Expedition 5 Flight Engineer Sergei Treschev, left, and NASA ISS Science Officer Peggy Whitson share a meal aboard the International Space Station. "My favorite space food was peanut butter. I'm not a big fan of it on the ground, but couldn't get enough of it in space." Astronaut Peggy Whitson,

Expedition 5 NASA ISS Science Officer Imagine being stuck in a house for months, not able to venture out to go to the grocery store whenever a particular food craving hits. All that you have to survive on is already stowed in the pantry. The items in this pantry have been predetermined long ahead of time, and if your taste buds happen to change, you are simply out of luck. The Space Food Systems Laboratory at Johnson Space Center (JSC) in Houston does all it can to ensure the astronauts are happy when it comes to their meals. Space Food Tidbits STS-112 Mission Specialist Sandy Magnus plans to enjoy a tortilla with her lunch. Flour tortillas are considered the favorite bread item of astronauts, because they do not give off crumbs. Read more Tidbits. More about Eating in Space Tidbits - Space Food Trivia "I'd Like to See a Menu, Please" Living in Space - Space Food Eating at Cafe ISS - by Astronaut Ed Lu Thanskgiving in Space 'Mmm, Chicken ...' Food choice is extremely important to astronauts, and the longer the flight, the more significant those choices become. The meals are stowed pantry-style onboard Space Station, so crewmembers can eat food items in any order they wish. For instance, if crewmembers want to have chicken three nights in a row, they can do that. "Being on Space Station, so much of what is going on is beyond their control," said Vickie Kloeris, JSC manager of Space Food Systems. "And so food is just a comfort thing that they would like to feel they have some input on or some control over. It's just a big psychological thing -- I don't know if we've flown anyone to Station that has not been concerned about their food." Emilce (Emmy) Vest, Food Services director and executive chef for JSC, agrees that comfort food is of the utmost importance, especially when astronauts are in space. "In situations where there is little outside stimulation and we're somewhat lonely, food becomes more of a focus because it gives us sensual and chemical stimulation," Vest said. "We also crave the social payoff in 'breaking bread' with our companions." The Space Food Systems Laboratory tries to vary the menus by allowing the crew to take bonus containers into space, in which they can request special, off-the-menu food items. These usually include commercially available candy bars, cookies or crackers -- anything with a long shelf life. Astronaut Steve Smith enjoys a meal in space. Read more about mission menus. Yet even with the special goodies sent to the Space Station ahead of time, astronauts inevitably return to Earth wishing that they could have had more food variety in space. More variety -- especially fresh food items -- often shows up when a Russian Progress vehicle docks to the Space Station. The unpiloted cargo spacecraft usually brings fresh items such as apples, oranges, grapefruits and other fruit items. The Russians also include interesting foods that Americans do not typically eat. "The Russians will fly things like raw onion and raw garlic, because that's more a part of their culture than part of our culture," Kloeris said. "But it's interesting because some of our American crewmembers have said that even though it didn't sound all that great ahead of time, it actually was nice to have it because it was something totally different." Happy Meals Choosing food items for Space Station crewmembers can also pose a challenge due to the fact that most crewmembers say that their tastes change while in orbit. While Kloeris notes that there is no real scientific data to support that theory, there is plenty of anecdotal data. Vickie Kloeris, JSC manager of Space Food Systems. For instance, astronauts seem to like spicier foods and tart beverages such as lemonade in space, while on the ground those items are not as appreciated. Astronaut Peggy Whitson's personal account of food echoes that thought. "When STS-112 visited, I told the commander that I wasn't opening the hatch unless they had salsa," said Whitson, the Expedition 5 Space Station Science Officer. "My favorite space food was peanut butter. I'm not a big fan of it on the ground, but couldn't get enough of it in space." The Space Food Systems Laboratory learns more from each crew about how to keep long-duration flight astronauts happy with their menus. And although food seems so basic to the ordinary person, it is much more important when you do not have ready access to a grocery store. "Taste is one of the first senses with which we explore the world," Vest said. "There are a lot of chemical reasons for food to be a comfort mechanism. However, our primitive brain is hardwired to equate food with 'home' and safety. When we're hungry, we're all two years old." Text and photos were provided by Johnson Space Center's Roundup.