9.2.2.2
The following document was updated on 02-21-89 and contains 4541 characters.

FOOD    Background, 1-3 
    Concepts 
    Eating is essential to survival. The food astronauts take into
    space must
    be lightweight
    require little storage space
    be nutritious
    be convenient to use
    need no refrigeration
    
    Dehydrated Foods for Space Travel
    Foods are dehydrated to meet weight restrictions for the Space
    Shuttle liftoff. They are later rehydrated in orbit when they are
    ready to be eaten. Water used for rehydration comes from the
    Shuttle's fuel cells. The fuel cells produce electricity by
    combining hydrogen and oxygen, resulting in water. Since water is
    an available by-product from the fuel cells, it is possible to
    send food in a dried form for later rehydration.
    
    More than a hundred different food items, such as cereals,
    spaghetti, scrambled eggs, and strawberries, go through this
    dehydration/rehydration process. When a strawberry is
    freeze-dried, it remains full-size in outline, with its color,
    texture, and quality intact. It can be rehydrated with saliva as
    it is chewed or by adding water to the package.
    
    Twenty varieties of drinks, including tea and coffee, are also
    dehydrated for use in space travel. But pure orange juice or whole
    milk cannot be included. If water is added to dehydrated orange
    crystals, there is no rehydration mixture--just orange "rocks" in
    water. If whole milk is rehydrated, the dried milk does not
    dissolve properly. It floats around in lumps and has a
    disagreeable taste. So skim milk must be used. Back in the l960s,
    General Foods developed a synthetic orange juice called Tang,
    which could be used in place of orange juice.
    
    Other Foods for Space Travel
    Shuttle food items are brought aboard in several different forms:
    NATURAL FORM
    Examples are graham crackers, pecan cookies, peanut butter,
    candy, gum
    THERMOSTABILIZED
    Cooked at moderate temperatures and sealed in cans. Examples
    are tuna fish, canned fruit in heavy syrup.
    IRRADIATED
    Preserved by exposure to ionizing radiation. Examples are meat
    and bread.
    INTERMEDIATE MOISTURE PROCESS
    Removing part of the water. Examples are dried apricots, pears,
    peaches
    
    Salt and pepper are packaged in liquid form because crystals would
    float around the cabin.
    You may want to mention that tobacco and liquor are barred from
    the Shuttle.
    
    Packaging Food for Space
    All food in space must be packaged in individual serving portions
    that allow easy manipulation in the weightless environment of an
    orbiting spacecraft. Packages can be off-the-shelf
    thermostabilized cans, flexible pouches, or semirigid containers.
    
    Food Preparation
    The variety of food carried into orbit is so broad that crew
    members enjoy a seven-day menu cycle. A typical dinner might consist
    of a shrimp cocktail, steak, broccoli, rice, fruit cocktail,
    chocolate pudding, and grape drink. To prepare the meal, the
    mission specialist chef takes a big plastic overwrap out of the
    food locker. The package is attached to a worktable. Inside the
    overwrap are four smaller plastic overwraps, each holding a
    complete meal of seven separate containers. Using a hollow needle
    attached to the hot water outlet, the chef injects a prescribed
    amount of water through a narrow passageway into the plastic bowls
    of dehydrated broccoli and rice.
    
    The chef kneads the packages through their flexible plastic tops
    and secures them in the oven along with the four precooked steaks.
    The steaks are packaged in flexible aluminum-backed plastic bags,
    called flex-pouches. The heat in the oven is 82 degrees Celsius,
    which does not harm the plastic containers. A fan circulates air
    so that the food is heated evenly.
    
    While these items warm in the oven, the mission specialist takes
    four trays from the galley and attaches them by magnets or clamps
    to a portable dining table hooked to the lockers. The mission
    specialist then adds cold water through the hollow needle to
    rehydrate the bowls of shrimp, chocolate pudding, and grape drink.
    A plastic straw with a clamp on it is inserted into the passageway
    of the grape drink. These cold items, along with the cans of fruit
    cocktail, the silverware, and a can opener, are assembled on the
    trays and held by magnets or Velcro tape. When the heated foods
    are ready, it is dinner time.