The issue of food is very
simple. An average human being consumes about 2.5 pounds of
food in which .3 pounds is converted into solid waste. For
the Mars mission, one human being would have consumed 913.125
pounds of food and produced 109.575 pounds of solid waste.
Eventhough that solid waste can be vented to outer space,
the numbers give us an idea of how much waste one can produce.
Saving weight for food can be extremely difficult. Unlike
water and air, it can not be converted into something a human
desperately needs. However, it can turn to fertilizer and
if we are going to grow plants on our space crafts, that fertilizer
can be used to help the plants grow faster and healthier.
Another way our astronauts can save weight is by simply creating
food aboard the space craft. They can carry varios seeds that
do not weight much. By adding wastes such as carbon dioxide
and solid waste, they can be grown to edible food. This way,
large amounts of weight can be reserved for other payloads.
The food that NASA's early astronauts had to eat in space
is a testament to their fortitude. John Glenn, America's first
man to eat anything in the near-weightless environment of
Earth orbit, found the task of eating fairly easy, but found
the menu to be limited. Other Mercury astronauts had to endure
bite-sized cubes, freezedried powders, and semiliquids stuffed
in aluminum tubes. Most agreed the foods were unappetizing
and disliked squeezing the tubes. Moreover, freeze-dried foods
were hard to rehydrate and crumbs had to be prevented from
fouling instruments.
The astronauts complained and on the Gemini missions eating
improved somewhat. The first things to go were the squeeze
tubes. Bite-sized cubes were coated with gelatin to reduce
crumbling, and the freeze-dried foods were encased in a special
plastic container to make reconstituting easier. With improved
packaging came improved food quality and menus. Gemini astronauts
had such food choices as shrimp cocktail, chicken and vegetables,
butterscotch pudding, and apple sauce, and were able to select
meal combinations themselves.
By the time of the Apollo program, the quality and variety
of food increased even further. Apollo astronauts were first
to have hot water, which made rehydrating foods easier and
improved the food's taste. These astronauts were also the
first to use the "spoon bowl," a plastic container
that could be opened and its contents eaten with a spoon.
The task of eating in space got a big boost in Skylab. Unlike
previous space vehicles for astronauts, Skylab featured a
large interior area where space was available for a dining
room and table. Eating for Skylab's three-member teams was
a fairly normal operation: footholds allowed them to situate
themselves around the table and "sit" to eat. Added
to the conventional knife, fork, and spoon was a pair of scissors
for cutting open plastic seals. Because Skylab was relatively
large and had ample storage area, it could feature an extensive
menu: 72 different food items. It also had a freezer and refrigerator,
a convenience no other vehicle offered.
The kinds of foods the Space Shuttle astronauts eat are
not mysterious concoctions, but foods prepared here on Earth,
many commercially available on grocery store shelves. Diets
are designed to supply each Shuttle crew member with all
the Recommended Dietary Allowances (RDA) of vitamins and
minerals necessary to perform in the environment of space.
Caloric requirements are determined by the National Research
Council formula for basal energy expenditure (BEE). For
women, BEE = 655 + (9.6 x W) + (1.7 x H) - (4.7 x A), and
for men, BEE = 66 + (13.7 x W) + (5 x H) - (6.8 x A), where
W = weight in kilograms, H = height in centimeters, and
A = age in years.
Shuttle astronauts have an astonishing array of food items
to choose from. They may eat from a standard menu designed
around a typical Shuttle mission of 7 days, or may substitute
items to accommodate their own tastes. Astronauts may even
design their own menus. But those astronaut-designed menus
must be checked by a dietitian to ensure the astronauts
consume a balanced supply of nutrients.
The standard Shuttle menu repeats after 7 days. It supplies
each crew member with three balanced meals, plus snacks.
Each astronaut's food is stored aboard the Shuttle and is
identified by a colored dot affixed to each package.
On the Space Shuttle, food is prepared at a galley installed
on the orbiter's mid-deck. The galley is a modular unit
that contains a water dispenser and an oven. The water dispenser
is used for rehydrating foods, and the galley oven is for
warming foods to the proper serving temperature.
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Almost
Like Eating At Home
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During a typical meal in space, a meal tray is used to
hold the food containers. The tray can be attached to an
astronaut's lap by a strap or attached to a wall. The meal
tray becomes the astronaut's dinner plate and enables him
or her to choose from several foods at once, just like a
meal at home. Without the tray, the contents of one container
must be completely consumed before opening another. The
tray also holds the food packages in place and keeps them
from floating away in the microgravity of space.
