UDC 94:574.4
https://doi.org/10.24158/fik.2017.6.22
Tkachenko Yury Leonidovich
Candidate of Technical Sciences, Associate Professor, Associate Professor of the Moscow State technical university named after N.E. Bauman
Morozov Sergey Dmitrievich
Senior Lecturer
Moscow State Technical
University named after N.E. Bauman
FROM THE HISTORY OF THE CREATION OF ARTIFICIAL ECOSYSTEMS
Tkachenko Yuri Leonidovich
PhD in Technical Science, Assistant Professor, Bauman Moscow State Technical University
Morozov Sergey Dmitrievich
Senior Lecturer, Bauman Moscow State Technical University
GLIMPSES OF HISTORY OF ARTIFICIAL ECOSYSTEMS" CREATION
Annotation:
The article considers the documentary facts of the creation of artificial ecosystems intended for use in space and terrestrial conditions. The pioneering role of K.E. Tsiolkovsky, who was the first to develop the concept of creating a closed habitat for people in space, and the influence of V.I. Vernadsky devoted to the biosphere, on approaches to the construction of artificial ecosystems. The decisive contribution of S.P. Korolev to the first practical implementation of Tsiolkovsky's projects for the construction of prototypes of space settlements. The most important historical stages of this process: experiments "Bios" (USSR), "Biosphere-2" (USA), "OEEP" (Japan), "Mars-500" (Russia), "Yuegun-1" (China).
Keywords:
artificial ecosystem, space settlements, closed habitat, K.E. Tsiolkovsky, S.P. Korolev, V.I. Vernadsky.
The article describes the documentary facts of artificial ecosystems" creation designed for space and terrestrial applications. The study shows the pioneering role of K.E. Tsiolkovsky who was the first to develop the concept of closed ecological systems for people in space and the influence of V.I. Vernadsky's biosphere works on the approaches to construct artificial ecosystems. The article presents the crucial contribution of S.P. Korolev to the first practical implementation of building the space habitat prototypes according to K.E. Tsiolkovsky's projects. The article describes the major historical stages of this process that are such experiments as BIOS (the USSR), Biosphere 2 (the USA), CEEF (Japan), Mars-500 (Russia), Yuegong-1 (China).
artificial ecosystem, space habitats, closed ecological system, K.E. Tsiolkovsky, S.P. Korolev, V.I. Vernadsky.
Introduction
The idea of the need to create an artificial closed human habitat was born simultaneously with the emergence of the dream of space flights. People have always been interested in the ability to move in air and outer space. In the XX century. practical space exploration started, and in the 21st century. Astronautics has already become an integral part of the world economy. Herald of astronautics, philosopher-cosmist K.E. Tsiolkovsky in "Monism of the Universe" (1925) wrote: "The technology of the future will make it possible to overcome the earth's gravity and travel throughout the solar system. After the settlement of our solar system, other solar systems of ours will begin to be populated. Milky Way. With difficulty a man will be separated from the earth. By "technology of the future" Tsiolkovsky meant not only rocket technology using the principle of jet propulsion, but also a system of human habitation in space, built in the image and likeness of the earth's biosphere.
The birth of the concept of "space biosphere"
K.E. Tsiolkovsky was the first to express the idea of using nature-like principles and biospheric mechanisms for the reproduction of oxygen, nutrition, fresh water and the disposal of waste generated for the life support of the crew of his "jet device". This question was considered by Tsiolkovsky in almost all of his scientific papers, philosophical and fantastic works. The possibility of creating such an environment is substantiated by the works of V.I. Vernadsky, who revealed the basic principles of the construction and functioning of the Earth's biosphere. Between 1909 and 1910, Vernadsky published a series of notes on observations of the distribution chemical elements in the earth's crust, and made a conclusion about the leading importance of living organisms for creating the circulation of matter on the planet. Having become acquainted with these works of Vernadsky and other works in the field of a then new scientific direction - ecology, Tsiolkovsky wrote in the second part of the article "The study of world spaces with jet devices" (1911): "As the earth's atmosphere is purified by plants with the help of the Sun, so can
renew our artificial atmosphere. Just as plants on Earth absorb impurities with their leaves and roots and provide food in return, so can plants taken on our journeys continuously work for us. Just as everything that exists on earth lives on the same amount of gases, liquids and solids, so we can live forever on the stock of matter we have taken.
The authorship of Tsiolkovsky also belongs to the project of a space settlement for a large number of inhabitants, for whom the renewal of the atmosphere, water and food resources is organized due to the closed cycle of chemicals. Tsiolkovsky describes such a "cosmic biosphere" in a manuscript that he kept until 1933, but was never able to finish:
“The community contains up to a thousand people of both sexes and all ages. Humidity is controlled by the refrigerator. He also collects all the excess water evaporated by people. The hostel communicates with the greenhouse, from which it receives purified oxygen and where it sends all the products of its excretions. Some of them in the form of liquids permeate the soil of greenhouses, others are directly released into their atmosphere.
When a third of the surface of the cylinder is occupied by windows, then 87% of the most more light, and 13% is lost. Passages are inconvenient everywhere...” (At this point the manuscript breaks off).
First experimental installations
The unfinished manuscript of Tsiolkovsky, entitled "Life in the Interstellar Environment", was published by the Nauka publishing house after more than 30 years - in 1964. The initiator of the publication was the general designer of space technology, Academician S.P. Korolev. In 1962, he, already having experience of successful space flight carried out by the first cosmonaut Yu.A. Gagarin on April 12, 1961, set a fundamentally new vector for the development of the space project: “We should start developing the “greenhouse according to Tsiolkovsky”, with gradually increasing links or blocks, and we should start working on “space harvests”. Which organizations will carry out these works: in the area of crop production and issues of soil, moisture, in the area of mechanization and "light-heat-solar" technology and its control systems for greenhouses? .
Creation of the world's first closed artificial ecosystem space assignment began with the meeting of S.P. Queen and directors of the Institute of Physics Siberian branch Academy of Sciences of the USSR (IP SB AS USSR) L.V. Kirensky, at which Korolev conveyed to Kirensky his proposals for a "space greenhouse". After that, a series of meetings were held at the Institute of Physics of the Siberian Branch of the USSR Academy of Sciences, where the question of which department would become the base for the development of work on the space program was decided. The task set by Korolev to create an artificial ecosystem in a sealed capsule, in which a person could stay for a long time in environmental conditions close to the earth, was entrusted to the department of protozoa. This unusual decision, as it turned out later, turned out to be correct: it was the simplest microalgae that were able to fully provide the crew with oxygen and clean water.
It is significant that in the same year - 1964, when the last manuscript of Tsiolkovsky saw the light, work began on the practical development of the first ever closed artificial ecological system, including human metabolism in the internal circulation of matter. In the Department of Biophysics of the Institute of Biophysics of the Siberian Branch of the USSR Academy of Sciences, later transformed into an independent Institute of Biophysics of the Siberian Branch of the USSR Academy of Sciences, the construction of the Bios-1 experimental facility began in Krasnoyarsk, in which I.I. Gitelzon and I.A. Terskov, who became the founders of a new trend in biophysics. The main task was to organize the provision of human oxygen and water. The first installation consisted of two components: a pressurized cabin with a volume of 12 m3, inside which a person was accommodated, and a special cultivator tank with a volume of 20 liters for growing common chlorella. The 7 experiments of various duration (from 12 hours to 45 days) showed the possibility of completely closing the gas exchange, that is, to ensure the production of oxygen and the utilization of carbon dioxide by microalgae. Through the vital processes of chlorella, a water cycle was also established, during which the water was purified in the amount necessary for drinking and meeting other needs.
In "Bios-1" experiments lasting more than 45 days did not work out, since the growth of microalgae stopped. In 1966, in order to develop an artificial ecosystem containing both lower and higher plants, Bios-1 was upgraded to Bios-2 by connecting an 8 m3 phytotron to the pressurized cabin. Phytotron is a special technical device for growing higher plants: vegetables and wheat under artificial lighting and microclimate conditions. Higher plants served as a source of food for the crew and provided air regeneration. Since higher plants also gave oxygen, it was possible to carry out experiments with the participation of two testers, which lasted 30, 73 and 90 days. The plant operated until 1970.
"Bios-3" was put into operation in 1972. This hermetic structure the size of a 4-room apartment, which is still operational, with a volume of 315 m3, was arranged in the basement of the Institute of Biophysics of the Siberian Branch of the Russian Academy of Sciences in Krasnoyarsk. Inside, the installation is divided by airtight bulkheads with locks into four compartments: two greenhouses for edible plants grown in phytotrons using a hydroponics method that does not require soil, a compartment for breeding chlorella that produces oxygen and clean water, and a compartment for crew members. In the living compartment there are sleeping places, a kitchen and dining room, a toilet, a control panel, devices for processing plant products and waste disposal.
In phytotrons, the crew grew specially bred dwarf wheat varieties containing a minimum of inedible biomass. Vegetables were also bred: onions, cucumbers, radishes, lettuce, cabbage, carrots, potatoes, beets, sorrel and dill. The Central Asian oil plant "chufa" was selected, which served as a source of vegetable fats indispensable for the human body. The crew received the necessary proteins by eating canned meat and fish.
Ten experimental colonizations were carried out in Bios-3 during the 1970s and early 1980s. Three of them lasted several months. The longest experience of continuous complete isolation of a crew of three lasted 6 months - from December 24, 1972 to June 22, 1973. This experiment had a complex structure and was carried out in three stages. Each stage had its own composition of researchers. M.P. were alternately inside the installation. Shilenko, N.I. Petrov and N.I. Bugreev, who worked for 4 months each. Participant of the experiment V.V. Terskikh stayed in Bios-3 for all 6 months.
Phytotrons "Bios-3" produced a sufficient harvest of grain and vegetables per day. Most of the time the crew spent on growing edible plants from seeds, harvesting and processing it, baking bread and cooking. In 1976-1977. passed an experiment that lasted 4 months, in which two testers were involved: G.Z. Asinyarov and N.I. Bugreev. From the autumn of 1983 to the spring of 1984, a 5-month experiment was conducted with the participation of N.I. Bugreeva and S.S. Alekseev, which completed the work of "Bios". N.I. Bugreev thus set an absolute record at that time for staying in a closed artificial environment, having lived in the installation for a total of 15 months. In the late 1980s, the Bios program was put on hold as its government funding stopped.
"Biosphere" behind glass
The baton in creating a closed habitat was picked up by the Americans. In 1984, Space Biospheres Ventures began building Biosphere 2, an enclosed experimental facility on a site in the US Arizona Desert.
The ideologists of Biosphere-2 were Mark Nelson and John Allen, who were imbued with the ideas of V.I. Vernadsky, uniting about 20 scientists abroad on the basis of the doctrine of the biosphere. In the USSR, the publishing house "Thought" in 1991 published a book by this group of authors "Catalogue of the Biosphere", which told about the upcoming experiment. Allen and Nelson wrote about their task of creating "cosmic biospheres" in the following way: "Armed with the great ideas, ideas and models of Vernadsky and other scientists, humanity is now willingly considering not only possible ways of interacting with the biosphere, but also ways of assisting its "mitosis" , adapting our earthly life for full participation in the fate of the Cosmos itself by creating the opportunity to travel and live in outer space.
"Biosphere-2" is a capital structure made of glass, concrete and steel, located on the territory of 1.27 hectares. The volume of the complex amounted to more than 200 thousand m3. The system was sealed, that is, it could be completely separated from the external environment. Inside it, aquatic and terrestrial ecosystems of the biosphere were artificially recreated: a mini-ocean with an artificial reef made of corals, a tropical forest - jungle, savannah, woodlands of thorny plants, desert, freshwater and saltwater swamps. The latter took the form of a winding riverbed flooded by an artificial ocean - an estuary planted with mangroves. Biological communities of ecosystems included 3800 species of animals, plants and microorganisms. Inside the "Biosphere-2" residential apartments were arranged for the participants in the experiment and agricultural sites, which made up a whole ranch called Sun Space.
On September 26, 1991, 8 people were isolated inside the complex of facilities - 4 men and 4 women. Experimenters - "bionauts", among whom was the ideologist of the project Mark Nelson, were engaged in traditional agriculture - rice growing. For this, rural and livestock farms were used, highly reliable tools were used, which had to be driven only by the muscular strength of a person. Grass, shrubs and trees were planted inside the installation. The researchers cultivated rice and wheat, sweet potatoes and beets, bananas and papaya, and other crops, which together produced 46 varieties of plant foods. The meat diet was provided by animal husbandry. Chickens, goats and pigs lived on the livestock farm. In addition, the bionauts raised fish and shrimp.
