What do ecosystems receive from space? Where do they come from? Ecosystem - elementary unit of the biosphere
1935 A. Tansley introduced the concept of “ecosystem” 1940 V.N. Sukachev – “Biocenosis”
Mixed forest ecosystem
1 – vegetation 2 – animals 3 – soil inhabitants 4 – air 5 – soil itself
Ecosystem– historically developed in a particular territory or water area, an open but integral stable system of living and non-living components.
Classification of ecosystems by size All ecosystems are divided into 4 categories
Microecosystems
Mesoecosystems
Macroecosystems (huge homogeneous spaces stretching for hundreds of kilometers (tropical forests, ocean))
Global ecosystem (biosphere)
Classification by degree of openness Open refers to the ability to exchange energy and information with the environment.
Isolated
Closed
Open ∞
The classification is based on a component such as vegetation. It is characterized by staticity and physiology.
Classifications by life form
Woody = forest
Herbaceous = meadow and steppe
Subshrubs = tundra and desert
Classification by ecosystem productivity
desert forest
Ecosystem structure
Types of connections in an ecosystem
Trophic (food)
Tropical (energy)
Teleological (informational)
food chain is a sequence of food units, each of which is a living organism.
grass hare wolf
Trophic level – a group of organisms assigned to any level of the food pyramid.
moose hawk
grass hare wolf
fox man
trophic connections are carried out by 3 functional groups of organisms:
Autotrophs(plants are organisms that synthesize organic substances from inorganic ones)
Heterotrophs(organisms that are not able to synthesize organic substances from inorganic ones through photosynthesis or chemosynthesis. They eat ready-made substances)
Decomposers(Destructors) (organisms (bacteria and fungi) that destroy dead remains of living beings, turning them into inorganic and simple organic compounds.)
Small (biological) cycle of substances in nature
Energy connections (tropical)
Submit two laws of ecology
The Law of Ecological Accumulative Energy This is the inherent ability of many ecosystems to concentrate the energy received by the body into complex organic substances and accumulate energy in huge quantities.
Law of nutrient flow
Efficiency (human) = 50% Efficiency (nature) = 10%
Information communications
In ecosystems, information can be transmitted in different ways:
Behavior
(still not known in plants)
Ecosystem Properties
Integrity is the property of an ecosystem to function as a single organism.
Resilience is the ability of an ecosystem to withstand an external system
Composition constancy is the ability of an ecosystem to maintain the composition of species in a relatively unchanged state.
Self-regulation is the ability of an ecosystem to automatically regulate the number of species through biological organs.
Biosphere. Structure and functions
Biosphere- in 1875, Austrian biologist Suess.
This is the lower part of the atmosphere, the entire hydrosphere, its upper part of the earth's lithosphere, inhabited by living organisms.
Theory of the origin of life
Cosmological This hypothesis is based on the idea that life was brought from space
Theological
A.I. theory Oparina
For his experiment, Oparin took a bottle with a solution of sugars
The coacervates of the drop absorbed the sugar. A semblance of a cell membrane appeared.
In 1924, Oparin published the monograph “The Origin of Life.” In 1926, “Biosphere” by V.I. Vernadsky. In Vernadsky’s monograph, 2 postulates stand out:
The planetary biochemical role in nature belongs to living organisms.
The biosphere has a complex organization.
Composition of the biosphere
Vernadsky identifies the composition of the biosphere 7 types of substance:
Inert– a substance that exists in nature before the appearance of the first living organisms (water, rocks, volcanic lava)
Biokosnoe- a substance of organic origin that has the properties of non-living. The result of the joint activity of living organisms (water, soil, weathering crust, sedimentary rocks, clay materials) and inert (abiogenic) processes.
Biogenic– a substance of organic origin, released into the environment during their life processes. (atmospheric gases, coal, oil, peat, limestone, chalk, forest litter, soil humus, etc.)
Radioactive
Scattered atoms – 50 km
Substance of cosmic origin
Living matter- all living organisms living in nature
Properties of organisms
Ubiquity of life - the ability of living organisms to live everywhere
Carrying out redox reactions
Ability to migrate chemical elements
Ability to migrate gases
The ability to carry out a small cycle of substances in nature
The ability to accumulate and concentrate chemical elements in one’s tissues
Humanity needed all the knowledge collected by scientists over hundreds of years to begin space flights. And then man was faced with a new problem - for the colonization of other planets and long-distance flights, it is necessary to develop a closed ecosystem, including providing the astronauts with food, water and oxygen. Delivering food to Mars, which is located 200 million kilometers from Earth, is expensive and difficult; it would be more logical to find ways to produce products that are easy to implement in flight and on the Red Planet.
How do microgravity affect seeds? What vegetables would be harmless if grown in heavy metal-rich soil on Mars? How to set up a plantation on board a spaceship? Scientists and astronauts have been looking for answers to these questions for more than fifty years.
The illustration shows Russian cosmonaut Maxim Suraev hugging plants in the Lada installation aboard the International Space Station, 2014.
Konstantin Tsiolkovsky wrote in “The Goals of Astronomy”: “Let us imagine a long conical surface or funnel, the base or wide opening of which is covered with a transparent spherical surface. It is directly facing the Sun, and the funnel rotates around its long axis (height). On the opaque inner walls of the cone there is a layer of moist soil with plants planted in it.” So he proposed artificially creating gravity for plants. Plants should be selected that are prolific, small, without thick trunks and parts not exposed to the sun. In this way, colonizers can be partially provided with biologically active substances and microelements and oxygen and water can be regenerated.
In 1962, the chief designer of OKB-1, Sergei Korolev, set the task: “We need to start developing the “Greenhouse (OR) according to Tsiolkovsky,” with gradually increasing links or blocks, and we need to start working on “cosmic harvests.”
Manuscript by K.E. Tsiolkovsky “Album of space travel”, 1933.
The USSR launched the first artificial Earth satellite into orbit on October 4, 1957, twenty-two years after Tsiolkovsky's death. Already in November of the same year, the mongrel Laika was sent into space, the first of the dogs that were supposed to open the way to space for people. Laika died from overheating in just five hours, although the flight was planned for a week - for this time there would have been enough oxygen and food.
Scientists have suggested that the problem arose due to a genetically determined orientation - the seedling should stretch towards the light, and the root - in the opposite direction. They improved the Oasis, and the next expedition took new seeds into orbit.
The onion has grown. Vitaly Sevastyanov reported to Earth that the arrows had reached ten to fifteen centimeters. “What arrows, what bow? We understand, this is a joke, we gave you peas, not onions,” they said from Earth. The flight engineer replied that the astronauts had grabbed two bulbs from home to plant them beyond the plan, and reassured the scientists - almost all of the peas had sprouted.
But the plants refused to bloom. At this stage they died. The same fate awaited the tulips, which bloomed in the Buttercup installation at the North Pole, but not in space.
But you could eat onions, which cosmonauts V. Kovalenok and A. Ivanchenkov successfully did in 1978: “You did a good job. Maybe now we’ll be allowed to eat an onion as a reward.”
Technology - youth, 1983-04, page 6. Peas in the Oasis installation
In April 1980, cosmonauts V. Ryumin and L. Popov received the “Malachite” installation with blooming orchids. Orchids are attached to the bark of trees and hollows, and scientists believe that they may be less susceptible to geotropism - the ability of plant organs to locate and grow in a certain direction relative to the center of the globe. The flowers fell off after a few days, but the orchids formed new leaves and aerial roots. A little later, the Soviet-Vietnamese crew from V. Gorbatko and Pham Tuay brought with them a grown Arabidopsis.
The plants did not want to bloom. The seeds sprouted, but, for example, the orchid did not bloom in space. Scientists needed to help plants cope with weightlessness. This was done, among other things, using electrical stimulation of the root zone: scientists believed that the Earth’s electromagnetic field could influence growth. Another method involved the plan described by Tsiolkovsky to create artificial gravity - plants were grown in a centrifuge. The centrifuge helped - the sprouts were oriented along the vector of the centrifugal force. Finally, the astronauts achieved their goal. Arabidopsis bloomed in the Light Block.
On the left in the image below is the Fiton greenhouse on board Salyut 7. For the first time in this orbital greenhouse, Thal's rhizoid (Arabidopsis) went through a full development cycle and produced seeds. In the middle is the “Svetoblok”, in which Arabidopsis bloomed for the first time on board Salyut-6. On the right is the on-board greenhouse “Oasis-1A” at the Salyut-7 station: it was equipped with a system of dosed semi-automatic watering, aeration and electrical stimulation of roots and could move vegetation vessels with plants relative to the light source.
"Fiton", "Svetoblok" and "Oasis-1A"
Installation "Trapezium" for studying the growth and development of plants.
Sets with seeds
Flight log of the Salyut-7 station, sketches by Svetlana Savitskaya
The world's first automatic greenhouse, Svet, was installed at the Mir station. Russian cosmonauts conducted six experiments in this greenhouse in the 1990-2000s. They grew lettuce, radishes and wheat. In 1996-1997, the Institute of Medical and Biological Problems of the Russian Academy of Sciences planned to grow plant seeds obtained in space - that is, to work with two generations of plants. For the experiment, we chose a hybrid of wild cabbage about twenty centimeters high. The plant had one drawback - the astronauts needed to pollinate.
The result was interesting - the seeds of the second generation were received in space, and they even sprouted. But the plants grew to six centimeters instead of twenty-five. Margarita Levinskikh, researcher at the Institute of Medical and Biological Problems of the Russian Academy of Sciences, tells that the magnificent work of plant pollination was carried out by the American astronaut Michael Fossum.
Roscosmos video about growing plants in space. At 4:38 - plants at the Mir station
In April 2014, SpaceX's Dragon cargo ship delivered the Veggie greens growing facility to the International Space Station, and in March, astronauts began testing the orbital planter. The installation controls light and nutrient supply. In August 2015, on the menu of astronauts, grown in microgravity conditions.
Lettuce grown on the International Space Station
This is what a plantation on a space station might look like in the future.
In the Russian segment of the International Space Station there is a Lada greenhouse for the Plants-2 experiment. At the end of 2016 or beginning of 2017, the Lada-2 version will appear on board. The Institute of Medical and Biological Problems of the Russian Academy of Sciences is working on these projects.
Space horticulture is not limited to zero-gravity experiments. To colonize other planets, humans will have to develop agriculture on soil that differs from that on Earth, and in an atmosphere that has a different composition. In 2014, biologist Michael Mautner cooked asparagus and potatoes on meteorite soil. To obtain soil suitable for cultivation, the meteorite was ground into powder. Experimentally, he was able to prove that bacteria, microscopic fungi and plants can grow on soil of extraterrestrial origin. The material of most asteroids contains phosphates, nitrates and sometimes water.
Asparagus grown on meteorite soil
In the case of Mars, where there is a lot of sand and dust, grinding the rock will not be necessary. But another problem will arise - the composition of the soil. The soil of Mars contains heavy metals, an increased amount of which in plants is dangerous for humans. Scientists from Holland have imitated Martian soil and, since 2013, have grown ten crops of several types of plants on it.
As a result of the experiment, scientists found that the content of heavy metals in peas, radishes, rye and tomatoes grown on simulated Martian soil is not dangerous for humans. Scientists continue to study potatoes and other crops.
Researcher Wager Wamelink inspects plants grown in simulated Martian soil. Photo: Joep Frissel/AFP/Getty Images
Metal Content of Crops Harvested on Earth and in Simulated Moon and Mars Soils
One of the important tasks is to create a closed life support cycle. Plants receive carbon dioxide and crew waste, in return they give oxygen and produce food. Scientists have the possibility of using single-celled algae chlorella as food, containing 45% protein and 20% fat and carbohydrates. But this theoretically nutritious food is not digested by humans due to the dense cell wall. There are ways to solve this problem. Cell walls can be broken down using technological methods using heat treatment, fine grinding or other methods. You can take with you enzymes developed specifically for chlorella, which astronauts will take with food. Scientists can also develop GMO chlorella, the wall of which can be broken down by human enzymes. Chlorella is not currently used for nutrition in space, but is used in closed ecosystems to produce oxygen.
The experiment with chlorella was carried out on board the Salyut-6 orbital station. In the 1970s, it was still believed that being in microgravity did not have a negative effect on the human body - there was too little information. They also tried to study the effect on living organisms using chlorella, whose life cycle lasts only four hours. It was convenient to compare it with chlorella grown on Earth.
The IFS-2 device was intended for growing fungi, tissue cultures and microorganisms, and aquatic animals.
Since the 70s, experiments on closed systems have been carried out in the USSR. In 1972, the work of “BIOS-3” began - this system is still in effect. The complex is equipped with chambers for growing plants in controlled artificial conditions - phytotrons. They grew wheat, soybeans, chufu lettuce, carrots, radishes, beets, potatoes, cucumbers, sorrel, cabbage, dill and onions. Scientists were able to achieve an almost 100% closed cycle in water and air and up to 50-80% in nutrition. The main goals of the International Center for Closed Ecological Systems are to study the principles of functioning of such systems of varying degrees of complexity and to develop the scientific basis for their creation.
One of the high-profile experiments simulating a flight to Mars and return to Earth was. For 519 days, six volunteers were kept in a closed complex. The experiment was organized by Rocosmos and the Russian Academy of Sciences, and the European Space Agency became a partner. There were two greenhouses “on board the ship” - lettuce grew in one, peas grew in the other. In this case, the goal was not to grow plants in conditions close to space, but to find out how important plants are for the crew. Therefore, the greenhouse doors were sealed with an opaque film and a sensor was installed to record each opening. In the photo on the left, Mars 500 crew member Marina Tugusheva works with greenhouses as part of an experiment.
Another experiment on board “Mars-500” is GreenHouse. In the video below, expedition member Alexey Sitnev talks about the experiment and shows a greenhouse with various plants.
The person will have many chances. It runs the risk of crashing during landing, freezing on the surface, or simply not making it. And, of course, die of hunger. Plant growing is necessary for the formation of a colony, and scientists and astronauts are working in this direction, showing successful examples of growing some species not only in microgravity conditions, but also in simulated soil of Mars and the Moon. Space colonists will definitely have the opportunity.
Scanned and processed by Yuri Abolonko (Smolensk)
NEW IN LIFE, SCIENCE, TECHNOLOGY
SUBSCRIBE POPULAR SCIENCE SERIES
COSMONAUtics, ASTRONOMY
7/1989
Published monthly since 1971.
Yu. I. Grishin
ARTIFICIAL SPACE ECOSYSTEMS
In the attachment of this issue:
SPACE TOURISM
CHRONICLE OF COSMONAUtics
ASTRONOMY NEWS
Publishing house "Knowledge" Moscow 1989
BBK 39.67
G 82
Editor I. G. VIRKO
| Introduction | 3 |
| Man in a natural ecosystem | 5 |
| A spaceship with a crew is an artificial ecosystem | 11 |
| Relay race of substances in the biological cycle | 21 |
| Do ecosystems have efficiency? | 26 |
| Artificial and natural biosphere ecosystems: similarities and differences | 32 |
| On biological life support systems for space crews | 36 |
| Green plants as the main link in biological life support systems | 39 |
| Achievements and prospects | 44 |
| Conclusion | 53 |
| Literature | 54 |
APPLICATION | |
| Space tourism | 55 |
| Chronicle of astronautics | 57 |
| Astronomy News | 60 |
Grishin Yu. I.
| G 82 |
ISBN 5-07-000519-7
The brochure is devoted to the problems of life support for spacecraft crews and future long-term space structures. Various models of artificial ecological systems, including humans and other biological links, are considered. The brochure is intended for a wide range of readers.
3500000000BBK 39.67
ISBN 5-07-000519-7© Publishing House "Knowledge", 1989
INTRODUCTION
The beginning of the 21st century may go down in the history of the development of earthly civilization as a qualitatively new stage in the exploration of circumsolar space: the direct settlement of natural and artificially created space objects with a long stay of people on these objects.
