Long-Term Space Nutrition

In pseudo-scientific movies and fantasy stories about astronauts, the question of food is usually presented as the simplest of all problems.

In pseudo-scientific movies and fantasy stories about astronauts, the question of food is usually presented as the simplest of all problems: the astronaut has an unlimited supply of highly nutritious food in the form of small pills and eats very quickly, washing down such pills with a sip of water. Unfortunately, astronauts do not currently have such food, and with modern cooking technology, the pills they take in science fiction movies would be the size of tennis balls.

From the very beginning of the development of manned spaceflight programs, both American and Soviet scientists paid little attention to the development of this form of highly concentrated nutrition. Instead, new methods were developed for processing and packaging conventional foods so that they were light, nutritious, low in coarse, indigestible substances, and as close as possible in structure, taste and color to natural foods. The entire complexity of this task can be imagined only if one knows the conditions under which mechanical and thermal influences space food should be stored.

The USA and the USSR have developed a space food that meets these severe requirements and has the following composition on average: 17% protein, 32% fat and 51% carbohydrates. American astronauts receive in their diet 2800-3200 kcal per person per day. Soviet cosmonauts receive approximately the same amount of food, but for flights in which an exit from a spacecraft is planned, the daily calorie intake is increased to 3,600 kcal.

Requirements for space power

The conditions of vital activity on board a space object (the state of weightlessness, emotional and mental stress, the limited volume of the ship's cabin) require a special approach to the diets of astronauts.

Mandatory requirements of space nutrition are:

Balanced diet according to the main irreplaceable factors in accordance with the theory of rational nutrition;

high energy value with minimal weight and volume;

resistance to various kinds of climatic and mechanical influences;

preservation of good quality for a long time.

Features of catering should include:

increased requirements for the strength of containers and packaging of products due to overloads;

Impossibility of using traditional dishes (plates, cups, glasses) due to weightlessness;

limiting the content of the liquid phase in products (however, products should not only be dry, briquetted or in the form of tablets; in terms of properties, they should be as close as possible to products consumed on earth);

· increased requirements for products that crumble and are hazardous to the health of astronauts (for example, crumbs getting into the throat in weightlessness, cockpit pollution, etc.);

The duration of the shelf life, the usefulness of the products in terms of composition, the limitation in weight and volume, the absence of inedible hours.

The listed dietary factors are the main ones in the selection of products for astronauts.

Starting from the first flights of cosmonauts, their diet has been improved, the assortment has expanded. There is the possibility of taking both liquid and solid food.

First, the products were packed in plastic film bags under vacuum. Later, the nutritional formula for astronauts was determined.

Due to the long stay in orbit, the crews of the Soyuz and Salyut spacecraft required rations with a long shelf life. This condition, together with the restriction on the mass and volume of the diet, necessitated the inclusion in its composition of predominantly dehydrated products in the form of concentrates, as well as canned food in jars and tubes with a high content of solids.

The complex of studies on the technology of dehydration and increasing the shelf life made it possible to obtain a wide range of freeze-dried products (food concentrates) and canned food with a high content of solids. Tests (120-day and annual) have shown the advantages of freeze-dried products. However, the use of the latter was limited by the technical capabilities of the ship - the lack of a device for heating water. Therefore, for Soyuz spacecraft with a flight duration of 1–4 days, a diet was developed that included canned meat snacks in cans No. 1 (100 g), first courses and juices in tubes (165 g). Of the freeze-dried products on board, only those that did not require restoration were used: meat in pieces, briquetted for “one bite”, curd pudding and curd with blackcurrant puree, as well as bakery, confectionery and fruit products, vobla, cheese in the form of pieces. Reception of canned foods was provided without heating, and dry foods - with pouring cold water.

