Food in Space
More than 20 years ago, astronaut John
Glenn became the first American to orbit the Earth. His mission lasted
nearly five hours and before splashing down in the Atlantic Ocean, Glenn
and his Mercury spacecraft completed three trips around the world.
Freeze-Drying & Freeze-Dried Food
Among the many tasks Glenn had to perform while in orbit were the first American space experiments in eating food in the weightless conditions of Earth orbit. Glenn's flight was too short to make eating a necessity but future flights were expected to last many days and even weeks. His experience would help design space food systems.
Eating in space for John Glenn turned out to be an easy though not too tasty experience. Before the flight, some experts were worried that, in weightlessness food would be hard to swallow and as a result, collect in the throat. Glenn found that eating in space was relatively easy and once the food reached the mouth, there was no problem in swallowing. Other Mercury astronauts following John Glenn were forced to endure bite-sized cubes, freeze dried foods, and semi-liquids in aluminum toothpaste-type tubes. They found the food unappetizing, had trouble rehydrating the freeze-dried foods, and disliked squeezing the tubes. Futhermore, crumbs from the bite-sized cubes had to be captured to prevent them from fouling instruments.
In the Gemini missions eating in space became more normal. The aluminum tubes of the Mercury program were replaced because the container weighed more than the food inside. Bite-sized food chucks were coated with an edible gelatin to reduce crumbling. Rehydratables were encased in an improved plastic container. To rehydrate food, water was injected into the pack through the nozzle of a water gun. After kneading the contents the food became a puree and was squeezed through a tube into the astronaut's mouth.
Not only were the food containers for the Gemini astronauts improved but the menu selections were enlarged enough to provide four days of meals before repeating any menus. A typical meal would include shrimp cocktail, chicken and vegetables, toast squares, butterscotch pudding, and apple juice. Before each flight, meal combinations were chosen by the astronauts themselves but the menus chosen were required to provide 2,800 calories per day. To provide proper balance, 16 to 17 percent of the menu consisted of protein, 30 to 32 percent fat, and 50 to 54 percent carbohydrate.
In the Apollo program, food packages were similar to those used on Gemini missions but the variety of food was considerably greater. Apollo astronauts had the added luxury of heated water for hot drinks and foods at a temperature of 67 degrees C (154 degrees F) and chilled water at 7 degrees C (45 degrees F). Water temperatures from the dispenser of the Gemini spacecraft hovered at the 21 degrees C (70 degrees F) ambient spacecraft temperature. With hot water available, food was easier to rehydrate and much improved in taste.
Further advances in Apollo food systems came with the introduction of the "spoon-bowl" package for rehydratable foods and retort pouches for thermostabilized foods. Following rehydration of the contents in the spoon-bowl, a pressure type, plastic zipper was opened and the food removed with a spoon. The moisture content in the food enabled it to cling to the spoon, making eating a more normal experience.
In 1973 and 1974, the Skylab spacecraft was occupied by three teams of astronauts. Space food systems there were much improved over systems used in Apollo, Gemini, and Mercury. Unlike previous space vehicles for astronauts, Skylab featured a large interior volume and space was available for a dining room table. The table was a pedestal where food trays were mounted. When dining, the three-astronaut teams would "sit down" in the air by means of foot and thigh restraints and eat in an almost normal fashion. The food trays not only held the food in place but also served as warming devices. Underneath three of eight cavities in the trays were warmers that could raise temperatures of foods needing heating to 66 degrees C (151 degrees F).
Food containers for the Skylab astronauts consisted of aluminum cans with full panel pull-out lids. Cans containing thermostabilized food had a build-in membrane to prevent spillage when removing the lid in can and had a water valve for rehydration. Canned, ready-to-eat foods were held in the can with a slit plastic cover. Instead of plastic drinking bags, Skylab drinking containers were collapsible bottles that expanded accordian style when filled with hot or cold water.
Eating on Skylab was a fairly normal operation. Knife, fork, and spoon were held magnetically to the food tray until needed. A pair of scissors was added to the usual utensils for cutting open the plastic membranes. With careful use of the utensils, food would remain in the cans until needed. On occasion however, a too rapid motion with a fork or spoon would cause a piece of meat or other food to drift away from the tray.
Because of its relatively large storage space, Skylab was able to feature an extensive menu of 72 different food items. Unique to Skylab was a freezer for foods such as filet mignon and vanilla ice cream and a refrigerator for chilling fruits and beverages. Enough food was carried to provide each astronaut with 1.9 kilograms (4.2 pounds) of food per day. This weight also included the weight of the primary food packaging.
In 1975, the last Apollo flights took place with the Apollo-Soyuz docking mission. The Apollo spacecraft did not have the freezer that Skylab featured but many of the food advances from Skylab and the earlier Apollo missions were incorporated. Because of the short duration of the flight (nine days), many short shelf-life items were added to the foods carried. Fresh breads and cheese were included as a part of 80 different varieties of food dined upon by the Apollo while others were placed in spoon-bowl packages or plastic drinking bags. To make eating easier, a food tray was carried on the mission. The tray did not warm the food as the Skylab tray did, but it held the food in place with springs and Velcro fasteners. The tray was secured to the crewmember's leg during meal time.
Information Provided by NASA