Food that's out of this world

Deseret News (Salt Lake City), Nov 12, 2008 by Valerie Phillips Deseret News

JOHNSON SPACE CENTER, HOUSTON -- "Houston, we've had a problem."

That phrase uttered in 1970 by astronauts aboard Apollo 13 might be a cliche to the rest of us, but it's something against which Michele Perchonok spends every workday guarding.

As the project manager over advanced food technology for NASA, she makes sure the astronauts are well-fed. When the space shuttle Endeavour is launched this week, it will be stocked with foods to supply nutritional requirements.

And it also will include a Thanksgiving-type menu of smoked turkey, candied yams, apple cranberry dessert and green beans almondine, said Perchonok, adding, "The commander said, 'We'll be there for Thanksgiving, so can we get a Thanksgiving meal up there?"'

Obviously, space food has come a long way from Tang, food cubes and squeeze-tubes of the '60s. "During the first Mercury mission, we didn't even know if they could chew and swallow food in space," she said. "So we started with toothpaste tubes of applesauce or soup."

A few weeks ago, Perchonok took a group of food writers on a tour of the Space Food Systems Laboratory at the Johnson Space Center in Houston. It looks part kitchen, part chemistry lab.

Food for space has to meet four requirements, explained Perchonok:

Safety: Because there's no refrigeration or freezers, much of the food is freeze-dried or heat-treated to prevent spoiling or food poisoning. And the food can't be crumbly, because crumbs float around and get into the equipment. "So potato chips are out," she said.

Nutrition: This isn't as important if it's a short mission. "We still consider our shuttle missions as camping trips," she said. "You don't have to eat that nutritiously, although our astronauts are very health-conscious. You could live on candy bars for two weeks if you needed to, although after two weeks, they come back with muscle and bone loss."

But for the six-month missions, nutrition is very important, she said.

Acceptability: "If it doesn't look right, taste or smell right, they won't eat it," she said.

Resource utilization: Food takes up a lot of mass in very small quarters. "We need to keep it at a minimum. It costs a lot just to lift 1 pound of food out of orbit," she said.

Crew members are limited to about 4 pounds of food per person per day, and that weight includes all the packaging.

They are allowed 2 liters of water per person a day for drinking, a half-liter to rehydrate freeze-dried foods and another half-liter for a sponge bath.

"Each liter weighs about 2 pounds, so we have to be careful with it. We are recycling more and more," she said.

One way to conserve water weight is to dehydrate the food. During the flight, water generated by the shuttle fuel cells can be used to rehydrate it just before eating.

Freeze-dried items include chicken consomme and cream of mushroom soup, macaroni and cheese, chicken and rice casseroles, and scrambled eggs. Breakfast cereals are packaged in with nonfat dry milk and sugar. Water is added to the package just before the cereal is eaten.

One popular item is shrimp cocktail, packaged with shrimp on one side of the package and cocktail sauce on the other. The water is added to the package through a one-way valve so that it can't seep out. When rehydrated and ready to serve, an "X" is cut onto the pouch with scissors.

The surface tension of the water helps hold the food in the pouch for eating, said Perchonok. "If it was dry, the food would just float away," she said.

Salt is suspended in a dropper bottle of water, and pepper in oil, to keep the granules from floating off and possibly clogging air vents or getting stuck in an astronaut's eyes. Velcro, bungee cords and magnetized silverware also help make the task of eating easier.

The space program also uses food that's been heat-processed to keep it from spoiling. It is packaged and eaten in flexible "retort" pouches. Some items include beef tips with mushrooms, tomatoes and eggplant, chicken a la king, and ham. There are also nine irradiated meat items obtained through the Department of Defense that are available to space crews, she said.

There are also some foods, such as dried beef jerky, nuts or cookies, bought from grocery stores and vacuum-packed in individual serving sizes. Fresh foods such as tortillas, apples, bananas, and carrot and celery sticks must be eaten within the first few days of flight so they don't spoil.

As the body adapts to weightlessness, physiological changes occur that requires different nutrition requirements:

-- Astronauts tend to lose bone and muscle. They have to limit the amount of sodium in their diet, because it can lead to further bone loss. The body usually makes its own vitamin D when the skin is exposed to sunlight, which helps with bone density. But spacecraft are shielded to avoid radiation, so Vitamin D supplements are recommended.

-- Astronauts have few red blood cells while in space, so they have to limit their intake of foods high in iron.

-- Astronauts practice "fluid loading," just before re-entering Earth's atmosphere. "When you go up, you lose some fluid," Perchonok said. "We have them drink consomme or Gatorade, so they don't get nauseous when they come back."