With the development of space nutrition, multi-component food products and an onboard nutrition system were created. At the Salyut-6 station, the ration was made up mainly of products preserved by heat sterilization (80%), and the ration for the Salyut-7 crew was composed mainly (65%) of food concentrates (dehydrated products). The change in the nature of the products is associated with the emergence of technical capabilities for their restoration and taking into account the experience of feeding previous expeditions. Thus, all the cosmonauts noted that canned food was "tacky" by the end of the second month of the flight. Similar remarks were made for foodstuffs preserved by heat sterilization, especially dinner dishes. At the same time, long-term tests (up to a year) of the diet, which includes a significant percentage of dehydrated foods (concentrates), showed that

At the same time, a complex technological problem was solved - the manufacture of freeze-dried products with a preliminary introduction of fat. Thanks to the selected modes, it was possible to obtain high-quality products with a shelf life of up to 18 months. At the same time, special packages of film materials were developed to restore the product in them.

The United States used the same principles as in Russia when providing space crews with food, however, the acquisition of space rations came from commercially available products. Over time, the assortment, technologies, catering have improved more and more.

At present, when selecting products and developing diets for American astronauts, as in our country, they take into account the nutritional value of the components, easy digestibility, attractive appearance, smell and taste, and the consistency that is optimal for use. Particular attention is paid to freeze drying and heat treatment. According to new technologies, it is possible to reduce (by 90%) the mass and volume of the product during freeze-drying, followed by food pressing (peas, cherries, meat cubes, meatballs). The mass and volume of these products are almost the same as chewing gum. The use of triple irradiation with y-rays from a source of cobalt-60 for sterilization made it possible to obtain meat dishes that retain their qualities for several years.

Thus, the composition of the astronauts' diet includes food concentrates - freeze-dried products (briquetted pork and beef, strawberries, potato pancakes), cooked by heat treatment in a package (beef in sauce, sausages, turkey, steak, slices of ham, chopped beef in sauce) , sterilized by irradiation (ham, natural steak, turkey in sauce), packed in soft sealed bags (cheese, peanuts in oil, chocolate cake with nuts, cocoa powder).

In recent years, a combined diet has been developed for Russian cosmonauts, consisting of the main and additional diets.

The basic diet is balanced in terms of irreplaceable factors and is compiled according to a six-day menu with the distribution of the daily set into three meals. The additional one has a high energy value and is designed to satisfy the individual tastes of astronauts. The composition of the supplementary diet includes products most highly valued by astronauts.

Food products used in the nutrition of astronauts undergo special preliminary (from 15 months to 2 years) and then acceptance tests. They are tested for the duration of storage under conditions corresponding to the stages of storage, transportation and operation in a real environment.

Cosmonauts from different countries participate in the implementation of space programs, therefore, when developing their diet, the features and traditions of national cuisine are taken into account.

Currently, new products for use in the daily nutrition of cosmonauts are being developed based on the achievements of Russian and foreign branch science using advanced technological methods and techniques, food additives and new packaging.

History of space nutrition research

The theoretical and practical principles underlying the scientific substantiation of nutrition and water supply in space flight were laid down in the IAM. Academician I.P. Pavlov in 1936-1943. and then at NIAM in 1947-1959. The basis was the work on the scientific substantiation of the nutrition of military pilots in long-term flights on airplanes.

Of course, the entire experience of in-flight catering and water supply for pilots could be more fully applied only in flights lasting up to 1 day. For longer flights, it was necessary to develop a rational diet in the form of autonomously operating daily rations. Such a task was not set before the nutrition of the flight crew, and it was always based on a combination of pre-flight, on-board and post-flight nutrition.

These studies showed that, along with the general provisions on rational nutrition in flight, the specific features of the metabolism in the pilot's body, the conditions for storing and eating food on board the aircraft, and the special selection of food that does not burden the body should be taken into account. The products included in the on-board ration must have a high nutritional value, be easily digestible, and contribute to the high-altitude stability of the body. Requirements for products were formulated taking into account their effect on gas formation in the gastrointestinal tract, on the body's need for water, suitability for consumption without additional culinary processing; requirements for the taste of products, the volume of individual meals and diet.