Difficulties began almost immediately after the start of the experiment. A week later, the Biosphere-2 technician reported that the amount of oxygen in the atmosphere was gradually decreasing and the concentration of carbon dioxide was increasing. It also turned out that the farm provided only 83% of the researchers' required diet. In addition, in 1992, breeding pest moths destroyed almost all rice crops. Throughout the winter of this year, cloudy weather persisted, which led to a decrease in oxygen production and plant nutrition. The artificial ocean became acidic due to the dissolution of a large amount of carbon dioxide in its water, due to which the coral reef died. The extinction of animals in the jungle and savannah began. Within two years, the oxygen concentration behind the glass dropped to 14% instead of the original 21% by volume.
"Bionauts" came out in September 1993, after a two-year stay "behind the glass." It is believed that "Biosphere-2" failed. Due to the small scale of the model, the "environmental catastrophe" in it occurred very quickly and showed all the perniciousness of the modern way of managing a person that creates environmental problems: lack of nutrition, removal of biomass, pollution of the atmosphere and hydrosphere, and a decrease in species diversity. The experience of "Biosphere-2" was of great ideological significance. One of the "bionauts" - Jane Pointer, giving lectures after the end of the experiment in "Biosphere-2", said: "It was only here that I realized for the first time how much a person is dependent on the biosphere - if all plants die, then people will have nothing to breathe and there will be nothing to eat. If all the water is contaminated, people will have nothing to drink.” The Biosphere-2 complex is still open to the public, as its authors believe that they have created a fundamentally new basis for public education in the field of environmental protection.
prototypes of the inhabited space stations
The installations created since the second half of the 1990s initially had a clear purpose - modeling the life support system of a spacecraft or a habitable base for flight conditions and exploration of Mars or the Moon. From 1998 to 2001, research was conducted in Japan at the CEEF (Closed Ecological Experimental Facility) facility, which is a closed artificial ecosystem. The purpose of the experiments was to study closed cycles of gas exchange, water circulation and nutrition while simulating the conditions of a Martian habitable base. The complex included a phytotron unit for growing plants, a compartment for breeding domestic animals (goats), a special geohydrospheric unit simulating terrestrial and aquatic ecosystems, and a habitable module for a crew of two. The area of plant plantings was 150 m2, livestock module - 30 m2, residential - 50 m2. The authors of the project were employees of the Tokyo Aerospace Institute K. Nitta and M. Oguchi. The object is located on the island of Honshu in the city of Rokkasho. There are no data on the conduct of long-term experiments to isolate people in this installation, the results of modeling the consequences have been published global warming climate and research on the migration of radionuclides in internal flows of matter.
Modeling of a closed habitat in simulating long-term space flights is carried out at the Institute of Biomedical Problems (IMBP) of the Russian Academy of Sciences (Moscow), founded by M.V. Keldysh and S.P. Korolyov in 1963. The basis of this work is the study of people staying in isolated conditions for a long time inside the Mars-500 complex. The experiment on 520-day isolation of the crew began in June 2010 and ended in November 2011. Male researchers took part in the experiment: A.S. Sitev, S.R. Kamolov, A.E. Smoleevsky (Russia), Diego Urbina (Italy), Charles Romain (France), Wang Yue (China). One of the modules of the complex includes a greenhouse for growing vegetables. Planting area does not exceed 14.7 m2 in a volume of 69 m3. The greenhouse served as a source of vitamins, supplementing and improving the diet of the participants in the experiment. The Mars-500 complex is based on physico-chemical, rather than biological, processes for providing the crew with oxygen and clean water using canned food reserves, therefore it differs significantly from the Bios-3 installation.
The most conceptually close to the Bios project is the Chinese complex Yuegun-1 (Lunar Palace). The complex reproduces the conditions of the lunar base. Yuegong-1 was developed at Beijing University of Aeronautics and Astronautics by Professor Li Hong. Scientists from Moscow and Krasnoyarsk advised the creators of the Chinese complex.
The Yuegong-1 complex occupies an area of 160 m2 with a volume of 500 m3 and consists of three semi-cylindrical modules. The first module is residential, which contains a saloon, cabins for three crew members, a waste processing system and a personal hygiene room. The other two modules house greenhouses for the production plant food. Grown plants accounted for more than 40% of the crew's diet. In terms of water and air, the closed environment of the installation was 99%.
The construction of the Yuegong-1 installation was completed on November 9, 2013. From December 23 to December 30, 2014, the testers, who were two university students, conducted a trial settlement of the Lunar Palace. The experiment itself was carried out for 105 days - from February 3 to May 20, 2014. A crew of three people took part in it: a man, Xie Beizhen, and two women, Wang Minjuan and Dong Chen. The experiment ended successfully and was widely reported in the Chinese media. Conclusion
The presented history of the creation of closed artificial ecosystems is a fragment of the global historical process development of mankind. Man, thanks to his ability to think, created practical astronautics and proved his ability to go beyond the planet. A deep study of the biospheric mechanisms of building and functioning of the habitat will allow people to create favorable conditions on the planets and their satellites, asteroids, and other space bodies. This activity will allow realizing the meanings of human existence.
IN AND. Vernadsky wrote about the spread of life over the Earth and outer space. Only a man with his mind is capable of leading the expansion of our biosphere further, up to the development of the studied boundaries of the Cosmos. Mankind needs to extend the biosphere to asteroids and the nearest space bodies to go further, beyond the studied limits of the universe. This is important for the preservation of not only our biosphere, but also the very biological species of man. As a result of the exploration of the near-Earth space, the Solar System, and then the outer space, foreseen by Tsiolkovsky, dynamic populations of mankind can be formed - that is, part of the people will permanently live on space bases outside the Earth. History as a science, thus, will go beyond the planetary framework and become truly the history of not only the Earth, but also the Cosmos.
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Mankind needed all the knowledge collected by scientists over hundreds of years to start space flights. And then a person faced a new problem - for the colonization of other planets and long-distance flights, it is necessary to develop a closed ecosystem, including - to provide astronauts with food, water and oxygen. Delivering food to Mars, which is 200 million kilometers from Earth, is expensive and difficult, it would be more logical to find ways to produce food that are easy to implement in flight and on the Red Planet.
How does microgravity affect seeds? What vegetables would be harmless if grown in heavy-metal-rich soil on Mars? How to set up a plantation aboard 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 Purposes of Astronautics: “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 to artificially create gravity for plants. Plants should be selected prolific, small, without thick trunks and parts that do not work in the sun. Thus, colonizers can be partially provided with biologically active substances and microelements and regenerate oxygen and water.
In 1962, the chief designer of OKB-1, Sergei Korolev, set the task: “We should start developing the “Greenhouse (OR) according to Tsiolkovsky”, with gradually increasing links or blocks, and we should start working on “space crops”.
Manuscript 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 of overheating in just five hours, although the flight was scheduled for a week - this time would have been enough oxygen and food.
Scientists have suggested that the problem arose due to the genetic orientation - the seedling should reach for the light, and the root - in the opposite direction. They improved the Oasis, and the next expedition took new seeds into orbit.
The bow has grown. Vitaly Sevastyanov reported to Earth that the arrows had reached ten to fifteen centimeters. “What arrows, what kind of bow? We understand that this is a joke, we gave you peas, not onions, ”they said from the Earth. The flight engineer replied that the astronauts took two bulbs from the house to plant them over the plan, and reassured the scientists - almost all the peas sprouted.
But the plants refused to bloom. At this stage, they died. The same fate awaited tulips, which bloomed in the Buttercup installation at the North Pole, but not in space.
But onions could be eaten, which was successfully done in 1978 by cosmonauts V. Kovalenok and A. Ivanchenkov: “They did a good job. Maybe now we will be allowed to eat the onion as a reward.
Technique - youth, 1983-04, page 6. Peas in the Oasis plant
Cosmonauts V. Ryumin and L. Popov in April 1980 received the Malachite installation with blooming orchids. Orchids thrive in tree bark and hollows, and scientists thought they might be less susceptible to geotropism, the ability of plant organs to orient and grow in a specific direction relative to the center of the globe. The flowers fell off after a few days, but at the same time, new leaves and aerial roots formed in the orchids. A little later, the Soviet-Vietnamese crew from V. Gorbatko and Pham Tuay brought with them a grown Arabidopsis.
The plants didn't 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, with the help of electrical stimulation of the root zone: scientists believed that the Earth's electromagnetic field could affect 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 centrifugal force vector. Finally, the astronauts got their way. Arabidopsis bloomed in Svetoblok.
On the left in the image below is the Fiton greenhouse aboard the Salyut-7. For the first time in this orbital greenhouse, Talya's rezukhovidka (Arabidopsis) went through a full development cycle and gave seeds. In the middle - "Svetoblok", in which Arabidopsis bloomed for the first time on board the Salyut-6. On the right is the onboard greenhouse "Oasis-1A" at the station "Salyut-7": it was equipped with a system of metered semi-automatic irrigation, aeration and electrical stimulation of the roots and could move the growing vessels with plants relative to the light source.
"Fiton", "Svetoblok" and "Oasis-1A"
Installation "Trapezia" for the study of growth and development of plants.
Seed kits
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 1990s-2000s. They grew lettuces, radishes and wheat. In 1996-1997, the Institute of Biomedical 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, a hybrid of wild cabbage about twenty centimeters high was chosen. The plant had one minus - the astronauts had to deal with pollination.
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 Biomedical Problems of the Russian Academy of Sciences, tells that the American astronaut Michael Fossum performed the jewelry work on pollination of plants.
Roscosmos video about growing plants in space. At 4:38 - plants at Mir station
In April 2014, the Dragon SpaceX cargo ship delivered a Veggie green growing facility to the International Space Station, and in March, astronauts began testing an orbital plantation. The installation controls the light and the supply of nutrients. In August 2015 on the astronauts menu , grown in microgravity.
Lettuce grown on the International Space Station
This is what a space station plantation might look like in the future
The Lada greenhouse operates in the Russian segment of the International Space Station for the Plants-2 experiment. At the end of 2016 or the beginning of 2017, the Lada-2 version will appear on board. The Institute of Biomedical Problems of the Russian Academy of Sciences is working on these projects.
Space crop production is not limited to experiments in zero gravity. Man, in order to colonize other planets, will have to develop agriculture on soil that is different from the earth, and in an atmosphere that has a different composition. In 2014, biologist Michael Mautner asparagus and potatoes on meteorite soil. In order to obtain soil suitable for cultivation, the meteorite was ground into powder. By experience, 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 meteor soil
In the case of Mars, where there is a lot of sand and dust, rock grinding is not needed. But there will be another problem - the composition of the soil. There are heavy metals in the soil of Mars, the increased amount of which in plants is dangerous for humans. Dutch scientists have mimicked Martian soil and have grown ten crops of several plant species on it since 2013.
As a result of the experiment, scientists found that the content heavy metals in peas, radishes, rye and tomatoes grown on simulated Martian soil is not dangerous to humans. Scientists continue to explore potatoes and other crops.
Researcher Wager Vamelink inspects plants grown on simulated Martian soil. Photo: Joep Frissel/AFP/Getty Images
Metal content in crops harvested on Earth and in soil simulations on the Moon and Mars
One of important tasks is to create a closed cycle of life support. Plants receive carbon dioxide and the waste products of the crew, in return they give oxygen and produce food. Scientists have the possibility of using chlorella single-celled algae containing 45% protein and 20% fat and carbohydrates as food. But this theoretically nutritious food is not absorbed by humans due to the dense cell wall. There are ways to solve this problem. Can be split cell walls technological methods, using heat treatment, grinding crayons or other methods. You can take with you enzymes developed specifically for chlorella, which the astronauts will take with food. Scientists can also bring out GMO chlorella, the wall of which can be broken down by human enzymes. Chlorella is no longer used for nutrition in space, but is used in closed ecosystems to produce oxygen.
The chlorella experiment was carried out on board orbital station Salyut-6. In the 1970s, it was still believed that being in microgravity did not negative influence on the human body - there was too little information. They also tried to study the effect on living organisms with the help of chlorella, the life cycle of which 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 1970s, experiments on closed systems have been carried out in the USSR. In 1972, the work of "BIOS-3" began - this system is still in operation. 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 have been able to achieve almost a 100% closed cycle for water and air, and up to 50-80% for 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 develop the scientific basis for their creation.
