Food For Space Flight
Space Food History
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 Shuttle Food System
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.
Food Preparation
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.
Almost Like Eating At Home
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.
Pantry
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.
Shuttle Extended Duration Missions
The length of Shuttle missions has
steadily increased from the first mission in 1981 of 2 days, to 14 days for
STS50 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 STS49 and 50. It has now permanently replaced the rigid
square rehydratable package.
Types of Foods
Weight and volume have always been primary design
factors for every piece of hardware launched into space. The Shuttle is no
exception. Weight allowed for food is limited to 3.8 pounds per person per day,
which includes the 1 pound of packaging for each person each day.
Foods are individually packaged and stowed for easy handling in the zero
gravity of space. All food is precooked or processed so it requires no
refrigeration and is either ready to eat or can be prepared simply by adding
water or by heating. The only exceptions are the fresh fruit and vegetables
stowed in the fresh food locker. Without refrigeration, the carrots and celery
must be eaten within the first two days of the flight or they will spoil.
Rehydratable (R) Food
Rehydratable items include both foods and
beverages. One way weight can be conserved during launch is to remove water in
the food system. During the flight, water is added back to the food just before
it is eaten. The Shuttle orbiter fuel cells, which produce electricity by
combining hydrogen and oxygen, provide ample water for rehydrating foods as
well as drinking and a host of other uses.
Foods packaged in rehydratable containers include soups like chicken consomme
and cream of
mushroom, casseroles like macaroni and cheese and chicken and rice, appetizers
like shrimp cocktail, and breakfast foods like scrambled eggs and cereals.
Breakfast cereals are prepared by packaging the cereal in a rehydratable
package with nonfat dry milk and sugar, if needed. Water is added to the
package just before the cereal is eaten.
Thermostabalized Food
Thermostabilized foods are heat processed to
destroy deleterious microorganisms and enzymes. Individual servings of
thermostabilized foods are commercially available in aluminum or bimetallic
cans, plastic cups, or in flexible retort pouches. Most of the fruits, and fish
such as tuna and salmon, are thermostabilized in cans. The cans open with
easy-open, full-panel, pullout lids. Puddings are packaged in plastic cups.
Most of the entrees are packaged in flexible retort pouches. This includes
products such as beef tips with mushrooms, tomatoes and eggplant, chicken ala
king, and ham. After the pouches are heated, they are cut open with scissors.
The food is eaten directly from the containers with conventional eating
utensils.
Intermediate (IM) Moisture Foods
Intermediate moisture foods are
preserved by restricting the amount of water available for microbial growth,
while retaining sufficient water to give the food a softtexture and let it be
eaten without further preparation. Water is removed or its activity restricted
with a water-binding substance such as sugar or salt. Intermediate moisture
foods usually range from 15 to 30 percent moisture, but the water present is
chemically bound with the sugar or salt and is not available to support
microbial growth. Dried peaches, pears, and apricots, and dried beef are
examples of this type of Shuttle food.
Natural Form (NF) Foods
Foods such as nuts, granola bars, and
cookies are classified as natural
form foods. They are ready to eat, packaged in flexible pouches, and require no
further processing for consumption in flight. Both natural form and
intermediate moisture foods are packaged in clear, flexible pouches that are
cut open with scissors.
Irradiated (I) Meat
Beef steak is the only irradiated product currently
used on Shuttle. Steaks are cooked, packaged in flexible, foil-laminated
pouches, and sterilized by exposure to ionizing radiation so they are stable at
ambient temperature.
Condiments
Condiments include commercially packaged individual pouches
of catsup, mustard, mayonnaise, taco sauce, and hot pepper sauce. Polyethylene
dropper bottles contain bulk
supplies of liquid pepper and liquid salt. The pepper is suspended in oil and
the salt is dissolved in water.
Shelf Stable Tortillas
Flour tortillas are a favorite bread item of the
Shuttle astronauts. Tortillas provide an easy and acceptable solution to the
bread crumb and microgravity handling problem, and have been used on most
Shuttle missions since 1985. However, mold is a problem with commercially
packaged tortillas, especially with the longer missions on the orbiter, which
has no refrigeration.
A shelf stable tortilla was developed for use on the Shuttle with extended
mission lengths. The tortillas are stabilized by a combination of modified
atmosphere packaging, pH (acidity), and water activity. Mold growth is
inhibited by removing the oxygen from the package. This is accomplished by
packaging in a high-barrier container in a nitrogen atmosphere with an oxygen
scavenger. Water activity is reduced to less than 0.90 in the final product by
dough formulation. This reduced water activity, along with a lower pH, inhibits
growth of pathogenic clostridia, which could be a potential hazard in the
anaerobic atmosphere created by the modified atmosphere.
Shuttle Galley
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.
Orbiter's Food Lockers
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.
Space Station Food System
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.
Daily Menu
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 food 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.
Meal preparation and consumption will involve a series of steps. A general meal
scenario is as follows:
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
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 Research and Development
Foods flown on space missions are researched and developed at the Food Systems
Engineering Facility (FSEF) at the NASA Johnson Space Center. The FSEF is
staffed by Food Scientists, Dietitians, and Engineers who support both the
Shuttle and Space Station food systems. Foods are analyzed for use on the
Shuttle through nutritional analysis, sensory evaluation, freeze drying,
rehydration, storage studies, packaging evaluations, and many other methods.
Before any food takes flight though, it must be tested by the FSEF personnel on
the NASA Zero-gravity KC-135 airplane, affectionately known as the "Vomit
Comet" to see how the food item will react in micro-gravity. A food item is
added to the menu only after it has undergone all the necessary research and
development, and is approved for flight.
Astronaut Menu Selection
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.
Baseline Shuttle Food List
Beef, Dried (IM)
Apple Cider |
Curator: Kim
Dismukes | Responsible NASA Official: John Ira Petty | Updated: 04/07/2002 |