With the increase in the duration of flights on airplanes, sanitary and hygienic requirements for the shelf life of on-board rations products were strengthened to prevent deterioration of their taste and the possibility of food poisoning. Recommendations have been developed to prevent fatigue during a long flight by increasing the content of vitamins in the onboard diet.

The direct prototype of the diet of astronauts for short-term flights should be considered on-board rations for military pilots during long-term flights at high altitudes at an atmospheric pressure in the cabin of less than 405 mm Hg. Art. This ration was developed by IAIKM in collaboration with technologists and includes canned products of puree and liquid consistency, packed in aluminum tubes.

Nutrition for astronauts during short-term flights

The problem of providing spacecraft crews with food and water in preparation for the first manned space flights was considered to be one of the main ones.

A team of researchers from the IA&KM G.A. Arutyunova solved this problem using the experience in providing food for the flight crew in long-term flights and in simulating space flight under ground conditions. In the course of carrying out work to provide cosmonauts with food and water during short-term flights on the Vostok and Voskhod spacecraft, power systems were created that meet a number of specific requirements.

The main requirements for the power supply system for short-term flights were formulated as follows:

§ food rations must be adequate to the energy consumption of astronauts and complete in terms of the composition of nutrients necessary to ensure metabolic processes in the body at an optimal level;

§ the products that make up the diet must have appropriate nutritional qualities;

§ indigestible substances should be contained in products in small quantities;

§ volume and weight of products should be kept to a minimum;

§ food must remain of good quality throughout the flight;

§ the possibility and convenience of eating in weightless conditions should be provided;

§ the food ration should be completed from products that are ready to eat without additional processing, slicing and, if possible, without heating in flight.

The food system on ships for short flights included the following elements: a) a set of food for the flight or a set of daily food rations; b) a container for their storage; c) devices that facilitate eating; d) a container for collecting and storing food residues and packaging freed from products.

Research on the development of food rations at the first stages was carried out under conditions simulating the work and rest regime of astronauts in the cockpit of an aircraft. This made it possible to roughly establish the nutritional value of the rations for each type of flight in terms of both the required energy content and chemical composition. At the same time, various types of food products, means of packaging, storing and receiving food in flight were evaluated.

Requirements for the nutritional value of the cosmonauts' daily food rations were substantiated taking into account domestic physiological nutritional standards and refined in the course of experiments carried out in a small volume room, in pressure and deaf chambers with the participation of test volunteers and future cosmonauts.

As a result of such studies, it was concluded that the energy content of the daily rations of cosmonauts during the first flights of the Vostok spacecraft should be at the level of 2800 kcal/day. The food intake regimen was set 4 times a day, with intervals between meals of 4-5 hours. The daily diet contained about 100 g of protein, 118 g of fat and 308 g of carbohydrates. Multivitamin tablets were included in the diet to prevent vitamin deficiency in the conditions of using canned foods and the expected increased consumption of vitamins under the influence of flight stress factors. The dragee included vitamins (in mg) C - 100, P - 50, B1 - 2, B2 - 2, B6 - 2, PP - 15, pantothenic acid - 10, E - 5.

Due to the specific conditions of storage and use of food in the cabin of the spacecraft, which did not have special refrigeration and kitchen equipment, certain requirements were imposed on food products and their packaging, as well as on the conditions for eating.

Food products must maintain good quality when stored in a ship's cabin, which has an air temperature of 20-25 ° C, which sharply limits their range. Perishable, freshly prepared foods and ready meals are of little use for these conditions. Food should be taken directly from the packaging without additional cooking. During the intake, food should not be a source of air pollution with small particles that could enter the respiratory tract with the inhaled air.