One of the high-profile experiments simulating a flight to Mars and returning to Earth was. For 519 days, six volunteers were in a closed complex. The experiment was organized by Rokosmos and Russian Academy sciences, and the European Space Agency became a partner. On the “board of the ship” there were two greenhouses - lettuce grew in one, peas in the other. In this case, the goal was not to grow the plants in close to space conditions, but to find out how important the plants are to 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, a member of the Mars-500 crew, Marina Tugusheva, works with greenhouses as part of an experiment.
Another experiment aboard the Mars-500 is GreenHouse. In the video below, expedition member Alexei Sitnev talks about the experiment and shows a greenhouse with various plants.
A person will have many chances. He runs the risk of crashing during landing, freezing on the surface, or simply not flying. And, of course, starve to death. Crop production is essential 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, but also in the simulated soil of Mars and the Moon. Space colonists will definitely have an opportunity.
Scanned and processed by Yuri Abolonko (Smolensk)
NEW IN LIFE, SCIENCE, TECHNOLOGY
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SPACE, ASTRONOMY
7/1989
Published monthly since 1971.
Yu. I. Grishin
ARTIFICIAL SPACE ECOSYSTEMS
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CHRONICLE OF SPACE
ASTRONOMY NEWS
Publishing house "Knowledge" Moscow 1989
BBC 39.67
G 82
Editor I. G. VIRKO
| Introduction | 3 |
| Man in natural ecosystem | 5 |
| Crewed Spaceship - Artificial Ecosystem | 11 |
| Relay race of substances in the biological cycle | 21 |
| Are ecosystems efficient? | 26 |
| Artificial and natural biosphere ecosystems: similarities and differences | 32 |
| About biological life support systems 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 the crews of spacecraft and future long-term functioning space structures. Various models of artificial ecological systems, including man 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 the earth's civilization as a qualitatively new stage in the development of near-solar outer space: the direct settlement of natural and artificially created space objects with a long stay of people on these objects.
It seems that quite recently the first artificial satellite of the Earth (1957) was launched into near-Earth space orbit, the first flight and photographing of reverse side of the Moon (1959), the first man went into space (Yu. A. Gagarin, 1961), the exciting moment of a man’s exit into outer space was shown on television (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 go into the past and become the property of history. In fact, they are only the beginning of the embodiment of the ideas formulated by the great K. E. Tsiolkovsky, who considered space not only as an astronomical space, but also as an environment for human habitation and life in the future. He believed that "if life did not spread throughout the universe, if it were tied to the planet, then this life would often be imperfect and prone to a sad end" (1928).
Today, possible variants of human biological evolution are already being predicted in connection with the resettlement 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 with the help of closed biotechnical life support systems, the creation of lunar and planetary bases, the space industry and construction, the use of extraterrestrial sources of energy and materials are also considered and solved.
The words of K. E. Tsiolkovsky are beginning to come true that “humanity will not remain forever on Earth, but in the pursuit of light and space, it will first timidly penetrate beyond the atmosphere, and then conquer all the circumsolar space” (1911).
At recent international meetings and forums on cooperation in outer space in the interests of further expanding scientific research into near-Earth and near-solar outer space, the study of Mars, the Moon, and other planets of the solar system, hopes were expressed that the implementation of major space programs that require huge material and technical and financial costs, will be carried out by the joint efforts of many countries within the framework of international cooperation. “Only the collective mind of mankind is capable of moving to the heights of the near-Earth space and further - to the 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 long stay and work on space stations remote from the Earth, spacecraft, planetary and lunar bases.
The most expedient way to solve this most important problem, according to many domestic and foreign researchers today, is the creation of closed biotechnical life support systems in long-term habitable space structures, i.e. artificial space ecological systems, including a person and other biological links.
In this brochure, we will attempt to outline the basic principles for constructing such systems, provide information on the results of large-scale ground-based experiments carried out in preparation for the creation of space biotechnical life support systems, indicate the problems that have yet to be solved on Earth and in space in order to ensure the required reliability of the functioning of these systems. systems in space conditions.
HUMAN IN THE NATURAL ECOSYSTEM
Before sending a person to a long space trip Let's 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 spacecraft, 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 XXI century. should already reach 6 billion, is the best evidence of the existence of a sufficiently effective and reliable mechanism for human life support on Earth.
So, what is necessary for a person on Earth to ensure his normal life and activities? It is hardly possible to give a short but exhaustive answer: all aspects of life, activity and human interests are too extensive and multifaceted. Restore in detail at least one of your lived days, and you will see that a person needs not so little.
Satisfaction of human needs for food, water and air, related to the 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 due to the metabolism within the body and with the external environment.
Consuming oxygen, water, nutrients, vitamins, 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 food proteins, fats and carbohydrates. Waste products are excreted from the body into the environment.
As you know, the intensity of metabolism and energy in the human body is such that an adult can exist without oxygen for only a few minutes, without water - about 10 days, and without food - up to 2 months. The external impression that the human body does not undergo changes is deceptive and false. 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, about 125 g of proteins are cleaved , 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 are restored and die, 1/75 of the bone cells of the skeleton and 1/20 of all integumentary skin cells of the body (i.e., through every 20 days a person completely “changes the skin”), about 140 hairs on the head and 1/150 of all eyelashes fall out and are replaced by new ones, etc. At the same time, on average, 23,040 breaths and exhalations take place, 11,520 liters pass through the lungs air, 460 liters of oxygen are absorbed, 403 liters of carbon dioxide are excreted from the body and 1.2–1.5 liters of urine containing up to 30 g of dense substances evaporate through the lungs 0.4 liters and excreted with sweat about 0.6 liters of water containing 10 g of dense substances, 20 g of sebum is formed.
Such 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 that are formed 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 products of metabolism 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 the balance of the exchange of the body with the environment in terms of matter and energy.
Everyone knows how these basic physiological needs of a person are realized in everyday real life: the five billionth crew of the spacecraft "planet Earth" receives or produces everything necessary for their life based on the reserves and products of the planet, which feeds, waters and clothes them, contributes to an increase in their numbers , with its atmosphere protects all living things from the adverse effects of cosmic rays. Here are a few figures that clearly characterize the scale of the main "barter" of man with nature.
The first constant human need is to breathe air. “You can’t breathe in the supply of air,” says a Russian proverb. If each person daily needs an average of 800 g of oxygen, then the entire population of the Earth should consume 1.5 billion tons of oxygen per year. The Earth's atmosphere has a huge renewable supply of oxygen: with a total weight earth's atmosphere 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, the oxygen of the atmosphere is used by the animal world, and is also spent on other oxidative processes, the scale of which is enormous on the planet. However, the reverse recovery 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 diverse organic compounds with simultaneous release of molecular oxygen. According to geochemists' calculations, all the plants of the Earth emit annually 400 billion tons of oxygen, 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 a person with atmospheric oxygen is successfully solved on Earth mainly with the help of photosynthesis processes 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 are carried out. Making up 2/3 of the human body weight, water plays a huge role in ensuring its vital activity. Water is associated not only with the intake of nutrients into the body, their absorption, distribution and assimilation, but also with the release of end products of metabolism.
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 breakdown of its functions and to poisoning by metabolic products, in particular nitrogen.
An additional amount of water is necessary for a person to ensure sanitary and household needs (washing, washing, production, animal husbandry, etc.). This amount significantly exceeds the physiological norm.
The amount of water on the surface of the Earth is huge, it is over 13.7 ∙ 10 8 km 3 in volume. However, the supply of fresh water suitable for drinking purposes is 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, the reserves of water on the spacecraft "Earth" 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. In the body, the processes of biological oxidation of proteins, fats and carbohydrates that come with food are continuously carried out. Complete food should include the necessary amounts of amino acids, vitamins and minerals. Food substances, as a rule, are broken down by enzymes in the digestive tract to simpler, low molecular weight compounds (amino acids, monosaccharides, fatty acid and many others), are absorbed and carried 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 energetically enriched compounds, and partially converted into heat and dissipated in environment.
The amount of food needed by the body depends mainly on the intensity of its physical activity. The energy of the basic metabolism, that is, such a 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 (respiration, heart function, intestinal peristalsis, 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 the consumption of more food. It has been established that the daily energy consumption by a person during mental and physical work of moderate severity is about 3000 kcal. The same calorie content should be the daily diet of a person. The calorie content of the diet is roughly 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 has been 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 caloric value of the diet. Variations in the composition of the diet for proteins, fats and carbohydrates arise, as a rule, due to changes in the physical activity of the body, but also depend on human habits, national dietary traditions, the availability of a particular food product and, of course, specific social opportunities to meet nutritional needs.
Each nutrient performs a specific function in the body. This is especially true for 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 largely be replaced by each other, but up to certain limits.
Ordinary human food completely covers the body's need for proteins, fats and carbohydrates, and also delivers the necessary minerals and vitamins.
However, in contrast to the unlimited supply of oxygen (air) and drinking water, which is still sufficient on the planet and the consumption of which is strictly regulated only in certain, as a rule, arid regions, the amount of food production is limited by the low productivity of the natural trophic (food) cycle, which consists of three basic levels: plants - animals - man. Indeed, plants form biomass using only 0.2% of the energy of sunlight coming to Earth. By consuming plant biomass for food, animals spend no more than 10-12% of their assimilated energy for their own needs. Ultimately, a person, by eating food of animal origin, provides the energy needs of his body with a very low coefficient of use of the initial solar energy.
Satisfying nutritional needs has always been the most difficult task of man. The passive use of the possibilities of nature in this direction is limited, since most of the globe is covered with oceans and deserts with low biological productivity. Only certain regions of the Earth, characterized by stable favorable climatic conditions, provide a high primary productivity of substances, by the way, by no means always acceptable from the standpoint of human nutritional needs. The growth of the Earth's population, its dispersal across all continents and geographical areas of the planet, including areas with adverse climatic conditions, as well as the gradual depletion of natural food sources have led to a state where the satisfaction of food needs on Earth has grown into a universal 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 is despite the fact that humanity at the end of the 20th century. it is generally distinguished by a rather high social organization, major achievements in the development of science, technology, industry and agricultural production, a deep understanding of its unity in the composition, the planet's biosphere.
Food is an important environmental factor not only for humans, but 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, rate of development, etc.) can change significantly. Nutritional (trophic) links between living organisms, as will be shown below, underlie both the biospheric (terrestrial) biological cycle of substances and artificial ecological systems, including humans.
The Earth will be able to provide everything necessary for those who live on it for a long time, if humanity spends the resources of the planet more rationally and carefully, solves environmentally competent issues of transforming nature, eliminates the arms race and puts an end to nuclear weapons.
The scientific basis for solving the problem of the life support of mankind on Earth, formulated by V. I. Vernadsky, is the transition of the Earth's biosphere into the noosphere, i.e. into such a biosphere that has been changed by scientific thought and transformed to meet all the needs of a numerically growing humanity (the sphere of reason). V. I. Vernadsky suggested that, having originated on Earth, the noosphere, as man explores circumstellar outer space, should turn into a special structural element space.
CREW SPACESHIP - ARTIFICIAL ECOSYSTEM
How to solve the problem of providing the crew of the spacecraft 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 happens in cases of short-term manned flights.
As the duration of the flight increases, more supplies are required. Therefore, it is necessary to carry out the regeneration of some consumable substances (for example, water), the processing of human waste and waste from technological processes of some ship systems (for example, regenerated carbon dioxide sorbents) to reuse these substances and reduce the 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 profitable and practically feasible only for large space expeditions lasting more than 1.5 - 3 years (AM Genin, D. Talbot, 1975). The decisive role in the creation of the circulation of substances in such expeditions is assigned, as a rule, to the processes of biosynthesis. 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 the ship, station, etc., are assigned to the so-called life support systems (LSS). A schematic representation of the main types of LSS for space crews is shown in fig. 1.
 Rice. Fig. 1. Schemes of the main types of life support systems for space crews: 1 - system in stock (all waste is removed); 2 - a system in stocks with partial physical and chemical recovery of substances (PCR) (part of the waste is removed, part of the stocks can be renewed); 3 - system with partial FCR and partial biological regeneration of substances by plants (BR) with a waste correction unit (WK); 4 - a system with a complete closed regeneration of substances (reserves are limited by microadditives). Designations: E - radiant or thermal energy, IE - energy source, W - waste, BB - bioblock with animals, dotted line - optional process |
LSS of space crews are the most complex complexes. Three decades of the space age have confirmed the sufficient efficiency and reliability of the created LSS, which successfully worked 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 research complex "Mir" with an improved life support system on board continues. All these systems have already provided flights for more than 200 cosmonauts from various countries.
