STEM Today

SPACE FOOD AND NUTRITION

STEM TODAY August 2016, No.11

SPACE FOOD AND NUTRITION

STEM TODAY August 2016 , No.11

CONTENTS SPACE FOOD AND NUTRITION Project Mercury Gemini Apollo Skylab Apollo­Soyuz Test Project Space Shuttle International Space Station (ISS)

Editorial Editor: Mr. Abhishek Kumar Sinha Editor / Technical Advisor: Mr. Martin Cabaniss

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Cover Page First Flower Grown in Space Station’s Veggie Facility On Jan. 16, 2016, Expedition 46 Commander Scott Kelly shared photographs of a blooming zinnia flower in the Veggie plant growth system aboard the International Space Station. Kelly wrote, "Yes, there are other life forms in space! #SpaceFlower #YearInSpace" Image Credit: NASA

Back Cover Moonset Viewed From the International Space Station Expedition 47 Flight Engineer Tim Peake of ESA took this striking photograph of the moon from his vantage point aboard the International Space Station on March 28, 2016. Peake shared the image on March 30 and wrote to his social media followers, "I was looking for #Antarctica - hard to spot from our orbit. Settled for a moonset instead."

Image Credit: ESA/NASA

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Editorial Dear Reader

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All young people should be prepared to think deeply and to think well so that they have the chance to become the innovators, educators, researchers, and leaders who can solve the most pressing challenges facing our world, both today and tomorrow. But, right now, not enough of our youth have access to quality STEM learning opportunities and too few students see these disciplines as springboards for their careers.

According to Marillyn Hewson, "Our children - the elementary, middle and high school students of today - make up a generation that will change our universe forever. This is the generation that will walk on Mars, explore deep space and unlock mysteries that we can’t yet imagine". "They won’t get there alone. It is our job to prepare, inspire and equip them to build the future - and that’s exactly what Generation Beyond is designed to do."

STEM Today will inspire and educate people about Spaceflight and effects of Spaceflight on Astronauts.

Editor Mr. Abhishek Kumar Sinha

Editorial Dear Reader The Science, Technology, Engineering and Math (STEM) program is designed to inspire the next generation of innovators, explorers, inventors and pioneers to pursue STEM careers.

According to President Barack Obama, "[Science] is more than a school subject, or the periodic table, or the properties of waves. It is an approach to the world, a critical way to understand and explore and engage with the world, and then have the capacity to change that world..."

STEM Today addresses the inadequate number of teachers skilled to educate in Human Spaceflight. It will prepare , inspire and educate teachers about Spaceflight. STEM Today will focus on NASA’S Human Research Roadmap. It will research on long duration spaceflight and put together latest research in Human Spaceflight in its monthly newsletter.

Editor / Technical Advisor Mr. Martin Cabaniss

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SPACE FOOD AND NUTRITION

Special Edition on Space Food and Nutrition

Project Mercury Initiated in 1958, completed in 1963, Project Mercury was the United States’ first man-in-space program. The objectives of the program, which made six manned flights from 1961 to 1963, were specific: • To orbit a manned spacecraft around Earth • To investigate man’s ability to function in space • To recover both man and spacecraft safely

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Because of the short duration,complete meals were not needed. The major meal was consumed prior to the flight. However, the Mercury astronauts did contribute to the development of spacefood. They tested the physiology of chewing, drinking,and swallowing solid and liquid foods in a microgravity environment. These first astronauts found themselve seating bite-sized cubes, freeze-dried foods, and semi-liquids in aluminum toothpastetype tubes. The food was unappetizing, and there were problems when they tried to rehydrate the freeze-dried foods.

The results of physiologic measurements and medical studies of Astronaut L. Gordon Cooper, Jr. made prior to, during, and following his flight as pilot of the spacecraft of the MA-9 mission are presented here. Astronaut Cooper withstood the stresses of flight situation with no evidence of degradation of his functional integrity as a pilot. He slept as part of the planned mission activities during his flight and reported that sleep was subjectively normal. Postflight examination of Astronaut Cooper revealed that he had developed dehydration. He exhibited an orthostatic hypotension accompanied by an accelerated pulse response in the postflight examinations. The pulse and blood pressure responses returned to normal while the pilot was sleeping between 9 hours and 19 hours after landing. A reversal of the ratio between neutrophiles and lymphocytes was noted in the peripheral blood at an examination accomplished 4 days after the mission. This lymphocytosis persisted for 2 weeks and subsided spontaneously by June 14, 1963. With respect to all other studies, the medical status of the pilot was found essentially unchanged between the preflight and postflight examinations[NASA-SP-45].

Close supervision of the pilot’s food intake began 7 days before the planned flight with special preparation of a normal balanced diet. In order to reduce the need for defecation during the mission, a low-residue diet was followed for 4 days before the launch. This diet was well tolerated, although the pilot did mention that appetite satisfaction was short-lived following the low-residue meals.

The astronaut stated [NASA-SP-45] that he did not feel particularly hungry during most of the flight and ate primarily because it had been scheduled. However, later in the flight he did feel hungry on one occasion and after eating felt better. Because of problems with the food containers and water nozzle during flight, he was unable to reconstitute properly the freezedehydrated food and could only eat one-third of a package of beef pot roast. Therefore, he subsisted on bite-sized cubed food and bite-sized peanut butter "sandwiches." He avoided the bitesized beef sandwiches, since they had crumbled in their package. His caloric intake during the flight was only 696 calories of the 2,369 calories available to him at launch. He rapidly tired of the cubed "snack-type" foods and this contributed to his low caloric intake. Typical samples of the food types carried aboard from the MA-9 flight are shown in figure.

The astronaut’s water intake was also limited. When the condensate transfer system would no longer permit

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Special Edition on Space Food and Nutrition fluid storage in the 3.86 pound- capacity main condensate bag during the flight he was forced to put condensate water into one of the drinking-water tanks before he had consumed all of its contents. Normal operational procedures required the exclusion of condensate water as a drinking-water source. He began drinking small amounts from his survival-kit water supply, as planned, but he wished to conserve this supply as much as possible. He was not really thirsty until during the last orbital pass, but he was so busy at that point that he did not take time to drink. Because condensate water was placed into the drinking-water tank in which all unknown amount of drinking water remained, it is impossible to make a precise statement as to his water intake during flight, but he did consume more than 1,500 cc.

He urinated without difficulty several times during flight and stated that bladder sensations were normal. The urine collection and transfer system worked well, and separate urine samples were obtained at four different times during the flight. It required, however, a considerable amount of time and effort to transfer the urine to the storage bags manually.

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The medical findings during the initial examination after desuiting indicate a moderate dehydration. This dehydration resulted from a reduced intake of food and water during the flight. The only real discomfort experienced during the flight was associated with the pressure suit being pulled tightly across the pilot’s knees. By the sixth or seventh orbital pass, his knees were becoming quite uncomfortable. He alleviated this discomfort somewhat by periodically sliding his feet up past the normal foot position into the tower area of the spacecraft. This action permitted the straightening of his legs to relieve most of the pressure and also allowed him to pull on the legs of the suit to gain a little slack around his knees.

The astronaut took 5 mg of dextro-amphetamine sulfate approximately 1 hour 20 minutes prior to retrofire on advice of the MCC surgeon. He stated that within 20 minutes he felt much more alert and confident and seemed to be "more on top of things." He had less tendency to drop off to sleep for the remainder of the flight.

There was no apparent degradation in the pilot’s performance following this medication. The pilot stated that the drug, as far as he could tell, had the same effects as test doses taken prior to flight.

During the last two orbital passes, the carbon-dioxide partial-pressure (PCO2 ) gage was noted to indicate a rise in the amount of carbon dioxide in the suit. The astronaut actuated the emergency oxygen flow rate for 30 seconds. It did not seem to change the pilot’s onboard reading noticeably, although telemetry signals indicated a slight drop. At this time the pilot closed his faceplate and felt that his respirations were deeper and more rapid. This change in respiration could not be confirmed by postflight examination of respiration and heart rate recordings. Although he felt more comfortable with the faceplate open, he kept it closed during the final orbital pass and the reentry as planned. The PCO2 gage indicated about 5 mm Hg at reentry. This concentration is not enough to cause symptoms of hypercapnia on the ground, and there was no apparent interference with the pilot’s normal responses.

The tube foods offered many challenges to food development. First, a method of removing the food from the tubewas needed. A small straw was placed into the opening. This allowed the astronauts to squeeze the contents from the tube directly into their mouths. This is similar to drinking your favorite soda from a straw, except that thefood was a thicker substance. Special materials were developed to coat the inner surface of the aluminum tubes to prevent the formation of hydrogen gas as a result of contact between metal and the acids contained in somefoods, such as applesauce. This aluminum tube packaging often weighed more than the food it contained.Because of this, a lightweight plastic container was developed for future flights.

During the later Mercury test flights, bite-sized foods were developed and tested. These were solid foods processed in the form of compressed, dehydrated bite-sized cubes. The cubes could be rehydrated by saliva secreted in the mouth as food was chewed. Foods floating about in a microgravity environment could damage equipment or be inhaled; therefore, the cubes were coated with an edible gelatin to reduce crumbling. These foods were vacuum-packed into individual serving-sized containers of clear, four-ply, laminated plastic film for storage. This packaging also provided protection against moisture, loss of flavor, and spoilage.

Gemini The Gemini food system consists of freeze-dried rehydratable foods and beverages, and bite-sized foods. Each item is vacuum packed in a laminated plastic bag. The items are then combined in units of one or two meals andvacuum packed in a heavy aluminum-foil overwrap. (Fig. 7-16.) The rehydratable food bag incorporates a cylindrical plastic valve which mates with the spacecraft water dispenser for injecting water into the bag. At the other end of the bag is a feeder spout which is unrolled and inserted into the mouth for eating or drinking the contents [NASA-SP-121].