Taking into account these requirements, only puree and liquid products packed in aluminum tubes and subjected to heat sterilization in autoclaves were included in the set of food ration products for flights on the Vostok-1 and Vostok-2 spacecraft. Each tube contained about 160 g of product. Food from such tubes was taken by the cosmonauts directly without heating. The set of products included canned purees (meat with vegetables, meat with prunes, meat with cereals), pates (meat, liver), juices (currant, plum, apple), chocolate cheese, coffee with milk.

In flights, Yu.A. Gagarin on the ship "Vostok-1" and G.S. Titov on the ship "Vostok-2" information was received about the possibility of human eating in orbital flight. The cosmonauts did not notice any difficulties in taking the tested products. There were also no changes in taste sensitivity. The results of evaluation of products by cosmonauts in the first short-term flights determined for the scientific team of IA&KM the further prospects for the use of various forms of products in the conditions of subsequent space flights.

However, it was not possible to adequately assess the adequacy of the diets for the needs of the cosmonauts' organisms in these flights due to the relative short duration of the flights, as well as methodological difficulties.

The nutrition of the cosmonauts on board the Vostok-3, Vostok-4, Vostok-5, Vostok-6, Voskhod-1, Voskhod-2 spacecraft was improved and improved by expanding the range of daily menu products by inclusion in the diet of a variety of foods of the usual dense consistency. In addition to liquid and puree-like products in aluminum tubes, the diet included meat dishes - cutlets, fried meat, beef tongue, etc., as well as sandwiches with pressed and chum caviar, pieces of vobla back, confectionery and bread products, fresh fruits.

The daily diet was divided into four meals: first breakfast, second breakfast, lunch and dinner. According to the flight program, the intervals between meals should not exceed 4-5 hours.

Repeated ground tests of such a diet under conditions with simulation of the life of cosmonauts in the cockpit showed that the developed set of products in terms of their taste, variety of dishes, feeling of satiety, convenience of eating is quite acceptable for short flights.

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Nutrition for astronauts on long flights (PREMIUM)

At the same time, it became obvious that the applied system had a number of disadvantages, primarily in relation to limited storage periods (5-6 days in a chilled form) on Earth; during transportation and in flight without refrigerators. For long flights, a completely different diet was required.

In 1965-1972 The staff of the nutrition department of the IA&KM carried out work on the physiological and hygienic substantiation of the nutrition systems of astronauts for a flight lasting 2 months or more in relation to the planned flights on spacecraft such as Soyuz and Salyut. After the transfer of work on the Soyuz project to the IBMP, all the efforts of the team were focused on the Salyut program.

In the course of these works, the influence of weightlessness, hypokinesia, altered gas composition of air, shifts in the mode of work and rest, prolonged neuro-emotional overload and fatigue, and long-term autonomy of nutrition were taken into account in the course of these works.

Based on the experience of feeding the cosmonauts on the Vostok and Voskhod spacecraft, the daily food rations included products that justified themselves in flights: puree-like soups in tubes, curd cream, and drinks. An essential moment in improving the nutrition of astronauts was the inclusion in the food system of a special heater: for tubes, cans and bread. Meat products were prepared in the form of traditional canned food in 100-gram cans, adopted in aviation. The assortment of bread and confectionery products was increased, which were baked in the form of small buns or briquettes "for one bite" and packed in a plastic bag.

Every day, twice a day, the astronauts had to take multivitamin pills containing vitamins A - 3300 IU, B1 - 2.58 mg, B2 - 2 mg, B6 - 3 mg, B12 - 12 mcg, C - 75 mg, E - 10 mg , nicotinamide - 10 mg, folic acid - 0.5 mg, calcium pantothenate - 3 mg, rutin - 10 mg. This complex is commonly known as Aerovit.

The diet was compiled according to a three-day menu with four meals a day. The calorie content of the diet was about 2803 kcal and it contained proteins - 139 g, fats - 88 g, carbohydrates - 345 g. The diet was balanced in terms of amino acids and mineral content in accordance with general physiological norms.

