Controlled Ecological Life Support System
Encyclopedia
Controlled Ecological Life Support Systems
(acronym CELSS) are a type of scientific endeavor to create a self-supporting life support system
for space stations and colonies typically through controlled closed ecological system
s, such as the BioHome
, BIOS-3
and Biosphere 2
.
during the famed "Space Race
" in the 1950s-60s. Originated by Konstantin Tsiolkovsky
and furthered by V.I. Vernadsky
, the first forays into this science were the use of closed, unmanned ecosystems, expanding into the research facility known as the BIOS-3
.
Then in 1965, manned experiments began in the BIOS-3
.
, thus far, has been limited to our own Earth
–Moon
system. Also, everything that astronauts would need in the way of life support (air, water
, and food
) has been brought with them. This may be economical for short missions of spacecraft
, but it is not the most elegant solution when dealing with the life support systems of a long-term craft (such as a generation ship
) or a settlement.
The aim of CELSS is to create a regenerative environment that can support and maintain human
life via agricultural means.
processing typically consists of stored air tank
s and CO2 scrubbers. The drawback to this method lies in the fact that upon depletion the tanks would have to be refilled; the scrubbers would also require replacement after they become ineffective.
There is also the issue of processing toxic fumes
, which come from the synthetic
materials used in the construction of habitats. Therefore the issue of how air quality is maintained requires attention; in experiments, it was found that the plants also removed volatile organic compounds offgassed by synthetic materials used thus far to build and maintain all man-made habitats.
In CELSS, air is initially supplied by external supply, but is maintained by the use of foliage plants, which create oxygen
in photosynthesis
(aided by the waste-byproduct of human respiration
, CO2). Eventually, the main goal of a CELSS environment is to have foliage plants take over the complete and total production of oxygen needs; this would make the system a closed, instead of controlled, system.
Of course, in a self-sustaining ecosystem, a place for crops to grow would be set aside, allowing foods to be grown and cultivated. The larger the group of people, the more crops would have to be grown.
As for water, experiments have shown that it would be derived from condensate
in the air (a byproduct of air conditioning
and vapors), as well as excess moisture from plants. It would then have to be filtered by some means, either by nature or by machine.
CELSS studied means of breaking down human waste
s and, if possible, integrating the processed products back into the ecology. For instance, urine
was processed into water, which was safe for use in toilet
s and watering plants.
Wastewater treatment makes use of plants, particularly aquatic, to process the wastewater. It has been shown that the more waste is treated by the aquatic plant
s (or, more specifically, their root system
s), the larger the aquatic plants grow.
In tests, such as those done in the BioHome
, the plants also made viable compost
as a growth medium
for crops.
conversion of energy into irrecoverable heat. However, if we consider radiant energy from sources like the sun to be part of the system (an example of such a system would be the Earth
itself) it can be considered closed for all practical purposes.
Controlled systems, by contrast, are dependent on certain outside factors for continuing operation. Maintenance
tends to be a common required input.
(acronym CELSS) are a type of scientific endeavor to create a self-supporting life support system
Life support system
In human spaceflight, a life support system is a group of devices that allow a human being to survive in space.US government space agency NASA,and private spaceflight companies...
for space stations and colonies typically through controlled closed ecological system
Closed ecological system
Closed ecological systems are ecosystems that do not rely on matter exchange with any part outside the system.The term is most often used to describe small manmade ecosystems...
s, such as the BioHome
BioHome
BioHome was a small facility created by NASA that could support one person in a fully functional habitat. One of the influences of the project being the results from data obtained on the 1973 Skylab 3 , where a total of 107 VOCs were offgassed by synthetic materials that composed the SL-3...
, BIOS-3
BIOS-3
BIOS-3 is a closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Russia.Its construction began in 1965, and was completed in 1972. BIOS-3 consists of a 315-cubic-metre habitat suitable for up to three persons, and was initially used for developing closed ecosystems capable of supporting...
and Biosphere 2
Biosphere 2
Biosphere 2 is a structure originally built to be an artificial, materially-closed ecological system in Oracle, Arizona by Space Biosphere Ventures, a joint venture whose principal officers were John P. Allen, inventor and Executive Director, and Margret Augustine, CEO...
.