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A typical meal consists of two rehydratable foods, two bite-sized items, and a beverage. The average menu provides between 2000 and 2500 calories per man per day. The crews favored menus with typical breakfast, lunch, and dinner selections at appropriate times corresponding to their daily schedule. Occasional leakage of the food bags occurred in use. Because of the hand pressure needed to squeeze the food out of the feeder spout, these leaks were most prevalent in the chunky, rehydratable items. A design change has been made to increase the spout width. The bite-sized foods were satisfactory for snacks but were undesirable for a sustained diet. These items were rich, dry, and, in some cases, slightly abrasive. In addition, some of the bite-sized items tended to crumble. In general, the flight crews preferred the rehydratable foods and beverages.

Drinking-Water Dispenser The drinking-water dispenser (Fig. 7-17) is a pistol configuration with a long tubular barrel which is designed to mate with the drinking port on the space-suit helmet. The water shutoff valve is located at the exit end of the barrel to minimize residual-water spillage. This dispenser was used without difficulty on Gemini 111, IV, and V [NASA-SP-121].

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In order to measure the crew’s individual water consumption, a water-metering dispenser (Fig. 7-18) was used on Gemini VI-A and VII. Similar to the basic dispenser, this design incorporates a bellows reservoir and a valve arrangement for dispensing water in 21 -ounce increments. A digital counter on the handle records each increment, dispensed. This dispenser operated satisfactorily on both missions.

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Food

The diet has been controlled for a period of 5 to 7 days before flight and, in general, has been of a low residue. The Gemini VII crew were on a regulated calcium diet of a low residue type for a period of 12 days before their 14-day mission. The inflight diet has consisted of freeze dehydrated and bite-size foods. A typical menu is shown in Table 25-III. The crew are routinely tested with the inflight menu for a period of several days before final approval of the flight menu is given. On the 4-day flight, the crew were furnished a menu of 2500 calories per day to be eaten at a rate of four meals per day. They enjoyed the time that it took to prepare the food, and they ate all the food available for their use. They commented that they were hungry within 2 hours of ingesting a meal and that, within 4 hours after ingesting a meal, they felt a definite physiological need for the lift produced by food.

These findings were in marked contrast to the 8-day mission where each crewmember was furnished three meals per day for a caloric value of 2750. Again these meals consisted of one juice, two rehydratable food items, and two bite-size items. The 8-day crew felt no real hunger, though they did feel a physiological lift from the ingestion of a meal. They ate very little of their bite-size food and subsisted principally on the rehydratable items. A postflight review of the returned food revealed that the average caloric intake per day varied around 1000 calories for this crew. Approximately 2450 calories per day was prepared for the 14-day mission and including ample meals for 14 23 days. Inflight and postflight analyses have revealed that this crew actually consumed about 2200 calories per day.

The bite-size foods for the crews were not as appetizing as had been expected. The rehydratable foods were good and were preferred to the bite-size foods. Preparing and consuming the meal takes time and must be done with care. The food is vacuum-packed to eliminate any waste volume, but this capability does not exist when the crew is trying to restow the empty food bags. Thus, they have a restowage problem. Most of the food is in a semiliquid form, and any that remains in the food bags is a potential source of free moisture in the cabin. The water has been good and cold. Even so, there seems to be a tendency to forget to drink regularly and in sufficient quantities.

Water Intake There has been an ample supply of potable water on all of these missions, consisting of approximately 6 pounds per man per day. Prior to the 4-day and 8-day missions, the water intake was estimated by calibrating a standard mouthful or gulp for each crewman; then, during the flight, the crew would report the water intake by such measurements.

On the 4-day mission, the water intake was less than desired in the first 2 days of the mission but increased during the latter part of the flight, varying from 2.5 to 5.0 pounds in a 24-hour period. The crew were dehydrated in the post-recovery period. On the 8-day mission, the crew did much better on their water intake, averaging 5.2 to 5.8 pounds per 24 hours, and they returned in an adequately hydrated state.

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Special Edition on Space Food and Nutrition For the 14-day mission, the water dispensing system was modified to include a mechanism whereby each activation of the water dispenser produced 12 ounce of water, and this activated a counter. The number of counts and the number of ounces of water were laboriously logged by the crew. It has been obvious that the crewmen must be reminded of their water intake, and when this is done they manage very well. The 14-day crew were well hydrated at the time of their recovery, and their daily water intake is presented in Figure 25-8.

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Gemini VII was decidedly different from previous Gemini flights in that the Gemini VII crew did not wear their suits during an extensive portion of the 14-day fight. Their food and water intake was more nearly optimal than in previous flights; this assured better hydration and electrolyte balance, and the Gemini VII exercise regimen was more rigorous than that utilized on previous flights [NASA-SP-121].

Apollo The earliest food systems used in the Project Mercury flights and the short duration Gemini Program flights resembled military survival rations. For the first long term flight, the two-week Gemini 7 mission, nutritional criteria became important considerations and began to constrain food system designers. Adequate provisions for energy and nutrients had to be made within an exceedingly small weight and volume envelope. This food system envelope, about .77 kg per man per day (1.7 pounds) and 1802 cm3 per man per day (110 cubic inches),

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also had to allow for all packaging materials needed to protect foods.

Because water produced as a by-product of fuel cell operation in the Gemini spacecraft could be made available, it became highly attractive from a food acceptance and weight savings standpoint to use dehydrated foods that could be reconstituted in flight. This was the departure point for the development of the Apollo food system, and systematic improvements were subsequently made as technology became available and the application was feasible.

The overall objective of the Apollo food system development program was to provide adequate and safe nutrition for man during the most ambitious space explorations ever attempted. This objective had to be achieved within many critical biological, operational, and engineering constraints. Details concerning the constraints are described in the Apollo Experience Report - Food Systems (NASA TN D-7720, July 1974).

Apollo food system technology[NASA-SP-368] evolved over a considerable period of time, with the aid of efforts from the U.S. Air Force Manned Orbiting Laboratory Program, the U.S. Army Natick Laboratories, industry, and universities. The earliest "space foods" were bite-sized foods suitable for eating with one’s fingers, and pureed foods, squeezed directly into the mouth from flexible metal toothpaste-type tubes. Extensive modifications in food and food packaging were made throughout Project Mercury and the Gemini and Apollo Programs. Modifications of the food system were especially necessary during the Apollo Program for the following reasons.

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Special Edition on Space Food and Nutrition • Inflight food consumption proved inadequate to maintain nutritional balance and body weight.

• Inflight nausea, anorexia and undesirable physiological responses experienced by some crewmen were believed to be partly attributable to the foods.

• Meal preparation and consumption required too much crew time and effort.

• Water for reconstitution of dehydrated foods was unpalatable initially and contained undesirable amounts of dissolved gases.

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• Functional failures occurred in the rehydratable food packages in the early Apollo flights.

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Each mission in the Apollo series had different objectives and requirements, and the scope of the Apollo food system was modified to fit the needs of each. The primary mission phases, from the vantage point of food provision, included times during which the crewmen occupied the Command Module (CM) and the Lunar Module (LM), and times when they were being transported in various vehicles from the recovery site to the NASA Lyndon B. Johnson Space Center in Houston, Texas. A contingency food system also was provided to be used if emergency decompression of the space vehicle occurred. For the Apollo 11 through 14 missions, a postflight quarantine period required a food system for use in the Mobile Quarantine Facility (MQF) and the Lunar Receiving Laboratory (LRL). Each of these environments presented a different set of constraints and requirements for the food system. Inflight metabolic balance studies were conducted on the Apollo 16 and 17 missions. These studies imposed unique requirements on the food system for preflight, inflight, and postflight measurements and control of dietary intake .

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Before an Apollo launch, each prime and backup crewmember evaluated available flight foods and selected the food items he preferred. Then the foods were assembled into nutritionally balanced menus which were reviewed by crewmembers and nutritionists for maximum acceptability within nutritional constraints. Finally, the astronauts were briefed on spacecraft food stowage, preparation, and waste disposal.

The initial Apollo inflight food system consisted of two basic food types: (1) lightweight, shelf-stable, dehydrated foods that required rehydration prior to consumption, and (2) ready-to-eat, dehydrated bite-sized foods.

Dehydrated foods were selected because of shelf life and because weight was critical in the Apollo vehicle Approximately 80 percent of the weight of fresh food is water; therefore, the removal of water resulted in a substantial reduction of food system weight. As was previously noted, water for rehydration was available as a by-product of fuel cell operation, wherein hydrogen is combined with oxygen to release electrical energy.

Freeze Dehydrated Foods The optimal method of dehydrating food is freeze dehydration, a technique preferred because of the remarkable preservation of quality in the resulting product Color, texture, flavor, nutrient Content, and reconstitution of foods which are properly freeze-dried closely approximate the original food. However, as with any other method of preservation, the food which is preserved cannot be of higher quality than the original.

The high quality of freeze-dried food derives largely from the technique of removing the water by sublimation directly from ice to vapor with minimum exposure of the food to heat. The food is frozen rapidly in circulating air at a temperature of approximately 233◦ K (-40◦ C). The frozen food is then placed in a vacuum chamber, where the pressure is reduced to less than 270 N/m2 (≈ 2 mm Hg). Energy in the form of heat is applied by means of heating plates maintained at temperatures of 298◦ to 303◦ K (≈ 25◦ to 30◦ C), depending on the product. Under vacuum, this heat source provides the energy required to sublime the ice while the temperature of the food is maintained below the eutectic point. The heat input is carefully controlled to provide optimum removal of water vapor, which is collected on condensers within the vacuum chamber. The core of ice in the food completely disappears when the food reaches a moisture content of approximately two percent. This residual moisture remains bound to the food, and the energy level required to free it is greater than that of sublimation.

Critical relationships exist between pressure and temperature during the drying process, and criteria were developed for each food employed in the system. These criteria were developed to assure the most rapid method of processing while maintaining organoleptic quality and preventing destruction of nutrients.