It seems that just recently the first artificial Earth satellite was launched into low-Earth space orbit (1957), the first flyby and photograph of the far side of the Moon was made (1959), the first man was in space (Yu. A. Gagarin, 1961), an exciting film was shown on television the moment of man's spacewalk (A. A. Leonov, 1965) and the first steps of astronauts on the surface of the Moon were demonstrated (N. Armstrong and E. Aldrin, 1969). But every year these and many other outstanding events of the space age become a thing of the past and become history. They, in fact, are only the beginning of the embodiment of the ideas formulated by the great K. E. Tsiolkovsky, who considered space not only as astronomical space, but also as the environment for human habitation and life in the future. He believed that “if life were not distributed throughout the universe, if it were confined to a planet, then this life would often be imperfect and subject to a sad end” (1928).
Today, possible options for human biological evolution are already being predicted in connection with the settlement of a significant part of the population outside the Earth, possible models of space exploration are being developed, and the transformative impact of space programs on nature, the economy and social relations is being assessed. The problems of partial or complete self-sufficiency of settlements in space using closed biotechnical life support systems, issues of creating lunar and planetary bases, space industry and construction, and the use of extraterrestrial energy sources and materials are also considered and solved.
The words of K. E. Tsiolkovsky are beginning to come true that “humanity will not remain on Earth forever, but in pursuit of light and space, it will first timidly penetrate beyond the atmosphere, and then conquer the entire circumsolar space” (1911).
At recent international meetings and forums on cooperation in space in the interests of further expanding scientific research of near-Earth and near-solar space, the study of Mars, the Moon, and other planets of the solar system, hopes were expressed that the implementation of large space programs requiring enormous material and technical resources and financial costs, will be carried out through the joint efforts of many countries within the framework of international cooperation. “Only the collective mind of humanity is capable of moving into the heights of near-Earth space and further into near-solar and stellar space,” said M. S. Gorbachev in his address to foreign representatives of the communist movement - participants in the celebration of the 70th anniversary of the Great October Revolution.
One of the most important conditions for the further exploration of outer space by man is to ensure the life and safe activities of people during their prolonged stay and work at space stations, spacecraft, planetary and lunar bases remote from the Earth.
The most expedient way to solve this most important problem, as many domestic and foreign researchers believe today, is the creation of closed biotechnical life support systems in long-term inhabited space structures, i.e., artificial space ecological systems that include humans and other biological links.
In this brochure we will try to outline the basic principles of constructing such systems, provide information on the results of large ground-based experiments carried out in preparation for the creation of space biotechnical life support systems, and indicate the problems that still need to be solved on Earth and in space in order to ensure the required reliability of the functioning of these systems in space conditions.
HUMAN IN A NATURAL ECOSYSTEM
Before sending a person on a long space journey, we will first try to answer the questions: what does he need to live normally and work fruitfully on Earth, and how is the problem of human life support on our planet solved?
Answers to these questions are needed to create life support systems for crews on manned spaceships, orbital stations and alien structures and bases. We can rightfully consider our Earth as a huge spaceship of natural origin, which has been making its endless orbital space flight around the Sun for 4.6 billion years. The crew of this ship today consists of 5 billion people. The rapidly growing population of the Earth, which by the beginning of the 20th century. was 1.63 billion people, and on the threshold of the 21st century. should already reach 6 billion, best evidence of the presence of a fairly effective and reliable mechanism for human life support on Earth.
So, what does a person on Earth need to ensure his normal life and activities? It is hardly possible to give a short but comprehensive answer: all aspects of human life, activity and interests are too extensive and multifaceted. Restore in detail at least one day of your life, and you will see that a person needs not so little.
Satisfying a person’s needs for food, water and air, which are basic physiological needs, is the main condition for his normal life and activity. However, this condition is inextricably linked with another: the human body, like any other living organism, actively exists thanks to the metabolism within the body and with the external environment.
Consuming oxygen, water, nutrients, vitamins, and mineral salts from the environment, the human body uses them to build and renew its organs and tissues, while receiving all the energy necessary for life from proteins, fats and carbohydrates in food. Waste products are excreted from the body into the environment.
As is known, the intensity of metabolism and energy in the human body is such that an adult can survive without oxygen for only a few minutes, without water for about 10 days, and without food for up to 2 months. The external impression that the human body does not undergo changes is deceptive and incorrect. Changes in the body occur continuously. According to A.P. Myasnikov (1962), during the day in the body of an adult weighing 70 kg, 450 billion erythrocytes, from 22 to 30 billion leukocytes, from 270 to 430 billion platelets are replaced and die, approximately 125 g of proteins are broken down , 70 g of fat and 450 g of carbohydrates with the release of more than 3000 kcal of heat, 50% of the epithelial cells of the gastrointestinal tract, 1/75 of the bone cells of the skeleton and 1/20 of all the integumentary skin cells of the body are restored and die (i.e. through every 20 days a person completely “changes his skin”), approximately 140 hairs on the head and 1/150 of all eyelashes fall out and are replaced with new ones, etc. On average, 23,040 inhalations and exhalations are made, 11,520 liters pass through the lungs air, 460 liters of oxygen are absorbed, 403 liters of carbon dioxide and 1.2–1.5 liters of urine containing up to 30 g of dense substances are excreted from the body, 0.4 liters are evaporated through the lungs and about 0.6 liters of water containing 10 g of dense substances, 20 g of sebum are formed.
This is the intensity of a person’s metabolism in just one day!
Thus, a person constantly, throughout his life, releases metabolic products and thermal energy generated in the body as a result of the breakdown and oxidation of food, the release and transformation of chemical energy stored in food. The released metabolic products and heat must be constantly or periodically removed from the body, maintaining the quantitative level of metabolism in full accordance with the degree of its physiological, physical and mental activity and ensuring a balance in the exchange of matter and energy between the body and the environment.
Everyone knows how these basic physiological needs of a person are realized in everyday real life: the five billion crew of the spaceship “Planet Earth” receives or produces everything necessary for their life on the basis of the reserves and products of the planet, which feeds, waters and clothes them, helps to increase their numbers , protects with its atmosphere all living things from the adverse effects of cosmic rays. Let us present a few figures that clearly characterize the scale of the main “exchange of goods” between man and nature.
The first constant human need is to breathe air. “You can’t breathe too much air,” says a Russian proverb. If each person requires an average of 800 g of oxygen every day, then the entire population of the Earth should consume 1.5 billion tons of oxygen per year. The Earth's atmosphere has huge renewable reserves of oxygen: with a total weight of the Earth's atmosphere of about 5 ∙ 10 15 tons, oxygen is approximately 1/5, which is almost 700 thousand times more than the annual oxygen consumption of the entire population of the Earth. Of course, in addition to people, atmospheric oxygen is used by the animal world, and is also spent on other oxidative processes, the scale of which on the planet is enormous. However, the reverse reduction processes are no less intense: thanks to photosynthesis, due to the radiant energy of the Sun, plants on land, seas and oceans constantly bind carbon dioxide released by living organisms in oxidative processes into a variety of organic compounds with the simultaneous release of molecular oxygen. According to geochemists, all plants on Earth release 400 billion tons of oxygen annually, while binding 150 billion tons of carbon (from carbon dioxide) with 25 billion tons of hydrogen (from water). Nine-tenths of this production is produced by aquatic plants.
Consequently, the issue of providing humans with air oxygen is successfully solved on Earth mainly through the processes of photosynthesis in plants.
The next most important human need is water.
In the human body, it is the environment in which numerous biochemical reactions of metabolic processes take place. Constituting 2/3 of the human body weight, water plays a huge role in ensuring its vital functions. Water is associated not only with the supply of nutrients to the body, their absorption, distribution and assimilation, but also with the release of metabolic end products.
Water enters the human body in the form of drinking and food. The amount of water required by the body of an adult varies from 1.5 - 2 to 10 - 15 liters per day and depends on his physical activity and environmental conditions. Dehydration of the body or excessive restriction in water intake leads to a sharp disruption of its functions and to poisoning by metabolic products, in particular nitrogen.
An additional amount of water is necessary for a person to meet sanitary and household needs (washing, laundering, production, animal husbandry, etc.). This amount significantly exceeds the physiological norm.
The amount of water on the Earth's surface is enormous; its volume is over 13.7 ∙ 10 8 km 3 . However, supplies of fresh water suitable for drinking purposes are still limited. The amount of precipitation (fresh water) falling on average per year on the surface of the continents as a result of the water cycle on Earth is only about 100 thousand km 3 (1/5 of the total amount of precipitation on Earth). And only a small part of this amount is effectively used by humans.
Thus, on spaceship Earth, water supplies can be considered unlimited, but the consumption of clean fresh water requires an economical approach.
Food serves the human body as a source of energy and substances involved in the synthesis of tissue components, in the renewal of cells and their structural elements. The body continuously carries out the processes of biological oxidation of proteins, fats and carbohydrates supplied with food. A nutritious diet should include the required amounts of amino acids, vitamins and minerals. Food substances, usually broken down by enzymes in the digestive tract into simpler, low-molecular compounds (amino acids, monosaccharides, fatty acids and many others), are absorbed and distributed by the blood throughout the body. The end products of food oxidation are most often carbon dioxide and water, which are excreted from the body as waste products. The energy released during the oxidation of food is partially stored in the body in the form of energy-enriched compounds, and partially converted into heat and dissipated in the environment.
The amount of food the body needs depends primarily on the intensity of its physical activity. The energy of the basal metabolism, i.e., such metabolism when a person is at complete rest, averages 1700 kcal per day (for men under the age of 30 weighing up to 70 kg). In this case, it is spent only on the implementation of physiological processes (breathing, heart function, intestinal motility, etc.) and ensuring the constancy of normal body temperature (36.6 ° C).
Physical and mental activity of a person requires an increase in energy expenditure by the body and consumption of more food. It has been established that a person’s daily energy consumption during moderate mental and physical work is about 3000 kcal. A person’s daily diet should have the same calorie content. The calorie content of the diet is approximately calculated based on the known values of the heat released during the complete oxidation of each gram of proteins (4.1 kcal), fats (9.3 kcal) and carbohydrates (4.1 kcal). The appropriate ratio of proteins, fats and carbohydrates in the diet is established by medicine in accordance with the physiological needs of a person and includes from 70 to 105 g of proteins, from 50 to 150 g of fats and from 300 to 600 g of carbohydrates within one calorie value of the diet. Variations in the composition of the diet in proteins, fats and carbohydrates arise, as a rule, due to changes in the body’s physical activity, but also depend on a person’s habits, national dietary traditions, the availability of a particular food product and, of course, specific social opportunities to meet nutritional needs.
Each of the nutrients performs specific functions in the body. This especially applies to proteins that contain nitrogen, which is not part of other nutrients, but is necessary for the restoration of its own proteins in the human body. It is estimated that in the body of an adult, at least 17 g of its own proteins are destroyed per day, which must be restored through food. Therefore, this amount of protein is the minimum required in the diet of every person.
Fats and carbohydrates can be largely replaced with each other, but up to certain limits.
Regular human food completely covers the body's need for proteins, fats and carbohydrates, and also supplies it with the necessary minerals and vitamins.
However, in contrast to the unlimited supplies of oxygen (air) and drinking water, which is still sufficient on the planet and the consumption of which is strictly rationed only in certain, usually arid regions, the amount of food products is limited by the low productivity of the natural trophic (food) cycle, consisting of three main levels: plants – animals – humans. Indeed, plants form biomass using only 0.2% of the solar energy coming to Earth. When consuming plant biomass for food, animals spend no more than 10–12% of the energy they assimilate for their own needs. Ultimately, a person, by consuming food of animal origin, meets the energy needs of his body with a very low utilization rate of the initial solar energy.
Meeting nutritional needs has always been the most difficult task of man. Passive use of nature's capabilities in this direction is limited, since most of the globe is covered by oceans and deserts with low biological productivity. Only certain regions of the Earth, characterized by stable favorable climatic conditions, provide high primary productivity of substances, which, by the way, are not always acceptable from the standpoint of human nutritional needs. The growth of the Earth's population, its dispersion across all continents and geographic zones of the planet, including zones with unfavorable climatic conditions, as well as the gradual depletion of natural food sources have led to a state where meeting food needs on Earth has grown into a universal human problem. Today it is believed that the global deficit of dietary protein alone is 15 million tons per year. This means that at least 700 million people in the world are systematically undernourished. And this despite the fact that humanity at the end of the 20th century. In general, it is distinguished by a fairly high social organization, major achievements in the development of science, technology, industry and agricultural production, and a deep understanding of its unity in composition, the biosphere of the planet.
Food is an important environmental factor not only for humans, but also for all animals. Depending on the availability of food, its diversity, quality and quantity, the characteristics of a population of living organisms (fertility and mortality, life expectancy, development rate, etc.) can significantly change. Food (trophic) connections between living organisms, as will be shown below, underlie both the biosphere (terrestrial) biological cycle of substances and artificial ecological systems that include humans.
The Earth will be able to provide those living on it with everything they need for a long time, if humanity uses the planet’s resources more rationally and carefully, solves the issues of transforming nature in an environmentally sound manner, eliminates the arms race and puts an end to nuclear weapons.
The scientific basis for solving the problem of life support for humanity on Earth, formulated by V.I. Vernadsky, lies in the transition of the Earth’s biosphere into the noosphere, that is, into a biosphere that has been changed by scientific thought and transformed to meet all the needs of a numerically growing humanity (sphere of reason). V.I. Vernadsky assumed that, having originated on Earth, the noosphere, as man explores circumstellar space, should turn into a special structural element of space.
SPACESHIP WITH CREW – ARTIFICIAL ECOSYSTEM
How to solve the problem of providing the crew of a spaceship with fresh, varied food, clean water and life-giving air? Naturally, the simplest answer is to take everything you need with you. This is what they do in cases of short-term manned flights.
As the flight duration increases, more supplies are required. Therefore, it is necessary to regenerate some consumable substances (for example, water), process human waste and waste from technological processes of some ship systems (for example, regenerated carbon dioxide sorbents) to reuse these substances and reduce initial reserves.
The ideal solution seems to be the implementation of a complete (or almost complete) circulation of substances within a limited volume of an inhabited space “house”. However, such a complex solution can be beneficial and practically feasible only for large space expeditions lasting more than 1.5 - 3 years (A. M. Genin, D. Talbot, 1975). The decisive role in creating the cycle of substances in such expeditions is usually assigned to biosynthesis processes. The functions of supplying the crew with food, water and oxygen, as well as removing and processing metabolic products and maintaining the required parameters of the crew’s habitat on a ship, station, etc. are assigned to the so-called life support systems (LSS). A schematic representation of the main types of life support systems for space crews is shown in Fig. 1.
 Rice. 1. Schemes of the main types of life support systems for space crews: 1 – system in reserve (all waste is removed); 2 – system on reserves with partial physical and chemical regeneration of substances (PCR) (part of the waste is removed, part of the reserves can be renewed); 3 – system with partial FCR and partial biological regeneration of substances by plants (BR) with a waste correction unit (BC); 4 – system with complete closed regeneration of substances (reserves are limited by microadditives). Designations: E - radiant or thermal energy, IE - energy source, O - waste, BB - bioblock with animals, dotted line - optional process |
The life support systems of space crews are extremely complex complexes. Three decades of the space era have confirmed the sufficient efficiency and reliability of the created life-support systems, which were successfully operated on the Soviet spacecraft Vostok and Soyuz, the American Mercury, Gemini and Apollo, as well as on the Salyut and Skylab orbital stations " The work of the Mir research complex with an improved life support system on board continues. All these systems have provided flights for more than 200 cosmonauts from various countries.
The principles of construction and operation of life support systems that have been and are currently used for space flights are widely known. They are based on the use of physical and chemical regeneration processes. At the same time, the problem of using biosynthesis processes in space LSS, and even more so the problem of constructing closed biotechnical LSS for space flights, still remains open.