Conventional eating utensils are used in space. Astronauts
use knife, fork, and spoon. The only unusual eating utensil
is a pair of scissors used for cutting open the packages.
Following the meal, food containers are discarded in the
trash compartment below the mid-deck floor. Eating utensils
and food trays are cleaned at the hygiene station with premoistened
towelettes.
Crews have reported that the Shuttle food system functions
well in space. It consists of familiar, appetizing, well-accepted
food items that can be prepared quickly and easily. A full
meal for a crew of four can be set up in about 5 minutes.
Reconstituting and heating the food takes an additional
20 to 30 minutes about the time it takes to fix a snack
at home, and far less than it takes to cook a complete meal.
A supplementary food supply that provides
approximately 2100 Kilocalories per person for two extra
days is stowed aboard the Shuttle for each flight. Pantry
items are flown in addition to the menu in case the flight
is unexpectedly extended because of bad weather at the landing
site or some other unforeseen reason. During the flight,
this food supply provides extra beverages and snacks. The
pantry items also can be exchanged for menu items in flight,
but all unused food packages are retained in the pantry
so they will be available in case they are needed later.
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Shuttle
Extended Duration Missions
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The length of Shuttle missions has steadily increased from
the first mission in 1981 of 2 days, to 14 days for STS-50
in June, 1992. Missions beyond 10 days are called Extended
Duration Orbiter (EDO) missions. In order to accommodate
the weight and volume of trash generated by the food system
on these longer missions, it was necessary to develop new
food and beverage packages. A trash compactor was also developed
to reduce the volume of the trash, and the new packages
were designed to be compatible with the compactor.
The beverage package is made from a foil laminate to provide
maximum barrier properties for a longer product shelf life.
A septum adapter is sealed in the package after the beverage
powder has been added. The septum adapter holds a septum
which interfaces with the galley water dispenser for the
addition of water, and with a straw for drinking the beverage.
Although the beverage package was designed for use on EDO
missions, it has replaced the square polyethylene beverage
package on all Shuttle missions. The EDO rehydratable food
package also is made from flexible material to aid in trash
compression. The rehydratable package consists of a flexible
bowl and lid with the septum adapter for adding water from
the galley. Velcro on the bottom of the package holds it
in the meal tray. After adding the required amount of water
to the package, it is placed in the oven if the food is
to be served hot, or directly onto the serving tray if it
is to be served cold. The top of the package is cut off
with a knife or scissors and the contents eaten with a fork
or spoon. The EDO rehydratable food package was tested on
STS-44, and used for all of the rehydratable foods on STS-49
and 50. It has now permanently replaced the rigid square
rehydratable package.
The Shuttle galley was redesigned in 1991 to reduce the
weight and volume and to update the electronics. The redesigned
galley weighs one-third less and occupies one-half the volume
of the original galley. The new galley delivers hot or cold
water from the rehydration station. The hot water temperature
is between 155 and 165deg.F. The hot and cold dispense quantities
can be selected in one-half ounce increments up to 8 ounces.
The forced air convection oven heats food and beverages
by conduction with a hot plate or by forced convection.
The temperature of the oven is maintained at 160 to 170deg.F.
The oven holds 14 rehydratable packages plus thermostabilized
pouches and beverages.
Meals are stowed aboard the orbiter in locker trays with
food packages arranged in the order they will be used. A
label on the front of the locker tray lists the locker contents.
A five-section net restraint keeps food packages from floating
out of the locker in microgravity while still allowing items
inside to be seen. Velcro strips secure sections of the
net, making it easily opened and the food items readily
accessible to the astronauts.
Food is packaged and stowed in the locker trays in Houston
about a month before each launch. Stowed food lockers and
shipping containers are kept under refrigeration. About
3 weeks before launch, the food lockers are shipped to Kennedy
Space Center (KSC) in Florida. There they are refrigerated
until they are installed in the Shuttle 2-3 days before
launch. Besides the meal and pantry food lockers, a fresh
food locker is packed at KSC and installed on the Shuttle
18 to 24 hours before launch. The fresh food locker contains
tortillas, fresh bread, breakfast rolls, and fresh fruits
and vegetables such as apples, bananas, oranges, and carrot
and celery sticks.
Foods chosen for the daily menu were selected based on
their commonality to everyday eating, the nutritional content
and their applicability to use in space. The Daily Menu
food supply is based on the use of frozen, refrigerated,
and ambient foods. Frozen food includes most entrees, vegetable,
and dessert items. Refrigerated food includes fresh and
freshtreated fruits and vegetables, extended shelf-life
refrigerated foods, and dairy products. Ambient foods include
thermostabilized, aseptic-fill, shelf-stable natural form
foods, and rehydratable beverages.