Bite-Sized Foods Bite-sized, ready-to-eat foods supplemented rehydratable foods for the first Apollo manned flight. These bite sized foods were either dehydrated (moisture less than two percent) or prepared so that water in the product would be bound and, therefore, not available for microbial growth. The latter category is generally referred to as intermediate-moisture food to differentiate it from fresh foods at one extreme and dehydrated food at the other. The intermediate-moisture foods (moisture less than 40 percent) are highly acceptable since they closely approximate the texture of fresh foods and are ready to eat without reconstitution. Even with this combination of foods, however, the range of texture and tastes was fairly limited for early Apollo astronauts, a situation that was gradually rectified throughout the program.

Packaging Packaging, like food items themselves, underwent substantial modification during the Apollo Program. Flexible packaging protected each individual portion of food and made handling and consumption easier. A series of re-

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design cycles finally resulted in a rehydratable food package that had (1) an improved, transparent barrier-film of laminated polyethylene-fluorohalocarbon-polyester-polyethylene; (2) a water injection port consisting of a one-way, spring-loaded valve; and (3) an improved opening that permitted food consumption in weightlessness with a conventional tablespoon.

Cold [≈ 283◦ K (10◦ C)] and hot [ ≈ 333◦ K (60◦ C)] water were available for food preparation. Following water injection with the Apollo water dispenser, the food package was kneaded to rehydrate the food and then opened for consumption. Early packages, shown in Figure 1, were fitted with plastic tubes through which rehydrated food was extruded into the mouth. This configuration was changed by the introduction of a spoon-bowl package, pictured in Figure 2 and described in greater detail in the following sections.Bite-sized, ready-to-eat foods were contained in packets made from the same plastic laminate material used for packaging rehydratable foods. These packets were opened simply by cutting with scissors (Figure 3) The food was eaten directly from the package or by use of the fingers.

Apollo 7 The food system for the first manned Apollo mission was basically that provided in the Gemini Program but featured a wider variety of foods. However, while the availability of 96 food items for the Apollo 7 flight contributed to better acceptance and increased consumption relative to Gemini foods, the time and trouble required for meal preparation was increased.

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Apollo 8 The first departure from heavy reliance on rehydratable foods occurred during the Apollo 8 flight. On Christmas day, 1968, during the first lunar orbital mission, the Apollo 8 astronauts opened packages of thermostabilized turkey and gravy and ate with spoons. This turkey entree required no water for rehydration because the normal water content (67 percent) had been retained. The thermally stabilized, ready-to-eat meal in a flexible can became known as a "wetpack," a term used to differentiate this package from the dehydrated space foods that required the addition of water before consumption. The flexible packs were made from a laminate of polyester, aluminum foil, and polyolefin.

Wet-type foods had not been used previously because of the disadvantages associated with high moisture content, particularly the requirement for sterility and the weight penalty associated with this type of food The improved crew acceptance of the product justified the weight increase. Technology for heat sterilization in flexible packages was sufficiently advanced by the time of Apollo 8 to assure a high quality product with minimal chance for failure.

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The Apollo 8 crew also used a conventional teaspoon to eat some foods, and found that this mode of food consumption in weightlessness was quite satisfactory. This finding led to food package redesign which made the use of spoons much more convenient.

Apollo 9 Beginning with the Apollo 9 mission, more wetpack items were added to the food system. The variety of foods provided for this flight made crew diets more typical of those consumed on Earth. The extensive use of wetpack containers without difficulty during this mission confirmed the potential for eating a substantial portion of food from open containers. The Apollo 9 crewmen experimented further by cutting open a rehydratable food package and eating its contents with a spoon; the experiment was successful.

During Apollo 9, the Lunar Module Pilot experienced nausea and vomiting. Menu manipulation in flight to reduce the tendency for nausea represented the first use of real-time food selection for countering undesirable physiological responses to vestibular stimuli. The Apollo 9 mission also included the first use of the Lunar Module food system.

Apollo 10 Evolution of the Apollo food system was continued with the Apollo 10 flight, during which the spoon-bowl package (see Figure 2) was introduced. The spoon-bowl package permitted convenient use of a spoon for consuming rehydrated foods. This modified package had a water inlet valve at one end and a large plastic-zippered opening on the other, which provided access to the rehydrated food with a spoon. Large pieces of dehydrated meat and vegetables could now be included to provide a more familiar and acceptable texture. As a result of this modification, some Apollo crewmen expressed a preference for selected foods in rehydratable form over the wetpack equivalent The feasibility of eating from open containers with spoons in weightlessness was first tested in aircraft flight, and subsequently verified during the flights of Apollo 8 and Apollo 9. Using jet aircraft flying parabolic patterns, numerous foods, packages, and utensils were tested. While these flights produced only brief periods of near-weightless conditions, the results indicated that spacecraft application of the spoon-bowl concept could be made successfully without dispersal of food particles throughout the vehicle.

Apollo 10 also marked the first successful use of conventional slices of fresh bread and sandwich spreads.

This bread had a shelf life at Apollo vehicle temperatures for at least four weeks when packaged in a nitrogen atmosphere (Figure 4). Provision of the bread allowed crewmen to make sandwiches using meat salad spreads provided in separate containers. The sandwich spreads were preserved by thermal processing and final package closing in a hyperbaric chamber. The process enhances preservation of natural flavor and texture by reducing thermal processing time and temperature.

An additional modification for the Apollo 10 mission was the introduction of the pantry concept. Locker space was reserved for an assembly of food to provide ad libitum selection of meal components. This method allowed for some versatility in menu planning and for inflight dietary modification. In all subsequent Apollo flights, pantry-stocked foods augmented prepackaged meals. Even though most astronauts expressed a desire prior to flight for real-time food selection, they typically reported that this often proved to be more trouble than it was worth.

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Special Edition on Space Food and Nutrition The Apollo 10 crewmen reported some discomfort from a feeling of fullness and gastric awareness immediately after eating. This was troublesome to individual astronauts throughout the Apollo Program. Many causes for this condition have been suggested. Among these are (1) aerophagia; (2) undissolved gases (oxygen and hydrogen); (3) reduced atmospheric pressure; (4) changes in gastrointestinal motility; and (5) shifts in intestinal microflora. Moreover, removal of water during the process of food dehydration is a complex phenomenon that causes many physical-chemical shifts at the cellular level. It is conceivable that, during the rehydration process, continued occurrence of microscopic phenomena could cause osmotic displacements sensed by the cells of the gastric or intestinal mucosa.

Apollo 11 New food items for the Apollo 1I flight included thermostabilized cheddar cheese spread and thermostabilized frankfurthers. Sandwich spreads were packaged in "401" aluminum cans, which featured a pull-tab for easy removal of the entire top of the can. This can proved successful and eventually became the nucleus for the development of the open-dish eating concept implemented in the Skylab Program.

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Command Module food for the first five days of the Apollo 11 mission was assembled in nominal meal packages (Figure 5). Forty-two man-meals (starting with day 1, meal B), an oral hygiene kit, and spoons were contained in a Command Module food locker. Command Module menus for each Apollo 11 astronaut are presented in Tables 3 (A, B). Because the wetpack food items included did not require reconstitution in flight, the menu was planned for consumption of wetpack foods during the midday meal when crew activity was highest. The wetpack foods were stowed separately from nominal meal packages.

A six-day supply of food and accessory items were stowed in pantry fashion (Figure 6) to permit some food selection based on real-time preference and appetite and to supplement the meal packages if more food was desired by an individual. The foods included beverages, salads, soups, meats, breakfast items, desserts, and bite-sized foods [ Table 3(D) for listing]. Primary food packages were placed in nonflammable overwraps, which served to keep food groups together and to partition the spacecraft food container for ease of retrieval in flight. Germicide tablets were provided for stabilization of any food residue remaining in the primary food packages.

Four lunar surface meal periods were scheduled. The Apollo 11 Lunar Module menu is outlined in Table 3(C).

Foods for the four nominal meals (two each of meals A and B), Spoons, wetpack food, extra beverages, and tubed ham sandwich spread were stowed in the Lunar Module food box. The remaining items (bread, candy, and dried fruit) were stowed in the utility-light compartment of the flight data file.

Another major component of the Apollo 11 food system was the system employed on the prime recovery ship in the Mobile Quarantine Facility (MQF) and, subsequently, at the Lunar Receiving Laboratory (LRL) at Johnson Space Center. A typical MQF menu is shown in Table 5. The MQF foods were used from time of splashdown until the crewmen entered the LRL. The menu contained primarily precooked, frozen entrees, which were reconstituted in a microwave oven in the MQF. The LRL system used the same type of entrees with the addition of a wider variety of frozen vegetables, salads, and snacks. The LRL food system also included a "first class" restaurant service. complete with table linens. china, and silverware which was available to the flight crew,

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Special Edition on Space Food and Nutrition their support team, and the lunar quarantine staff of approximately 20 scientists and technicians.

Apollo 12 The food system for Apollo 12 was quite similar to that which had proven successful for Apollo 11. Freeze dehydrated scrambled eggs were introduced and were well accepted by the crew. Other changes in the menu were directed toward meeting individual crewmember nutrient requirements.

Apollo 13 The Apollo 13 inflight explosion and loss of fuel cell systems tested the food system in an emergency situation in which fluid and electrolyte intakes were critical for life support. After the accident, crew nutrient consumption was limited by the amount of available water. Beverage bags proved to be extremely useful as an emergency means of storing water that was rapidly being depleted. The use of these packages and the availability of wetpack foods for providing fluids for the Apollo 13 crewmen has been largely credited with maintaining the health of the astronaut- throughout the emergency.

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The beverage packages found other uses during Apollo missions and proved to be versatile, durable, and reliable. They were used in experiments on the separation of gas from liquids in weightlessness and also served as head supports on the couch during reentry of the Command Module in at least one mission. The Apollo 13 food system included the first dehydrated natural orange juice. Orange juice had not been employed in space food systems previously because the dehydration methods available failed to prevent fusion of natural sugars with the formation of an insoluble mass. The provision of fruit juices further improved the quality and nutritional value of the food system.

Apollo 14 The Apollo 14 flight marked the first time space crewmen returned to Earth without a significant change in body weight. The Commander and the Lunar Module Pilot had consumed essentially all of their programmed food supply. The Apollo 14 food system included an in-suit drinking device. This allowed the astronauts to better maintain fluid balance during extensive lunar surface operations.