The principles of construction and operation of LSS, which were 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 applying biosynthesis processes in space LSS, and even more so the problem of constructing closed biotechnical LSS for space flights, is still open.
There are different, sometimes directly opposite points of view on the possibility and expediency of the practical implementation of such systems in general and in spacecraft in particular. The following are cited as arguments against: complexity, lack of knowledge, energy intensity, unreliability, unsuitability, etc. However, the vast majority of experts consider all these issues to be solved, and the use of biotechnical LSS as part of future large space settlements, lunar, planetary and interplanetary bases, and others remote extraterrestrial structures - inevitable.
The inclusion of the crew in the LSS along with numerous technical devices of biological links, 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 LSS, in which a stable dynamic balance 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.
A manned spacecraft includes at least one actively functioning biological link - a person (crew) with his microflora. At the same time, man and microflora exist in interaction with the environment artificially created in the spacecraft, providing a stable dynamic balance of the biological system in terms of matter and energy flows.
Thus, even with the full provision of life for the crew in the spacecraft due to the reserves of substances and in the absence of other biological links, a manned spacecraft is already an artificial space ecological system. It can be completely or partially isolated in substance 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 a constant removal of heat, is a necessary condition for the functioning of any artificial space ecosystem.
The 21st century poses new, even more ambitious tasks for mankind in the further exploration of outer space. (Apparently, it would be more accurate to say that humanity sets these tasks for the 21st century.) The specific shape 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 , a construction space platform, a complex of residential buildings 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 controlled biosynthesis processes and controlled transformation of matter and energy in the biological links of ecosystems.
Today we can say that the tasks and programs of advanced space research were defined in the USSR and the USA at the state level until approximately the year 2000. With regard to 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 USA and Great Britain) revealed the picture reflected in the following table:
| years | Stage content |
| 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 | First manned flight to Jupiter. |
| 2030 – 2050 | Flights within the solar system, using the natural resources of the solar system, including the moon. |
| 2045 – 2060 | First flight of an unmanned probe outside the solar system. |
| 2045 – 2070 | The first manned flight to the borders of the solar system. |
| 2050 – 2100 | Establishing contacts with extraterrestrial intelligence. |
The famous American physicist J. O "Neill, who deals with the problems of future space settlements of mankind, published his forecast back in 1974, in which 10 thousand people were supposed to work in space in 1988. 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 should be ensured and an ecologically closed habitat system should 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 number of crew and with an increasing distance of a spacecraft from the Earth, it becomes necessary to carry out the biological regeneration of consumables, and primarily food, directly on board the spacecraft. At the same time, not only technical and economic (mass and energy) indicators testify in favor of biological LSS, but also, no less important, indicators of the biological reliability of a person as a determining link in an artificial space ecosystem. Let us explain the latter in more detail.
There are a number of studied (and so far unexplored) connections of the human body with wildlife, without which its successful long-term life is impossible. These include, for example, its natural trophic relationships, which cannot be completely replaced by food from the stocks stored on the ship. So, some vitamins that a person needs on a mandatory basis (food carotenoids, ascorbic acid, etc.) are unstable during storage: under terrestrial conditions, the shelf life, for example, of vitamins C and P is 5-6 months. Under the influence of cosmic 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 the Earth, as was the case during the record-breaking annual space flight at the Mir station. In addition, medical and biological studies have shown that under the conditions of space flight, an increased intake of vitamins by astronauts is required. Thus, during flights under the Skylab program, the astronauts' consumption of vitamins of group B and vitamin C (ascorbic acid) increased approximately 10 times, vitamin A (axerophthol) - 2 times, vitamin D (calciferol) - slightly higher than the earth's norm. It has now also been established that vitamins of biological origin have clear advantages over purified preparations of the same vitamins obtained by chemical means. This is due to the fact that vitamins are found in the composition of biomass in combination with a number of other substances, including stimulants, and when eaten, they have more effective action 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 whole complex of water-soluble and partially fat-soluble vitamins, carbohydrates, biologically active substances and fiber that a person needs. The role of these food components in the metabolism is enormous (V. I. Yazdovsky, 1988). Naturally, the existing process of preparing space rations, which involves strict processing modes (mechanical, thermal, chemical), cannot but reduce the effectiveness of individual important food components in human metabolism.
Apparently, one should also take into account the possible cumulative effect of cosmic radioactive radiation on food products stored for a long time on the ship.
Consequently, it is not enough just to meet the calorie content of food with the established norm; 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” some properties of biologically active molecules and then transfer this information to living cells seems to be beginning to clarify the ancient folk fairy tale wisdom about “living” and “dead” water. If this discovery is confirmed, then the fundamental problem of water regeneration on long-term spacecraft arises: is water, purified or obtained by physicochemical 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 some chemical elements (including stable oxygen isotopes O 16, O 17, O 18), as well as to capture a small difference in the strength of chemical bonds of isotopes in the molecules of 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 the air is slightly heavier than oxygen from water. Living organisms "feel" this difference, although it can be quantitatively determined only by special instruments, mass spectrometers. Prolonged breathing of chemically pure oxygen under space flight conditions can lead to intensification oxidative processes in the human body and to pathological changes in the 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 formed by plants that kill or suppress bacteria, microscopic fungi, and protozoa. The presence of phytoncides in the ambient air, as a rule, is beneficial for the human body and causes a feeling of freshness in the air. So, for example, the commander of the third American crew of the Skylab station emphasized that his crew inhaled air enriched with lemon phytoncides with pleasure.
In known cases of infection of people with bacteria that settle in air conditioners ("legionnaires' disease"), phytoncides would be a strong disinfectant, and in relation to air conditioning systems in closed ecosystems, they could exclude such a possibility. As studies by M. T. Dmitriev showed, phytoncides can act not only directly, but also indirectly, increasing the bactericidal action of the air and increasing the content of light negative ions that have a beneficial effect on the human body. The number of unwanted heavy positive ions in the air is thus reduced. Phytoncides, which are a kind of carriers of the protective function of plants from the microflora of the environment, are not only released into the air surrounding the plant, but also contained in the biomass of the plants themselves. Garlic, onion, mustard and many other plants are the richest in phytoncides. By eating them, a person carries out an imperceptible, but very effective fight against infectious microflora that enters the body.
Speaking about the importance for humans of biological links in an artificial space ecosystem, 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 astronauts who had to perform experiments with higher plants aboard space stations were unanimous in their assessments. So, L. Popov and V. Ryumin at the Salyut-6 orbital station took good care of the plants in the experimental greenhouses Malachite (interior stained glass greenhouse with tropical orchids) and Oasis (experimental greenhouse with vegetable and vitamin plant cultures). They watered, monitored the growth and development of plants, carried out routine inspections and work with the technical part of the greenhouses, and simply admired the living interior of orchids in rare moments of rest. “Biology research has brought 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, it became less comfortable at the station. So said after landing L. Popov. “Working with Malachite aboard the space complex has always given us special satisfaction,” V. Ryumin added to L. Popova.
At a press conference on October 14, 1985, dedicated to the results of work in orbit by cosmonauts V. Dzhanibekov and G. Grechko aboard the Salyut-7 orbital station, the flight engineer (G. Grechko) said: “To every living thing, to every sprout in space, the attitude is special, careful: they remind of the Earth, cheer up.
Thus, astronauts need higher plants 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 an astronaut in his long, difficult and intense mission. And wasn’t this the aesthetic side and the 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 it as another next question: "What can you have on board a heavy interplanetary ship or a heavy orbital station (or in a greenhouse) from ornamental plants that require a minimum of costs and care?" And the first answer to this question has already been received today: these are tropical orchids that seem to like 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 an unconscious spiritual need for contact with wildlife becomes a real force, which is supported by rigorous scientific facts that testify to economic efficiency and technical feasibility of maximum approximation of artificial biospheres to natural environment that raised humanity. From this point of view, the strategic direction towards the creation of biological LSS seems to be very correct.” And further: “Attempts to isolate man from nature are extremely uneconomical. Biological systems, better than any other, will ensure the circulation of substances in large space settlements.
One of the fundamental advantages of biological systems in comparison with non-biological ones is the potential possibility of their stable functioning with a minimum scope of control and management functions (E. Ya. Shepelev, 1975). This advantage is due to the natural ability of living systems that are in constant interaction with the environment to carry out the correction of 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, its readiness) to make the necessary adjustments to the process of the circulation of substances in an artificial ecosystem.
The degree of complexity of artificial space ecosystems can be different: from the simplest systems in stocks, systems with physical and chemical regeneration of substances and the use of individual biological links to systems with a practically 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 predetermined and calculated on the basis of a quantitative analysis of the processes of the biological cycle 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 LSS for future large space settlements. The creation of such systems today is still at the stage of calculations, theoretical constructions and ground testing for pairing individual biological links with the test crew.
The main goal of developing experimental biotechnical LSS is to achieve a stable, practically closed circulation of substances in an ecosystem with a crew and a relatively independent existence of an artificially formed biocenosis in a mode of long-term dynamic equilibrium based on predominantly internal control mechanisms. Therefore, a thorough study of the processes of the biological cycle of substances in the Earth's biosphere is required in order to use the most effective of them in biotechnical LSS.
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 mineral substances of inanimate nature and atmospheric carbon dioxide. These substances are included in the composition of the organic biomass of plant organisms, which has a large supply of energy obtained by converting the radiant energy of the Sun in the process of photosynthesis. Plant biomass is transformed through food chains in animal and human organisms (heterotrophic organisms) using some of these substances and energy for their own growth, development and reproduction. Organisms-destroyers (destructors, 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, there is a multi-cycle migration of substances and chemical elements 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%, therefore, one can speak of its complete isolation only conditionally. The main cycles of the biosphere are the cycles of carbon, nitrogen, oxygen, phosphorus, sulfur and other biogenic elements.
The natural biological cycle involves both living and non-living substances.
Living matter is biogenic, since it is formed only through the reproduction of living organisms already existing on Earth. Inanimate matter present in the biosphere can be either of biogenic origin (fallen bark and leaves of trees, fruits that have ripened and separated 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 released from earth's interior gases).
The living matter of the planet by its mass makes up 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 a set of all transformations of matter and energy in the process of continuously occurring biochemical reactions in the body.
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 amount, 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 that enter the body from outside) and dissimilation (decomposition of organic substances caused by the need to release energy for the life of the body).
Thermodynamic non-equilibrium stability. In accordance with the second law (beginning) of thermodynamics, the presence of energy alone is not enough to do work, but the presence of a potential difference, or energy levels, is also necessary. Entropy serves as a measure of the "loss" of the potential difference by any energy system and, accordingly, a measure of the loss of the ability to perform work by this system.
In processes occurring in inanimate nature, the performance of work leads to an increase in the entropy of the system. So, for heat transfer, the direction of the process uniquely determines the second law of thermodynamics: from a hotter body to a less heated one. In a system with a zero temperature difference (at the same temperature of the bodies), the maximum entropy is observed.
Living matter, living organisms, unlike inanimate nature, oppose this law. Never being in equilibrium, they constantly perform work against its establishment, which, it would seem, should legitimately occur as a correspondence to existing external conditions. Living organisms constantly expend energy to maintain a specific state of the living system. This most important feature is known in the literature as the Bauer principle, or the principle of stable non-equilibrium of living systems. This principle shows that living organisms are open non-equilibrium systems that differ from non-living 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 non-equilibrium dynamic system. The living matter of the system is a carrier of enormous potential energy,
Ability to self-reproduce 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 man, tends 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 wildlife.
The high rates of metabolic reactions in living organisms, which are 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, for the growth of each unit of biomass or the accumulation of 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 one.
The capacity for diversity, renewal and evolution. The living matter of the biosphere is characterized by different, but very short (on a cosmic scale) life cycles. The life span of living beings ranges from a few hours (and even minutes) to hundreds of years. In the course 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. At the same time, even within the framework of biochemical uniformity and unity organic world(all modern living organisms are built mainly from proteins) wildlife is distinguished by a huge morphological diversity and a 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 inanimate matter is only about 2 thousand. The morphological diversity of wildlife is also great: the plant kingdom on Earth includes almost 500 thousand species, and animals - 1 million 500 thousand.