The question of the possibility and expediency of using rations for nutrition in space with a nutritional value that corresponds in most factors (nutrient content and balance, energy value, diet, etc.) to terrestrial physiological nutritional standards in force at that time in our country, has been a constant focus of nutrition research. The successful experience of using domestic standards in the development of "reactive soldering" in 1958 and subsequently confirmed the scientific validity of this approach. Under space conditions, one of the terrestrial variants of the environment is eventually created in a habitable cabin (with the exception of weightlessness). Therefore, the body's needs for nutrients and energy are generally similar to those on the earth in similar hygienic conditions. Additionally, the needs of the body must be clarified in model experiments on Earth and in the first flights in space, while the need is being clarified, first of all, in such nutrients as vitamins, essential amino acids, fiber, macroelements Ca, K, Mg, etc. approach has justified itself, both here and in the United States. Such a diet was supposed to be used in flights up to 1 month, while the cosmonauts were guaranteed a fairly rational diet, balanced in nutritional value in accordance with the physiological recommendations of the Institute of Nutrition of the USSR Academy of Medical Sciences, developed in 1960-1968.

A fairly large cooperation was created, including more than 20 scientific and industrial organizations of the food, meat and dairy, chemical and other industries to develop a large range of products and their reliable packaging for long-term storage without refrigeration and use in weightless conditions.

In connection with the tasks of ensuring longer flights, work was completed in 1971 on the physiological and hygienic substantiation of the diet of cosmonauts during a long flight (3 months or more) based on sublimated products. Sublimation of products allows you to get high quality products while maintaining the natural color, taste and smell. Ready-made products (soups, main courses with side dishes and meat, drinks, milk) prepared by sublimation are suitable for long-term storage (9-12 months), ready for use directly from the package after they are reconstituted with water. This provided for the use of cold and hot water, regenerated using a special installation from atmospheric moisture. Such rations were successfully used in the model of the Salyut ship for up to 90 days.

In 1974, within the framework of research on the development of methods and means of medical support for long-term human space flights on the space complex, the development of physiological, hygienic and operational requirements for the food and water supply system as a whole was completed. The following were developed: biotechnology of the spacecraft crew nutrition system for a flight duration of 30 days, including the organization and technology of nutrition using heat-preserved and sublimated products, from cooking to food waste storage; biotechnology of food and drinking water supply based on the use of canned water; on-board instruction on nutrition and water supply for astronauts in flight, as well as a methodology for assessing the system of nutrition and water supply for astronauts in flight.

All these works made it possible to prepare the provision of the Salyut-3 and Salyut-5 crew with food and water in sufficient quantities to maintain health and working capacity in flight. For the first time in flight, the recovery of sublimated products was carried out using a special installation for the regeneration of water from atmospheric moisture, which made it possible to conclude that the use of this power supply and water supply system is promising. Rations and products of this type were successfully used in flights to Salyut and Mir for up to 1 year.

A group of employees of the nutrition department, together with representatives of the All-Union Research Institute of the Canning Industry, are evaluating options for laying new food rations for the crew of the Salyut 3 orbital station

In 1970-1975. studies were carried out to develop a water-food ration and diet for pilot-cosmonauts in sealed spacesuits. The work was carried out as part of research to prepare for a flight to the Moon and landing an astronaut on its surface. The diet was developed on the basis of fruit and berry juices with the addition of carbohydrates, minerals and protein hydrolyzate and provided a person with food and water in a sealed space suit for 5 days. MTTs were worked out for the engineering part of the power system. These studies made it possible to determine the timing of feeding with liquid mixtures without the use of a colostomy bag in a spacesuit.