The food safety regimen throughout the Apollo Program included the production and final packaging of all food items in a Class 100 000 filtered-air cleanroom to maintain low microbiological counts of Apollo foods. Foods were also examined for the presence of heavy metals. The only deviation from perfect performance in the food safety area was a failure in the early detection of mercury contamination in the Apollo 14 tuna fish salad. The mercury content ways in excess of maximum limits established by the U.S. Food and Drug Administration. The tuna fish was removed from the food system shortly prior to launch, and a nutritionally equivalent substitute from the pantry was used to supplement the menu. Only two foods (tunafish salad and shrimp cocktail) were found to contain significant quantities of any of these potentially toxic elements and compounds. Tunafish salad contained 0.76 ppm of mercury, and shrimp cocktail contained 0.38 ppm of mercury. Foods from these lots were removed from the inventory of flight food supplies [NASA TN D-7720].

Apollo 15 Apollo 15 crewmen consumed solid food while working on the lunar surface. High nutrient density food bars were installed inside the full pressure suit (Figure 7). Figure 8 shows a view of the neck ring area of the Apollo lunar surface pressure suit with the in-suit food bar and the in-suit drink device installed. The in-suit drink device was designed to provide water or fruit flavored beverages. This crew was the first to consume all of the mission food provided. Negligible weight losses, after equilibration for fluid losses, reaffirmed that the diet provided adequately for the crew’s energy requirements. The typical Apollo menu ultimately provided energy equivalent to 155±17 kJ/kg (37±4 kcal/kg) of body weight. Sliced fresh bread that had been pasteurized by exposure. to 50 000 rads of cobalt-60 gamma irradiation was first used for the Apollo 15 flight.

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Apollo 16 Electrocardiographic recordings for Apollo 15 crewmen indicated occasional arrhythmias believed to be possibly linked to a potassium deficit. In an effort to prevent recurrence of a similar situation in the Apollo 16 crew, a requirement was levied to provide 140´s5 milliequivalents of potassium in the Apollo 16 diets daily during flight and for 72 hours both before and after flight. In addition, nutrient intake and absorption for each Apollo 16 crewman was monitored during the entire period, beginning 72 hours before flight and ending 72 hours after flight. This control of nutrient intake afforded maximum opportunity to detect physiological changes accompanying transition to and from the weightless state.

The requirement for 140Âą5 mEq of potassium could not be met by menu manipulations using unmodified flight-qualified Apollo foods. Therefore, potassium fortification of qualified inflight foods was investigated, and the development of modified preflight and postflight foods was undertaken. It was found that Apollo 16 beverages and soups could be modified by the addition of 10 mEq per sewing of potassium in the form of potassium gluconate (2.35 gm per serving).

The physiological safety of potassium gluconate for food fortification and supplementation was verified by a search of the literature concerning its use and effects and by three studies involving human volunteers. The compatibility of this level of potassium with individual flight crewmembers was tested by providing each individual with fortified foods for consumption and evaluation. Apollo 16 grape drink, orange drink, pineapple orange drink, pineapple-grapefruit drink, grapefruit with sugar, and cocoa were fortified with potassium gluconate, for am average daily inflight potassium intake of approximately 100 mEq. Real-time adjustments in nutrition were applied by menu rearrangements to counteract the gastrointestinal awareness reported by one crewmember and believed to be associated with dietary potassium intake.

Apollo 17 In addition to a liberal usage of previously described improved foods, the Apollo 17 system was modified by the inclusion of shelf-stable ham steak that had been sterilized by exposure to cobalt-60 gamma irradiation (3.7 megarads) The Apollo 17 food system also incorporated a fruit cake that provided complete nutrition in shelf-

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Special Edition on Space Food and Nutrition stable, intermediate-moisture, ready-to-eat form. Both proved to be highly acceptable to the crewmen. This type of intermediate-moisture food was included in the Skylab contingency food system and is being evaluated for use in the Space Shuttle food program.

Most of the Apollo crewmembers did not eat all the food available. Among the reasons for reduced appetite were decreased hunger, a feeling of fullness in the abdomen, nausea (Berry & Homick, 1973), and preoccupation with the critical mission tasks. Dislike of the food and inadequate rest during the mission were minor problems (Berry, 1970). The evidence suggests that either weightlessness or some other aspect of the mission environment caused the crewmen to restrict their food intake below quantities available and below quantities necessary to maintain body weight.

A reasonable estimate of the energy requirement during a flight can be obtained by correlating careful measurements of food intake with losses or gains in body tissue. The data reveal a mean energy intake of 7384 Âą 1735 kJ/day for astronauts during the Apollo missions. If this intake is compared to the NAS, NRC Recommended Daily Dietary Allowance of about 12 000 kJ/day, it is apparent that an average energy deficit was incurred by each Apollo astronaut.

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To quantitate the metabolic energy demands throughout the mission and to help define body composition changes, efforts were made during the Apollo 16 mission to control nutrient intake at a constant level throughout the preflight, inflight, and postflight periods. It was believed that stabilizing dietary intake would afford maximum opportunity for detecting body composition changes caused by adaptation to weightlessness.

The mean loss in body weight between the day of the preflight total body water determination and the day of recovery was 3.9 kg. Measurements of total body water loss by tritiated water dilution indicated a mean decrease of 1.77 liters.

When body water loss was converted into lean body mass lost, it was determined that the three crewmembers lost fat in addition to lean body mass because the lean body mass loss does not equal the recorded weight loss. The daily caloric expenditure of the Apollo 16 crewmen can be calculated from the known caloric value of metabolized fat (37.6 kJ/gm and of lean body mass (16.7 kJ/gm). For the three crewmembers, the mean daily caloric expenditure was 17 347 kJ. Changes in total body potassium measured both by radioactive (potassium 42) dilution and by balance techniques did not reveal a significant loss of lean body mass, an indication that a fat and fluid loss occurred rather than a lean body mass loss. If only body fat were lost, the energy requirement for the three Apollo 16 crewmen would be 21 556, 12 043, and 14 291 kJ/day, with a mean of 15 963 kJ (Johnson et al., 1970).

In an alternate method of summarizing the data, each crewman’s body mass loss was calculated from the differences between his mean body weight obtained 30, 15, and 5 days before flight and his weight immediately after flight.

Total body water lost was defined as the mass regained by each astronaut during the 24-hour period following recovery. In this instance, it was assumed that the mean weight loss that was not due to either water or protein loss was due to loss of fat. By this method, a larger loss in body fat was calculated to have occurred in all crewmembers.

Because of difficulties in controlling the respiratory cycle during body volume measurement (Peterson & Herron, 1971), the calculated changes in body composition included the effect of respiration as a random variable; thus, the data have too large a variance for calculation of individual changes in body fat.

During the Apollo 17 mission, a complete collection of urine and feces samples was added to a record of dietary intake so that metabolic balance measurements could be made. By using the results of this study, the energy balance of each crewmember during the Apollo 17 mission was estimated. Each crewmember decreased his intramission energy intake. During the mission, this intake decreased from a mean of 141.3 kJ/kg body weight to 109.1 kJ/kg and represented a 23 percent decrease in the caloric intake of the crewmen. This decrease would result in a net mean deficit in caloric intake of 30 129 kJ throughout the mission (Johnson et al., 1974).

The mean weight loss of the Apollo 17 crewmen was 3.3 kg. Nitrogen balance data reveal a loss of approximately I kg of protein, and the remaining loss can be attributed to fat. A mean caloric deficit of approximately 104 500 kJ is, therefore, assumed to have occurred (Johnson et al., 1974; Leach et al., 1974).

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Special Edition on Space Food and Nutrition Body tissue losses were first calculated for each astronaut by averaging successive body weights obtained before the mission and subtracting the body weights measured 24 hours after recovery (Rambaut et al., 1973). It had been assumed that any decrease in body mass between the preflight weight and the weight recorded 24 hours after recovery represented water lost. An average of 1.5 kg weight was not regained during this 24-hour period.

If this loss was composed entirely of fat, it would represent an additional inflight expenditure of approximately 5643 kJ/day. Commencing with Apollo 16, food and fluid intake, urinary and fecal output, and total body water were measured for each crewman before, during, and after the flight. From these measurements were derived estimates of protein loss, lean body mass, and total body fat. Body volume was estimated by stereophotogrammetry, and body density was calculated. From all these data, it became apparent that crewmembers had lost fat in addition to losing lean body mass.

Losses of musculoskeletal constituents (Rambaut et al., 1973; Vogel et al., 1974) and a variety of fluid and electrolyte anomalies have been detected by biochemical investigations associated with the Gemini, Apollo, Voskhod, and Soyuz flights. The electrolyte anomalies were particularly pronounced during the Apollo 15 mission and may have been associated with inflight cardiac arrhythmias and postflight changes in exercise performance and cardiovascular responses.

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Certain therapeutic measures including the elevation of dietary potassium intake were partly responsible for the lack of significant metabolic disturbances following the Apollo 16 mission. Similar elevations in dietary potassium were effected for the Apollo 17 crewmembers. The negative nitrogen and potassium balances that were observed during the Apollo 17 mission are indicative of a loss in the body mass.

Nutrient Intake Measurements The quantity of individual nutrients consumed during all Apollo missions is presented in Table I as a composite estimate derived from numerous measurements. The crewmen were provided with prepackaged meals that were normally consumed in a numbered sequence. Foods omitted or incompletely consumed were logged.

During the Apollo 16 and 17 missions only, these deviations from programmed menus were reported to flight controllers in real time. Snack items consumed that were not in the programmed prepackaged menus were also recorded in the flight logs. On all Apollo flights, most food residue and unopened food packages were returned; the residue was weighed only to provide more precise information on inflight food consumption and to verify inflight logging procedures. For the Apollo 16 and 17 missions, nutrient intake information was obtained for 72 hours before flight and for approximately 48 hours after flight.