A living organism that has formed 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 transferring 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 lifespan 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 environment.
The evolutionary process is characteristic mainly of higher organisms.
The collectivity of existence. Living matter actually exists on Earth in the form of biocenoses, and not separate isolated species (populations). The relationship of populations is due to their trophic (food) dependencies from each other, without which the very existence of these species is impossible.
These are the main qualitative features of living matter participating in the biospheric biological cycle of substances. In quantitative terms, the intensity of biomass accumulation in the biosphere is such that, on average, every eight years, the entire living substance of the Earth's biosphere is renewed. Having completed their life cycle, organisms return to nature everything that they took from it during their life.
The main functions of the living matter of the biosphere, formulated by the Russian 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 involvement in the cycle ), environment-forming (changes in the physico-chemical parameters of the medium) and transport (substance transfer) functions.
DO ECOSYSTEMS HAVE EFFICIENCY?
Let us now try to answer the question: is it possible to evaluate the effectiveness of the biological cycle of substances from the standpoint of meeting the nutritional needs of a person as the top trophic link of this cycle?
An approximate answer to the question posed can be obtained on the basis of the 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 circulation are subject to continuous qualitative change, then the energy of these substances does not disappear, but is distributed in directed flows. Transferring from one trophic level of the biological cycle to another, biochemical energy is gradually transformed and dissipated. The transformation of the energy of matter in trophic levels does not occur arbitrarily, but in accordance with known patterns, and therefore it is controllable within a particular biogeocenosis.
The concept of "biogeocenosis" is similar to the concept of "ecosystem", but the former carries a stricter semantic load. If an ecosystem is called almost any autonomously existing natural or artificial biocomplex (anthill, aquarium, swamp, trunk of a dead tree, forest, lake, ocean, Earth's biosphere, spacecraft 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 a supraorganismal level, i.e. a single organism cannot be an ecosystem.
The biological cycle of substances is an integral part of the earth's biogeocenosis. As part of specific local biogeocenoses, the biological cycle of substances is possible, but not necessary.
Energy connections always accompany trophic connections in biogeocenosis. Taken together, they form the basis of any biogeocenosis. In the general case, five trophic levels of biogeocenosis can be distinguished (see table and Fig. 2), through which all its components are distributed sequentially along the chain. Usually, several such chains are formed in biogeocenoses, which, branching and crossing 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. Autotrophs use either light solar energy (phototrophs) or the energy of oxidation of certain mineral compounds (chemotrophs) as an energy source for this process. Phototrophs obtain carbon necessary for synthesis from carbon dioxide.
Conventionally, the process of photosynthesis in green plants (lower and higher) can be described as the following chemical reaction:
Ultimately, from energy-poor inorganic substances (carbon dioxide, water, mineral salts, microelements), organic matter (mainly carbohydrates) is synthesized, which is a carrier of energy stored in chemical bonds formed substance. In this reaction, the formation of one gram-molecule of a substance (180 g of glucose) requires 673 kcal of solar energy.
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/m 2 . At the same time, only a 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 water layer with microalgae is reflected or passes through the leaf or layer uselessly, and the absorbed radiation is mostly spent on water evaporation during plant transpiration.
As a result, the average energy efficiency of the photosynthesis process of the entire vegetation cover of the globe is about 0.3% of the energy of sunlight entering the Earth. Under favorable conditions for the growth of green plants and with the assistance of man, individual plantations of plants can bind the energy of light with an efficiency of 5 - 10%.
Organisms of the subsequent trophic levels (consumers), consisting of heterotrophic (animal) organisms, ultimately provide 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 thermal energy and dissipated into the environment in the process of recombining carbohydrates with oxygen. Using plant biomass as food, animals subject it to oxidation during respiration. In this case, the process opposite to photosynthesis occurs, in which the energy of food is released and, with a certain efficiency, is spent on the growth and vital activity of a heterotrophic organism.
In quantitative terms, in biogeocenosis, plant biomass should "outstrip" 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 the energy metabolism of a heterotrophic organism depends on its mass. With an increase in the size of the body, the intensity of metabolism, calculated per unit weight and expressed in the amount of oxygen absorbed per unit time, noticeably decreases. At the same time, in a state of relative rest (standard metabolism), the dependence of the intensity of the animal’s metabolism on its mass, which has the form of a function y \u003d Ah k (X- the weight of the animal, A And k- coefficients), turns out to be valid both for organisms of the same species that change their size in the process of growth, and animals of different weights, but representing a certain group or class.
At the same time, the indicators of the level of metabolism of various troupes of animals already differ significantly from each other. These differences are especially significant for animals with an active metabolism, which are characterized by energy costs for muscle work, in particular for motor functions.
The energy balance of an animal organism (consumer of any level) for a certain period of time in the general case can 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 - energy of the main exchange, E 2 - energy consumption of the body, E 3 - the energy of the "clean" products of the body, E 4 - energy of unused food substances, E 5 - the energy of excrement and excretions of the body.
Food is the only source of normal intake of energy into the animal and human body, which ensures its vital activity. The concept of "food" has a 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.
Value E for a person is an average of 2500 kcal per day. basal metabolic energy E 1 represents the energy of metabolism 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 related to 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 almost the same.
Component E 2 includes the body's energy consumption for thermoregulation when the ambient temperature changes, as well as for different kinds activities and work of the body: chewing, digestion and assimilation of food, muscle work during the movement of the body, etc. E 2 is significantly influenced by the ambient temperature. When the temperature rises and falls from the optimal level for the body, additional energy costs are required to regulate it. The process of regulating a constant body temperature is especially developed in warm-blooded animals and humans.
Component E 3 includes two parts: the energy of growth of the body's own biomass (or population) and the energy of additional production.
The increase in own biomass takes place, as a rule, in a young growing organism, 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 with a lack of food (the body loses weight).
The energy of additional production lies in the substances produced by the body for reproduction, protection from enemies, etc.
Each individual is limited by the minimum amount of products created in the course of its life. A relatively high indicator of the creation of secondary products can be considered an indicator of 10 - 15% (of the consumed feed), which is typical, for example, for locusts. The same indicator for mammals that spend a significant amount of energy on thermoregulation is at the level of 1 - 2%.
Component E 4 - this is the energy contained in the substances of food that was not used by the body and did not get inside the body for one reason or another.
Energy E 5 contained in the excretions of the body as a result of incomplete digestibility and assimilation of food, ranges from 30-60% of the 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 the food chain, the efficiency (COP) of each trophic link (level) averages about 10%. This means that at each subsequent trophic level of the food goal, products are formed that do not exceed 10% of the energy of the previous one in terms of calories (or in terms of mass). With such indicators, the overall efficiency of the use of 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 product reproduction, the bulk of the Earth's population fully provides itself with a balanced diet not only through primary, but also secondary producers. As for a living organism separately, the efficiency of using food (energy) in some of them is quite high and exceeds the efficiency of many technical means. For example, a pig turns 20% of the food energy consumed into high-calorie meat.
The efficiency of the use of food energy by consumers is usually evaluated in ecology with the help of ecological pyramids of energies. The essence of such pyramids lies in the 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 rectangles correspond to the number of individuals at each level of the food chain) and biomass pyramids (the same applies to the amount of total biomass of organisms at each level).
However, the pyramid of energies gives the most complete picture of functional organization biological communities within a particular food chain, as it allows to take into account the dynamics of the passage of food biomass along this chain.
ARTIFICIAL AND NATURAL BIOSPHERE ECOSYSTEMS: SIMILARITIES AND DIFFERENCES
K. E. Tsiolkovsky was the first to propose the creation in a space rocket of a closed system of circulation of all substances necessary for the life of the crew, i.e. a closed ecosystem. He believed that in a spaceship in miniature all the main processes of the transformation of substances that take place in the Earth's biosphere should be reproduced. 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 the biological cycle of substances rapidly developed in the USA, the USSR and some other countries in the late 50s and early 60s. Undoubtedly, this was facilitated by the successes of cosmonautics, which opened the era of space exploration with the launch of the first artificial Earth satellite in 1957.
In subsequent years, as these works were expanded and deepened, most researchers could be convinced that the problem posed turned out to be much more complex than originally thought. It required not only terrestrial, but also space research, which, in turn, necessitated significant material and financial costs and was held back 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 in the current cycle of the circulation of substances of these systems of some biological links and humans. A complex of scientific studies was also carried out to develop technologies for cultivating biological objects in weightlessness on board space satellites, ships and stations: Cosmos-92, Cosmos-605, Cosmos-782, Cosmos-936, Salyut-6 and others. The results of the research today allow us to formulate some provisions that are taken as a basis for the construction of future closed space ecosystems and biological life support systems for astronauts.
So, what is common for large artificial space ecosystems and natural biosphere. ecosystems? First of all, this is their relative isolation, their main characters are man and other living biological links, the biological cycle of substances and the need for an energy source.
Closed ecological systems- these are systems with an organized cycle of elements, in which substances used at a certain rate for the biological exchange of some links, with the same average speed are regenerated from the final products of their metabolism to the initial state by other links and are reused in the same cycles of biological exchange (Gitelzon et al., 1975).
At the same time, an ecosystem can remain closed even without achieving a complete circulation of substances, irreversibly consuming part 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 terrestrial substances and elements in the repeatedly repeated chemical cycles of the earth's circulation is quite large and, as already noted, ensures the reproduction of individual cycles by 90 - 98%.
In an artificial closed ecosystem, it is impossible to repeat all the diversity of the processes of the terrestrial 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 a person, 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 terrestrial biological cycle, although the main patterns that determine the course and efficiency of processes in its individual biological links can be applied to characterize such links in an artificial ecosystem. In the Earth's biosphere actors there are almost 500 thousand plant species and 1.5 million animal species 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 dramatically increases the "responsibility" of each living organism included in the artificial ecosystem, and imposes increased requirements on its biological stability under 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 is carried out at its characteristic speed. In an artificial ecosystem, the number of such cycles is limited, the role of each cycle in the circulation of substances; increases many times, and the coordinated rates of the processes in the system must be strictly maintained as a necessary condition for the stable operation of the biological LSS.
The presence of dead-end processes in the biosphere does not significantly affect the natural cycle of substances, since the Earth still has significant reserves of substances involved in the cycle for the first time. In addition, the mass of substances of dead-end processes is immeasurably less than the buffer capacity of the Earth. In artificial space LSS, the always existing general restrictions on mass, volume, and energy consumption impose corresponding restrictions on the mass of substances involved 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 isolation, requires appropriate compensation from the stocks of starting substances, and, consequently, an increase in these stocks in the system.
The most important feature of the biological cycle of substances in the considered artificial ecosystems is the determining role of man in the quality and quantitative characteristics circulation of matter. The cycle in this case is carried out ultimately in the interests of meeting the needs of a person (crew), which is the main determining link. The remaining biological objects are performers of the functions of maintaining the human environment. Proceeding from this, for each biological species in an artificial ecosystem, the most optimal conditions for existence are created to achieve the maximum productivity of the species. In the Earth's biosphere, the intensity of biosynthesis processes is determined mainly by the influx 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 about 10 times lower than outside the Earth's atmosphere. In addition, in order to survive and develop, every living organism constantly needs to adapt to living conditions, take care of finding food, spending a significant part of 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 LSS - the satisfaction of human nutritional needs.
Unlike the Earth's biosphere, in artificial ecosystems, 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 influences, depleted soils and unsuitable territories, Chemical properties water, etc.).
These and other differences contribute to the achievement of a significantly greater efficiency of substance transformation in artificial ecosystems, a higher rate of implementation of cycles of circulation, and higher values of the efficiency of the biological human life support system.
ON BIOLOGICAL SYSTEMS OF LIFE SUPPORT OF SPACE CREW
Biological LSS is an artificial set of biological objects (microorganisms, higher plants, animals), consumables and technical means, which are selected in a certain way, interrelated and interdependent biological objects, providing in a limited enclosed space the basic physiological needs of a person in food, water and oxygen, mainly on the basis of a stable biological circulation of matter.
The necessary combination in biological LSS of living organisms (biological objects) and technical means allows us to call these systems also biotechnical. At the same time, under technical means refers to 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 gaseous environment, illumination of living space, sanitary and hygienic indicators of water quality, prompt collection, processing or disposal of waste and etc.). The main technical means of biological LSS include subsystems for energy supply and conversion of energy into light, regulation and maintenance of the gas composition of the atmosphere in a limited enclosed space, thermal control, space greenhouse blocks, kitchens and means of physical and chemical regeneration of water and air, processing, transportation and mineralization devices waste to others. A number of processes for the regeneration of substances in the system can also be effectively carried out by physicochemical methods (see the figure on page 52).
