Astronauts living aboard the International Space Station kept enjoying their favorite foods through missions lasting six months to nearly a year. Their ratings stayed steady because crew members found preferred items early, returned to them often and usually passed over foods they disliked.
A study in Frontiers in Psychology examined 1,772 food ratings from 15 astronauts. The results suggest that a menu can appear acceptable even as each astronaut relies on a smaller personal set of meals. Such selective eating could become a larger concern during a journey to Mars, where supplies may be packed years in advance and resupply will be unavailable.
The research, led by Grace L. Douglas at NASA’s Johnson Space Center, gives mission planners a clearer view of how people use a restricted food supply over time. Food must deliver enough calories and nutrients, yet astronauts also need meals they are willing to eat repeatedly while living far from Earth.
How astronauts rated their meals
The study followed eight male and seven female astronauts who spent between 166 and 355 days aboard the ISS. Once a week, each participant recorded the foods and drinks consumed during one meal, then scored every item on a nine-point scale. A score of one meant extreme dislike, while nine meant extreme liking.
Astronauts could also describe the meal’s appearance, flavor, texture, preparation and setting. After returning to Earth, they took part in interviews about their overall experience. NASA’s technical record includes the study details and manuscript, along with figures showing how ratings varied among crew members.
The weekly reports covered 434 different foods and beverages. Researchers used the number of times an item appeared as a rough sign of how often an astronaut selected it. They also counted the unique items rated by each person to estimate menu variety.
Favorite foods stayed popular
The team expected repeated eating to lower food ratings as missions continued. Instead, scores for chosen items remained stable. Astronauts appeared to identify their favorites early, then kept selecting and enjoying them.
Foods with higher scores were also rated more often, although the statistical effect was modest. Mission length had no clear relationship with average food ratings. Astronauts serving longer missions rated more unique foods, which was expected because they had more weeks in orbit, yet longer stays did not make their selected meals less acceptable.
Food acceptability describes how much a person likes a food at a particular moment. Flavor plays a major role, while smell, appearance, texture, temperature and even portion size can influence the experience. In microgravity, preparation equipment and packaging add further limits to how a meal can be served.
Most dishes had only one fan
Personal preference produced one of the study’s clearest results. Of the 434 foods and drinks rated, 254 were scored by only one astronaut. Fewer than half appeared in reports from more than one crew member.
The large spread shows why a food judged acceptable during testing may still divide a flight crew. NASA includes foods in the shared system after sensory panels give them acceptable scores, yet individual astronauts can have very different reactions to the same dish.
NASA’s Space Food Systems Laboratory develops and packages flight foods while studying future exploration menus. The ISS standard supply contains about 200 shelf-stable foods and beverages. Roughly 80 percent comes from a shared system, while about 20 percent may include crew-specific menu foods chosen by individual astronauts.
Menu fatigue still appeared
Stable ratings tell only part of the meal story. More than half of the astronauts left comments suggesting that they experienced some degree of menu fatigue, meaning boredom or frustration linked to a repetitive and limited supply. Among nine astronauts who reported signs of fatigue, the first comments generally appeared between one and four months into the mission.
Astronauts could keep giving high scores to favorite foods while becoming tired of the wider menu. Someone who dislikes many available choices may repeatedly eat a small group of preferred items. The liked foods remain pleasant, while the overall sense of variety shrinks.
Repeated food containers were a particular source of frustration. “It’s disheartening to open the same food week after week,” Astronaut A wrote during the mission. Other comments described cravings, boredom, or the feeling of eating mainly to obtain nutrition.
The study recorded one meal each week, so it captured only a sample of each astronaut’s full diet. It also used food ratings as a sign of preference rather than measuring every bite consumed. The results therefore identify selection patterns and possible risks, while future work will need to connect those patterns with total calorie intake, body mass and nutrient levels.