For the Apollo 17 mission, a five day metabolic balance study was performed approximately two months before the mission by using the flight menus and collecting urine and fecal wastes. Low residue diets were generally used commencing three days before each Apollo flight in order to reduce fecal mass and frequency during the first few days of flight.

Fecal Measurements Fecal samples were returned from all Apollo flights and analyzed for a variety of constituents either by nuclear activation analysis or by wet chemistry techniques.

Metabolic Balance Analysis of blood obtained postflight on early Apollo missions, together with certain endocrinological and electrocardiographic changes in Apollo 15, made it desirable to measure urine volume and bring back samples of urine on Apollo 16. During this mission, it was also possible to continue to return fecal samples and to continue to measure nutrient intake. Sufficient data were therefore available to conduct a partial metabolic study.

For a more detailed metabolic balance study in conjunction with Apollo 17, accurate measurements of fluid intake and output were performed approximately two months before the mission. A five-day food compatibility/metabolic study was performed in which the three Apollo 17 prime and backup crewmembers consumed their flight foods, and metabolic collections were performed. The study was designed to obtain baseline data on

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Special Edition on Space Food and Nutrition the excretory levels of electrolytes and nitrogen in response to the Apollo 17 flight menus. The crewmembers consumed the flight menu foods for five complete days. During the last three days of this test, complete urine and fecal collections were made.

Beginning 64 hours before Apollo 17 lift-off and continuing throughout the mission until 44 hours following recovery, all food and fluid intake was measured. For the Lunar Module Pilot, these collections continued until suit donning; for the Commander and the Command Module Pilot, collection continued until approximately 12 hours before lift-off. All urine was collected, measured, sampled, and returned for analysis. Urine was collected before and after flight in 12-hour pools. Complete stool collections were performed.

All deviations from programmed food intake were logged and reported. All foods were consumed according to preset menus arranged in four-day cycles. Every food item used during the flight was derived from a lot of food that had been analyzed for the constituents to be measured. Inflight water consumption was measured by use of the Skylab beverage dispenser. During the preflight and postflight periods, conventional meals were prepared in duplicate for each astronaut. One duplicate of each meal was analyzed in addition to the residue from the other duplicates to measure intake and output.

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Apollo 17 inflight urine samples were collected by means of a biomedical urine sampling system (BUSS). Each BUSS consisted of a large pooling bag, which could accommodate as much as four liters of urine collected during a day, and a sampling bag, which could accommodate as much as 120 cc. The BUSS was charged with 30 mg of lithium chloride. The lithium chloride concentration in the sample bag was used as a means of determining total urine volume. Each BUSS also contained boric acid to effect stabilization of certain organic constituents.

The inflight urine collection periods began with suit doffing at approximately 00:07:00 ground elapsed time (GET). The collection periods were the times between scheduled effluent dumps and were approximately 24 hours each. During undocked flight of the Command Module, urine was collected only from the Command Module Pilot. During periods in which the crewmen were suited, urine was collected in the urine collection and transfer assembly and subsequently dumped overboard without sampling. However, urine collected in the Commander and Command Module Pilot assemblies during the Command Module extravehicular activities (255:00:00 to 260:00:00 GET) was also returned.

For the Apollo 17 mission, the periods during which urine was not collected are as follows: • Commander and Command Module Pilot-lift-off to suit doffing (00:00:00 to 00:07:00 GET) • Command Module Pilot - Lunar Module activation and lunar descent (108:00:00 to 114:30:00GET) • Command Module Pilot-rendezvous (187:00:00 to 195:00:00 GET) • Commander and Lunar Module Pilot-Lunar Module activation, lunar descent, lunar surface operations and rendezvous (107:00:00 to 208:00:00 GET)

Urine collected from the Commander and the Command Module Pilot from rendezvous to the beginning of the first collection period after rendezvous (approximately 197:00:00 to 208:00:00 GET) was also dumped directly overboard. Each BUSS was marked with the name of the crewmember and the ground elapsed time of collection. Following each collection period, the urine pool was thoroughly mixed before a sample was taken.

The urine samples represented a 24-hour void and were subsequently analyzed for electrolytes, nitrogen, and creatine. All fecal samples collected from each crewmember for the following periods were returned: beginning 64 hours before lift-off, during the mission, and for 44 hours after the flight. Inflight fecal samples were chemically preserved for storage in the spacecraft.

Body Volume Measurements For the Apollo 16 crewmembers, a measurement of body volume was made by stereophotogrammetry, using a special computer program, three times before the flight and three times after the flight (Peterson & Herron, 1971). Body density was calculated from body volume and weight. Density was used to calculate the percentage of fat by means of the following formula.

(495/ body density) - 450 = percent fat Changes in calculated lean body mass and total body fat were converted into caloric equivalents by means of standard values of 37.6 kJ/gm for fat and 16.7 kJ/gm for protein.

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Total body water was measured by means of potassium-42 dilution (Johnson et al, 1974) Lean body mass was calculated as follows LBM = (total body water)/73 body weight - LBM = total body fat The nutritional composition of the typical Apollo inflight diet is given in Table 2 This diet, which is characteristically high in protein and carbohydrate and low in residue and fat, was not necessarily consumed by all astronauts in its entirety.

A typical Apollo diet was analyzed for vitamins, and results were compared with Recommended Daily Dietary Allowances (NAS, NRC, 1968). The data indicate the Apollo diet provided an excess of some vitamins (A, E, C, B12 , B6 , and riboflavin) and marginal amounts of others (nicotinate, pantothenate, thiamine, and folic acid).

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The average intake of protein, fat, and carbohydrate for the Apollo 7 through 17 crewmen is given in Table 3. Fiber intake measurements are given for the Apollo 12, 15, 16, and 17 missions.

The quantity of energy supplied by dehydrated food for the Apollo 15 to 17 missions is given in Table 4.

The average energy intake of each Apollo crewmember is given in Table 5. These energy values were calculated from the composition of the food consumed. Average energy intakes expressed on the basis of body weight are given in Table 6. For comparison, the average energy intake of selected Apollo crewmembers during a mission and on the ground is given in Table 7.

The average intakes of calcium, phosphorus, sodium, and potassium for each Apollo crewman are given in Table 8. Diets for the Apollo 16 and 17 missions were fortified with potassium gluconate. The contribution of supplementary potassium gluconate to the total intake for the Apollo 15, 16, and 17 crewmen is given in Table 9. Inflight fecal samples were analyzed for inorganic constituents using nuclear activation analyses and wet chemistry techniques. The findings were summarized by Brodzinsky and co-workers (1971). Inflight fecal samples were also analyzed for total fat, fatty acids, and conjugated and unconjugated bile acids (Tables 10

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and 11). Data on fat absorption in flight (Apollo 16 and 17) are given in Table 12.

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Apollo 16 Metabolic Study The input and output of various elements, particularly potassium, were carefully examined in the Apollo 16 balance study and a detailed assessment of energy metabolism was made (Johnson et al., 1974). The average daily inflight potassium intake for the Commander was 113.6 milliequivalents. During the mission, potassium was lost by the fecal route at a rate of approximately 6.4 mEq/day, whereas approximately 18.8 mEq/day were lost before the flight and 20.5 mEq/day after the flight. During the mission, absorbed potassium levels were 107.2 mEq, whereas preflight and postflight levels were 94.8 and 77.6 mEq, respectively. During the extravehicular and lunar surface periods, the Commander consumed a maximum of 152.4 mEq daily.

The average daily inflight potassium intake for the Lunar Module Pilot was 114.7 mEq, compared with an average daily preflight intake of 110.5 mEq and an average daily postflight intake of 97.5 mEq. During the preflight, inflight, and postflight phases, the average daily fecal losses were 33.5, 11.1, and 31.0 mEq, respectively. The absorbed daily potassium levels for preflight, inflight, and postflight phases were 77.0,103.6, and 66.5 mEq, respectively. Although these levels were less than the recommended levels of 150 mEq per day, they were adequate for groundbased requirements. A peak level of 148 mEq per day was consumed by the Lunar Module Pilot during lunar surface activities.

For the Command Module Pilot, average daily preflight, inflight, and postflight dietary potassium intakes were 94.3, 79.9, and 82.4 mEq, respectively. Fecal samples for the same periods indicated that potassium levels were 27.6, 6.3, and 26.2 mEq, respectively. Available daily preflight, inflight, and postflight potassium level- were, therefore, 66.7, 73.6, and 56.2 mEq, respectively.

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Input and output data on sodium, chloride, and calcium levels for the Apollo 16 crewmembers are summarized in Table 13. In the analysis of the balance study performed for the Apollo 17 mission, inflight metabolic data were compared with those obtained during the five-day control study conducted approximately two months prior to flight. Rigorous intake and output measurements were accomplished immediately before the flight and after the flight to detect gross changes; however, the duration of these periods was not sufficient to establish reliable metabolic baselines.

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For the Apollo 17 Command Module Pilot, water consumption from all sources was considerably lower during the flight than during the control balance study (Table 14). Inflight urine outputs were also proportionately lower for all three crewmembers than those established during the control study. When the conditions of tem-

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perature and humidity that prevailed during the flight are considered, it is estimated that in insensible water loss of 900 to 1200 cc/day occurred. This loss was equivalent to the preflight loss. Total body water measurements also did not support the tendency toward negative water balance (Section III, Chapter 2, Clinical Biochemistry).

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Based on numbers adjusted for equilibrium during the control phase and insensible losses, all three crewmembers were in negative calcium balance during the inflight period (Table 14). The negative balance was particularly pronounced for the Command Module Pilot. For two of the crewmembers, the negative calcium balance persisted after the flight. All crewmembers had exhibited a pronounced positive balance during the five-day control period study possibly because the flight diets contained a higher calcium level than did the customary daily intake of these crewmembers (Table 14). As can be expected from the negative calcium balance, phosphorus balance was generally negative during the flight.

All three crewmembers demonstrated a sustained negative nitrogen balance during the flight (Table 14). Occasional negative nitrogen balances of small magnitude were also detected before the flight. Diminished nitrogen retention is supportive evidence for the general musculoskeletal deterioration noted on previous flights and during groundbased hypokinetic simulations of flight-type conditions.