Biological objects of LSS together with a person form a biocomplex. The species and number 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 during the entire specified period. The size (scale) of the biocomplex and the number of species of living organisms represented in the biocomplex depend on the required productivity, the degree of closeness of the LSS 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 of selection of living organisms in the composition of the biocomplex can be borrowed from the ecology of natural terrestrial communities and controlled biogeocenoses, based on the established trophic relationships of biological objects.
The selection of biological species for the formation of trophic cycles of biological LSS is the most difficult task.
Each biological object participating in a biological LSS requires for its life activity a certain living space (ecological niche), which includes not only a purely physical space, but also a set of necessary living conditions for a given biological species: ensuring its lifestyle, mode of nutrition, and environmental conditions. Therefore, for the successful functioning of living organisms as a link in a biological LSS, the volume of space occupied by them should not be too limited. In other words, there must be limiting minimum dimensions of a manned spacecraft, below which the possibility of using biological LSS links in it is excluded.
In the 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 masses into it. At the same time, such a closed biological LSS with the regeneration of all substances necessary for a person and an unlimited operating time is today more of a theoretical than a practically real system, if we keep in mind those of its options that are considered for space expeditions in the near future.
In the thermodynamic sense (in terms of energy), any ecosystem cannot be closed, since the constant energy exchange of the living links of the ecosystem with the surrounding space is a necessary condition for its existence. The Sun can serve as a source of free energy for biological LSS of spacecraft in near-solar space. However, the need for a significant amount of energy for the functioning of large-scale biological LSS requires effective technical solutions to the problem of continuous collection, concentration and input of solar energy into a spacecraft, as well as the subsequent discharge of low-potential energy into outer space. thermal energy.
A special question that arises in connection with the use of living organisms in space flights is how does prolonged weightlessness affect them? Unlike other factors of space flight and outer space, the effect of which on living organisms can be simulated and studied on Earth, the effect of weightlessness can only be established directly in space flight.
GREEN PLANTS AS THE MAIN LINK OF BIOLOGICAL LIFE SUPPORT SYSTEMS
Higher land plants are considered the main and most likely elements of the biological life support system. They are able not only to produce food that is complete by most criteria for humans, but also to regenerate 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 certain level followed by light saturation of photosynthesis. 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 provided maximum photosynthesis under artificial conditions, was 150–200 W/m 2 (Nichiporovich, 1966). The productivity of plants (spring wheat, barley) reached 50 g of biomass per day per 1 m 2 (up to 17 g of grain per 1 m 2 per day). In other experiments performed with the aim of choosing the light regimes for radish cultivation in closed systems, the yield of root crops was up to 6 kg per 1 m 2 in 22–24 days with a biological productivity of up to 30 g of biomass (in dry weight) per 1 m 2 per day (Lisovsky , Shilenko, 1970). For comparison, we note that in the field, the average daily productivity of crops is 10 g per 1 m 2.
The biocycle: "higher plants - man" would be ideal for the life support of man, if in a long space flight it was possible to be satisfied with the nutrition of proteins and fats only of vegetable origin and if plants could successfully mineralize and utilize all human waste.
The space greenhouse, however, will not be able to solve the whole range of issues assigned to the biological LSS. It is known, for example, that higher plants are not able to provide participation in the circulation of a number of substances and elements. Thus, sodium is not consumed by plants, leaving open the problem of NaCl (common salt) cycling. The fixation of molecular nitrogen by plants is impossible without the help of 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 above-mentioned norms is 65% of the total calorie content of the diet (the average calorie content of the daily food ration of an astronaut at the Salyut-6 station was 3150 kcal), then in order to obtain the required amount of plant biomass, a greenhouse with an estimated area of one person at least 15 - 20 m 2. Taking into account plant waste that is not eaten (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 the greenhouse can be significantly increased by additional use of the inedible part of the resulting biomass. There are various ways to utilize biomass: obtaining nutrients by extraction or hydrolysis, physicochemical 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 LSS, individual issues of the complete circulation 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 assigned the function of reproducing the minimum required amount of fresh herbs containing vitamins. A greenhouse with a planting area of 3 - 4 m 2 can fully meet the needs of one person for vitamins. In such ecosystems, based on the partial use of the biocycle of higher plants - man, the main load on the regeneration of substances and the life support of the crew is performed by systems with physicochemical processing methods.
The founder of practical astronautics, S.P. Korolev, dreamed of a space flight that was 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 top-priority tasks of space biotechnology in the following way: “We should start developing a “greenhouse according to Tsiolkovsky”, with gradually building up links or blocks, and we should start working on “space harvests”. What is the composition of these crops, what crops? Their effectiveness, usefulness? Reversibility (repeatability) of crops from their own seeds, based on the long-term existence of the greenhouse? Which organizations will carry out these works: in the area of crop production (and issues of soil, moisture, etc.), in the area of mechanization and “light-heat-solar” technology and its control 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 the "Tsiolkovsky greenhouse" is created, i.e. such a greenhouse that during a long space flight will supply a person with the necessary fresh 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 should be provided. The greenhouse should also be equipped with devices for distributing light and air conditioning, blocks for preparing, distributing and supplying nutrient solutions, collecting transpiration moisture, etc. Soviet and foreign scientists are successfully working on the creation of such large-scale greenhouses for spacecraft now in the near future.
Space crop production today is still at the initial stage of its development and requires new special studies, since many questions related to the response of higher plants to the extreme conditions of space flight, and primarily to weightlessness, still remain unexplained. The state of weightlessness has a very significant impact on many physical phenomena, on the vital activity and behavior of living organisms, and even on the operation of onboard equipment. The effectiveness of the influence of dynamic weightlessness can therefore be evaluated only in so-called full-scale experiments carried out directly on board orbital space stations.
Experiments with plants in natural conditions were previously carried out at 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 weightlessness and in the field of action. centrifugal forces. In the "Vazon" device, the processes of growing onions on a feather were worked out as a vitamin supplement to the astronauts' diet. Arabidopsis planted in an isolated chamber on an artificial nutrient medium bloomed for the first time in the conditions of weightlessness in the "Svetoblok" device, and Arabidopsis seeds were obtained in the "Fiton" device. A wider range of tasks was solved in the Oasis research facilities, which consisted of cultivation, lighting, water supply, forced ventilation, and telemetric temperature control units. In the "Oasis" plant, cultivation regimes with electrical stimulation were practiced on pea and wheat plants as a means of reducing the effect of unfavorable factors associated with the absence of gravity.
A number of experiments with higher plants under space flight conditions were carried out in the USA at the Skylab and Spacelab stations and aboard the Columbia (Shuttle).
Numerous experiments have shown that the problem of growing plants on space objects under conditions significantly different from ordinary terrestrial ones has not yet been fully resolved. Still not uncommon, for example, are cases when plants stop growing at the generative stage of development. We still have to carry out a significant amount of scientific experiments 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 help eliminate the negative impact various factors space flight on plants.
In addition to higher land 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 freshwater microscopic alga 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. Assimilation of carbon dioxide, the culture releases oxygen. With intensive cultivation, 30 - 40 liters of chlorella suspension can completely provide gas exchange for one person. In this case, biomass is formed, which, according to 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 the chlorella biomass can vary depending on the cultivation conditions, which makes it possible to conduct a controlled biosynthesis process. The productivity of intensive cultures of chlorella in laboratory cultivation ranges from 30 to 60 g of dry matter per 1 m 2 per day. In experiments on special laboratory cultivators with high illumination, the yield of chlorella reaches 100 g of dry matter per 1 m 2 per day. Chlorella is the least affected by weightlessness. Its cells have a strong cellulose-containing membrane and are most resistant to adverse conditions of existence.
The disadvantages of chlorella as a link in an artificial ecosystem include the discrepancy between the CO 2 assimilation coefficient and the human respiration coefficient, the need for increased CO 2 concentrations 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. Single-celled algae in general (in particular, chlorella), in contrast to higher plants, are devoid of regulatory devices and require automated control of the biosynthesis process for reliable effective functioning in culture.
The maximum efficiency values in the 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 culture productivity and low energy consumption are usually contradictory requirements, since the maximum efficiency values are achieved at relatively low culture optical densities.
At present, 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 become more and more complicated. It is necessary to solve the main issues of the formation of biological LSS for future long-term space expeditions today, since scientific experiments performed with the links of biological LSS are characterized by a long duration from the beginning to the moment 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 of biological LSS, as well as the need to obtain reliable information on the long-term consequences of trophic and other links of biolinks, which for living organisms can usually manifest themselves only in subsequent generations. Methods for the accelerated conduct of such biological experiments do not yet exist. It is this circumstance that requires a significantly ahead of time laying of experiments on the study of energy and mass transfer processes in biological LSS, including a person.
It is clear that the main issues of creating biological LSS for space crews must be preliminarily worked out and solved 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 hermetic chambers, stands simulating space flight conditions, etc. In complex ground experiments performed in hermetic chambers with the participation of test groups, the compatibility of systems and links with each other and with a person is determined, the stability of biological links in a long-term functioning artificial ecosystem is determined, the effectiveness and reliability of the decisions made are evaluated, and a choice is made of a variant of a biological LSS for its final in-depth study in relation to a specific space object or flight.
In the 1960s and 1970s, a number of unique scientific experiments were carried out in the USSR aimed at creating biological LSS for crews of artificial space ecosystems. In November 1968, a long (one-year) experiment was completed in the USSR with the participation of three testers. Its main objectives were to test and develop the technical means and technologies of an integrated LSS based on physical and chemical methods of regeneration of substances and a biological method for 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 m 2 , 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 a person staying in it and the repeated use of transpiration water without its regeneration for irrigating the substrate was established. Partial regeneration of substances was carried out in the greenhouse, providing a minimum isolation of food and oxygen - by 3 - 4%.
In 1970, an experimental model of a life support system was demonstrated at the VDNKh of the USSR, presented by the All-Union Research Biotechnical Institute of the Glavmikrobioprom of the USSR and designed to determine the optimal composition of a complex of biotechnical blocks and their mode of operation. The life support system of the layout was designed to meet the needs of three people in 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 liters and a greenhouse with a usable area of about 20 m2 (Fig. 3). The reproduction of animal food products was entrusted to the chicken cultivator.
 Rice. 3. Appearance greenhouses |
A series of experimental studies ecosystems including humans. 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 indicator of the total closure of the circulation of substances equal to 38% (regeneration of the atmosphere and water).
The experiment with the three-link system "man - higher plants - microalgae" was carried out for 30 days. The goal is to study the compatibility of a person with higher plants with a completely closed gas exchange and a partially closed water exchange. At the same time, an attempt was made to close the food chain by plant (vegetable) biomass. The results of the experiment showed the absence of a mutual depressing effect of the links of the system through the common atmosphere during the time of the experiment. The minimum size of the planting area of a continuous crop of vegetables was determined to fully meet the needs of one person in fresh vegetables under the chosen mode of cultivation (2.5 - 3 m 2).
By introducing the fourth link into the system - a microbial cultivator designed to process non-food plant waste and return them to the system, a new experiment with a person lasting 73 days was started. During the experiment, the gas exchange of links was completely closed, and water exchange was almost completely closed (excluding samples on chemical analysis) and partially food metabolism. During the experiment, a deterioration in the productivity of higher plants (wheat) was revealed, which was explained by the accumulation of plant metabolites or associated microflora in the nutrient medium. A conclusion was made about the inexpediency of introducing a mineralization link of human solid excretions into the system based on the technical and economic indicators of a four-link biological system.
In 1973, a six-month experiment was completed on the life support of a crew of three in a closed ecosystem with a total volume of about 300 m 3, which included, in addition to the testers, links of higher and lower plants. The experiment was carried out in three stages. At the first stage, which lasted two months, all the crew's needs for oxygen and water were met by higher plants, including wheat, beets, carrots, dill, turnips, kale, radishes, cucumbers, onions and sorrel. Wastewater from the household compartment was fed into the nutrient medium for wheat. Solid and liquid secretions of the crew were removed from the pressurized volume to the outside. The nutritional requirements of the crew were met partly by higher plants, and partly by dehydrated foods from stocks. Every day in the link of higher plants from a planting area of about 40 m 2 1953 g of biomass (in dry weight) was synthesized, including 624 g of edible, which amounted to 30% of the total crew requirement. At the same time, the need for oxygen for three people was fully provided (about 1500 liters per day). The closure of the system "man - higher plants" 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 met by higher (wheat and vegetable crops) and lower plants, the crew's liquid excretions were sent to the algae reactor, and the solid excretions were dried to return water to the cycle. The crew meals were carried out similarly to the first stage. A deterioration in the growth of wheat was revealed due to an increase in the amount of waste water supplied with a nutrient medium per unit of planting area, which was halved.
