It's every astronaut for himself when it comes to eating in space.
"No one worries about table manners," says Norm Thagard, who took a turn on Mir in 1995.
Although having a meal in a weightless environment often looks like fun, whose who've been in space say that things that would be easy to eat on Earth are much more difficult to manage.
"There's a fascination with the absence of gravity," says former astronaut Charlie Walker, who accumulated 20 days in space on three Shuttle missions in the mid 1980s. "It's a wonderfully different experience being weightless and having the freedom of space flight, but we encounter differences in the ways we prepare food."
Astronauts have to be careful if, for example, they lift a spoon of beef Stroganoff from its container. After it begins moving toward their mouth, it keeps moving rapidly in a straight line. A simple shift of the head, and food splatters on the astronaut's face or the cabin wall.
"Once food is put into motion by your hand and a spoon, it takes on a life of its own," says Mr. Walker.
He, Professor Thagard, and other astronauts say food plays a bigger role on long missions. Variety in taste and texture is necessary to help break up boredom. And crews use meals as a time to socialize and bond.
"Food takes on more importance when you are deprived of something. It is extremely important for morale," said Vickie Kloeris, a food technologist at Johnson Space Center in Houston.
Ms. Kloeris was part of a 90-day test last year in an Earth-based capsule that simulated space conditions. Her group, like astronauts on Mir and on NASA shuttle missions, ate at least one meal a day together.
Food also takes on an integral role in a bartering system, Mr. Walker says. One astronaut may trade nuts or shrimp cocktail from their special pantry tray in return for a colleague's camera to photograph their home town as they fly over.
Walker developed a craving for shrimp cocktail, and stockpiled it on his second and third missions. He was able to trade some of his stash for more M&Ms. "In orbit you can crave something you don't normally eat on Earth, and someone else may have that in their pantry," he says.
Although astronauts now can choose the food they eat on missions, some say eating everything out of packets is not all it's cracked up to be.
In his four weeks on Mir, Thagard had to eat steak that he squeezed like a Popsicle out of its packaging. Tubes of food are necessary since eating off of plates poses problems. For example, if rice is dry rather than gooey, the individual grains float in all different directions about the cabin, Mr. Walker says.
But even food packets are cumbersome. The only way to assemble them in one location is to use velcro to fasten them to a surface in the cabin. Then they can be eaten one at a time, squeezing meat and macaroni from tubes and drinking soup with a straw.
Walker emphasizes the need for variety. Some astronauts find food tastes bland in space, so they welcome spicy foods. "Tensions can develop when a person doesn't have a variety to eat from," he says.
Ms. Kloeris says astronauts who have test-grown lettuce on shuttle missions enjoy having a fresh vegetables and watching the plants grow.
Kloeris, a meat-eater, says she liked the 10-day vegetarian diet served during the capsule experiment. But she and other space-food experts say that getting omnivores to adapt to a largely vegetarian diet may take some doing.