Sodium intakes during the flight were all less than 250 mEq/day. Intake and output measurements for sodium indicated positive balances for this element during the flight for all three crewmembers (Table 14). However, sodium output in sweat was not measured and this route of excretion could have accounted for all the apparent "positive balance" and even have resulted in a slight negative balance for sodium.

Sodium balance was positive during the flight for all three crewmembers (Table 15) if insensible losses are neglected.

In compliance with previous recommendations based on observed inflight potassium deficits, inflight potassium intakes were maintained above normal ground-based intakes (73 to 97 mEq/day) (Table 15). Potassium retention during the flight was significantly less than that established during the control study. A summary of overall metabolic balance for Apollo 17 crewmembers with all numbers adjusted to reflect equilibrium during the control period is presented in Table 15.

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Special Edition on Space Food and Nutrition Anthropometric Measurements A summary of body weight changes based on the mean of the weights on 30,15, and 5 days before lift-off compared to those obtained immediately after recovery is presented in Table 16. The weight changes during the 24-hour period immediately following recovery are also given. Body volume was measured before and after the Apollo 16 mission by stereophotogrammetry. An analysis of densitometric data is presented in Table 17.

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Skylab

The Skylab food system (Fig.1-1) was developed to provide a balanced and palatable diet which also met the necessary requirements for calories, electrolytes, and other constituents for the metabolic balance experiment (ch. 18). Seventy foods were available from which the crew could select their in-flight diets. Food types included frozen, thermostablized, and freeze-dried foods. Menus were planned for 6-day turnaround cycles. Each crewman was required to consume his individually planned diet for 21 days preflight, throughout the flight, and for 18 days postflight. Approximately one ton of food was stowed in the Orbital Workshop at launch to provide approximately 400 man-days of food. The ambient foods were packaged in 6-day supply increments and stowed; these were moved by the crewmen to the galley area for direct stowage, preparation, and eating. The galley area contained a freezer, a food chiller, and a pedestal which provided hot and cold water outlets, attachment points for three food trays, and body restraints which afforded each crewman the opportunity to sit down to eat.

Each food tray contained seven recessed openings to hold cans or other containers, three of which had heaters for warming the food. The food cans were constructed with membranes or other designed devices which restrained the food within the container when in zero-gravity and allowed the crew to eat with conventional tableware. Drinks in a powdered form were packaged into individual bellows-like containers constructed with a drinking valve. Water, when needed, was added from the hot or cold water outlets located on the pedestal.

The cremnen drank from the container by collapsing the bellows. The variety of foods provided and the general design of the food system were acceptable to the Skylab crewmen. At the suggestion of the returned Skylab 2 crew, more and varied spices were included in the later missions to improve the taste of the food.

The extension of the Skylab 4 mission for an additional 28 days required 250 pounds of additional Skylab food to be launched in the Command Module. This extra weight and the resulting stowage volume were excessive, therefore, a highdensity, high-caloric type food bar was stowed in the Command Module to provide the caloric requirements for the mission extension. The crewmen’s in-flight menus were modified to include

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approximately 800-1000 calories of the food bars every third day. For Skylab 4, in addition to the 50 pounds of high-caloric type food bars, approximately 100 pounds of other Skylab-type food and drinks were launched in the Command Module.

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The Skylab Orbital Workshop was launched on May 20, 1973. The loss of the micrometeoroid shield exposed the skin of the workshop causing an increase in internal workshop temperatures and the partial deployment of the solar panels reduced the electrical power supply available for experiments and systems operation. The Orbital Workshop failure also caused a 10-day delay in the launch of Skylab 2 which impacted the medical program. This necessitated that the health stabilization, controlled feeding, and biosample collection be extended. The exposure of the skin of the workshop caused an elevation in both wall and spacecraft air temperature. The plot shown in figure 1-19 illustrates the temperatures in the food stowage area exceeded 327.59 K (130 ◦ F). In the 10-day period before the launch of Skylab 2, a thermal screen was developed which the crew could deploy to shield and insulate the orbital workshop.

The Skylab food system was large and complex corrared to systems used on previous space-flight missions.

Approximately 17000 individual food packages and support items weighing more than 1133 kg (2500 lb) were sent into space on board the orbital workshop (OWS) during the Skylab 1 Saturn V launch. In addition, some 2200 items having a total weight of approximately 159 kg(350 lb) were launched on the three manned Skylab missions. The food system provided the Skylab crewmen with nourishing food and beverages for 171 days and provided the accessory items needed for food preparation and consumption [NASA-TM-X-58139].

According to Dr. Gibson , who was a scientist astronaut and Scientist Pilot on Skylab 4,"We experienced hunger on two different occasions because of the types of diet we were on. In order to extend our mission from 56 to 84 days, we supplemented our meals with high-density food bars every third day. During those days, we had the same amount of minerals and number of calories as we had on other days but the amount of food bulk was greatly reduced, so we ended up fairly hungry on every third day. Second, we noticed, especially early in the mission, that we tended to get hungry in 3, 4, maybe 5 hours after a meal as opposed to the normal 6 to 7 hours as one does on Earth. We don’t know whether that was an effect of zero-gravity or whether that effect was from charging real hard continuously the first couple of weeks.".

Food Items Rehydratable , thermostabilized , frozen , and natural-state foods were established as acceptable food types.

Beverages requested by crewmen that could be developed for the Skylab food system were coffee ; tea with lemon and sugar l cocoa ; instant breakfast drink (chocolate flavored) ; lemonade ; and orange , grape , strawberry , apple , grape-fruit , and cherry flavored drinks . Foods that could be processed in wafer form included bacon , sliced dried beef , dried apricots , cheddar cheese crackers , biscuits (cracker type), dry roasted peanus , butter cookies , vanilla wafers , mints , and hard candy . Food that could be frozen were filet mignon , prime rib of beef , pork loin with dressing and gravy , lobster Newburg , pre-buttered rolls , coffeecake , and vanilla ice cream . Thermostablized foods include peanut butter , tuna sandwich spread , chili with meat , hotdogs with tomato sauce , turkey and gravy , white bread , stewed tomatoes , applesauce , peaches , pears , pineapple , butterscotech and lemon puddings , fruit jam , and catsup. Rehydratable foods used in the Skylab Program were crisp rice cereal; sugar-coated cornflakes; scrambled eggs; sausage patties; potato, turkey and rice, and pea soups; salmon salad; shrimp cocktail; beef hash; chicken and gravy; chicken and rice; pork and scalloped potatoes; veal and barbecue sauce; spaghetti and meat sauce; mashed potatoes; mashed sweet potatoes; German potato salad; macaroni and cheese; green beans; asparagus; cream style corn; creamed peas; strawberries; and peach ambrosia with pecans.

Skylab food system requirements, package designs, and launch configurations is available in NASA’s report: SKYLAB FOOD SYSTEM (NASA-TM-X-58139),October 1974.

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Apollo-Soyuz Test Project American astronauts on the Apollo-Soyuz TestProject were provided meals similar to those consumed on Apollo and Skylab flights. As a result of Apollo and Skylab experimentation, data now exist showing relationships between ground-based and in-flight energy requirements. It is recognized that the best estimates of ground-based energy requirements are made on the basis of lean body mass (LBM); i.e., muscle mass. Accurate determination of LBM may be obtained from a total body count of gamma radiation emitted by the body’s natural burden of potassium-40 (40 K).

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The whole-body counter method of determining LBM is based on the assumption that the potassium content of LBM is nearly constant and that body fat is essentially free of potassium. In this context, the body is considered to be composed of two compartments, the fat compartment and the fat-free LBM compartment. Since 0.0119 percent of all naturally occurring K is the radioactive isotope 40 K, a measure of this isotope is an indirect measure of the total K. The whole-body counter measures 40 K. Total K is calculated and LBM is determined by use of appropriate constants.

It was anticipated that the average daily in-flight energy intake in the Apollo-Soyuz Test Project (ASTP) would fall short of Skylab intakes and would more closely approximate the averages observed during Apollo flights (i.e., approximately 29 kcal/kg/day) because of the brevity of the mission and the failure to achieve metabolic stabilization. For this reason, certain nutrients, in particular sodium (Na) and K, were concentrated in those foods for which the crew displayed the highest preference and which were deemed most likely to be consumed.

As much as possible of the minimum nutrient requirements were included in a basic diet of approximately 18002000 kilocalories (kcal). Despite these measures, an awareness of the true energy demands should be kept in mind for understanding the degree of metabolic deficiency that was incurred.

Lean body mass was determined by measurement of total body 40K in the low-background radiation counting facility at the NASA Lyndon B. Johnson Space Center after appropriate calibration with similar counting facilities at U.S. Air Force School of Aviation Medicine and at Battelle N.W. Laboratories. Additional calibration in the technique was accomplished using 42 K. Potassium-42 has a 12.36-hour half-life and emits beta rays having a maximum energy of 3.52 MeV and a gamma ray having an energy of 1.525 MeV. The gamma ray energy is close enough to that of 40 K (1.46 Me V) to enable direct comparison of the photopeak areas for calibration purposes. For calibration, the same amount of 42 K ingested by the volunteer is placed in a 500-ml bottle, and the bottle is filled with water. A weighed quantity of potassium nitrate (KN03 ) is placed in the same size bottle and dissolved in water, and the solution is diluted to the same volume as the 42K solution.

It has been demonstrated that the calibration factors for all whole-body counter techniques depend on the weight of the subject. The single mathematical expression log10 (g) = A + B (Wkg ) will fit the curve of calibration factors obtained for subjects whose weights range from 43.88 kg to 157 kg. The actual calibration factor found for a particular subject may differ by as much as 10 percent from the value predicted by the regression line. The exchangeable K content of the body, as measured by the isotope-dilution technique, is very close to 92 percent of the total body K for all active subjects, including those who have starved for several weeks and lost considerable weight. The results of LBM determinations performed on the prime crewmembers are as follows.