There are different, sometimes directly opposite, points of view on the possibility and feasibility of the practical implementation of such systems in general and in spacecraft in particular. The arguments against are given as follows: complexity, lack of knowledge, energy intensity, unreliability, inadaptability, etc. However, the overwhelming majority of experts consider all these issues to be solvable, and the use of biotechnical life-support systems as part of future large space settlements, lunar, planetary and interplanetary bases and others remote extraterrestrial structures - inevitable.
The inclusion in the crew's life support system, along with numerous technical devices, of biological units, the functioning of which is carried out according to the complex laws of the development of living matter, requires a qualitatively new, ecological approach to the formation of biotechnical life support systems, in which a stable dynamic equilibrium and consistency of the flows of matter and energy in all links must be achieved systems. In this sense, any habitable spacecraft should be considered as an artificial ecological system.
An inhabited spacecraft includes at least one actively functioning biological link - a person (crew) with his microflora. At the same time, humans and microflora exist in interaction with the environment artificially created in the spacecraft, ensuring a stable dynamic equilibrium of the biological system in terms of flows of matter and energy.
Thus, even with full provision for the life of the crew in the spacecraft due to the reserves of substances and in the absence of other biological links, the habitable spacecraft is already an artificial space ecological system. It can be completely or partially isolated in matter from the external environment (outer space), but its energy (thermal) isolation from this environment is completely excluded. A constant exchange of energy with the environment, or at least constant heat removal, is a necessary condition for the functioning of any artificial space ecosystem.
The 21st century poses new, even more ambitious tasks for humanity in the further exploration of outer space. (Apparently, it would be more accurate to say that humanity is setting these tasks for the 21st century.) The specific appearance of the future space ecosystem can be determined depending on the purpose and orbit of the space structure (interplanetary manned spacecraft, near-Earth orbital station, lunar base, Martian base , construction space platform, complex of residential structures on asteroids, etc.), crew size, duration of operation, power supply and technical equipment and, of course, on the degree of readiness of certain technological processes, including processes of controlled biosynthesis and processes of controlled transformation of matter and energy in biological links of ecosystems.
Today we can say that the tasks and programs of advanced space research have been defined in the USSR and the USA at the state level until approximately the year 2000. Regarding the tasks of the next century, scientists are still speaking in the form of forecasts. Thus, the results of a study published in 1984 (and carried out back in 1979 by an employee of the Rand Corporation through a questionnaire survey of 15 leading specialists in the United States and Great Britain) revealed a picture reflected in the following table:
| Years | Contents of the stage |
| 2020 –2030 | Colonization of the Moon and outer space by large contingents of people (more than 1000 people). |
| 2020 – 2071 | Development of artificial human intelligence. |
| 2024 – 2037 | The first manned flight to Jupiter. |
| 2030 – 2050 | Flights within the Solar System, use of natural resources of the Solar System, including the Moon. |
| 2045 – 2060 | The first flight of an unmanned probe beyond the solar system. |
| 2045 – 2070 | The first manned flight to the boundaries of the solar system. |
| 2050 – 2100 | Establishing contacts with extraterrestrial intelligence. |
The famous American physicist J. O'Neil, who deals with the problems of future space settlements of mankind, published his forecast back in 1974, which in 1988 assumed that 10 thousand people would work in space. This forecast did not come true, but today many experts It is believed that by 1990, 50–100 people will be continuously working in space.
The well-known specialist Dr. Puttkamer (Germany) believes that the period from 1990 to 2000 will be characterized by the beginning of the settlement of near-Earth space, and after 2000 the autonomy of space inhabitants must be ensured and an ecologically closed habitat system must be created.
Calculations show that with an increase in the duration of a person’s stay in space (up to several years), with an increase in the size of the crew and with the increasing distance of the spacecraft from the Earth, the need arises to carry out biological regeneration of consumable substances, and above all food, directly on board the spacecraft. At the same time, not only technical and economic (mass and energy) indicators testify in favor of biological life support, but also, no less important, indicators of the biological reliability of humans as a determining link in the artificial space ecosystem. Let us explain the latter in more detail.
There are a number of studied (and so far unexplored) connections between the human body and living nature, without which its successful long-term life activity is impossible. These include, for example, its natural trophic connections, which cannot be completely replaced by food from the supplies stored on the ship. Thus, some vitamins that are absolutely necessary for humans (food carotenoids, ascorbic acid, etc.) are unstable during storage: under terrestrial conditions, the shelf life of, for example, vitamins C and P is 5–6 months. Under the influence of space conditions, over time, a chemical restructuring of vitamins occurs, as a result of which they lose their physiological activity. For this reason, they must either be constantly reproduced biologically (in the form of fresh food, such as vegetables), or regularly delivered from Earth, as was the case during the record-breaking annual space flight on the Mir station. In addition, medical and biological studies have shown that under conditions of space flight, an increased intake of vitamins is required by astronauts. Thus, during flights under the Skylab program, astronauts’ consumption of B vitamins and vitamin C (ascorbic acid) increased approximately 10 times, vitamin A (axerophthol) - 2 times, vitamin D (calciferol) - slightly higher than the earthly norm. It has now also been established that vitamins of biological origin have clear advantages over purified preparations of the same vitamins obtained chemically. This is due to the fact that biomass contains vitamins in combination with a number of other substances, including stimulants, and when consumed they have a more effective effect on the metabolism of a living organism.
It is known that natural plant food products contain all plant proteins (amino acids), lipids (essential fatty acids), the entire complex of water-soluble and partially fat-soluble vitamins, carbohydrates, biologically active substances and fiber. The role of these food components in metabolism is enormous (V.I. Yazdovsky, 1988). Naturally, the existing process of preparing space rations, which involves harsh processing regimes (mechanical, thermal, chemical), cannot but reduce the effectiveness of individual important food components in human metabolism.
Apparently, the possible cumulative effect of cosmic radioactive radiation on food products stored for a long time on the ship should also be taken into account.
Consequently, just meeting the calorie content of food with the established norm is not enough; it is necessary that the astronaut’s food be as varied and fresh as possible.
The discovery by French biologists of the ability of pure water to “remember” certain properties of biologically active molecules and then transmit this information to living cells seems to begin to clarify the ancient folk fairy wisdom about “living” and “dead” water. If this discovery is confirmed, then a fundamental problem of water regeneration on long-term spacecraft arises: is water purified or obtained by physical and chemical methods in multiple isolated cycles capable of replacing biologically active “living” water?
It can also be assumed that a long stay in an isolated volume of a spacecraft with an artificial gaseous habitat obtained by chemical means is not indifferent to the human body, all generations of which have existed in an atmosphere of biogenic origin, the composition of which is more diverse. It is hardly accidental that living organisms have the ability to distinguish isotopes of certain chemical elements (including stable isotopes of oxygen O 16, O 17, O 18), as well as to detect small differences in the strength of chemical bonds of isotopes in molecules H 2 O, CO 2 and etc. It is known that the atomic weight of oxygen depends on the source of its production: oxygen from air is slightly heavier than oxygen from water. Living organisms “feel” this difference, although only special mass spectrometers can determine it quantitatively. Prolonged breathing of chemically pure oxygen under space flight conditions can lead to intensification of oxidative processes in the human body and to pathological changes in lung tissue.
It should be noted that air, which is of biogenic origin and enriched with plant phytoncides, plays a special role for humans. Phytoncides are biologically active substances constantly produced by plants that kill or suppress bacteria, microscopic fungi, and protozoa. The presence of phytoncides in the surrounding air is, as a rule, beneficial for the human body and causes a feeling of freshness in the air. For example, the commander of the third American crew of the Skylab station emphasized that his crew enjoyed inhaling air enriched with lemon phytoncides.
In known cases of human infection with bacteria settling in air conditioners (“Legionnaires’ disease”), phytoncides would be a strong disinfectant, and in relation to air conditioning systems in closed ecosystems they could eliminate this possibility. As research by M. T. Dmitriev has shown, phytoncides can act not only directly, but also indirectly, increasing the bactericidal capacity of the air and increasing the content of light negative ions, which have a beneficial effect on the human body. This reduces the number of unwanted heavy positive ions in the air. Phytoncides, which are unique carriers of the protective function of plants from environmental microflora, are not only released into the air surrounding the plant, but are also contained in the biomass of the plants themselves. Garlic, onions, mustard and many other plants are richest in phytoncides. By consuming them as food, a person carries out an imperceptible but very effective fight against infectious microflora that enters the body.
Speaking about the importance of biological links in an artificial space ecosystem for humans, one cannot fail to note the special positive role of higher plants as a factor in reducing the emotional stress of astronauts and improving psychological comfort. All the astronauts who had to carry out experiments with higher plants on board space stations were unanimous in their assessments. Thus, L. Popov and V. Ryumin at the Salyut-6 orbital station enjoyed caring for plants in the experimental greenhouses “Malachite” (interior-stained glass greenhouse with tropical orchids) and “Oasis” (experimental greenhouse with vegetable and vitamin plant crops). They carried out watering, monitored the growth and development of plants, carried out preventive inspections and work on the technical part of the greenhouses, and simply admired the living interior of orchids in rare moments of rest. “Biological research gave us a lot of pleasure. We had, for example, the Malachite installation with orchids, and when we sent it to Earth, we felt some kind of loss, the station became less comfortable.” This is what L. Popov said after landing. “Working with Malachite on board the space complex has always given us special satisfaction,” added V. Ryumin to L. Popov.
At a press conference on October 14, 1985, dedicated to the results of the work in orbit of cosmonauts V. Dzhanibekov and G. Grechko on board the Salyut-7 orbital station, the flight engineer (G. Grechko) said: “To all living things, to every sprout in space has a special, caring attitude: they remind you of the Earth and lift your spirits.”
Thus, higher plants are needed by astronauts not only as a link in an artificial ecological system or an object of scientific research, but also as an aesthetic element of the familiar earthly environment, a living companion of the astronaut in his long, difficult and intense mission. And isn’t it this aesthetic side and psychological role of the greenhouse on board the spacecraft that S.P. Korolev had in mind when, in preparation for the upcoming space flights, he formulated the following question as the next one: “What can you have on board a heavy interplanetary spacecraft or a heavy orbital spacecraft?” station (or in a greenhouse) from ornamental plants that require a minimum of cost and care? And the first answer to this question has already been received today: these are tropical orchids, which seem to have liked the atmosphere of the space station.
Discussing the problem of ensuring the reliability and safety of long-term space flights, Academician O. G. Gazenko and co-authors (1987) rightly point out that “sometimes the unconscious spiritual need for contact with living nature becomes a real force, which is supported by strict scientific facts indicating economic efficiency and the technical feasibility of bringing artificial biospheres as close as possible to the natural environment that nurtured humanity. From this point of view, the strategic direction towards the creation of biological life support systems seems very correct.” And further: “Attempts to isolate man from nature are extremely uneconomical. Biological systems will ensure the circulation of substances in large space settlements better than any other.”
One of the fundamental advantages of biological systems in comparison with non-biological ones is the potential for their stable functioning with a minimum volume of control and management functions (E. Ya. Shepelev, 1975). This advantage is due to the natural ability of living systems, which are in constant interaction with the environment, to correct processes for survival at all biological levels - from a single cell of one organism to populations and biogeocenoses - regardless of the degree of understanding of these processes at any given moment by a person and his ability or inability (or rather, his readiness) to make the necessary adjustments to the process of circulation of substances in an artificial ecosystem.
The degree of complexity of artificial space ecosystems can be different: from the simplest systems on reserves, systems with physico-chemical regeneration of substances and the use of individual biological links, to systems with an almost closed biological cycle of substances. The number of biological links and trophic chains, as well as the number of individuals in each link, as already mentioned, depend on the purpose and technical characteristics of the spacecraft.
The efficiency and main parameters of an artificial space ecosystem, including biological links, can be determined in advance and calculated based on a quantitative analysis of the processes of biological circulation of substances in nature and an assessment of the energy efficiency of local natural ecosystems. The next section is devoted to this issue.
RELAY OF SUBSTANCES IN THE BIOLOGICAL CYCLE
A closed ecological system formed on the basis of biological links should be considered as an ideal life support system for future large space settlements. The creation of such systems today is still at the stage of calculations, theoretical constructions and ground testing to interface individual biological links with the test crew.
The main goal of testing experimental biotechnical life-support systems is to achieve a stable, almost closed cycle of substances in an ecosystem with a crew and the relatively independent existence of an artificially formed biocenosis in a long-term dynamic equilibrium mode based primarily on internal control mechanisms. Therefore, a thorough study of the processes of the biological cycle of substances in the Earth’s biosphere is required to use the most effective of them in biotechnical life-support systems.
The biological cycle in nature is a circular relay race (circulation) of substances and chemical elements between soil, plants, animals and microorganisms. Its essence is as follows. Plants (autotrophic organisms) absorb energy-poor inanimate minerals and atmospheric carbon dioxide. These substances are included in the organic biomass of plant organisms, which has a large supply of energy obtained through the conversion of radiant energy from the Sun during the process of photosynthesis. Plant biomass is transformed through food chains in animal and human organisms (heterotrophic organisms) using part of these substances and energy for their own growth, development and reproduction. Destroying organisms (decomposers, or decomposers), including bacteria, fungi, protozoa, and organisms that feed on dead organic matter, mineralize waste. Finally, substances and chemical elements are returned back to the soil, atmosphere or aquatic environment. As a result, a multi-cycle migration of substances and chemical elements occurs through a branched chain of living organisms. This migration, constantly supported by the energy of the Sun, constitutes the biological cycle.
The degree of reproduction of individual cycles of the general biological cycle reaches 90–98%, so we can only talk about its complete closure only conditionally. The main cycles of the biosphere are the cycles of carbon, nitrogen, oxygen, phosphorus, sulfur and other nutrients.
Both living and nonliving substances participate in the natural biological cycle.
Living matter is biogenic, since it is formed only through the reproduction of living organisms already existing on Earth. Non-living matter present in the biosphere can be either of biogenic origin (fallen bark and leaves of trees, ripened and separated fruits from the plant, chitinous covers of arthropods, horns, teeth and hair of animals, bird feathers, animal excrement, etc.), and abiogenic (products of emissions from active volcanoes, gases released from the bowels of the earth).
The living matter of the planet by its mass constitutes an insignificant part of the biosphere: the entire biomass of the Earth in dry weight is only one hundred thousandth of a percent of the mass of the earth's crust (2 ∙ 10 19 tons). However, it is living matter that plays a decisive role in the formation of the “cultural” layer of the earth’s crust, in the implementation of a large-scale relay race of substances and chemical elements between a huge number of living organisms. This is due to a number of specific features of living matter.
Metabolism (metabolism). Metabolism in a living organism is the totality of all transformations of matter and energy in the process of biochemical reactions continuously occurring in the body.
The continuous exchange of substances between a living organism and its environment is the most essential feature of life.
The main indicators of the body's metabolism with the external environment are the quantity, composition and calorie content of food, the amount of water and oxygen consumed by a living organism, as well as the degree to which the body uses these substances and the energy of food. Metabolism is based on the processes of assimilation (transformation of substances entered into the body from the outside) and dissimilation (decomposition of organic substances caused by the need to release energy for the functioning of the body).
Thermodynamic nonequilibrium stability. In accordance with the second law (law) of thermodynamics, to perform work, the presence of energy alone is not enough, but the presence of a potential difference, or energy levels, is also necessary. Entropy is a measure of the “loss” of potential difference by any energy system and, accordingly, a measure of the loss of the ability to produce work by this system.
In processes occurring in inanimate nature, the performance of work leads to an increase in the entropy of the system. Thus, for heat transfer, the direction of the process uniquely determines the second law of thermodynamics: from a more heated body to a less heated one. In a system with zero temperature difference (at the same temperature of the bodies), maximum entropy is observed.
Living matter, living organisms, unlike inanimate nature, counteract this law. Never being in equilibrium, they constantly work against its establishment, which, it would seem, should legally occur as a correspondence to existing external conditions. Living organisms constantly expend energy to maintain the specific state of the living system. This most important feature is known in the literature as the Bauer principle, or the principle of stable disequilibrium of living systems. This principle shows that living organisms are open nonequilibrium systems that differ from nonliving ones in that they evolve in the direction of decreasing entropy.