Original concept
CELSS was first pioneered by the Soviet UnionSoviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
during the famed "Space Race
Space Race
The Space Race was a mid-to-late 20th century competition between the Soviet Union and the United States for supremacy in space exploration. Between 1957 and 1975, Cold War rivalry between the two nations focused on attaining firsts in space exploration, which were seen as necessary for national...
" in the 1950s-60s. Originated by Konstantin Tsiolkovsky
Konstantin Tsiolkovsky
Konstantin Eduardovich Tsiolkovsky was an Imperial Russian and Soviet rocket scientist and pioneer of the astronautic theory. Along with his followers the German Hermann Oberth and the American Robert H. Goddard, he is considered to be one of the founding fathers of rocketry and astronautics...
and furthered by V.I. Vernadsky
Vladimir Vernadsky
Vladimir Ivanovich Vernadsky was a Russian/Ukrainian and Soviet mineralogist and geochemist who is considered one of the founders of geochemistry, biogeochemistry, and of radiogeology. His ideas of noosphere were an important contribution to Russian cosmism. He also worked in Ukraine where he...
, the first forays into this science were the use of closed, unmanned ecosystems, expanding into the research facility known as the BIOS-3
BIOS-3
BIOS-3 is a closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Russia.Its construction began in 1965, and was completed in 1972. BIOS-3 consists of a 315-cubic-metre habitat suitable for up to three persons, and was initially used for developing closed ecosystems capable of supporting...
.
Then in 1965, manned experiments began in the BIOS-3
BIOS-3
BIOS-3 is a closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Russia.Its construction began in 1965, and was completed in 1972. BIOS-3 consists of a 315-cubic-metre habitat suitable for up to three persons, and was initially used for developing closed ecosystems capable of supporting...
.
Rationale
Space travelHuman spaceflight
Human spaceflight is spaceflight with humans on the spacecraft. When a spacecraft is manned, it can be piloted directly, as opposed to machine or robotic space probes and remotely-controlled satellites....
, thus far, has been limited to our own Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
–Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
system. Also, everything that astronauts would need in the way of life support (air, water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
, and food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
) has been brought with them. This may be economical for short missions of spacecraft
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
, but it is not the most elegant solution when dealing with the life support systems of a long-term craft (such as a generation ship
Generation ship
A generation ship is a hypothetical type of interstellar ark starship that travels across great distances between stars at a speed much slower than the speed of light...
) or a settlement.
The aim of CELSS is to create a regenerative environment that can support and maintain human
Human
Humans are the only living species in the Homo genus...
life via agricultural means.
Air Revitalization
In non-CELSS environments, air replenishment and CO2Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
processing typically consists of stored air tank
Oxygen tank
An oxygen tank is a storage vessel for oxygen, which is either held under pressure in gas cylinders or as liquid oxygen in a cryogenic storage tank.Oxygen tanks are used to store gas for:* industrial processes including the manufacture of steel and monel...
s and CO2 scrubbers. The drawback to this method lies in the fact that upon depletion the tanks would have to be refilled; the scrubbers would also require replacement after they become ineffective.
There is also the issue of processing toxic fumes
Outgassing
Outgassing is the release of a gas that was dissolved, trapped, frozen or absorbed in some material. As an example, research has shown how the concentration of carbon dioxide in the Earth's atmosphere has sometimes been linked to ocean outgassing...
, which come from the synthetic
Chemical synthesis
In chemistry, chemical synthesis is purposeful execution of chemical reactions to get a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions...
materials used in the construction of habitats. Therefore the issue of how air quality is maintained requires attention; in experiments, it was found that the plants also removed volatile organic compounds offgassed by synthetic materials used thus far to build and maintain all man-made habitats.
In CELSS, air is initially supplied by external supply, but is maintained by the use of foliage plants, which create oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
in photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
(aided by the waste-byproduct of human respiration
Respiration (physiology)
'In physiology, respiration is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction...
, CO2). Eventually, the main goal of a CELSS environment is to have foliage plants take over the complete and total production of oxygen needs; this would make the system a closed, instead of controlled, system.
Food / Consumables Production
As with all present forays into space, crews have had to store all consumables they require prior to launch. Typically, hard-food consumables were freeze dried so that the craft's weight could be reduced.Of course, in a self-sustaining ecosystem, a place for crops to grow would be set aside, allowing foods to be grown and cultivated. The larger the group of people, the more crops would have to be grown.