The measurements were made on December 2 and 3, 1974. For comparison, the total exchangeable K estimated by the 42 K exchange technique for the Skylab crewmembers is given in Table 6-I.Lean body mass measurements, derived from data on total exchangeable K, have been used as a basis for expressing caloric expenditure in Sky-

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Special Edition on Space Food and Nutrition lab crewmembers. The results of these computations arc shown in Table 6-II. It can be seen, therefore, that the Skylab crewmembers had a caloric intake at a level of 45.68 Âą 4.50 kcal/kg/day. Based on in-flight changes in total body weight, muscle mass, and body volume, it appears that an average daily energy intake of 49.0 Âą 3.5 kcal/kg/day would have resulted in negligible body weight loss in Sky lab crewmembers.

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On the basis of Skylab energy consumption data and ASTP total body K measurements, the energy required to maintain LBM during the ASTP mission was predicted. The results of this prediction are shown in the following table together with estimated energy based on subjective evaluation by the individual of his menus.

(Changes in crew body weights are also included.)

In-Flight Food Flight menus were designed to meet comparable individual energy requirements under normal gravity conditions, specified nutrient levels, and crew-selected preferred foods. Energy requirements calculated for each crewman were 2815, 2760, and 2554 kcal/day for the ACDR, the CMP, and the DMP, respectively. Based on crew menu acceptance, evaluations, and compatibility tests, an average daily caloric intake of 2820 kcal was provided for the ACDR and the CMP, and 3165 kcal was provided for the DMP. Estimates of in-flight food consumption based on daily reports indicate that averages of 2900, 3000, and 2867 kcal/day were consumed by the ACDR, the CMP, and the DMP, respectively. To meet the specified daily nutrient levels, some of the beverages were fortified with either calcium lactate or potassium gluconate. Calcium (Ca) fortified beverages were limited to two per man per day, whereas only one K-fortified beverage was required for each 4-day menu cycle.

The crew selected a 4-day menu cycle as used previously on Apollo missions rather than the 6-day cycle used during Skylab missions. The average daily nutrient intakes for the proposed and estimated in-flight food consumption for each crewman are shown in Table 6-III. In addition to the scheduled meals, a pantry containing

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Special Edition on Space Food and Nutrition beverages and snack foods was supplied. These foods could be used to substitute or supplement the normal meal items. New food for this mission included dehydrated compressed pea bars and spinach bars; irradiated breakfast rolls; thermostabilized/irradiated turkey, corned beef, and charcoal broiled steak; thermostabilized cranberry sauce; tuna and salmon in cans which required a can opener; commercial cookies and graham crackers; dehydrated beef patty, pears, and potato patty; intermediate moisture almonds and cheese slices; and dried beef jerky.

In general, the crew was satisfied with the quality and quantity of flight food provided. No gastrointestinal problems were encountered during the mission. Appetites during flight were reported to be the same as during the preflight period. The CMP reported changes in the taste of foods during flight and indicated that salty foods tasted best to him. As on previous Apollo missions, the crew reported gas in the hot water supply which interfered with complete rehydration of the food. Throughout the mission, high-priority activities and work schedules frequently precluded adequate time for meal preparation and food consumption.

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Postflight comments from the crew indicated that the potable water was of good quality. No out-of-specification conditions were noted in the microbiological and chemical analyses conducted. Preflight chlorination was accomplished 19 hours before launch. The level of chlorine measured 2 hours later was sufficient for microbial control. In-flight chlorinations were accomplished approximately on schedule, and no in-flight problems were experienced. As in previous flights, some gas was present, particularly in the hot water.

Postflight analyses indicated a lack of residual chlorine in the potable water. This deficiency remains unexplained since the records indicate that the last in-flight chlorination was accomplished 17 hours before landing.

Chemical analyses of postflight samples showed all levels within specification limits. Microbiological results were positive for Flavobacterium species at levels of 105 microorganisms/ml.

Space Shuttle 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

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Special Edition on Space Food and Nutrition 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.

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.

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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 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.

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.

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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.

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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, foillaminated 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

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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 165â—Ś 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 170â—Ś 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.

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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.

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Meal preparation and consumption will involve a series of steps. A general meal scenario is as follows: • Collect meal tray and utensils • Display preselected meal on the computer • Locate food using location display function • Prepare food items for heating • Place items to be heated in oven • Enter cook control codes and press "start" • Rehydrate beverages • Place beverages on meal tray • Retrieve refrigerated foods • Place refrigerated food in meal tray • Retrieve items from oven

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• Place heated foods in meal tray • Eat • Place used containers in trash compactor • Clean and stow meal tray and utensils • Safe Haven 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 85◦ 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.

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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.

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Hypohydration in Shuttle Crew Maintenance of adequate hydration status during space flight is important to minimize the incidence of kidney stones and to reduce postflight orthostatic hypotension. The purpose of this study was to compare self reported water intake from food and fluids before and during space flight with the deuterium oxide method for measuring water intake.

Fourteen astronauts (age 44+5 yrs, weight 76.3+7.6 kg, height 177.2+7.7 cm) monitored their food and fluid intake for 5 days after consuming a dose of deuterium oxide 60 days before, and 2 days after the launch of Shuttle flights lasting from 8 to 14 days. Preflight water intakes from diet diary (DD) and deuterium elimination (DE) were 2.64+0.39 and 3.22+0.56 I/day respectively. Inflight water intakes from DD and DE were 2.17+0.52 and 2.18±0.52 I/day respectively.

Water intake during space flight was significantly lower than before flight, regardless of the method used (p<0.005), and showed that several astronauts did not consume the minimum recommended water intake of 2.0 I/day. Hypohydration may have contributed to the 1.4+ 1.3 kg weight loss during flight [Everett Gibson et.al.].

Iodine in spacecraft water systems Iodine was used as a bactericidal agent in spacecraft water systems. Some individuals who have consumed iodine-purified water have been found to have changes in their thyroid hormone status and a higher incidence of thyroid disease. One finding was an increase in blood thyroid stimulating hormone (TSH) concentration immediately after spaceflight. Studies of Skylab crewmembers documented increased circulating TSH and thyroxine (T4) concentrations, with slight reductions in triiodothyronine (T3). The earlier Apollo flights showed similar trends in data from postflight sample collections.

Beginning in 1997, hardware was flown on the Space Shuttle that allowed the removal of iodine from the water before it was consumed. With brief exceptions (short periods just after launch, or when landing was delayed and the system was not redeployed), the implementation of the iodine removal system during the entire duration of the mission greatly reduced the iodine intake of Space Shuttle crews. When this was reported in 2000, data were available from one Shuttle flight on which iodine was removed from the water system and no change in circulating TSH was documented.

Data are reported on 224 male and 49 female crewmembers on Space Shuttle missions for whom preflight and postflight data were available. The mean ± SD bodyweight,height, and age for subjects before installation of the iodine removal system were 75 ± 11 kg, 176 ± 16 cm, and 41 ± 5 yr, respectively. The mean bodyweight, height, and age of subjects who flew after installation of the system were 75 ± 14 kg, 177 ± 10 cm, and 43 ±

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Special Edition on Space Food and Nutrition 5 yr, respectively.

In 1997, hardware was developed which, through the use of an ion-exchange resin, significantly reduced the content of iodine in the drinking water. Before implementation of this iodine removal system, Space Shuttle water contained about 4 mg.L−1 iodine. After implementation of the system, the approximate iodine concentration in the water was 0.25 mg.L−1 . Historically, spacecraft water systems have provided even greater iodine concentrations, which on Skylab missions were 11.2 mg iodine.L−1 Results of all data analyses are shown in Table I . Total T4 and free T4 were elevated in male subjects after flight and T3 was lower after flight, regardless of iodine status( Table I ). After the iodine removal system was in place, T4 was higher, even before flight, in the men. Conversely, T3 was lower in male subjects who flew during this period.

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In the period before iodine was removed from the Space Shuttle water system, TSH was elevated after flight in male ( N = 136, F = 19.3, P < 0.001) subjects and tended to be elevated in female ( N = 29, F = 3.6, P = 0.06) subjects, as determined by separate repeated-measures two-way ANOVA with time and iodine removal system as grouping factors. After implementation of the iodine removal system, the preflight and postflight means were not significantly different ( Table I ).

The increase in serum TSH on landing day after early Shuttle flights was related to the consumption of iodinated water during spacefl ight, because the same increase was not observed after implementation of the iodine removal system. The thyroid responses to iodine and spaceflight were generally similar in men and women. That is, after flights with iodinated water, both men and women tended to have higher circulating TSH concentrations, whereas after implementation of the iodine removal system, neither men nor women had a change in circulating TSH levels.

However, the effect did not always reach the same level of statistical significance in women as in men. The reason for this may have been the smaller N for women or the confounding effects of the menstrual cycle and related endocrine shifts. The prefl ight differences between genders were expected, given the differences in normal ranges. The iodine removal system does effectively remove iodine from Space Shuttle water, so that its concentration in drinking water is about 0.25 mg.L−1 .

Spacecraft Water Exposure Guidelines for Selected Waterborne Contaminants Space Toxicology Group has compiled all official spacecraft water exposure guidelines into a single document, released as JSC 63414 (Last revised - November 2008).

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Microgravity Experiment Research Locker Incubator (MERLIN)

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Special Edition on Space Food and Nutrition International Space Station (ISS) The fuel cells, which provide electrical power for the Space Shuttle, produce water as a by product, which isthen used for food preparation and drinking. However, onthe ISS, the electrical power will be produced by solar arrays. This power system does not produce water. Water will be recycled from a variety of sources, but that will not be enough for use in the food system.

Therefore, most of the food planned for the ISS will be frozen, refrigerated, or thermostabilized (heat processed, canned, andstored at room temperature) and will not require the addition of water before consumption.

Although many of thebeverages will be in the dehydrated form, concentrated fruit juices will be added to the beverages offered and will be stored in the onboard refrigerator.