This feature is characteristic of the biosphere as a whole, which is also a nonequilibrium dynamic system. The living matter of the system is a carrier of enormous potential energy,
The ability for self-reproduction and high intensity of biomass accumulation. Living matter is characterized by a constant desire to increase the number of its individuals, to reproduce. Living matter, including humans, strives to fill all the space acceptable for life. The intensity of reproduction of living organisms, their growth and accumulation of biomass is quite high. The rate of reproduction of living organisms, as a rule, is inversely proportional to their size. The variety of sizes of living organisms is another feature of living nature.
High rates of metabolic reactions in living organisms, three to four orders of magnitude higher than the rates of reactions in inanimate nature, are due to the participation of biological accelerators - enzymes - in metabolic processes. However, to increase each unit of biomass or accumulate a unit of energy, a living organism needs to process the initial mass in quantities one or two orders of magnitude higher than the accumulated mass.
Capacity for diversity, renewal and evolution. The living matter of the biosphere is characterized by different, very short (on a cosmic scale) life cycles. The lifespan of living creatures ranges from several hours (and even minutes) to hundreds of years. In the process of their life activity, organisms pass through themselves atoms of chemical elements of the lithosphere, hydrosphere and atmosphere, sorting them and binding chemical elements in the form of specific substances of the biomass of a given type of organism. Moreover, even within the framework of the biochemical uniformity and unity of the organic world (all modern living organisms are built mainly from proteins), living nature is distinguished by its enormous morphological diversity and variety of forms of matter. In total, there are more than 2 million organic compounds that make up living matter. For comparison, we note that the number of natural compounds (minerals) of nonliving matter is only about 2 thousand. The morphological diversity of living nature is also great: the plant kingdom on Earth includes almost 500 thousand species, and animals - 1 million 500 thousand.
A formed living organism within one life cycle has limited adaptive capabilities to changes in environmental conditions. However, the relatively short life cycle of living organisms contributes to their constant renewal from generation to generation by transmitting information accumulated by each generation through the genetic hereditary apparatus, and taking this information into account by the next generation. From this point of view, the short life span of organisms of one generation is the price they pay for the need for the survival of the species as a whole in a constantly changing external environment.
The evolutionary process is characteristic mainly of higher organisms.
Collectivity of existence. Living matter actually exists on Earth in the form of biocenoses, and not individual isolated species (populations). The interconnection of populations is due to their trophic (food) dependencies on each other, without which the very existence of these species is impossible.
These are the main qualitative features of living matter participating in the biosphere biological cycle of substances. In quantitative terms, the intensity of biomass accumulation in the biosphere is such that, on average, every eight years all living matter in the Earth’s biosphere is renewed. Having completed their life cycle, organisms return to nature everything that they took from it during their lives.
The main functions of living matter in the biosphere, formulated by the domestic geologist A.V. Lapo (1979), include energy (biosynthesis with energy accumulation and energy transformation in trophic chains), concentration (selective accumulation of matter), destructive (mineralization and preparation of substances for inclusion in the cycle ), environment-forming (change in physical and chemical parameters of the environment) and transport (substance transfer) functions.
DO ECOSYSTEMS HAVE EFFICIENCY?
Let us now try to answer the question: is it possible to assess the effectiveness of the biological cycle of substances from the standpoint of meeting the nutritional needs of humans as the apex trophic link of this cycle?
An approximate answer to the question posed can be obtained on the basis of an energy approach to the analysis of biological cycle processes and the study of energy transfer and productivity of natural ecosystems. Indeed, if the substances of the cycle are subject to continuous qualitative changes, then the energy of these substances does not disappear, but is distributed in directed flows. Transferred from one trophic level of the biological cycle to another, biochemical energy is gradually transformed and dissipated. The transformation of the energy of matter at trophic levels does not occur arbitrarily, but in accordance with known patterns, and therefore it is controlled within a specific biogeocenosis.
The concept of “biogeocenosis” is similar to the concept of “ecosystem”, but the former carries a more strict semantic load. If an ecosystem is called almost any autonomously existing natural or artificial biocomplex (anthill, aquarium, swamp, dead tree trunk, forest, lake, ocean, Earth's biosphere, spaceship cabin, etc.), then biogeocenosis, being one of the qualitative levels of the ecosystem , is specified by the boundaries of its obligatory plant community (phytocenosis). An ecosystem, like any stable set of living organisms interacting with each other, is a category applicable to any biological system only at the supraorganism level, i.e., an individual organism cannot be an ecosystem.
The biological cycle of substances is an integral part of the earth’s biogeocenosis. Within specific local biogeocenoses, biological circulation of substances is possible, but not required.
Energy connections always accompany trophic connections in biogeocenosis. Together they form the basis of any biogeocenosis. In general, five trophic levels of biogeocenosis can be distinguished (see table and Fig. 2), through which all its components are distributed sequentially along the chain. Typically, several such chains are formed in biogeocenoses, which, branching and intersecting many times, form complex food (trophic) networks.
Trophic levels and food chains in biogeocenosis
Organisms of the first trophic level - primary producers, called autotrophs (self-feeding) and including microorganisms and higher plants, carry out the processes of synthesis of organic substances from inorganic ones. As an energy source for this process, autotrophs use either light solar energy (phototrophs) or the energy of oxidation of certain mineral compounds (chemotrophs). Phototrophs obtain the carbon necessary for synthesis from carbon dioxide.
Conventionally, the process of photosynthesis in green plants (lower and higher) can be described in the form of the following chemical reaction:
Ultimately, organic matter (mainly carbohydrates) is synthesized from energy-poor inorganic substances (carbon dioxide, water, mineral salts, microelements), which is the carrier of energy stored in the chemical bonds of the formed substance. In this reaction, 673 kcal of solar energy is required to form one gram molecule of a substance (180 g of glucose).
The efficiency of photosynthesis directly depends on the intensity of light irradiation of plants. On average, the amount of radiant solar energy on the Earth's surface is about 130 W/m2. In this case, only part of the radiation contained within the wavelength range from 0.38 to 0.71 microns is photosynthetically active. A significant part of the radiation falling on a plant leaf or a layer of water with microalgae is reflected or passes through the leaf or layer uselessly, and the absorbed radiation is mostly spent on the evaporation of water during plant transpiration.
As a result, the average energy efficiency of the photosynthetic process of the entire plant cover of the globe is about 0.3% of the energy of sunlight entering the Earth. In conditions favorable for the growth of green plants and with human assistance, individual plantations can bind light energy with an efficiency of 5–10%.
Organisms of subsequent trophic levels (consumers), consisting of heterotrophic (animal) organisms, ultimately ensure their livelihoods at the expense of plant biomass accumulated in the first trophic level. The chemical energy stored in plant biomass can be released, converted into heat and dissipated into the environment in the process of reverse combination of carbohydrates with oxygen. Using plant biomass as food, animals subject it to oxidation during respiration. In this case, the reverse process of photosynthesis occurs, in which food energy is released and, with a certain efficiency, is spent on the growth and vital activity of a heterotrophic organism.
In quantitative terms, in a biogeocenosis, plant biomass should be “ahead” of animal biomass, usually by at least two orders of magnitude. Thus, the total biomass of animals on the earth’s land does not exceed 1–3% of its plant biomass.
The intensity of energy metabolism of a heterotrophic organism depends on its mass. With an increase in the size of the body, the metabolic rate, calculated per unit of weight and expressed in the amount of oxygen absorbed per unit of time, noticeably decreases. Moreover, in a state of relative rest (standard metabolism), the dependence of the animal’s metabolic rate on its mass, which has the form of a function y = Ax k (X– weight of the animal, A And k- coefficients), turns out to be valid both for organisms of the same species that change their size during growth, and for animals of different weights, but representing a certain group or class.
At the same time, the indicators of the level of metabolism of different groups of animals already differ significantly from each other. These differences are especially significant for animals with an active metabolism, which are characterized by energy expenditure on muscle work, in particular on motor functions.
The energy balance of an animal organism (consumer of any level) for a certain period of time can generally be expressed by the following equality:
E = E 1 + E 2 + E 3 + E 4 + E 5 ,
Where E– energy (calorie content) of food (kcal per day), E 1 – basal metabolic energy, E 2 – energy consumption of the body, E 3 – energy of the body’s “clean” production, E 4 – energy of unused food substances, E 5 – energy of excrement and body secretions.
Food is the only source of normal energy entering the animal and human body, which ensures its vital functions. The concept of “food” has different qualitative content for different animal organisms and includes only those substances that are consumed and utilized by a given living organism and. are necessary for him.
Magnitude E for a person is an average of 2500 kcal per day. Basal metabolic energy E 1 represents metabolic energy in a state of complete rest of the body and in the absence of digestive processes. It is spent on maintaining life in the body, is a function of the size of the body surface and is transformed into heat given off by the body to the environment. Quantitative indicators E 1 is usually expressed in specific units per 1 kg of mass or 1 m 2 of the surface of the body. Yes, for a person E 1 is 32.1 kcal per day per 1 kg of body weight. Per unit surface area E 1 different organisms (mammals) are practically the same.
Component E 2 includes the body’s energy consumption for thermoregulation when the ambient temperature changes, as well as for various types of activity and body work: chewing, digestion and assimilation of food, muscle work when moving the body, etc. By the amount E 2 the ambient temperature has a significant influence. When the temperature rises and falls from the optimal level for the body, additional energy expenditure is required to regulate it. The process of regulating constant body temperature in warm-blooded animals and humans is especially developed.
Component E 3 includes two parts: the energy of growth of the organism’s own biomass (or population) and the energy of additional production.
An increase in one’s own biomass occurs, as a rule, in a young growing organism that is constantly gaining weight, as well as in an organism that forms reserve nutrients. This part of the component E 3 can be equal to zero, and also take negative values when there is a lack of food (the body loses weight).
The energy of additional production is contained in substances produced by the body for reproduction, protection from enemies, etc.
Each individual is limited to the minimum amount of products created in the process of its life. A relatively high rate of creation of secondary products can be considered an indicator of 10–15% (of consumed feed), characteristic, for example, of locusts. The same indicator for mammals, which spend a significant amount of energy on thermoregulation, is at the level of 1 – 2%.
Component E 4 is the energy contained in food substances that were not used by the body and did not enter the body for one reason or another.
Energy E 5, contained in body secretions as a result of incomplete digestion and assimilation of food, ranges from 30–60% of food consumed (in large ungulates) to 1–20% (in rodents).
The efficiency of energy conversion by an animal organism is quantitatively determined by the ratio of net (secondary) production to the total amount of food consumed or the ratio of net production to the amount of digested food. In a food chain, the efficiency (efficiency) of each trophic link (level) averages about 10%. This means that at each subsequent trophic level of a food goal, products are formed that do not exceed in caloric content (or in terms of mass) 10% of the energy of the previous one. With such indicators, the overall efficiency of using primary solar energy in the food chain of an ecosystem of four levels will be a small fraction of a percent: on average, only 0.001%.
Despite the seemingly low value of the overall efficiency of production reproduction, the majority of the Earth's population fully provides itself with a balanced diet not only from primary, but also from secondary producers. As for a living organism individually, the efficiency of food (energy) use in some of them is quite high and exceeds the efficiency indicators of many technical means. For example, a pig converts 20% of the food energy consumed into high-calorie meat.
The efficiency of consumers' use of energy supplied by food is usually assessed in ecology using ecological energy pyramids. The essence of such pyramids is a visual representation of the links of the food chain in the form of a subordinate arrangement of rectangles on top of each other, the length or area of which corresponds to the energy equivalent of the corresponding trophic level per unit time. To characterize food chains, pyramids of numbers are also used (the areas of the rectangles correspond to the number of individuals at each level of the food chain) and pyramids of biomass (the same in relation to the amount of total biomass of organisms at each level).
However, the energy pyramid provides the most complete picture of the functional organization of biological communities within a specific food chain, since it allows one to take into account the dynamics of the passage of food biomass through this chain.
ARTIFICIAL AND NATURAL BIOSPHERE ECOSYSTEMS: SIMILARITIES AND DIFFERENCES
K. E. Tsiolkovsky was the first to propose creating a closed system in a space rocket for the circulation of all substances necessary for the life of the crew, i.e., a closed ecosystem. He believed that in a spacecraft, all the basic processes of transformation of substances that take place in the Earth's biosphere should be reproduced in miniature. However, for almost half a century this proposal existed as a science fiction hypothesis.
Practical work on the creation of artificial space ecosystems based on the processes of biological circulation of substances rapidly developed in the USA, USSR and some other countries in the late 50s and early 60s. There is no doubt that this was facilitated by the successes of astronautics, which opened the era of space exploration with the launch of the first artificial Earth satellite in 1957.
In subsequent years, as these works expanded and deepened, most researchers could be convinced that the problem posed turned out to be much more complex than originally thought. It required carrying out not only ground-based but also space research, which, in turn, necessitated significant material and financial costs and was hampered by the lack of large spacecraft or research stations. Nevertheless, in the USSR during this period, separate terrestrial experimental samples of ecosystems were created with the inclusion of some biological links and humans in the current cycle of the circulation of substances of these systems. A set of scientific studies was also carried out to develop technologies for cultivating biological objects in zero gravity on board space satellites, ships and stations: “Cosmos-92”, “Cosmos-605”, “Cosmos-782”, “Cosmos-936”, “Salyut-6” and others. The research results today allow us to formulate some provisions that are taken as the basis for the construction of future closed space ecosystems and biological life support systems for astronauts.
So, what is common to large artificial space ecosystems and the natural biosphere. ecosystems? First of all, this is their relative isolation, their main characters are humans and other living biological units, the biological cycle of substances and the need for an energy source.
Closed ecological systems are systems with an organized cycle of elements, in which substances used at a certain rate for biological exchange by some units are regenerated at the same average speed from the final products of their exchange to their original state by other units and are again used in the same cycles of biological exchange. (Gitelzon et al., 1975).
At the same time, the ecosystem can remain closed without achieving a complete cycle of substances, irreversibly consuming some of the substances from previously created reserves.
The natural terrestrial ecosystem is practically closed in matter, since only terrestrial substances and chemical elements participate in the cycles of circulation (the share of cosmic matter that annually falls on the Earth does not exceed 2 × 10–14 percent of the Earth’s mass). The degree of participation of earthly substances and elements in repeatedly repeating chemical cycles of the earth’s cycle is quite high and, as already noted, ensures the reproduction of individual cycles by 90–98%.
In an artificial closed ecosystem it is impossible to replicate all the diversity of processes in the earth's biosphere. However, one should not strive for this, since the biosphere as a whole cannot serve as an ideal of an artificial closed ecosystem with humans, based on the biological cycle of substances. There are a number of fundamental differences that characterize the biological cycle of substances artificially created in a limited enclosed space for the purpose of human life support.
What are these main differences?
The scale of the artificial biological cycle of substances as a means of ensuring human life in a limited enclosed space cannot be comparable with the scale of the earth's biological cycle, although the basic patterns that determine the course and efficiency of processes in its individual biological links can be applied to characterize similar links in an artificial ecosystem. In the Earth's biosphere, the actors are almost 500 thousand species of plants and 1.5 million species of animals, capable of replacing each other in certain critical circumstances (for example, the death of a species or population), maintaining the stability of the biosphere. In an artificial ecosystem, the representativeness of species and the number of individuals are very limited, which sharply increases the “responsibility” of each living organism included in the artificial ecosystem and places increased demands on its biological stability in extreme conditions.
In the Earth's biosphere, the circulation of substances and chemical elements is based on a huge number of diverse, independent and cross cycles, not coordinated in time and space, each of which occurs at its own characteristic speed. In an artificial ecosystem, the number of such cycles is limited, the role of each cycle in the cycle of substances; increases many times over, and the agreed rates of processes in the system must be strictly maintained as a necessary condition for the sustainable operation of a biological life-support system.