Vegetables and breakfast choices fell short
Crew comments repeatedly pointed to limited quantities and variety among fruits and vegetables. Popular items could disappear quickly from the shared supply, leaving soups, nuts, or less desired foods available for longer periods. A crew in which several people share the same favorites may use those foods faster than planners expected.
Breakfast raised another concern. Some astronauts wanted more eggs and other protein-rich choices. Cereal was welcomed by certain crew members, while others found the morning selection too narrow. The differences reinforce the difficulty of designing a fixed menu for people with distinct eating habits.
Texture also influenced satisfaction. Astronauts sometimes craved crunchy foods, fresh produce, or meals that felt more like food eaten at home. Crumb-producing foods create practical problems in microgravity because loose pieces can float through the cabin, so engineers must balance texture with spacecraft safety.
Temperature affected ratings as well. One astronaut said orange juice was much better when chilled. Refrigerators and chillers require space, electrical power and added equipment, which may limit their use in small exploration vehicles.
Condiments and personal foods added variety
ISS crews have several ways to refresh the standard menu. Personal selections, foods supplied by international partners, occasional fresh deliveries and condiments can introduce different flavors. Astronauts also combine packaged items to create meals that feel new.
“Almost everything could benefit from condiments. I wish there was greater variety in condiments and more plentiful,” Astronaut J wrote. Sauces and seasonings offer a relatively simple way to change repeated meals, especially when the basic ingredients must remain the same.
International partner foods from ESA, JAXA and the Canadian Space Agency can broaden the menu further. Crew members reported that access to dishes from several space agencies helped reduce boredom. Personal spreads and other familiar foods also allowed astronauts to recreate parts of their routines from Earth.
Many of these options depend on regular cargo flights to the ISS. Fresh fruit can arrive aboard a resupply spacecraft and late deliveries can include short-lived treats. Deep-space crews will need a food supply that remains safe and appealing for years without such deliveries.
Why Mars missions raise the risk
A Mars expedition may require food to be launched before the final crew leaves Earth. If an astronaut assignment changes after the supplies have departed, the packed preference foods may suit someone else. Every replacement item must also fit strict limits on mass, storage volume, packaging and shelf life.
NASA lists inadequate food and nutrition among its human spaceflight risks. A crew member who regularly avoids available meals may consume too few calories or miss key nutrients. Over a long mission, reduced intake can affect body mass, health, mental performance and the physical ability to complete demanding work.
The shared nature of the supply adds another problem. If one person relies heavily on a small set of foods, those items become less available to everyone else. The study included an astronaut who described this effect when another crew member’s eating pattern used up several popular foods more quickly.
Deep-space exploration also removes the quick return option available in low Earth orbit. A Mars crew may spend years away from home, with launch windows and planetary motion controlling when travel is possible. Food planning must therefore support the entire mission even when preferences differ or change.
Building a deep-space menu
Future menus may benefit from more vegetables, greater breakfast variety and additional protein-rich foods. Rotating meal packs could prevent crews from opening identical containers week after week. A wider range of condiments may help astronauts adjust flavors without adding large amounts of heavy equipment.
Preparation systems will be just as important as the food itself. Rehydrating a freeze-dried meal to the desired texture can improve its appeal, while heating or chilling certain items can make them easier to enjoy repeatedly. Designers must weigh those benefits against the water, power, crew time and cabin space required.
Food production aboard a spacecraft or planetary base could eventually provide fresh ingredients, but crops must grow reliably before crews can depend on them. Prepackaged food has a long history in spaceflight and remains easier to store, prepare and monitor. Its flavor and nutritional quality can decline during years of storage, which gives researchers another challenge to solve.
“If we’re going to start exploring and start becoming more Earth-independent, we need to start understanding how we produce the foods,” Douglas said in NASA’s Menu for Mars discussion.
The ISS study suggests that a successful Mars food system will need enough choice for each astronaut to build a satisfying personal menu without exhausting the foods preferred by crewmates. Future studies can test candidate menus during long isolation experiments, track nutrition alongside food ratings and identify the amount of variety needed to protect crew health throughout a multiyear mission.