Similar to the Space Shuttle, the ISS beverage package ismade from a foil and plastic laminate to provide for alonger product shelf life. An adapter located on the package will connect with the galley, or kitchen area, so thatwater may be dispensed into the package. This water will mix with the drink powder already in the package.

The adapter used to add water also holds the drinking straw for the astronauts. The food package is made from a microwaveable material. The top of the package is cut off with a pair of scissors, and the contents are eaten with a fork or spoon.

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The ISS crew members eat international foods, as the crew members are from many different countries. Right now, half of the space food items on board the ISS are American foods and half are Russian foods. Japanese, European, and Canadian food items are available also. The astronauts and cosmonauts have more than 300 food items to choose from.

Crumbs are not allowed, as they can float around the cabin and could float into someone’s eye (or nose) or into instruments, or clog air vents. Also, the food must not float away while an astronaut is trying to eat it, so packages and foods are designed to make this less of a problem in space. Another challenge for food system developers is trash. Wrappers and empty packages must be compressible to minimize the amount of trash on the spacecraft. The garbage truck doesn’t stop by the International Space Station, and there are very few opportunities to get trash off the vehicle.

In fact, trash is disposed of only when space vehicles such as the Space Shuttle, the Soyuz capsules, and other cargo vehicles visit the ISS and then depart. This happens about once a month, and even these vehicles have limited amounts of space available, so trash must be as compact as possible.

Food storage is a big issue for space travelers. Until recently, the ISS had no freezers or refrigerators for food, so the food has had to be "shelf stable" and not likely to spoil for at least 6 to 12 months. Food for a Mars mission will need to be stable for up to 5 years.

Recently, a small refrigerator-freezer known as MERLIN (Microgravity Experiment Research Locker/Incubator) and General Laboratory Active Cryogenic ISS Experiment Refrigerator (GLACIER) was flown to the ISS. It can be used to store a small amount of fresh food and drinks. This is especially helpful for drinks, which up to now have been pretty much room temperature.

Before each mission, astronauts select their favorite foods from the available flight foods, and they taste the foods they have selected to make sure that they really do like them. The most popular space food is shrimp cocktail, in part because of the spicy sauce! Even for an International Space Station flight, the foods have to be able to sit on the shelf (a shelf in the pantry, not in the refrigerator or freezer) and still be tasty for at least 9 months.

Salt and Pepper Dispensers If astronauts sprinkled salt and pepper on their food in space, the salt and pepper would simply float away. The seasoning could clog air vents, contaminate equipment, or get stuck in an astronaut’s eyes, mouth or nose. To prevent floating particles, crews use salt and pepper in a liquid form.

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Image Credit :NASA.

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Taste in Space From the early 1960s, astronauts found that their taste buds did not seem to be as effective when they were in space. Why does this happen in space? This is because fluids in the body get affected by the reduced gravity conditions (also called fluid shift). On Earth, gravity acts on the fluid in our bodies and pulls it into our legs. In space, this fluid is distributed equally in the body. This change can be seen in the first few days of arriving in space when astronauts have a puffy face as fluid blocks the nasal passages.

The puffy face feels like a heavy cold and this can cause taste to be affected in the short term by reducing their ability to smell.

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- On Ground: An astronaut will be blindfolded and asked to pinch his nose when tasting a number of different food items to identify the flavours. He will then be given the correct answer and asked to scale the intensity of the flavours from 0-10 where 0= not perceived and 10= maximum possible intensity. Between each sample he can remove his hand from his nose to answer and rinse his mouth out with water.

- On Board: The same astronaut will perform the same tasting session as previously on ground. With a blindfold on and pinching his nose he will be asked to attempt to identify the flavours of the same food items as the ground experiment. He will be given the correct answer and asked again to scale the intensity from 0-10.

Salt intake may lead to bone loss in orbit

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SOLO - SOdium LOading in Microgravity (Sodium retention in microgravity) Astronauts on a long-term space mission will participate in two planned sessions (1. In-flight session 2.

Baseline Data collection either pre-or postflight).

Each session includes 2 study phases, each study phase consist of 5 days and the morning of day 6. During 2x5 days they follow a diet of constant low and normal sodium intake, controlled (high) fluid consumption and isocaloric nutrition. The other nutrients in all study phases should meet the recommended ISS intake values, with nutrient intake being monitored. During the last two days of each study phases (day 5 and morning of day 6) samples from 24 hour urine collection are essential to analyze sodium, calcium and bone resorption marker. During one of the study phases body weights need to be measured in the morning of the 4th and 6th day of each study phase to estimate skin fluid loss. Metabolic fluid and sodium balances are calculated on day 5. In the morning of day 5 of each study phase blood will be drawn for the analysis of fluid and electrolyte regulating hormones, as well as bone turnover markers. Blood gas analyses with the PCBA device will be performed in the morning of day 5 of each study phase. The same measurements will be performed in each study phase in space and on ground.

Nine crew members, during their long-duration flights in 2010 and 2011, followed low- and highsalt diets. The expected results may show that additional negative effects can be avoided either by reducing sodium intake or by using a simple alkalizing agent like bicarbonate to counter the acid imbalance.

Preliminary results show that high sodium chloride intake leads to higher calcium excretion, which may lead to bone loss in the long run. As expected bone formation is not different between the two salt regimes. Markers of bone resorption show high individual differences and need to be further investigated in combination with sodium retention patterns.

Omega-3 fatty acids is associated with protective effect on bone In human studies, authors evaluated whether NF-ÎşB activation was altered after short-duration spaceflight and determined the relationship between intake of omega-3 fatty acids and markers of bone resorption during bed rest and the relationship between fish intake and bone mineral density after long-duration spaceflight.

NF-ÎşB was elevated in crew members after short-duration spaceflight, and higher consumption of fish (a rich source of omega-3 fatty acids) was associated with reduced loss of bone mineral density after flight (p<.05). Also supporting the cell study findings, a higher intake of omega-3 fatty acids was associated with less N-telopeptide excretion during bed rest (Pearson r=-0.62, p<.05).

Together these data provide mechanistic cellular and preliminary human evidence of the potential for EPA to counteract bone loss associated with spaceflight [Capacity of omega-3 fatty acids or eicosapentaenoic acid to counteract weightlessness-induced bone loss by inhibiting NF-kappaB activation: from cells to bed rest to astronauts].

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Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism during Spaceflight and Recovery (Pro K) Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism during Spaceflight and Recovery (Pro K) investigation is NASAâ&#x20AC;&#x2122;s first evaluation of a dietary countermeasure to lessen bone loss of astronauts.

Pro K proposes that a flight diet with a decreased ratio of animal protein to potassium will lead to decreased loss of bone mineral. Pro K has impacts on the definition of nutritional requirements and development of food systems for future exploration missions, and could yield a method of counteracting bone loss that would have virtually no risk of side effects.

NASA Image: ISS030E033506 - View of PRO-K Food Container Contents.

Though the mechanism of bone mineral loss associated with space flight is not completely understood, it likely involves multiple factors. The Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism During Spaceflight and Recovery (Pro K) experiment studies the role of dietary intake patterns as one of these factors associated with bone mineral loss in space flight. The protocol is designed to evaluate the influence of acid and base precursors in the diet. The concept that diet can alter acid-base balance in the body is not new, and it is also well documented that a decrease in blood pH caused by acidic products of metabolism (metabolic acidosis) negatively affects bone; particularly in ground-based analogs of space flight.

This protocol tests the hypothesis that the ratio of acid precursors to base precursors (specifically animal protein and potassium, respectively) in the diet predicts changes in the loss of bone mineral during space flight and recovery. In two preflight and four inflight sessions, the ratio of animal protein to potassium in the diet is controlled during 4-day periods. In one inflight and 3 postflight sessions, the crewmemberâ&#x20AC;&#x2122;s self-selected diet is monitored over 4 days. The sessions in which diet is controlled or monitored allow researchers to evaluate the effects of diet on bone loss and on bone recovery following flight.

If successful, the study could lead to improvements in bone health during space flight, including development of a countermeasure that is virtually risk free and requires no additional stowage, crew time, power, or other constrained resources.

Capillary Effects of Drinking in the Microgravity Environment (Capillary Beverage) The results of recent capillary experiments performed aboard the International Space Station (ISS) are employed to design cups for drinking liquids in space in a manner similar to on Earth, where the effects of surface

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The objectives of the tests are to demonstrate cup geometries that exploit capillary forces enabling crew members to drink a variety of aqueous drinks in space, from simple fluids like water and juice, to more complex fluids such as cocoa, coffee, espresso and fruit smoothies. High-resolution video imagery of the wicking is expected to be of broad public interest with educational opportunities to continue discussions of living and working in space. The cups are also expected to be appealing to the crew members in addition to providing new data of applied scientific value with validation and verification of state of the art capillary design methodologies.

The specific goals of the Capillary Effects of Drinking in the Microgravity Environment (Capillary Beverage) experiment are to primarily (1) image the drinking phenomena for quantitative assessment of the process and general performance of the cup and to (2) demonstrate earth-like drinking from a cup that exploits capillary forces rather than gravitational forces during the casual consumption of a variety of onboard drinks.

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Astronaut demos drinking coffee in space

Dr. Pettit demonstrated his take on a zero-gravity coffee cup Space Applications Crew members in space have to drink and eat using specially designed equipment because gravity affects the way fluids behave. Capillary Beverage studies cups that use the combined effects of surface tension, wetting, and cup shape to move liquids around, potentially making it easier to take a drink and reducing the weight and volume of drinking bags that must be sent to space. The investigation also demonstrates how research aboard the ISS can be used to design new systems for the ISS, from new drinking cups to passive fluid control systems.

Earth Applications Space Cups are too small to be of practical use on Earth, but their design is relevant to several fields that use micro-fluidics, including medical research and drug delivery. The fluid flow processes used by the Space Cups relate to lab-on-a-chip technologies, which use fluid dynamics to transport and analyze very small amounts of liquids. In addition, members of the public can view high-resolution video of crew members drinking water, coffee, espresso and hot chocolate from the Space Cups, which inspire educational discussions about living and working in space.

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