At the third stage, only vegetable crops were left in the link of higher plants, and the algae reactor performed the main load on the regeneration of the atmosphere of the hermetic volume. Wastewater was not added to the plant nutrient solution. Nevertheless, at this stage of the experiment, plants were found to be intoxicated by the hermetic atmosphere. The closure of the system, including chlorella, which utilizes human liquid excretions, increased to 91%.
During the experiment, special attention was paid to the issue of equalizing temporal fluctuations in the exchange of exometabolites in the crew. To this end, the testers lived according to a schedule that ensured the continuity of ecosystem management and the uniformity of the level of mass transfer in the process of autonomous existence of the ecosystem. For 6 months of the experiment, there were 4 testers in the system, one of whom lived in it continuously, and three - for 6 months, being replaced according to the schedule.
The main result of the experiment is a proof of the possibility of implementing a biological life support system autonomously controlled from within in a limited enclosed space. The analysis of indicators of physiological, biochemical and technological functions of the testers did not reveal directed changes caused by their stay in the artificial ecosystem.
In 1977, a four-month experiment was carried out 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 maintain the productivity of higher plants in a closed ecosystem. At the same time, the possibility of increasing the closure of the system by increasing the share of the crew's food ration reproduced in it was also studied. Two testers participated in the experiment (during the first 27 days - three testers). The sown area of the phytotron was about 40 m2. The set of higher plant cultures included wheat, chufa, beets, carrots, radishes, onions, dill, cabbage, 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 from the 5th day and lasted up to 24 days. Further, thermal catalytic purification of the atmosphere was switched 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 the burning of straw and cellulose, the reproduced part of the crew's diet was brought up to 60% by weight (up to 52% by calorie content).
The water exchange in the system was partially closed: the condensate of transpirational moisture of plants served as a source of drinking and partially sanitary water; culture medium with the addition of domestic waste water, and the water balance was maintained by the introduction of distilled water in amounts that compensated for the withdrawal of human liquid excretions from the system.
Upon completion of the experiment, no negative reactions of the body of the testers to the complex effect of the conditions of a closed system were found. Plants fully provided the testers with oxygen, water and the main part of plant food.
In the same year, 1977, a month and a half experiment was completed with two testers at the Institute of Biomedical Problems of the USSR Ministry of Health. The experiment was carried out to study a model of a closed ecosystem, which included a greenhouse and a plant with chlorella.
The performed experiments showed that when the 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 excretions adversely affected the development of higher plants, and some additional physico-chemical treatment of the air entering the greenhouse was required.
Abroad, work aimed at creating promising LSS is most intensively carried out in the USA. Research is carried out in three directions: theoretical (determination of the structure, composition and calculated characteristics), experimental ground (testing of individual biological units) and experimental flight (preparation and conduct of biological experiments on manned spacecraft). The NASA centers and firms that develop spacecraft and systems for them are dealing with the problem of creating biological LSS. Universities are involved in many prospective studies. A department of biosystems has been created at NASA, which coordinates work on the program for the creation of a controlled biotechnical LSS.
The project of creation in the USA of a grandiose artificial structure called "Biosphere-2" aroused great interest among environmental specialists. This structure of glass, steel and concrete is a completely sealed volume of 150,000 m 3 and covers 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 a tropical forest, a tropical savannah, a lagoon, shallow and deep-water zones of the ocean, a desert, etc. Biosphere-2 also houses the living quarters of testers, laboratories, workshops, agricultural greenhouses and fish ponds, waste processing systems and other service systems and technical means necessary for human life. The glass ceilings and walls of the compartments of Biosphere-2 should ensure the flow of radiant solar energy to its inhabitants, among which eight volunteer testers will be in the first two years. They will have to prove the possibility of active life and activity in isolated conditions on the basis of the internal biospheric circulation of substances.
The Institute of Ecotechnics, which led the creation of Biosphere-2 in 1986, plans to complete its construction this year. Many reputable scientists and technical specialists have joined the project implementation.
Despite the significant cost of the work (at least $30 million), the implementation of the project will make it possible to carry out 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 industries economy (biological purification and regeneration of water, 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. Schweikart.
The practical significance of the above experiments lies not only in solving certain issues of creating closed space ecosystems, including humans. No less important are the results of these experiments for understanding the laws of ecology and the biomedical foundations of human adaptation to extreme environmental conditions, clarifying the potential of biological objects in intensive cultivation modes, developing waste-free and environmentally friendly technologies to meet human needs for high-quality food, water and air in artificial environments. isolated habitable structures (underwater settlements, polar stations, settlements of geologists in the Far North, defense structures, etc.).
In the future, one can imagine entire waste-free and environmentally friendly cities. For example, the director of the International Institute for System Analysis, C. Marchetti, believes: “Our civilization will be able to exist peacefully, and, moreover, in better conditions than the current ones, locking itself in island cities that are completely self-sufficient, not dependent on the vicissitudes of nature, not needing any natural raw materials, nor in natural energy and guaranteed against 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 of the problem of creating large artificial ecosystems, including man and based on a completely or partially closed biological cycle of substances, is of great importance not only for the further progress of astronautics. In an era when “we saw with such frightening clarity that a second front, the ecological front, is approaching the front of the nuclear and space threat and is on a par with it” (from the speech of the Minister of Foreign Affairs of the USSR E. A. Shevardnadze at the 43rd session of the General Assembly of the United Nations), one of the real ways out of the approaching ecological crisis can be the way of creating practically 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.
This is a fundamentally new scientific and technical problem, the results of the solution of which can be of great importance for the protection and conservation 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, and the solution of the food program at a high modern scientific and technical level. The cosmic is inseparable from the terrestrial, therefore, even today, the results of space programs give a significant economic and social effect in the most various fields National economy.
The cosmos serves and must serve people.
LITERATURE
Blinkin S. A., Rudnitskaya T. V. Phytoncides around us. – M.: Knowledge, 1981.
Gazenko O. G., Pestov I. D., Makarov V. I. Mankind and space. – M.: Nauka, 1987.
Dadykin V.P. Space crop production. – 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 bygone 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 VV At the crossroads of ecology. - M.: Thought, 1985
Sytnik K. M., Brion A. V., Gordetsky A. V. Biosphere, ecology, nature protection. - Kyiv: Naukova Dumka, 1987.
Experimental Ecological Systems Including Man / 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 flights into space. Tourists visit terrestrial objects - spaceports, flight control centers, "star" cities, enterprises for the development and manufacture of elements of space technology, are present and observe the launch of flying spacecraft and launch vehicles.
Terrestrial space tourism began in July 1966, when the first bus tours of the NASA launch sites at Cape Kennedy were organized. In the early 1970s, tourists on buses visited the site of complex No. 39, from which the astronauts launched when flying to the Moon, the vertical assembly building (hangar over 100 m high), where the Saturn-V launch vehicle was assembled and tested and the spacecraft was docked. spacecraft "Apollo", the parking lot of the unique caterpillar chassis delivering the launch vehicle to launch pad, and much more. In a special cinema they watched newsreel of space events. At that time, up to 6 - 7 thousand tourists made such an excursion daily in the summer, and about 2 thousand in the off season. Unorganized tourists increased the flow of visitors by about 20 - 25%.
From the very beginning, such excursions have gained wide popularity. Already in 1971, their four millionth participant was recorded. During some launches (for example, to the Moon), the number of tourists amounted to hundreds of thousands.
Another direction is direct space tourism. Although today it is in its infancy, its prospects are wide. In addition to the purely tourist aspect, here we must keep in mind the strategic and economic aspects.
The strategic aspect is the possible partial settlement of mankind 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 travels, familiarity with equipment, life support devices in space will allow a person to more successfully live and work on Earth in conditions of environmental degradation, use space "grounded" technical means and systems.
The economic aspect of space tourism is also very important for astronautics. Some experts see space tourism, oriented towards the use of the personal funds of space tourists, as a significant source of funding for space programs. In their opinion, an increase in the cargo flow into space as a result of space tourism compared to the current one by 100 times (which is realistic) will, in turn, reduce the unit cost of launching a unit of payload by 100–200 times for the entire cosmonautics as a whole without attracting additional government investment.
According to experts, the annual expenditure of mankind on tourism is expressed in the amount of about 200 billion pounds. Art. In the coming decades, space tourism could account for 5% of this figure, i.e. 10 billion pounds. Art. It is believed that if the cost of a space tour is optimally balanced and at the same time a sufficiently high flight safety is ensured (comparable at least to the level of flight safety on a modern passenger jet liner), then about 100 million people would express a desire to make a space trip in the coming decades. According to other estimates, by 2025 the flow of space tourists will amount to 100 thousand people annually, 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, the training of an astronaut is about 1 million rubles, a serial launch vehicle costs 2–3 million rubles, and 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 were carried out in a purely tourist version: not to fill it with complex scientific equipment, thereby increasing the number of passengers, to prepare them for flight not according to the cosmonaut program, but according to a simpler one, etc. It was it would be interesting to more accurately determine the cost of the tour, but this should 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 space flight transport ships of the second and third generation will be commensurate with the cost of flying on a passenger jet aircraft, which will predetermine mass space tourism. Nevertheless, experts suggest that the cost of the tour for the first tourists will be about $ 1 million. In the following decades, it will rapidly decrease and reach $ 100 thousand. As an optimally saturated space tourism infrastructure, including a fleet of spacecraft, is reached, hotels in the orbits of the Earth and on the Moon, in-line production of tourist equipment, training in security measures, etc., in the conditions of mass tourism, the cost of a tour will drop to 2 thousand dollars. This means that the cost of launching a payload into outer space should be no more than $20/kg. Currently, this figure is 7-8 thousand.
There are still many difficulties and unresolved problems on the way of space tourism. However, space tourism is a reality of the 21st milestone. In the meantime, 260 people from ten countries of the world have already contributed money to one of the American organizations that has begun 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. Departure date open. It will be put on the ticket, as they say, in 20-30 years.
Yet the Americans are not the first here. In 1927, the world's first international spacecraft exhibition took place in Moscow on Tverskaya Street. It compiled lists of those wishing to fly to the Moon or Mars. There were many who wanted to. Maybe one of them has not yet lost hope of going on the first tourist trip into space.
CHRONICLE OF SPACE*
* Continued (see No. 3, 1989). Based on materials from various information agencies and periodicals, data are given on the launch of some artificial Earth satellites (AES), starting from November 15, 1989. Launches of the AES "Cosmos" are not registered. They are regularly reported, for example, by the journal "Priroda", thin and send interested readers. A separate appendix is devoted to manned space flights.
ON NOVEMBER 15, 1988, for the first time in the Soviet Union, a test launch of the Energia universal rocket and space transport system with the Buran reusable spacecraft was carried out. Having completed a two-orbit unmanned flight, the Buran orbital spacecraft successfully landed in automatic mode on the runway of the Baikonur Cosmodrome. The Buran ship was built according to the scheme of a tailless aircraft with a delta wing of variable sweep. Able to perform a controlled descent in the atmosphere with a 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 in the tail section of the ship, two groups of engines for maneuvering are located at the end of the tail section and in front of the hull. The heat-shielding coating, which consists of almost 40,000 individual profile tiles, is made of special materials - high-temperature quartz and organic fibers, as well as carbon-based material. The first flight of the Buran reusable 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 television broadcast satellite Ekran 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 receivers for collective use.
On DECEMBER 11, 1988, from the Kourou cosmodrome in French Guiana, with the help of the Western European Ariane-4 launch vehicle, two communications satellites were launched into geostationary orbit - the English Skynet-4B and Astra-1, belonging to the Luxembourg consortium SES. The Astra-1 satellite is intended for rebroadcasting television programs to local distribution centers in Western European countries. The satellite has 16 medium power transponders, most of which are leased by British Telecom. The estimated standing point of the satellite "Astra-1" 19.2 ° W. e. Initially, the British satellite was supposed to be launched with the help of the American Space Shuttle. However, the Challenger accident in January 1986 violated these plans, and it was decided to use the Arian launch vehicle for launch. The launch of two satellites was carried out by the Arian-4 launch vehicle, equipped with two solid propellant and two liquid boosters. The Arianspace consortium announced to potential consumers that this rocket model is capable of delivering a payload of 3.7 tons to a transfer orbit with an apogee altitude of 36,000 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. 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 Panamsat-1.