As for water, experiments have shown that it would be derived from condensate
Condensate
Condensate may refer to:* The liquid phase produced by the condensation of steam or any other gas* The product of a chemical condensation reaction, other than water* Natural gas condensate, in the natural gas industry- Quantum physics :...
in the air (a byproduct of air conditioning
Air conditioning
An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...
and vapors), as well as excess moisture from plants. It would then have to be filtered by some means, either by nature or by machine.
Wastewater Treatment
Early space-flight had travelers either ejecting their wastes into space or storing it for a return trip.CELSS studied means of breaking down human waste
Human waste
Human waste is a waste type usually used to refer to byproducts of digestion, such as feces and urine. Human waste is most often transported as sewage in waste water through sewerage systems...
s and, if possible, integrating the processed products back into the ecology. For instance, urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
was processed into water, which was safe for use in toilet
Toilet
A toilet is a sanitation fixture used primarily for the disposal of human excrement, often found in a small room referred to as a toilet/bathroom/lavatory...
s and watering plants.
Wastewater treatment makes use of plants, particularly aquatic, to process the wastewater. It has been shown that the more waste is treated by the aquatic plant
Aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...
s (or, more specifically, their root system
Root system
In mathematics, a root system is a configuration of vectors in a Euclidean space satisfying certain geometrical properties. The concept is fundamental in the theory of Lie groups and Lie algebras...
s), the larger the aquatic plants grow.
In tests, such as those done in the BioHome
BioHome
BioHome was a small facility created by NASA that could support one person in a fully functional habitat. One of the influences of the project being the results from data obtained on the 1973 Skylab 3 , where a total of 107 VOCs were offgassed by synthetic materials that composed the SL-3...
, the plants also made viable compost
Compost
Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost is a key ingredient in organic farming. At its most essential, the process of composting requires simply piling up waste outdoors and waiting for the materials to break down from anywhere...
as a growth medium
Growth medium
A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants like the moss Physcomitrella patens.There are different types of media for growing different types of cells....
for crops.
Closed versus Controlled
Closed systems are completely self-reliant with the ability to have a feedback system for efficiency. A closed system in the truest sense of the phrase is physically impossible, since input energy is required to balance entropicEntropy
Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...
conversion of energy into irrecoverable heat. However, if we consider radiant energy from sources like the sun to be part of the system (an example of such a system would be the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
itself) it can be considered closed for all practical purposes.
Controlled systems, by contrast, are dependent on certain outside factors for continuing operation. Maintenance
Maintenance, Repair and Operations
Maintenance, repair, and operations or maintenance, repair, and overhaul involves fixing any sort of mechanical or electrical device should it become out of order or broken...
tends to be a common required input.
Notable CELSS Projects
- For a full list of CELSS projects, see Category: Controlled Ecological Life Support Systems.
- BioHomeBioHomeBioHome was a small facility created by NASA that could support one person in a fully functional habitat. One of the influences of the project being the results from data obtained on the 1973 Skylab 3 , where a total of 107 VOCs were offgassed by synthetic materials that composed the SL-3...
- Biosphere 2Biosphere 2Biosphere 2 is a structure originally built to be an artificial, materially-closed ecological system in Oracle, Arizona by Space Biosphere Ventures, a joint venture whose principal officers were John P. Allen, inventor and Executive Director, and Margret Augustine, CEO...
- BIOS-3BIOS-3BIOS-3 is a closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Russia.Its construction began in 1965, and was completed in 1972. BIOS-3 consists of a 315-cubic-metre habitat suitable for up to three persons, and was initially used for developing closed ecosystems capable of supporting...
- Biosphere J http://www.ecotechnics.edu/1996.html
- Controlled Environment Systems Research Facility, The University of Guelph
- Biotron Experimental Climate Change Research Facility, The University of Western Ontario
Other types of Regenerative Ecological Systems
- Environmental Control and Life Support System (acronym ECLSS)
- Engineered Closed/Controlled EcoSystem (acronym ECCES)
- SpomeSpomeA spome is any hypothetical system closed with respect to matter and open with respect to energy capable of sustaining human life indefinitely. The term was coined in 1966 by Isaac Asimov in a paper entitled "There’s No Place Like Spome", published in Atmosphere in Space Cabins and Closed...