Can you eat in space? What do you eat in space?  

These might seem like ridiculous questions now—after all, who hasn’t sampled astronaut ice cream—but they were very real concerns at the advent of the space program. 

John Glenn was the first American to eat in space aboard Friendship 7 in 1962. At that time, it was not known if ingestion and absorption of nutrients were possible in microgravity. Glenn's consumption of applesauce and beef with vegetables, pureed and packed in tubes, and xylose sugar tablets with water, demonstrated that people could eat, swallow, and digest food in a weightless environment. 

Foods taken into space must be light-weight, compact, tasty and nutritious. They must also keep for long periods without refrigeration. 

Space food prepared during the Mercury program of the early 1960s was based on the same research done to develop Army survival rations. Much of it was rather tasteless foods mashed up and packed into tubes to be sucked up through a straw. While Glenn and the other Mercury astronauts experienced no problems in chewing, drinking, swallowing, or digesting, the food was not considered very enjoyable. 

As our human spaceflight missions advanced in their complexity, so too did the food. 

Dehydrated, freeze-dried, and bite-sized foods, coated with gelatin or oil to prevent crumbling, were introduced during Project Gemini. On-board hydrogen-oxygen fuel cells provided a source of water that could be used to moisten dehydrated or freeze-dried foods.  Freeze-dried foods are prepared by quick-freezing cooked items, which are then placed in a vacuum chamber where they are heated to remove all water. Natural oils, however, are retained. The items are then vacuum-packed in four-ply laminated containers with a water valve at one end. A freeze-dried meal would be rehydrated using a water gun to inject cold water into the package. After cutting the package open with scissors, the meal was then ready to eat. 

However, Gemini astronauts didn’t always follow the rules. During Gemini 3, John Young surprised fellow astronaut Virgil Grissom with a corned beef sandwich on rye he purchased at a delicatessen.

By the time of the Apollo program, space food was getting more sophisticated … and better tasting, largely due to the work of Rita Rapp and her team. Rapp worked closely with astronauts to create recipes that appealed to their preferences. Rapp also develop a special spoon bowl so astronauts’ experience of eating in microgravity was more reminiscent of eating on Earth. Once the food was rehydrated, the top of the pouch could be torn off and food scooped out easily. Additionally, a more sophisticated water system provided both hot and cold water for the preparation of food. Gemini spacecraft provided only cold water, so all re-hydrated foods on those missions were eaten cold. 

While the types of food available and the packaging used for Apollo program foods got more sophisticated, Apollo also introduced a new question: What if astronauts had to eat or drink in their spacesuits? For instance, if the Apollo spacecraft cabin should become depressurized, the astronauts would have to live in their spacesuits and would not be able to eat solid foods. The Contingency Feeding System, carried on Apollo 11, would have allowed an astronaut to eat liquid foods through a small port in their helmet. 

As astronauts worked on the lunar surface for long periods of time, they also grew hungry and thirsty. Beginning with Apollo 13, a pouch and straw were added inside the astronaut spacesuits to allow crew members to drink while they worked on the Moon. The Apollo 15 astronauts enjoyed apricot food bars, strategically placed inside their helmets to be accessible, for a snack during the increasingly long work periods on the lunar surface. 

The next major advancement in the quality and variety of space food occurred in 1973 leading up to the Skylab Program. Skylab was the first U.S. space station, using left over Apollo Program equipment. The third stage of a Saturn V rocket was converted into a habitable module that could be visited by astronaut crews. The space station had a full galley in which the astronauts could replicate the idea of eating in a kitchen, complete with a table and trays with heating elements for each of the crew to use for heating up tins of food. 

Skylab relied on solar cells for power, instead of water-producing fuel cells. Dehydrated foods were limited in order to conserve the water supply. Skylab was equipped with a refrigerator so that frozen foods could be carried. This provided the opportunity to carry a special treat for the crew—ice cream. 

Space food continued to improve as astronauts spent longer and longer in space. Resupply missions for the International Space Station, and until 2011 the Space Shuttle, supplemented the astronaut diet with fresh produce like oranges and apples. There are also ongoing experiments to improve available food—whether growing leafy greens, radishes, and grasses like wheat, or learning how to bake a cookie in space.  

If you were headed to space, what snacks would you want to pack?