The presence of dead-end processes in the biosphere does not significantly affect the natural cycle of substances, since on Earth there are still significant quantities of reserves of substances involved in the cycle for the first time. In addition, the mass of substances in dead-end processes is immeasurably less than the Earth's buffer capacity. In artificial space LSS, the always existing general restrictions on mass, volume and energy consumption impose corresponding restrictions on the mass of substances participating in the cycle of biological LSS. The presence or formation in this case of any dead-end process significantly reduces the efficiency of the system as a whole, reduces the indicator of its closedness, requires appropriate compensation from the reserves of initial substances, and, consequently, an increase in these reserves in the system.
The most important feature of the biological cycle of substances in the artificial ecosystems under consideration is the determining role of humans in the qualitative and quantitative characteristics of the cycle of substances. The circulation in this case is carried out ultimately in the interests of satisfying the needs of the person (crew), who is the main driving force. The remaining biological objects perform the functions of maintaining the human environment. Based on this, each biological species in an artificial ecosystem is provided with the most optimal conditions of existence to achieve maximum productivity of the species. In the Earth's biosphere, the intensity of biosynthesis processes is determined primarily by the flow of solar energy into a particular region. In most cases, these possibilities are limited: the intensity of solar radiation on the Earth's surface is approximately 10 times lower than outside the Earth's atmosphere. In addition, every living organism, in order to survive and develop, constantly needs to adapt to living conditions, take care of finding food, spending a significant part of its vital energy on this. Therefore, the intensity of biosynthesis in the Earth’s biosphere cannot be considered optimal from the standpoint of the main function of biological life-supporting liquids – meeting human nutritional needs.
Unlike the Earth's biosphere, artificial ecosystems exclude large-scale abiotic processes and factors that play a noticeable, but often blind role in the formation of the biosphere and its elements (weather and climate impacts, depleted soils and unsuitable territories, chemical properties of water, etc.).
These and other differences contribute to achieving significantly greater efficiency of transformation of matter in artificial ecosystems, a higher speed of implementation of circulation cycles, and higher efficiency values of the human biological life support system.
ABOUT BIOLOGICAL LIFE SUPPORT SYSTEMS FOR SPACE CREWS
Biological life support is an artificial set of specifically selected, interconnected and interdependent biological objects (microorganisms, higher plants, animals), consumable substances and technical means, providing in a limited enclosed space the basic physiological needs of a person for food, water and oxygen, mainly on the basis of sustainable biological circulation of substances.
The necessary combination of living organisms (bioobjects) and technical means in biological life-support systems allows us to call these systems also biotechnical. In this case, technical means are understood as subsystems, blocks and devices that provide the required conditions for the normal life of biological objects included in the biocomplex (composition, pressure, temperature and humidity of the gas environment, illumination of the living space, sanitary and hygienic indicators of water quality, operational collection, processing or waste disposal, etc.). The main technical means of biological life support include subsystems for energy supply and energy conversion into light, regulation and maintenance of the gas composition of the atmosphere in a limited enclosed space, temperature control, space greenhouse units, kitchens and means of physical and chemical regeneration of water and air, processing, transportation and mineralization devices waste etc. A number of processes for the regeneration of substances in the system can also be effectively carried out using physico-chemical methods (see figure on page 52).
Biological objects of LSS together with humans form a biocomplex. The species and numerical composition of living organisms included in the biocomplex is determined so that it can ensure a stable, balanced and controlled metabolism between the crew and the living organisms of the biocomplex over the entire specified period. The dimensions (scale) of the biocomplex and the number of species of living organisms represented in the biocomplex depend on the required productivity, the degree of closure of the life support system and are established in connection with the specific technical and energy capabilities of the space structure, the duration of its operation, and the number of crew members. The principles for selecting living organisms into a biocomplex can be borrowed from the ecology of natural terrestrial communities and managed biogeocenoses, based on the established trophic relationships of biological objects.
The selection of biological species for the formation of trophic cycles of biological life-supporting liquids is the most difficult task.
Each biological object participating in a biological life-sustaining system requires for its life activity a certain living space (ecological niche), which includes not only purely physical space, but also a set of necessary living conditions for a given biological species: ensuring its way of life, method of nutrition, and environmental conditions. Therefore, for the successful functioning of living organisms as a part of a biological life-support system, the volume of space they occupy should not be too limited. In other words, there must be maximum minimum dimensions of a manned spacecraft, below which the possibility of using biological life support components in it is excluded.
In an ideal case, the entire initially stored mass of substances, intended for the life support of the crew and including all living inhabitants, should participate in the circulation of substances inside this space object without introducing additional mass into it. At the same time, such a closed biological life-support system with the regeneration of all substances necessary for humans and an unlimited operating time is today more theoretical than a practically real system, if we bear in mind those variants of it that are being considered for space expeditions in the near future.
In the thermodynamic sense (in terms of energy), any ecosystem cannot be closed, since constant energy exchange between the living parts of the ecosystem and the surrounding space is a necessary condition for its existence. The Sun can serve as a source of free energy for biological life support systems of spacecraft in circumsolar space. However, the need for a significant amount of energy for the functioning of large-scale biological life support systems requires effective technical solutions to the problem of continuous collection, concentration and input of solar energy into a spacecraft, as well as the subsequent release of low-potential energy into outer space thermal energy.
A special question that arises in connection with the use of living organisms in space flight is how they are affected by prolonged weightlessness? Unlike other factors of space flight and outer space, the effect of which on living organisms can be imitated and studied on Earth, the effect of weightlessness can only be determined directly in space flight.
GREEN PLANTS AS THE BASIC LINK OF BIOLOGICAL LIFE SUPPORT SYSTEMS
Higher terrestrial plants are considered the main and most probable elements of the biological life support system. They are capable of not only producing food that is complete according to most criteria for humans, but also regenerating water and the atmosphere. Unlike animals, plants are able to synthesize vitamins from simple compounds. Almost all vitamins are formed in the leaves and other green parts of plants.
The efficiency of biosynthesis of higher plants is determined primarily by the light regime: with an increase in the power of the light flux, the intensity of photosynthesis increases to a certain level, after which light saturation of photosynthesis occurs. The maximum (theoretical) efficiency of photosynthesis in sunlight is 28%. In real conditions, for dense crops with good cultivation conditions, it can reach: 15%.
The optimal intensity of physiological (photosynthetically active) radiation (PAR), which ensured maximum photosynthesis under artificial conditions, was 150–200 W/m2 (Nichiporovich, 1966). The productivity of plants (spring wheat, barley) reached 50 g of biomass per day per 1 m2 (up to 17 g of grain per 1 m2 per day). In other experiments carried out to select light regimes for the cultivation of radishes in closed systems, the yield of root crops was up to 6 kg per 1 m 2 in 22 - 24 days with biological productivity up to 30 g of biomass (in dry weight) per 1 m 2 per day (Lisovsky , Shilenko, 1970). For comparison, we note that in field conditions the average daily productivity of crops is 10 g per 1 m 2.
The biocycle: “higher plants - man” would be ideal for human life support if during a long space flight one could be satisfied with the nutrition of proteins and fats only of plant origin and if plants could successfully mineralize and utilize all human waste.
The space greenhouse, however, will not be able to solve the entire range of issues assigned to the biological life support system. It is known, for example, that higher plants are not able to ensure participation in the cycle of a number of substances and elements. Thus, sodium is not consumed by plants, leaving open the problem of the NaCl (table salt) cycle. Fixation of molecular nitrogen by plants is impossible without the help of root nodule soil bacteria. It is also known that, in accordance with the physiological norms of human nutrition approved in the USSR, at least half of the daily norm of dietary proteins should be proteins of animal origin, and animal fats - up to 75% of the total norm of fats in the diet.
If the calorie content of the plant part of the diet in accordance with the mentioned standards is 65% of the total calorie content of the diet (the average calorie value of the daily food ration of an astronaut at the Salyut-6 station was 3150 kcal), then to obtain the required amount of plant biomass, a greenhouse with an estimated area of one person at least 15 - 20 m2. Taking into account plant waste that is not consumed for food (about 50%), as well as the need for a food conveyor for continuous daily reproduction of biomass, the actual area of the greenhouse should be increased by at least 2–3 times.
The efficiency of a greenhouse can be significantly increased with the additional use of the inedible part of the resulting biomass. There are various ways to utilize biomass: obtaining nutrients by extraction or hydrolysis, physico-chemical or biological mineralization, direct use after appropriate cooking, use in the form of animal feed. The implementation of these methods requires the development of appropriate additional technical means and energy costs, so the optimal solution can only be obtained taking into account the total technical and energy indicators of the ecosystem as a whole.
At the initial stages of the creation and use of biological life-supporting liquids, certain issues of the complete cycle of substances have not yet been resolved; part of the consumable substances will be taken from the reserves provided on board the spacecraft. In these cases, the greenhouse is entrusted with the function of reproducing the minimum required amount of fresh herbs containing vitamins. A greenhouse with a planting area of 3–4 m2 can fully meet the vitamin needs of one person. In such ecosystems, based on the partial use of the biocycle of higher plants - humans, the main load for the regeneration of substances and the life support of the crew is performed by systems with physico-chemical processing methods.
The founder of practical cosmonautics, S.P. Korolev, dreamed of a space flight not bound by any restrictions. Only such a flight, according to S.P. Korolev, will mean victory over the elements. In 1962, he formulated a set of priority tasks for space biotechnology as follows: “We need to start developing a “greenhouse according to Tsiolkovsky”, with gradually increasing links or blocks, and we need to start working on “space harvests.” What is the composition of these crops, what crops? Their effectiveness, usefulness? Reversibility (repeatability) of crops from your own seeds, based on the long-term existence of the greenhouse? What organizations will carry out this work: in the area of crop production (and issues of soil, moisture, etc.), in the area of mechanization and “light-heat-solar” technology and its regulation systems for greenhouses, etc.?”
This formulation reflects, in fact, the main scientific and practical goals and objectives, the achievement and solution of which must be ensured before a “greenhouse according to Tsiolkovsky” is created, i.e., a greenhouse that will supply a person with the necessary fresh food during a long space flight. food of plant origin, as well as purify water and air. The space greenhouse of future interplanetary spacecraft will become an integral part of their design. In such a greenhouse, optimal conditions for sowing, growth, development and collection of higher plants must be provided. The greenhouse must also be equipped with devices for light distribution and air conditioning, units for the preparation, distribution and supply of nutrient solutions, collection of transpiration moisture, etc. Soviet and foreign scientists are successfully working on the creation of such large-scale greenhouses for spacecraft in the near future.
Space plant growing today is still at the initial stage of its development and requires new special research, since many questions related to the reaction of higher plants to the extreme conditions of space flight, and above all to conditions of weightlessness, still remain unclear. The state of weightlessness has a very significant impact on many physical phenomena, on the life activity and behavior of living organisms, and even on the operation of on-board equipment. The effectiveness of the influence of dynamic weightlessness can therefore only be assessed in so-called full-scale experiments carried out directly on board orbital space stations.
Experiments with plants under natural conditions were previously carried out on the Salyut stations and satellites of the Cosmos series (Cosmos-92, 605, 782, 936, 1129, etc.). Particular attention was paid to experiments on growing higher plants. For this purpose, various special devices were used, each of which was given a specific name, for example, “Vazon”, “Svetoblok”, “Fiton”, “Biogravistat”, etc. Each device, as a rule, was intended to solve one problem. Thus, a small centrifuge “Biogravistat” served for a comparative assessment of the processes of growing seedlings in zero gravity and in the field of centrifugal forces. The “Vazon” device tested the processes of growing onions as a vitamin supplement to the astronauts’ diet. In the “Svetoblok” device, for the first time, an Arabidopsis plant, planted in an isolated chamber on an artificial nutrient medium, bloomed under zero-gravity conditions, and in the “Fiton” device, Arabidopsis seeds were obtained. A wider range of problems was solved in the Oasis research installations, consisting of cultivation units, lighting, water supply, forced ventilation and a telemetric temperature control system. In the “Oasis” installation, cultivation regimes with electrical stimulation were tested on pea and wheat plants as a means of reducing the effect of unfavorable factors associated with the lack of gravity.
A number of experiments with higher plants under space flight conditions were carried out in the USA at Skylab, Spacelab and on board Columbia (Shuttle).
Numerous experiments have shown that the problem of growing plants on space objects under conditions significantly different from ordinary earthly ones has not yet been fully solved. It is also not uncommon, for example, for cases when plants stop growing at the generative stage of development. There is still a significant amount of scientific experimentation to be carried out to develop the technology of cultivating plants at all stages of their growth and development. It will also be necessary to develop and test the designs of plant cultivators and individual technical means that will help eliminate the negative influence of various factors of space flight on plants.
In addition to higher terrestrial plants, lower plants are also considered as elements of the autotrophic link of closed ecosystems. These include aquatic phototrophs - unicellular algae: green, blue-green, diatoms, etc. They are the main producers of primary organic matter in the seas and oceans. The most widely known is the freshwater microscopic algae Chlorella, which many scientists prefer as the main biological object of the producing link of a closed space ecosystem.
Chlorella culture is characterized by a number of positive features. By assimilating carbon dioxide, the culture releases oxygen. With intensive cultivation, 30–40 liters of chlorella suspension can completely ensure the gas exchange of one person. In this case, biomass is formed, which, in terms of its biochemical composition, is acceptable for use as a feed additive, and, with appropriate processing, as an additive to the human diet. The ratio of proteins, fats and carbohydrates in chlorella biomass can vary depending on cultivation conditions, which allows for a controlled biosynthesis process. The productivity of intensive chlorella cultures during laboratory cultivation ranges from 30 to 60 g of dry matter per 1 m2 per day. In experiments on special laboratory cultivators under high light, the yield of chlorella reaches 100 g of dry matter per 1 m2 per day. Chlorella is least affected by weightlessness. Its cells have a durable cellulose-containing shell and are most resistant to unfavorable living conditions.
The disadvantages of chlorella as a link in an artificial ecosystem include the discrepancy between the coefficient of CO 2 assimilation and the coefficient of human respiration, the need for increased concentrations of CO 2 in the gas phase for the effective operation of the biological regeneration link, some discrepancy in the needs of chlorella algae for biogenic elements with the presence of these elements in human excretions, the need for special treatment of chlorella cells to achieve biomass digestibility. Unicellular algae in general (in particular, Chlorella), unlike higher plants, lack regulatory devices and require automated control of the biosynthesis process for reliable effective functioning in culture.
The maximum efficiency values in experiments for all types of algae are in the range from 11 to 16% (the theoretical efficiency of light energy utilization by microalgae is 28%). However, high crop productivity and low energy consumption are usually contradictory requirements, since maximum efficiency values are achieved at relatively low optical densities of the crop.
Currently, the unicellular alga Chlorella, as well as some other types of microalgae (Scenedesmus, Spirulina, etc.) are used as model biological objects of the autotrophic link of artificial ecosystems.
ACHIEVEMENTS AND PROSPECTS
With the accumulation of practical experience in the study and development of near-Earth space, space research programs are becoming more and more complex. It is necessary to solve the main issues of the formation of biological life-support systems for future long-term space missions today, since scientific experiments performed with parts of biological life-support systems are characterized by a long duration from the beginning until the final result is obtained. This is due, in particular, to the relatively long development cycles that objectively exist in many living organisms chosen as links in biological life support systems, as well as the need to obtain reliable information on the long-term consequences of trophic and other connections of biolinks, which for living organisms can usually appear only in subsequent generations. There are no methods for accelerating such biological experiments yet. It is precisely this circumstance that requires the launching of experiments to study energy and mass transfer processes in biological life-support systems, including humans, significantly ahead of time.
It is clear that the main issues of creating biological life support systems for space crews must first be worked out and resolved in ground conditions. For these purposes, special technical and medical-biological centers have been created and are being created, including powerful research and testing bases, large-volume pressurized chambers, stands simulating space flight conditions, etc. In complex ground-based experiments carried out in pressurized chambers with the participation of groups of testers, The compatibility of systems and links with each other and with humans is determined, the stability of biological links in a long-functioning artificial ecosystem is clarified, the effectiveness and reliability of the decisions made is assessed, and a choice of a biological life support option is made for its final in-depth study in relation to a specific space object or flight.