In 1983 - 1984 a study was conducted on the correspondence of in-flight meals to the needs of the cosmonauts' body in short-term and long-term flights in relation to the tasks of the professional activities of the crews of reusable spacecraft (RSC). The main development of these diets was entrusted to the IBMP of the Ministry of Health of the USSR. Based on the results of the physiological and hygienic assessment of the food rations for ISC crews, summarizing the experience of providing food to the crews in previous space flights, as well as taking into account the life characteristics of these crews, recommendations were developed for further improvement of the TTT for onboard food rations. Exploratory studies have been carried out to change the diet in order to accelerate the adaptation of the astronauts' organism to weightlessness conditions.

In order to further improve the balance of the most important nutrients in the diet of astronauts in 1970-1975. a lot of research work was carried out to study the dynamics in flight of the content of free amino acids in the blood plasma of astronauts before and after the flight. These unique studies made it possible to confirm that the body is generally adequately supplied with amino acids, with the exception of sulfur-containing ones, which requires the improvement of the diet in this direction.

In the early 1980s, the space range included more than 200 items. But during perestroika, the industry involved in the production of these products gradually began to decline. The reason was banal - funding cuts. Accordingly, the range has also been reduced. Since the production of space food is a costly thing, it was not possible to re-equip the workshops for the needs of a wide profile. The entire system of space cuisine created in the USSR has practically stopped.

In 1991-1992 the situation became almost critical. A balanced diet was no longer varied, astronauts complained, and food developers tried to raise money for further work. Here the Americans came to the rescue. According to the Gore-Chernomyrdin agreement of 1994 on the joint Russian-American programs "Mir" - "Shuttle", cooperation in the field of space nutrition was also supposed.

It was still easier for the Americans than for the Russians - the fact is that in the United States, mass consumption products are used for space food. NASA is just doing the verification and additional processing. And Russia, according to a long-established provision, does not have the right to use mass-produced products for the needs of space.

Now, according to the agreement, the Russian and American sides supply space products on a parity basis. Before compiling an individual diet for each member of the expedition, both in America and in Russia, an introductory tasting is held at the Cosmonaut Training Center. The astronauts evaluate the proposed products on a ten-point scale - those who scored five or less points do not get on board.

Based on the results of the tastings, a diet balanced in terms of assortment and nutritional value is compiled, designed for an 8-day cycle, after 8 days the menu is repeated. Nutrition specialists pay special attention to people who fly for the first time. Although so far no drastic changes in taste have been noticed in orbit (say, sweet does not seem sour, and salty does not seem sweet), certain changes in preferences do occur. Suppose, on Earth, a person did not like cottage cheese, but in space, cottage cheese became his favorite food. And some chicken, which he ate with pleasure on Earth, and does not want to see.

In orbit, they eat almost the same thing as on their home planet. The menu includes Borodino bread, honey cakes, ham, azu, pork in sweet and sour sauce, quail, pike perch, cheese, sturgeon, green cabbage soup and borscht, cottage cheese, cutlet with mashed potatoes, strawberries, cookies, chocolate, tea and coffee. Tubes, which have become a symbol of space nutrition, are now rarely used - food is mostly packaged in cans. Food is warmed up by placing it in special cells of an electric heater on the desktop, or eaten directly from the packages. They also eat fresh fruits and vegetables in space. At the same time, the preferences of national cuisine are preserved. If American astronauts, as a rule, order citrus fruits (grapefruits, oranges and lemons), then Russians prefer apples, onions, tomatoes, garlic.

Conclusion

The development of nutrition for space flights is an important scientific and practical task. The difficult physical conditions of space, the difficulties of delivery and storage require specific packaging and increase the requirements for the stability of products during storage. The working conditions of astronauts and physiological changes in the human body require the development of a balanced and complete diet. At the same time, one should not forget about the emotional component of astronauts' nutrition - after all, this is one of the few opportunities for recreation, as well as a reminder of the Earth - in this regard, space food should have high palatability and resemble its earthly counterparts as much as possible. The development of such products is a complex task that requires the involvement of a wide range of specialists, from confectioners to physiologists and engineers.