forced air convection oven to heat the meals that need warming.
It takes about 20 to 30 minutes to reconstitute and heat a meal. Each astronaut has a meal tray that holds the food containers. The tray can be attached to either the astronaut's lap or a wall. After the meal, the containers are placed in a trash compartment that sits underneath the middeck floor. Astronauts clean eating utensils and trays with pre-moistened, sanitized towelette.
Because today's astronauts usually stay in space for several weeks or months, at most, they're able to carry all the food they'll need onboard. But in the future, space missions could be significantly extended. To get to NASA's intended destination -- Mars -- and back again will take two years. Astronauts will need to carry foods that have a three to five year shelf life. They'll also need to start growing their own foods.
NASA plans to grow fruits and vegetables on space farms -- greenhouses that are temperature-controlled, artificially lit and employ a hydroponic system, which uses nutrients instead of typical soil. Crops might include soybeans, peanuts, spinach, cabbage, lettuce and rice. Wheat berries and soybeans can be grown and processed into pasta or bread. The astronauts would then prepare these foods into home-cooked meals in a galley kitchen. According to NASA, a sample Martian dinner menu might include spinach and tomato crouton salad, wheat pasta with tomato sauce and a chocolate peanut butter soymilk shake.
To find out more about space food and related topics, visit our links page.
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More Great Links
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- "Taking Humdrum Astronaut Food, and Kicking it up a Notch." The New York Times, August 29, 2006.