In the 60s and 70s, a number of unique scientific experiments were carried out in the USSR aimed at creating biological life support systems for crews of artificial space ecosystems. In November 1968, a long-term (year-long) experiment with the participation of three testers was completed in the USSR. Its main goals were to test and test the technical means and technologies of an integrated life support system based on physico-chemical methods of regeneration of substances and a biological method of replenishing human needs for vitamins and fiber when cultivating green crops in a greenhouse. In this experiment, the sown area of the greenhouse was only 7, 5 m2, biomass productivity per person averaged 200 g per day. The set of crops included Khibiny cabbage, borage, watercress and dill.
During the experiment, the possibility of normal cultivation of higher plants in a closed volume with human presence in it and the repeated use of transpiration water without its regeneration for irrigating the substrate was established. In the greenhouse, partial regeneration of substances was carried out, ensuring a minimum restriction of food and oxygen - by 3 - 4%.
In 1970, at the Exhibition of Economic Achievements of the USSR, an experimental model of a life support system was demonstrated, presented by the All-Union Scientific Research Biotechnical Institute of the Glavmicrobioprom of the USSR and intended to determine the optimal composition of a complex of biotechnical units and their operating mode. The life support system of the mock-up was designed to satisfy the needs of three people for water, oxygen and fresh plant products for an unlimited period of time. The main regeneration blocks in the system were represented by an algae cultivator with a capacity of 50 l and a greenhouse with a useful area of about 20 m2 (Fig. 3). The reproduction of animal food products was entrusted to the chicken cultivator.
 Rice. 3. Exterior of the greenhouse |
A series of experimental studies of ecosystems including humans was carried out at the Institute of Physics of the Siberian Branch of the USSR Academy of Sciences. An experiment with a two-link system “man – microalgae” (chlorella) lasting 45 days made it possible to study the mass transfer between the links of the system and the environment and achieve an overall closedness of the cycle of substances equal to 38% (regeneration of the atmosphere and water).
The experiment with a three-link system “human – higher plants – microalgae” was carried out for 30 days. The goal is to study the compatibility of humans with higher plants under completely closed gas exchange and partially closed water exchange. At the same time, an attempt was made to close the food chain through plant (vegetable) biomass. The results of the experiment showed the absence of mutual inhibitory influence of the system links through the general atmosphere during the experiment. The minimum planting area for a continuous vegetable crop was determined to fully meet the needs of one person for fresh vegetables under the selected cultivation regime (2.5 - 3 m2).
With the introduction of the fourth link into the system - a microbial cultivator designed to process non-food plant waste and return it to the system, a new experiment with a person lasting 73 days was started. During the experiment, gas exchange of the units was completely closed, water exchange was almost completely closed (excluding samples for chemical analysis), and food exchange was partially closed. During the experiment, a deterioration in the productivity of higher plants (wheat) was revealed, explained by the accumulation of plant metabolites or accompanying microflora in the nutrient medium. It was concluded that it was inappropriate to introduce a mineralization link for solid human excretions into the system based on the technical and economic indicators of the four-link biological system.
In 1973, a six-month experiment was completed on the life support of a crew of three people in a closed ecosystem with a total volume of about 300 m 3, which included, in addition to testers, links of higher and lower plants. The experiment was carried out in three stages. During the first stage, which lasted two months, all the crew's oxygen and water needs were met by higher plants, which included wheat, beets, carrots, dill, turnips, kale, radishes, cucumbers, onions and sorrel. Wastewater from the domestic compartment was supplied to the wheat growing medium. Solid and liquid secretions of the crew were removed from the pressurized volume to the outside. The crew's nutritional needs were satisfied partly by higher plants, and partly by dehydrated foods from reserves. Every day, 1953 g of biomass (in dry weight), including 624 g of edible, was synthesized in the higher plants from a planting area of about 40 m2, which amounted to 30% of the crew’s total needs. At the same time, the oxygen needs of three people were fully met (about 1500 liters per day). The closedness of the “human – higher plants” system at this stage was 82%.
At the second stage of the experiment, part of the greenhouse was replaced by a link of lower plants - chlorella. The crew's needs for water and oxygen were satisfied by higher (wheat and vegetable crops) and lower plants, the crew's liquid secretions were sent to an algae reactor, and solid secretions were dried to return the water to the cycle. The crew's meals were carried out similarly to the first stage. A deterioration in wheat growth was revealed due to an increase in the amount of waste water supplied with the nutrient medium per unit of planting area, which was reduced by half.
At the third stage, only vegetable crops were left in the higher plants section, and the main load for regenerating the atmosphere of the hermetic volume was performed by the algae reactor. No waste water was added to the plant nutrient solution. Nevertheless, at this stage of the experiment, intoxication of plants by the atmosphere of the hermetic volume was discovered. The closedness of the system, including chlorella, which utilizes human liquid secretions, increased to 91%.
During the experiment, special attention was paid to the issue of equalizing temporary fluctuations in the exchange of exometabolites of the crew. For this purpose, the testers lived according to a schedule that ensured continuity of ecosystem management and uniformity of the level of mass transfer during the autonomous existence of the ecosystem. During the 6 months of the experiment, there were 4 testers in the system, one of whom lived in it continuously, and three - for 6 months each, being replaced according to a schedule.
The main result of the experiment is proof of the possibility of implementing a biological life support system, autonomously controlled from within, in a limited enclosed space. Analysis of the physiological, biochemical and technological functions of the test subjects did not reveal any directional changes caused by their stay in the artificial ecosystem.
In 1977, a four-month experiment was conducted at the Institute of Physics of the Siberian Branch of the USSR Academy of Sciences with an artificial closed ecosystem “man - higher plants”. The main task is to find a way to preserve the productivity of higher plants in a closed ecosystem. At the same time, the possibility of increasing the closedness of the system by increasing the proportion of the crew’s food ration that can be reproduced in it was also studied. Two testers participated in the experiment (three testers during the first 27 days). The sown area of the phytotron was about 40 m2. The set of crops of higher plants included wheat, chufa, beets, carrots, radishes, onions, dill, kale, cucumbers, potatoes and sorrel. In the experiment, forced circulation of the internal atmosphere was organized along the contour “living compartment – phytotrons (greenhouse) – living compartment.” The experiment was a continuation of the previous experiment with a closed ecosystem “man – higher plants – lower plants”.
During the experiment, the first stage of which reproduced the conditions of the previous one, a decrease in plant photosynthesis was revealed, which began on the 5th day and lasted up to 24 days. Next, thermocatalytic purification of the atmosphere was turned on (afterburning of accumulated toxic gaseous impurities), as a result of which the inhibitory effect of the atmosphere on plants was removed and the photosynthetic productivity of phytotrons was restored. Due to the additional carbon dioxide obtained from burning straw and cellulose, the reproducible part of the crew's diet was increased to 60% by weight (up to 52% by calorie content).
The water exchange in the system was partially closed: the source of drinking and partially sanitary water was the condensate of plant transpiration moisture, a nutrient medium with the addition of household waste water was used to irrigate wheat, and the water balance was maintained by introducing distilled water in quantities that compensated for the removal of human liquid excretions from the system .
At the end of the experiment, no negative reactions of the testers’ bodies to the complex effects of the conditions of a closed system were detected. Plants fully provided the testers with oxygen, water and the main part of plant food.
Also in 1977, a month and a half experiment with two test subjects at the Institute of Medical and Biological Problems of the USSR Ministry of Health was completed. The experiment was conducted to study a closed ecosystem model that included a greenhouse and a chlorella plant.
The experiments performed showed that when carrying out biological regeneration of the atmosphere and water in an artificial ecosystem with the help of green plants, lower plants (chlorella) have greater biological compatibility with humans than higher ones. This follows from the fact that the atmosphere of the living compartment and human emissions adversely affected the development of higher plants and some additional physical and chemical treatment of the air entering the greenhouse was required.
Abroad, work aimed at creating promising life-support systems is most intensively carried out in the United States. Research is carried out in three directions: theoretical (determining the structure, composition and design characteristics), experimental ground (testing of individual biological links) and experimental flight (preparing and conducting biological experiments on manned spacecraft). NASA centers and companies developing spacecraft and systems for them are working on the problem of creating biological life-support systems. Many forward-looking studies involve universities. NASA has created a biosystems department that coordinates work on the program for creating a controlled biotechnical life-support system.
The project to create a grandiose artificial structure in the United States, called “Biosphere-2,” aroused great interest among environmental specialists. This glass, steel and concrete structure is a completely sealed volume equal to 150,000 m 3 and covering an area of 10,000 m 2. The entire volume is divided into large-scale compartments in which physical models of various climatic zones of the Earth are formed, including tropical forest, tropical savanna, lagoon, shallow and deep ocean zones, desert, etc. “Biosphere-2” also houses living quarters for testers, laboratories, workshops, agricultural greenhouses and fish ponds, waste treatment systems and other service systems and technical means necessary for human life. The glass ceilings and walls of the Biosphere-2 compartments should ensure the flow of radiant solar energy to its inhabitants, which will include eight volunteer testers during the first two years. They will have to prove the possibility of active life and activity in isolated conditions based on the internal biosphere circulation of substances.
The Institute of Ecotechnics, which led the creation of Biosphere-2 in 1986, plans to complete its construction this year. Many respected scientists and technical specialists joined the project.
Despite the significant cost of the work (at least $30 million), the implementation of the project will make it possible to conduct unique scientific research in the field of ecology and the Earth’s biosphere, to determine the possibility of using individual elements of “Biosphere-2” in various sectors of the economy (biological purification and water regeneration, air and food). “Such structures will be necessary for the creation of settlements in outer space, and perhaps for the preservation of certain types of living beings on Earth,” says US astronaut R. Schweickart.
The practical significance of the mentioned experiments lies not only in solving individual issues of creating closed space ecosystems that include humans. The results of these experiments are no less important for understanding the laws of ecology and the medical and biological foundations of human adaptation to extreme environmental conditions, clarifying the potential capabilities of biological objects in intensive cultivation modes, developing waste-free and environmentally friendly technologies to meet human needs for quality food, water and air in artificial isolated inhabited structures (underwater settlements, polar stations, geologists' villages in the Far North, defense structures, etc.).
In the future, we can imagine entire waste-free and environmentally friendly cities. For example, the director of the International Institute for Systems Analysis, C. Marchetti, believes: “Our civilization will be able to exist peacefully, and, moreover, in conditions better than the current ones, locked in island cities that are completely self-sufficient, not dependent on the vicissitudes of nature, not in need of any natural resources.” raw materials, neither in natural energy nor guaranteed from pollution.” Let us add that this requires the fulfillment of only one condition: the unification of the efforts of all mankind in peaceful creative work on Earth and in space.
CONCLUSION
The successful solution to the problem of creating large artificial ecosystems, including humans and based on a fully or partially closed biological cycle of substances, is of great importance not only for the further progress of astronautics. In an era when “with such frightening clarity we saw that a second front, the environmental one, was approaching the front of the nuclear-space threat and was joining it” (from the speech of USSR Foreign Minister E. A. Shevardnadze at the 43rd session of the General Assembly UN Assembly), one of the real ways out of the approaching environmental crisis may be the creation of virtually waste-free and environmentally friendly intensive agro-industrial technologies, which should be based on the biological cycle of substances and more efficient use of solar energy.
We are talking about a fundamentally new scientific and technical problem, the results of which can be of great importance for the protection and preservation of the environment, the development and widespread use of new intensive and waste-free biotechnologies, the creation of autonomous automated and robotic complexes for the production of food biomass, the solution of the food program at a high level. modern scientific and technical level. The cosmic is inseparable from the earthly, therefore, even today the results of space programs have a significant economic and social effect in various areas of the national economy.
Space serves and must serve people.
LITERATURE
Blinkin S. A., Rudnitskaya T. V. Phytoncides are around us. – M.: Knowledge, 1981.
Gazenko O. G., Pestov I. D., Makarov V. I. Humanity and space. – M.: Nauka, 1987.
Dadykin V.P. Space plant growing. – M.: Knowledge, 1968.
Dazho R. Fundamentals of ecology. – M.: Progress, 1975.
Closed system: man - higher plants (four-month experiment) / Ed. G. M. Lisovsky. – Novosibirsk-Nauka, 1979.
Cosmonautics. Encyclopedia. / Ed. V. P. Glushko - M.: Soviet Encyclopedia, 1985.
Lapo A.V. Traces of past biospheres. – M.: Knowledge, 1987.
Nichiporovich A. A. Green leaf efficiency. – M.: Knowledge 1964.
Fundamentals of space biology and medicine. / Ed. O G Gazenko (USSR) and M. Calvin (USA). – T. 3 – M.: Nauka, 1975.
Plotnikov V.V. At the crossroads of ecology. – M.: Mysl, 1985
Sytnik K. M., Brion A. V., Gordetsky A. V. Biosphere, ecology, nature conservation. – Kyiv: Naukova Dumka, 1987.
Experimental ecological systems including humans / Ed. V. N. Chernigovsky. – M.: Nauka, 1975
Yazdovsky V.I. Artificial biosphere. – M.: Nauka, 1976
Application
SPACE TOURISM
V. P. MIKHAILOV
In the context of the tourism boom that began everywhere in the 60s, experts drew attention to the possibility of space travel for tourism purposes.
Space tourism is developing in two directions. One of them is purely terrestrial - without space flights. Tourists visit earthly objects - cosmodromes, flight control centers, “star” towns, enterprises for the development and production of space technology elements, and attend and observe the launch of flying spacecraft and launch vehicles.
Earth-based space tourism began in July 1966, when the first bus tours of NASA's launch facilities at Cape Kennedy were organized. In the early 70s, tourists by bus visited the site of complex No. 39, from which astronauts launched on their flight to the Moon, the vertical assembly building (a hangar over 100 m high), where the Saturn-V launch vehicle was assembled and tested and the spacecraft was docked the Apollo ship, the parking lot of the unique tracked chassis that delivers the launch vehicle to the launch pad, and much more. In a special cinema hall they watched newsreels of space events. At that time, up to 6–7 thousand tourists took such an excursion every day in the summer, and about 2 thousand in the low season. Unorganized tourists increased the flow of visitors by another 20–25%.
From the very beginning, such excursions gained wide popularity. Already in 1971, their four millionth participant was recorded. During some launches (for example, to the Moon), the number of tourists was hundreds of thousands.
Another direction is direct space tourism. Although today it is in its infancy, its prospects are broad. In addition to the purely tourist aspect, one must take into account the strategic and economic aspects.
The strategic aspect lies in the possible partial settlement of humanity within the solar system. Of course, this is a matter of the distant future. Settlement will occur over hundreds of years and millennia. A person must get used to living in outer space, settle down in it, accumulate certain experience - unless, of course, any terrestrial or cosmic cataclysms occur, when this process needs to be accelerated. And space tourism is a good model for working out this process. On the other hand, the experience of ensuring human life in space, accumulated during tourist travel, familiarity with equipment and life support devices in space will allow a person to live and work more successfully on Earth in conditions of environmental deterioration, and to use space-based “earthed” technical means and systems.
The economic aspect of space tourism is also very important for astronautics. Some experts see space tourism, focused on the use of personal funds of space tourists, as a significant source of funding for space programs. In their opinion, an increase in cargo flow into space as a result of space tourism by 100 times compared to the current one (which is realistic) will, in turn, reduce the specific cost of launching a unit of payload by 100 - 200 times for the entire cosmonautics as a whole without involving additional government investments.
According to experts, the annual expenditure of humanity on tourism amounts to about 200 billion pounds. Art. In the coming decades, space tourism could account for 5% of this figure, i.e. £10 billion. Art. It is believed that if the cost of a space tour is optimally balanced and at the same time sufficiently high flight safety is ensured (comparable to at least the level of flight safety on a modern passenger jet airliner), then about 100 million people would express a desire to make a space trip in the coming decades. According to other estimates, the flow of space tourists will amount to 100 thousand people annually by 2025, and over the next 50 years the number of people who have been in space will reach about 120 million people.