Astronauts will choose 28 day flight menus approximately
120 days prelaunch. Additions, deletions, or substitutions
to a standard Space Station menu will be made using a Space
Station foodlist.
The packaging system for the Daily Menu food is based on
single service, disposable containers. Food items will be
packaged as individual servings to facilitate inflight changes
and substitutions to preselected menus. Single service containers
also eliminates the need for a dishwasher. A modular concept
that maintains a constant width dimension is utilized in
the package design. This design permits common interface
of food packages with restraint mechanisms (stowage compartments,
oven, etc.) and other food system hardware such as the meal
tray. Five package sizes were designed to accommodate common
serving sizes of entrees, salads, soups, and dessert items.
Several fresh fruits, bread, and condiments will be provided
in bulk packages.
The food required for a 90 day mission will be delivered
to the station in the PLM. Daily menu frozen, refrigerated
and ambient foods will be stowed in 14 day supply increments.
The HAB galley will accommodate a 14 day food supply. Food
will be transferred from the PLM to the HAB every two weeks.
Unused food will be returned to the proper stowage environment
in the PLM with each 14 day food transfer. Inventory control
will be maintained on the unallocated food returned to the
PLM for use in case the Shuttle is late in delivering the
next food set.
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Space
Station Food System
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Space Station will become operational on a full time basis
with a crew of 4. Later, the crew size will grow to a maximum
of 8 people. The crew will reside in the Habitation Module
(HAB). Food and other supplies will be resupplied every 90
days by exchanging the Pressurized Logistics Module (PLM).
The food system for SS will be considerably different from
the Shuttle food system. Since the electrical power for
SS will be from solar panels, there is no extra water generated
onboard. Water will be recycled from the cabin air, but
that will not be enough for use in the food system. Most
of the food planned for SS will be frozen, refrigerated,
or thermostabilized and will not require the addition of
water before consumption. Many of the beverages will be
in the dehydrated form. Food will be heated to serving temperature
in a microwave/forced air convection oven. One oven will
be supplied for each group of 4 astronauts.
The SS food system consists of 3 different supplies of
food; Daily Menu, Safe Haven, and Extra Vehicular Activity
(EVA) food.
The Safe Haven food system is provided to sustain crewmembers
for 22 days under emergency operating conditions resulting
from an on-board failure. A goal of the system is to utilize
a minimal amount of volume and weight. The Safe Haven food
system is independent of the daily menu food and will provide
at least 2000 calories daily per person. The Safe Haven
food system will be stored at ambient temperatures which
range from 60 to 85deg.F. Therefore, the food must be shelf-stable.
Thermostabilized entrees and fruits, intermediate moisture
foods, and dehydrated food and beverages will be used to
meet the shelf-stable requirement. The shelf life of each
food item will be a minimum of two years.
EVA food consisting of food and drink for 8 hours (500
calories of food, and 38 oz. of water) will be available
for use by a crewmember during each EVA activity. EVA water
and food containers will be cleaned and refilled with galley
subsystems.
Food evaluations are conducted approximately eight to nine
months before the flight. During the food evaluation sessions,
the astronaut is given the opportunity to sample a variety
of foods and beverages available for flight. A pack of information
is given to each astronaut to use in planning their personal
preference menus. Included in the packet is a standard menu,
training menu, past flight menus the astronaut has chosen,
and the baseline shuttle food and beverage list.
Astronauts select their menu approximately five months
before flight. The menus are analyzed for nutritional content
by the Shuttle Dietitian and recommendations are made to
correct any nutrient deficiencies based on the Recommended
Dietary Allowances. The menus are then finalized and provided
to the Flight Equipment Processing Contractor (FEPC) in
Houston three months before launch. The FEPC processes,
packages, and stows the food in the Shuttle lockers before
being transferred to KSC.
Whet your readers' appetite with little-known food facts from
space that give new definition to eating out.
The first American astronaut to eat in space dined on applesauce
squeezed from a no-frills, aluminum toothpaste-like tube.
Since then, food technology has cooked up better ways to
prepare, package and preserve space fare in a tastier, more
appetizing fashion.
Today, humans are living in space aboard the International
Space Station for as long as six months at a time. As America
journeys back to the Moon and on to Mars, advances for food
to withstand years in space will serve up more improvements
in space and on Earth.