On DECEMBER 22, 1988, in the USSR, the Molniya launch vehicle was launched into a highly elliptical orbit with an apogee altitude of 39,042 km in the Northern Hemisphere in order to ensure the operation of the long-range telephone and telegraph radio communication system and the transmission of television programs by the Orbit system.
On DECEMBER 23, 1988, the 24th satellite of the PRC was launched from the Xichang Cosmodrome in the PRC with the help of the Long March-3 launch vehicle. It is the fourth Chinese communications satellite to be launched into geostationary orbit. The commissioning of the satellite will complete the transfer of all national television programs to retransmission via a satellite system. Premier of the State Council of the People's Republic of China Li Peng was present at the launch of the artificial satellite.
On DECEMBER 25, 1988, in the USSR, the Soyuz launch vehicle launched the Progress-39 automatic cargo spacecraft into orbit, designed 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 launch vehicle was launched into a highly elliptical orbit with an apogee altitude of 38,870 km in the Northern Hemisphere of the next (75th) Moliya-1 communications satellite. This satellite is operated as part of 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 JANUARY 26, 1989, the next (17th) communication satellite "Horizont" was launched in the USSR by the "Proton" launch vehicle. Launched into geostationary orbit at 53° E. he received the international registration index "Stationary-5". The Gorizont satellite is used to transmit television programs to the network of ground stations Orbita, Moskva and Intersputnik, as well as to communicate with ships and aircraft using additional repeaters.
ON JANUARY 27, 1989, the Ariane-2 launch vehicle was launched into the transfer orbit by the Intelsat-5A satellite (model F-15) for use in the global commercial satellite communications system of the international ITSO consortium. Transferred to the geostationary orbit at 60° E. The satellite will replace the Intelsat-5A satellite (model F-12) located there, launched in September 1985.
FEBRUARY 10, 1989 in the USSR, the Soyuz launch vehicle launched the Progress-40 automatic cargo spacecraft, designed 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 on the deployment in open space of two large-sized multi-link structures that were in a folded state on the outer surface of the Progress-40 spacecraft. At the command of on-board automation, these structures were opened one by one. Their deployment was carried out through the use of elements from a material with a shape memory effect. On March 5, the propulsion system was turned on on the ship. As a result of deceleration, the ship entered the atmosphere and ceased to exist.
FEBRUARY 15, 1989 USSR The launch vehicle "Molniya" was launched into a highly elliptical orbit with an apogee altitude of 38,937 km in the Northern Hemisphere of the next (76th) communications satellite "Molniya-1". 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.
MARCH 16 in the USSR, the Soyuz launch vehicle launched the Progress-41 automatic cargo spacecraft, designed to supply the Soviet orbital station Mir. The ship docked with the station on 18 March.
Chronicle of manned flights 1
1 Continued (see No. 3, 1989).
2 The numbers in brackets indicate the number of space flights, including the last one.
3 Expedition to the Mir station.
4 Cosmonauts A. Volkov and S. Krikalev remained on the crew of the Mir station. December 21, 1988, together with J.-L. Chretien, V. Titov and M. Manarov returned to earth from the Mir station, having made the longest 1-year flight in the history of astronautics.
ASTRONOMY NEWS
THREADS IN WONDERLAND
We have already mentioned in our short notes about one of the cosmological consequences of some models of the Grand Unification - the prediction of the existence of cosmological filaments. These are one-dimensional extended structures with a high linear mass density (~Ф 0 2 , where Ф 0 is a nonzero vacuum average) and a thickness of ~1/Ф 0 .
Among many realistic models of the Grand Unification (since there are also non-realistic ones), the most successful are those schemes that include mirror particles that are strictly symmetrical in their properties to the corresponding ordinary particles. Mirror twins acquire not only matter particles (electrons, quarks), but also interaction-carrier particles (photons, W-bosons, gluons, etc.). In schemes of this kind, the violation of complete symmetry leads to a transition from ordinary particles to mirror ones. The threads that appear in these models are called Alice threads. They are distinguished from "ordinary" cosmological threads by the following additional property: going around the thread changes the specularity of the object.
It follows from this “mirror-like” property that the definition of specularity itself becomes relative: if we consider a macroscopic object to be ordinary 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, electromagnetic radiation, perceived by us as normal to the left of Alice's thread, to the right of it will be mirrored. Our conventional electromagnetic receivers will not be able to register it.
But this is all in theory. Are there any possible observational manifestations of alice filaments? All those properties that ordinary cosmological threads have, Alice's threads also have. But unlike the first, Alice's threads must change the relative specularity of particles and rays of light in the course of their evolution. The existence of mirror particles leads to the fact that stars and, probably, globular clusters should have the same specularity, while galaxies and larger inhomogeneities (clusters, superclusters) consist of an equal number of mirror and ordinary particles. At the same time, their average characteristics (spectrum, luminosity, mass and velocity distribution, etc.) are the same. Therefore, if we cannot “resolve” the galaxy into individual stars, then we cannot even notice the passage of Alice’s thread between them and the galaxy, because both the mirror and ordinary luminosities and the spectra of the galaxy are completely symmetrical.
One can try to detect the manifestation of Alice's filament (as well as the cosmological filament of any nature, by the way) by the effect of gas glow in the shock wave caused by it. The latter is formed when the substance is perturbed by the conical gravitational field of the thread. True, it is difficult to separate the luminosity of the gas in the shock wave behind the filament from the background of the general luminosity of such a gas. The same applies to the perturbation of the temperature of the relic radiation in the direction of the filament. Therefore, the most promising, according to theorists, is the search for the effect of a gravitational lens due to Alice's thread.
IS A CONSTANT PERMANENT?
This is the Newtonian 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 must change with the age of the Universe (with the expansion of the Universe G, for example, should decrease).
None of the experiments done to date have provided any evidence for impermanence. G. Only the upper limits of such a change have been established - about 10–11 parts per year. Recently, American scientists have confirmed this estimate by observing a double radio pulsar.
The binary pulsar PSR 1913+16, discovered in 1974, consists of neutron star, which rotates around another compact object. It so happens 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 binary pulsar changes. Its rate of change predicted under the assumption of constancy G, agrees well with the observed one.
The observations of American scientists allow us to estimate the limit on variability G small difference between observations and predictions general theory 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" SUPERNOVA-87
Australian and American astronomers have detected a fairly large increase in infrared radiation from a supernova from the LMC. By itself, the fact of such radiation is nothing special. His outburst is incomprehensible and unexpected.
Several hypotheses have been proposed. According to one of them, a pulsar "shines" "settled" in the gas ejected by an exploded star (although the radiation of the pulsar should be shorter-wavelength). According to the second hypothesis, the gases from the explosion condense into solid macroparticles, which, when heated, emit infrared radiation.
The third hypothesis is also “dusty”. Thousands and thousands of years before the explosion, the original star was losing gas that had collected around it. The dust shell stretched out around the supernova for almost a light year, the length of time it took the light from the exploding star to reach the dust cloud. The heated dust re-radiates in the infrared, and it takes another year for the radiation to reach terrestrial observers. This explains the time elapsed from the registration of a supernova explosion to the detection of an infrared burst.
MISSING MASS
If modern theory The evolution of stars is true (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 is the 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 studied three bright planetary nebulae (or rather, their faintly luminous shells). With the help of the spectra obtained by them, the mass of both the shell and the nebula itself was calculated. The problem of mass deficit has become clear - 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 shell differ - the shell 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 envelope gas. One of the assumptions explaining this paradox is that the energy for heating the shell is supplied by a fast "wind" blowing from the central star.
WARNING - FLASH
The American satellite SMM, designed to study the Sun, predicted its premature "death" - deorbiting. Data from this satellite suggests that, according to 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 that impede radio communications and navigation, interfere with the operation of radars, pose a very definite danger to: spacecraft crews, damage delicate electronic parts of satellites, etc.
Solar flares emit harsh ultraviolet radiation that heats the upper atmosphere. As a result, the height of its upper (conditional) boundary increases. In short, the atmosphere is "disturbed", which is primarily reflected in satellites in low orbits. Their lifespan is shortening. At one time, this happened to the American Skylab station, which deorbited 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 not fully understood.
NEW TELESCOPES
Mount Mauna Kea (4170 m, Hawaii, USA) will soon become an astronomical Mecca. In addition to the telescopes that already exist at the observatory located on this mountain, new, more powerful optical telescopes are being designed (and already being built).
The University of California is building a 10-meter telescope, due to be completed and installed in 1992. It will consist of 36 hexagonal conjugated mirrors arranged in three concentric rings. Electronic sensors installed at all ends of the segment mirrors will transmit data on 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 displacements 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 allow you to look at vast distances, study quasars, discover new stars and galaxies.
Four separate telescopes (8 m in diameter each), brought together by fiber optics into a single focal plane, are supposed to be built in the Southern Observatory (Chile) by 8 Western European countries - co-owners of this observatory. The construction of the first mirror (i.e. the first telescope) is scheduled for completion by 1994, and the remaining three by 2000.
WHAT COMES FROM WHERE
As you know, 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 rare mineral scapolite 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 a large amount of carbon dioxide as part of its crystal structure (carbonate). There are many scapolites on Mars.
So, in an ecosystem, we see the interaction of a life community, consisting of many organisms, with the 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, lake 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 (producers). These include living beings capable of building organic substances from inorganic environmental materials. This work is carried out mainly by green plants, which produce organic compounds from carbon dioxide, water and minerals with the help of solar energy. This process is called photosynthesis. With it, oxygen (O 2) is released. Organic substances produced by plants are used for food by animals and humans, oxygen is used for respiration.
3. Consumers (consumers). They use herbal products. Organisms that feed only on plants are called first-order consumers. Animals that eat only (or mainly) 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 corpses, turning them back into raw materials - water, minerals, CO 2, which is suitable for producers, turning it into components again into organic substances.
Decomposers are many worms, insect larvae and other small soil organisms. Bacteria, fungi and other microorganisms that convert living matter into mineral matter are called mineralizers.
The 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 closed space of the ship, making do with limited supplies of food, oxygen and energy. At the same time, it is desirable, if possible, to restore and reuse the spent reserves of the substance and waste. For this, special regeneration units are provided in the spacecraft, and recently experiments have been carried out with living organisms (plants and animals), which should participate in the processing of the astronaut's waste products using the energy of sunlight.
Let's compare the artificial ecosystem of a spaceship with any natural one, for example, the ecosystem of a pond. Observations show that the number of organisms in this biotope remains - with some seasonal fluctuations - basically 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, 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 the simplified spaceship artificial ecosystem, the pond ecosystem is capable of self-sustaining. Unlimited growth is hampered by interactions between producer plants, on the one hand, and consumer and decomposer animals and plants, on the other.
Consumers can reproduce only as long as they do not overuse the supply of available nutrients. If they multiply excessively, their increase in numbers will stop on its own, as they will not have enough food. Producers, in turn, require a constant supply of minerals. Reducers, or destructors, decompose organic matter and thereby increase the supply of mineral substances. They recycle waste products again. 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 in the highest degree 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: animals eat plants, other animals eat the former, a person eats both plants and animals. This process is called the food chain. Examples of food chains: plants - herbivore - predator; cereal - field mouse - fox; fodder plants - cow - man. As a rule, each species feeds on more than one single species. Therefore, food chains intertwine to form a food web. The more closely connected organisms are through food webs and other interactions, the more resilient the community is against potential disruption. Natural, undisturbed ecosystems strive for balance. The equilibrium state 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 (decomposers), 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 fastest decomposition and recycling of such waste by encouraging the development of decomposers, for example, by composting. So man learns from nature.
In terms of energy input, natural and anthropogenic (man-made) ecosystems are similar. Both natural and artificial ecosystems - homes, cities, transportation systems - require energy from outside. But natural ecosystems receive energy from an almost eternal source - the Sun, which, moreover, "producing" energy, does not pollute the environment. Man, on the contrary, feeds the processes of production and consumption mainly at the expense of final energy sources - coal and oil, which, along with energy, provide dust, gases, heat and other waste that harm the environment and cannot be processed within the artificial ecosystem itself. Let's not forget that 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.