How much can a space tour cost these days? Let's estimate the upper limit of the "tour package". In the USSR, training an astronaut costs about 1 million rubles, a serial launch vehicle costs 2–3 million rubles, a two-seat spacecraft costs 7–8 million rubles. Thus, a “flight for two” will be approximately 11–13 million rubles, not counting the so-called ground support. This figure could be significantly reduced if the spacecraft was designed in a purely tourist version: not filling it with complex scientific equipment, thereby increasing the number of passengers, preparing them for the flight not according to the astronaut program, but according to a simpler one, etc. It was It would be interesting to determine the cost of a tourist flight more accurately, but this must be done. economists in the field of rocket and space technology.
There are other ways to reduce the cost of a tourist flight into space. One of them is the creation of a special reusable tourist ship. Optimists believe that the cost of a flight on second- and third-generation space transport ships will be comparable to the cost of a flight on a passenger jet, which will predetermine mass space tourism. And yet, experts suggest that the cost of the tour for the first tourists will be about $1 million. In subsequent decades, it will quickly decrease and reach $100 thousand. As the optimally saturated space tourism infrastructure, including a fleet of spacecraft, is achieved, hotels in the orbits of the Earth and on the Moon, continuous production of tourist equipment, training in safety measures, etc., in the conditions of mass tourism, the cost of the tour will drop to 2 thousand dollars. This means that the cost of launching a payload into outer space should be no more 20 dollars/kg. Currently this figure is 7–8 thousand.
There are still many difficulties and unresolved problems on the path of space tourism. However, space tourism is a reality and a 21st milestone. In the meantime, 260 people from ten countries have already contributed money to one of the American organizations that began working in this direction for the development and implementation of a space tourist flight. Some American travel agencies have begun selling tickets for the first Earth-to-Moon tourist flight. The departure date is open. It will be stamped on the ticket, it is believed, in 20 to 30 years.
Yet the Americans are not the first here. In 1927, the world's first international exhibition of spacecraft took place on Tverskaya Street in Moscow. It compiled lists of those wishing to fly to the Moon or Mars. There were a lot of people interested. Maybe some of them have not yet lost hope of going on the first tourist trip into space.
CHRONICLE OF COSMONAUtics*
* Continued (see No. 3, 1989). Based on materials from various news agencies and periodicals, data is provided on the launch of some artificial Earth satellites (AES), starting from November 15, 1989. Launches of the Cosmos satellite are not registered. They are regularly reported, for example, by the journal Nature, and we refer interested readers. A separate appendix is devoted to manned space flights.
ON NOVEMBER 15, 1988, the first test launch of the universal rocket and space transport system "Energia" with the reusable spacecraft "Buran" was carried out in the Soviet Union. Having completed a two-orbit unmanned flight, the Buran orbital vehicle successfully landed in automatic mode on the landing strip of the Baikonur Cosmodrome. The Buran ship is built according to the design of a tailless aircraft with a delta wing of variable sweep. Capable of making controlled descent in the atmosphere with lateral maneuver up to 2000 km. The length of the ship is 36.4 m, the wingspan is about 24 m, the height of the ship standing on the chassis is more than 16 m. The launch weight is more than 100 tons, of which 14 tons are fuel. Its cargo compartment can accommodate a payload weighing up to 30 tons. A pressurized cabin for the crew and equipment with a volume of more than 70 m 3 is built into the bow compartment. The main propulsion system is located at the rear of the ship; two groups of engines for maneuvering are located at the end of the tail section and in the front of the hull. The thermal protective coating, consisting of almost 40 thousand individually profiled tiles, is made of special materials - high-temperature quartz and organic fibers, as well as carbon-based material. The first flight of the reusable Buran spacecraft opens a qualitatively new stage in the Soviet space research program.
ON DECEMBER 10, 1988, the Proton launch vehicle launched the next (19th) Soviet satellite of the Ekran television broadcast into orbit. Launched into geostationary orbit at 99°E. (international registration index “Stationary T”), these satellites are used to transmit television programs in the decimeter wavelength range to the regions of the Urals and Siberia to subscriber receiving devices for collective use.
ON DECEMBER 11, 1988, from the Kourou spaceport in French Guiana, with the help of the Western European Ariane-4 launch vehicle, two communications satellites were launched into geostationary orbit - the English Sky-net-4B and the Astra-1 belonging to the Luxembourg consortium SES. The Astra-1 satellite is intended for retransmission of television programs to local distribution centers in Western European countries. The satellite has 16 medium-power repeaters, most of which are leased by the British organization British Telecom. The estimated position of the satellite “Astra-1” is 19.2° W. d. Initially, the English satellite was supposed to be launched using the American Space Shuttle. However, the Challenger accident in January 1986 disrupted these plans, and they decided to use the Ariane launch vehicle for the launch. The launch of two satellites was carried out by the Ariane-4 launch vehicle, equipped with two solid propellant and two liquid boosters. The Arianespace consortium announced to potential consumers that this rocket model is capable of delivering a payload weighing 3.7 tons to a transfer orbit with an apogee altitude of 36 thousand km. In this version, Ariane-4 is used for the second time. The first launch of the launch vehicle in this configuration was a test launch. Then, in 1988, with its help, three satellites were launched into orbit: the Western European meteorological Meteosat-3 and the amateur radio Amsat-3, as well as the American communications satellite Panamsat-1.
ON DECEMBER 22, 1988, in the USSR, the Molniya LV launched into a highly elliptical orbit with an apogee height of 39,042 km in the Northern Hemisphere the next (32nd) Molniya-3 satellite in order to ensure the operation of a long-distance telephone and telegraph radio communication system and the transmission of television programs according to the Orbit system.
ON DECEMBER 23, 1988, the 24th satellite of the People's Republic of China was launched from the Xichang Cosmodrome using the Long March-3 launch vehicle. This is the fourth Chinese communications satellite launched into geostationary orbit. The commissioning of the satellite will complete the transition of all national television programs to rebroadcast via the satellite system. Premier of the State Council of the People's Republic of China Li Peng was present at the launch of the satellite.
ON DECEMBER 25, 1988, in the USSR, the Soyuz launch vehicle launched into orbit the automatic cargo spacecraft Progress-39, intended to supply the Soviet orbital station Mir. The ship docked with the station on December 27, undocked from it on February 7, 1989, and on the same day entered the atmosphere and ceased to exist.
ON DECEMBER 28, 1988, in the USSR, the Molniya LV was launched into a highly elliptical orbit with an apogee altitude of 38,870 km in the Northern Hemisphere by the next (75th) communication satellite Moliya-1. This satellite is operated as part of a satellite system used in the Soviet Union for telephone and telegraph radio communications, as well as the transmission of television programs via the Orbit system.
ON JANUARY 26, 1989, the Proton LV launched the next (17th) Horizon communications satellite in the USSR. Placed into geostationary orbit at 53°E. etc., it received the international registration index “Stationar-5”. The Horizon satellite is used to transmit television programs to a network of ground stations "Orbita", "Moscow" and "Intersputnik", as well as for communication with ships and aircraft using additional repeaters.
JANUARY 27, 1989 The Ariane-2 launch vehicle launched the Intelsat-5A satellite (F-15 model) into a transfer orbit for use in the global commercial satellite communications system of the ITSO international consortium. Transferred to a stationary point in geostationary orbit 60° east. d., the satellite will replace the Intelsat-5A satellite located there (model F-12), launched in September 1985.
ON FEBRUARY 10, 1989, in the USSR, the Soyuz launch vehicle launched the automatic cargo spacecraft Progress-40, intended to supply the Soviet orbital station Mir. The ship docked with the station on February 12 and undocked from it on March 3. After undocking, an experiment was carried out to deploy in open space conditions two large multi-link structures that were folded on the outer surface of the Progress-40 spacecraft. At the command of the on-board automation, these structures were opened one by one. Their deployment was carried out through the use of elements made of material with a shape memory effect. On March 5, the propulsion system on the ship was turned on. As a result of braking, the ship entered the atmosphere and ceased to exist.
ON FEBRUARY 15, 1989, the USSR Molniya LV was launched into a highly elliptical orbit with an apogee altitude of 38,937 km in the Northern Hemisphere by the next (76th) Molniya-1 communications satellite. This satellite is included in the satellite system used in the Soviet Union for telephone and telegraph radio communications, as well as the transmission of television programs via the Orbita system.
ON MARCH 16, in the USSR, the Soyuz launch vehicle launched the automatic cargo spacecraft Progress-41, intended to supply the Soviet orbital station Mir. The ship docked with the station on March 18.
Chronicle of Manned Flights 1
1 Continued (see No. 3, 1989).
2 The number of space flights, including the last one, is indicated in parentheses.
3 Expedition to the Mir station.
4 Cosmonauts A. Volkov and S. Krikalev remained in the crew of the Mir station. December 21, 1988, together with J.-L. Chretien returned to earth from the Mir station, V. Titov and M. Manarov, who completed the longest flight in the history of astronautics, lasting 1 year.
ASTRONOMY NEWS
THREAD IN WONDERLAND
We have already mentioned in our short notes about one of the cosmological consequences of some Grand Unification models - the prediction of the existence of cosmological threads. These are one-dimensional extended structures with a high linear mass density (~Ф 0 2, where Ф 0 is a non-zero vacuum average) and a thickness of ~1/Ф 0.
Among the many realistic models of the Grand Unification (since there are also non-realistic ones), the most successful are those that include mirror particles, strictly symmetrical in their properties to the corresponding ordinary particles. Not only particles of matter (electrons, quarks), but also particles that carry interactions (photons, W-bosons, gluons, etc.). In schemes of this kind, violation of complete symmetry leads to a transition from ordinary particles to mirror ones. The threads appearing in these models are called Alice threads. They are distinguished from “ordinary” cosmological threads by the following additional property: walking around the thread changes the specularity of the object.
From this “mirror” property it follows that the very definition of specularity becomes relative: if a macroscopic object is considered ordinary by us when we go around the thread on the left, then it turns out to be mirrored if the thread goes around on the right (or: vice versa). In addition, the electromagnetic radiation that we perceive as normal to the left of Alice’s thread will be mirrored to the right of it. Our ordinary electromagnetic receivers will not be able to register it.
But this is all in theory. Are there any possible observational manifestations of alice threads? All the properties that ordinary cosmological threads have are also found in Alice’s threads. But unlike the first, Alice’s threads must change the relative specularity of particles and light rays during their evolution. The existence of mirror particles leads to the fact that stars and, probably, globular clusters should have one specularity, while galaxies and larger inhomogeneities (clusters, superclusters) consist of an equal number of mirror and ordinary particles. Moreover, their average characteristics (spectrum, luminosity, distribution of masses and velocities, etc.) are the same. Therefore, if we cannot “resolve” the galaxy into individual stars, then we cannot even notice the passage of the Alice filament between them and the galaxy, because both the specular and ordinary luminosity and spectra of the galaxy are completely symmetrical.
You can try to detect the manifestation of the Alice thread (as, indeed, a cosmological thread of any nature) by the gas glow effect it causes in the shock wave. The latter is formed when matter is perturbed by the conical gravitational field of the thread. True, the luminosity of the gas in the shock wave behind the filament is difficult to separate from the background of the general luminosity of such gas. The same applies to the disturbance of the temperature of the cosmic microwave background radiation in the direction of the filament. Therefore, the most promising, according to theorists, is the search for the gravitational lens effect caused by the Alice thread.
IS IT CONSTANT?
We are talking about Newton's gravitational constant G. There are many theories that predict the need to change it. However, not only it, but also other fundamental constants - in some models of superstring theory, for example, these constants should change with the age of the Universe (with the expansion of the Universe G, for example, should decrease).
None of the experiments conducted to date have provided any evidence in favor of inconstancy G. Only the upper limits of this change have been established - about 10–11 parts per year. Recently, American scientists confirmed this assessment by observing a double radio pulsar.
Discovered in 1974, the binary pulsar PSR 1913+16 consists of a neutron star orbiting another compact object. It just so happened that the rate of change of its orbital period is known with amazingly high accuracy.
General relativity predicts that such a binary system will emit gravitational waves. In this case, the orbital period of the double pulsar changes. The rate of its change, predicted under the assumption of constancy G, coincides perfectly with the observed one.
Observations by American scientists allow us to estimate the limit on variability G by the small difference between observations and predictions of general relativity. This estimate, as already mentioned, gives a value of the order of 10–11 parts per year. So most likely G never changes.
"LIGHT ECHO" OF SUPERNOVA-87
Australian and American astronomers have detected a fairly strong increase in infrared radiation from the LMC Supernova. The fact of such radiation in itself is nothing special. His outburst is incomprehensible and unexpected.
Several hypotheses have been proposed. According to one of them, a pulsar “sits” in the gas ejected by an exploding star (although the pulsar radiation should be shorter wavelength). According to the second hypothesis, gases from the explosion condense into solid macrodust particles, which, when heated, emit infrared radiation.
The third hypothesis is also “dust”. Thousands and thousands of years before the explosion, the original star was losing gas that had collected around it. The dust shell stretched around the Supernova for almost a light year - that's how long it took light from the exploding star to reach the dust cloud. The heated dust re-radiates in the infrared, and the radiation takes another year to reach observers on Earth. This explains the time that elapsed from the registration of the Supernova explosion to the detection of the flash of infrared radiation.
MISSING MASS
If the modern theory of the evolution of stars is correct (and there seems to be no reason to doubt this), then low-mass stars (with a mass less than the mass of the Sun) do not “have the temper” to end their lives in the form of a planetary nebula - a luminous cloud of gas, in the center of which remnant of the original star.
However, for quite a long time this prohibition was mysteriously violated - in many cases the mass of the planetary nebula turned out to be less than the mass of the Sun. English and Dutch astronomers examined three bright planetary nebulae (or rather, their faintly luminous shells). Using the spectra they obtained, the mass of both the shell and the nebula itself was calculated. The problem of mass deficiency has become clearer - there is much more matter in the shell than in the nebula itself. Initially, the stars - the “organizers” of planetary nebulae - should be heavier. The missing mass is in the shell.
But then a new mystery arose. The gas temperatures calculated for the nebula and the envelope differ - the envelope turned out to be 2 times hotter than the nebula. It would seem that it should be the other way around, because the central star is obliged to heat the shell gas. One of the assumptions that explains this paradox: the energy for heating the shell is supplied by a fast “wind” blowing from the central star.
WARNING - FLASH
The American SMM satellite, designed to study the Sun, predicted its premature “death” - leaving orbit. The data obtained from this satellite suggests that, according to experts from the National Oceanic and Atmospheric Administration, we will spend the next four years in an environment of increased solar activity. With all the ensuing consequences - magnetic storms, complicating radio communications and navigation, interfering with the operation of radars, posing a definite danger to spacecraft crews, damaging delicate electronic parts of satellites, etc.
Solar flares emit hard ultraviolet radiation that heats the upper atmosphere. As a result, the height of its upper (conditional) border increases. In short, the atmosphere becomes “disturbed,” which primarily affects satellites in low orbits. Their lifespan is shortening. At one time, this happened with the American Skylab station, which left orbit ahead of schedule. The same fate, as already mentioned, awaits the SMM satellite.
Cycles of solar activity have been known for a long time, but the nature of the processes that cause these phenomena remains incompletely understood.
NEW TELESCOPE
Mount Mauna Kea (4170 m, Hawaii, USA) will soon become an astronomical Mecca. In addition to the telescopes already existing at the observatory located on this mountain, new, more powerful optical telescopes are being designed (and already under construction).
The University of California is building a 10-meter telescope, due to be completed and installed in 1992. It will consist of 36 hexagonal conjugate mirrors arranged in three concentric rings. Electronic sensors installed at all ends of the segment mirrors will transmit data about their current position and orientation relative to each other to the computer, which will issue commands to the active mirror drives. As a result, the continuity of the composite surface and its shape is ensured under the influence of mechanical movements and wind loads.
On the same Mauna Kea in 1995, it is planned to install a 7.5-meter telescope developed by Japanese scientists. It will be located more than a hundred meters from the American one. This “asparagus” will be the most powerful optical-interferometric system, which will make it possible to look at enormous distances, study quasars, and discover new stars and galaxies.
Four separate telescopes (each 8 m in diameter), combined by fiber optics into a single focal plane, are proposed to be built at the Southern Observatory (Chile) by 8 Western European countries - co-owners of this observatory. Construction of the first mirror (i.e., the first telescope) is scheduled to be completed by 1994, and the remaining three by 2000.
WHAT COMES FROM WHERE
As is known, the Martian atmosphere has a fairly high concentration of carbon dioxide. This gas escapes into space, so its constant concentration must be maintained by some source.
Experts believe that such a source is the mineral scapolite, rare on Earth (on our planet it is a semi-precious stone containing, in addition to carbon, silicon, oxygen, also sodium, calcium, chlorine, sulfur, hydrogen), which can store large amounts of carbon dioxide as part of its crystalline structure (carbonate). There is a lot of scapolite on Mars.
So, in an ecosystem we see the interaction of a life community consisting of many organisms with characteristic environmental factors acting on this community. Ecosystems are usually classified according to the most important environmental factors. So, they talk about marine, terrestrial or land, coastal or littoral, lacustrine or limnic ecosystems, and so on. How is the ecosystem built?
It usually consists of four main elements:
1. Non-living (abiotic) environment. These are water, minerals, gases, as well as non-living organic matter and humus.
2. Producers (manufacturers). These include living beings capable of building organic substances from inorganic materials in the environment. This work is performed mainly by green plants, which produce organic compounds from carbon dioxide, water and minerals using solar energy. This process is called photosynthesis. It releases oxygen (O2). Organic substances produced by plants are used as food for animals and humans, and oxygen is used for respiration.
3. Consumers (consumers). They use plant products. Organisms that feed only on plants are called first-order consumers. Animals that eat only (or predominantly) meat are called second-order consumers.
4. Reducers (destructors, decomposers). This group of organisms decomposes the remains of dead creatures, such as plant remains or animal carcasses, turning them back into raw materials - water, minerals, CO 2, which is suitable for producers, who turn them into components again into organic substances.
Decomposers include many worms, insect larvae and other small soil organisms. Bacteria, fungi and other microorganisms that convert living matter into mineral are called mineralizers.
An ecosystem can also be artificial. An example of an artificial ecosystem, extremely simplified and incomplete compared to natural ones, is a spaceship. Its pilot has to live for a long time in the confined space of the ship, making do with limited supplies of food, oxygen and energy. In this case, it is desirable, if possible, to recover and reuse spent reserves of the substance and waste. For this purpose, special regeneration installations are provided in the spacecraft, and recently experiments have been conducted with living organisms (plants and animals), which should participate in the processing of astronaut waste using the energy of sunlight.
Let's compare the artificial ecosystem of a spaceship with some natural one, for example, the ecosystem of a pond. Observations show that the number of organisms in this biotope remains - with some seasonal fluctuations - essentially constant. Such an ecosystem is called stable. Equilibrium is maintained until external factors change. The main ones are the inflow and outflow of water, the supply of various nutrients, and solar radiation.
Various organisms live in the pond ecosystem. So, after the creation of an artificial reservoir, it is gradually populated by bacteria, plankton, then fish, and higher plants. When development has reached a certain peak and external influences remain unchanged for a long time (the influx of water, substances, radiation, on the one hand, and the outflow or evaporation, the removal of substances and the outflow of energy, on the other), the pond ecosystem stabilizes. A balance is established between living beings.
Like a simplified artificial ecosystem of a spaceship, a pond ecosystem is capable of self-sustaining. Unlimited growth is hampered by interactions between producer plants, on the one hand, and animal and plant consumers and decomposers, on the other.
Consumers can reproduce only as long as they do not overuse the supply of available nutrients. If they multiply excessively, their numbers will stop increasing on their own because they won't have enough food. Producers, in turn, require a constant supply of minerals. Reducers, or destructors, decompose organic matter and thereby increase the supply of minerals. They again put waste products into circulation. And the cycle begins again: plants (producers) absorb these minerals and, with the help of solar energy, again produce energy-rich nutrients from them.
Nature operates extremely economically. The biomass created by organisms (the substance of their bodies) and the energy contained in it are transferred to the rest of the ecosystem members: animals eat plants, other animals eat the former, humans eat both plants and animals. This process is called the food chain. Examples of food chains: plants - herbivore - predator; cereal - field mouse - fox; food plants - cow - man. As a rule, each species feeds on more than one species. Therefore, food chains intertwine to form a food web. The more closely organisms are connected through food webs and other interactions, the more resilient the community is to possible disturbances. Natural, undisturbed ecosystems strive for balance. The state of equilibrium is based on the interaction of biotic and abiotic environmental factors.
Maintaining closed cycles in natural ecosystems is possible due to two factors: the presence of decomposers (reducers), which use all waste and residues, and the constant supply of solar energy. In urban and artificial ecosystems there are few or no decomposers, and waste - liquid, solid and gaseous - accumulates, polluting the environment. It is possible to promote the rapid decomposition and recycling of such waste by encouraging the development of decomposers, for example, through composting. This is how man learns from nature.
In terms of energy input, natural and anthropogenic (man-made) ecosystems are similar. Both natural and artificial ecosystems - houses, cities, transport systems - require an external supply of energy. But natural ecosystems receive energy from an almost eternal source - the Sun, which, moreover, while “producing” energy, does not pollute the environment. Man, on the contrary, fuels the processes of production and consumption mainly due to the final sources of energy - coal and oil, which, along with energy, produce dust, gases, thermal and other waste that is harmful to the environment and cannot be processed within the artificial ecosystem itself. Let us not forget that even when consuming such “clean” energy as electricity (if it is produced at a thermal power plant), air pollution and thermal pollution of the environment occur.
Subject:“Man and his place in nature.”
Goals.
Educational:
- continue systematic work on the formation of an elementary holistic picture of the world among younger schoolchildren;
- introduce artificial ecosystems of cities and villages as places of human life (habitat);
- teach to see the difference in the economies of ancient people and modern people, to understand the specifics of artificial ecosystems;
- teach students to find contradictions between the human economy and nature and propose ways to eliminate them;
- to form a concept of an ecological type of economy that is harmoniously combined with nature.
Educational:
- develop the ability to cognize and understand the world around us, meaningfully apply the acquired knowledge to solve educational, cognitive and life problems;
- develop speech and logical thinking;
Educators:
- to cultivate a caring attitude towards the nature around us, economical use of natural resources, and a caring attitude towards the world.
Lesson type: lesson of learning new material.
Type of training: problematic.
Main stages of the lesson:
- Introduction of new knowledge based on previous experience.
- Reproduction of new knowledge.
Equipment:
- video recordings to demonstrate the ecosystem of the city and village;
- work page;
- reference diagrams;
- illustrations of a reasonable combination of civilization and nature.
DURING THE CLASSES
I. Activation of knowledge and formulation of the problem.
1. Guys, today we have the first lesson of the last section of our textbook and our entire course “The World and Man”. The title of this section is, in my opinion, a little unusual. What makes it so unusual?
There is a note on the board: “How should we live?”
It turns out that this question worries many people on our planet, regardless of what country they live in and what language they communicate with each other. But the main thing is that these people are not indifferent to the fate of our planet, our common home.
I am convinced that you and I should not stand aside and try to look for the answer to this question.
Do you know what it is conference? And is it possible to call our lesson “ lesson-conference”?
Dictionary: “Conference- a meeting, meeting of various organizations, including educational ones, to discuss some special issues.”
(Children read the interpretation of the word “conference” on the work page and discuss the question posed).
And now I propose, reflecting on our special question “How do we live?" And " Man and his place in nature”, remember what we know and have studied.
2. Blitz – quiz “Test your knowledge”:
- The Ural Mountains separate Europe and Asia;
- America was discovered by Christopher Columbus;
- The Volga, Ob, Yenisei, Lena, Amur are the rivers of our country;
- There are other continents south of Antarctica;
- If you are careful with the use of water, light, i.e. save energy, then nature will be preserved and people will live easier;
- The Sahara Desert is located in South America;
- Travelers visited each other from island to island on foot;
- Collecting edible plants and hunting wild animals is the oldest human activity;
- An ecosystem is a community of living and inanimate nature on earth in which everyone feels at home.
- An ecological system is a cell of the living shell of the Earth.
(Children listen to these statements and put “+” in the table on the work page if they agree with the statement, and “-” if they disagree with the statement. After completing the task, the teacher hangs a checklist on the board, and students conduct self-monitoring and self-checking of the completed task.).
3. Solving the crossword puzzle in pairs.
- Scientist who studies ecosystems.
- Living organisms that eat other organisms.
- The smallest “scavengers”.
- Organisms that “eaters” feed on.
4. Problem dialogue.
Yes, these are our friends Lena and Misha. Let's listen to them...
Lena: Man, developing science and technology, violates natural ecosystems. So he can live without them?
Misha: No, Lena, you're wrong. A person, like any other organism, needs other members of his ecosystem, because he must breathe, eat, and participate in the cycle of substances.
And again, for the third time, we hear the same word. How many of you paid attention to him? Indeed this is the word "Ecosystem". (Posted on the board).
What is an ecosystem?
(Children consult the dictionary on the work page and give different definitions.)
What types of ecosystems are there?
– Natural– natural;
– artificial are ecosystems created by human hands.
Give an example of natural ecosystems; artificial ecosystems.
5. Statement of the problem.
Children, what do you think, in which of the ecosystems you listed is there a place for humans, for you and me?
II. Collaborative discovery of knowledge.
1. Let us consider at our conference the issues that we have to study and discuss:
- two person households;
- where does a person live;
- how achievements of science and technology affect people’s lives, how they are useful, why they are harmful, and what dangers lurk in their use.
2. Independent acquaintance with two types of human economy from the pages of a textbook.
3. Collective work with the class through problem-solving conversation in order to systematize the acquired knowledge:
- What did ancient people do?
- Did they differ from wild animals in the way they obtained food?
- If they appropriated ready-made natural resources, then what could their farm be called? Form a word from the verb “to appropriate” that answers the question what kind of farm? (Appropriating).
- Why did people later learn to breed domestic animals and cultivated plants?
- Where did people start living?
- What became their main occupation?
- If people began to produce food and other products necessary for life, then what can their economy be called? Form a word from the verb “to produce” that answers the question what type of farm? (Producing)
4. Demonstration of two ecological pyramids:
- Which of them symbolizes the appropriating economy, and which the producing economy?
- Which of them can be correlated with a natural ecosystem, and which with an artificial ecosystem?
- What would you call this ecosystem?
(Ecosystem of a field, garden, barnyard, poultry house, livestock farm - agricultural ecosystem)
This is the first artificial ecosystem created by people. Peasants engaged in agricultural work live here.
The second artificial ecosystem created by people for their own lives is the city ecosystem.
If fields, gardens, and farmyards resemble natural ecosystems, then the city is striking in its inconsistency with the natural environment. Instead of the rustling of leaves and the singing of birds, in the city we hear the noise of engines, the creaking of brakes, the knock of tram wheels on the rails. On the plain, stone mountains rise from multi-story buildings. Unfortunately, there are few green plants in the city. It is precisely because of the lack or absence of greenery that people - city dwellers on weekends try to leave the city to the countryside, to the forest, to breathe fresh air, to take a break from the city noises. Sometimes people believe that modern man is almost independent of nature. This is a very dangerous misconception.
Remember! Man in the past, present and future is connected with nature by many invisible threads. Take care of her!
But, despite everything, the city is an ecosystem that people have created for living in it.
5. Complete task 2 on page 59.
- What opportunities did humans gain by creating artificial ecosystems?
- What is the relationship between natural and artificial ecosystems? Why?
- What is human strength?
- Has this always benefited humans and the environment?
- Is the cycle in nature closed or not?
- What happens under the influence of human management? (Environmental pollution, extinction of plants and animals, reduction in soil fertility, shortage of fuel, etc.)
6. Complete task 3 on page 59.
- What are the consequences of a person's use of the power he possesses?
- What does this lead to?
- What needs to be fixed?
- If the cycle becomes closed, then this type of economy can be called... (ecological).
- What to do? Can we help?
Let's return to the concept "ecosystem".
(The definition is posted on the board)
Ecosystem- this is such an interconnection (commonwealth) of living and inanimate nature, in which all its inhabitants feel at home.
7. Work on keywords:
- Commonwealth
- Live nature
- Inanimate nature
- All? Who's everyone?
- How are you at home?
III. Workshop on independent application and use of acquired knowledge.
- Answers to questions on page 59.
- Complete 2–3 optional tasks (1, 4, 5, 7, 8).
- Fill out the table on the work page. Calculate your points and you will find out how well you take care of nature in the city's ecosystem.
| 1 | ||
| 1 | ||
| 1 | ||
| 1 | ||
| I fed the birds all winter. | 2 | |
| I don't disturb the birds at the nest. | 1 | |
| I made a residential nesting house for birds. | 3 | |
| 1 | ||
| I planted a tree. | 5 |
13–16 points - you are a great fellow, a conservationist. Everyone can follow your example.
9–12 points – you know how to be friends with nature.
Less than 9 points - you have something to think about. Try to be more careful about the nature around you.
IV. Summing up the lesson - conference.
- Exchange of opinions on completing tasks;
- What new did you learn in the lesson?
- Why is human power a big threat to the entire world around us?
A person has two paths. The first is for all people to fly into space together and settle on other planets. But if this becomes possible, it will not be very soon, maybe in hundreds and hundreds of years.
The second way is to adapt to nature, learn not to destroy it, not to disrupt an established economy, and try to begin to restore what has been destroyed and damaged. And treat the current nature with care, protecting what remains. Perhaps this path is the only possible one.
V. Homework.
Lesson No. 12, task 6.
ANNEX 1
WORK PAGE
Student(s)______________________________
TOPIC: “How should we live?Man and his place in nature.”
Plan.
- Two man's farms.
- Where does a person live?
- How should we live?
Exercise 1. Blitz - quiz.
Task 2. Crossword.
- Scientist who studies ecosystems.
- Living organisms that eat other organisms (plants and animals).
- A gas necessary for breathing by all living organisms.
- What does the ecosystem receive from space?
- The smallest “scavengers”.
- Organisms that process waste and remains of living organisms.
- The organ of a plant in which the transformation of inanimate substances into organic material for all organisms occurs.
- Fertilizing to increase plant yield.
- Organisms that eaters feed on.
- The top fertile layer of soil from which the plant receives water and nutrients.
Task 3. Discovery of new concepts.
1.____________________
2.____________________
3.____________________
4.____________________
5.____________________
6.____________________
7.____________________
8.____________?_______
Task 4. Table - test.
| Useful stuff | Completion sign | Points |
| I turn off the light when I leave the room. | 1 | |
| I turn off the tap when I leave the bathroom. | 1 | |
| I try not to pick flowers in the forest and park. | 1 | |
| I don’t break trees for a fire, but take dead wood. | 1 | |
| I fed the birds all winter. | 2 | |
| I don't disturb the birds at the nest. | 1 | |
| I made a bird nesting house. | 3 | |
| I take care of house plants and animals. | 1 | |
| I planted a tree. | 5 |
APPENDIX 2
DICTIONARY.
CONFERENCE - a meeting of various organizations, including educational organizations, to discuss some special issues.
ECOSYSTEM– living organisms living together and that piece of land on which they feel at home.
ECOSYSTEM- a small part of the biosphere. In this system you can find many elements of the biosphere: air, soil, water, rocks.
ECOSYSTEM– the unity of living and inanimate nature, in which living organisms of different professions are able to jointly maintain the circulation of substances.
ECOSYSTEM – it is a community of living organisms in unity with the place in which they live.
ECOSYSTEM – This is such a relationship between living and inanimate nature, in which all inhabitants feel at home.
