Difference between revisions of "In-situ resource utilization"

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The use of local resources is called '''in-situ resource utilization''' or ISRU. This concept is critical to the survival of an [[Foundation of an Autonomous Colony|autonomous]] or [[Semi-autonomous colony|semi-autonomous]] [[settlement]].
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__NOTOC__
[[File:Colony ISRU.png|thumb|600x600px]]
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<imagemap>
==Ressources==
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File:MH ISRU.jpg|thumb|757x757px|In Situ resources Utilisation. Copyright R. Heidmann
{{expandsec}}
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 +
rect 60 170 250 260 [[Dust collector]]
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rect 400 70 500 140 [[Compression]]
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rect 500 70 600 140 [[Carbon monoxide]]
 +
rect 400 170 500 240 [[Compression]]
 +
rect 500 170 600 240 [[Carbon dioxide]]
 +
rect 60 290 110 360 [[Nitrates]]
 +
rect 160 290 250 360 [[Atmospheric processing]]
 +
rect 500 290 600 360 [[Nitrogen]]
 +
rect 500 410 600 470 [[Oxygen]]
 +
rect 600 410 700 470 [[Sabatier process]]
 +
rect 720 410 820 470 [[Methane]]
 +
rect 60 520 130 590 [[water]]
 +
rect 160 520 250 590 [[Electrolysis]]
 +
rect 500 520 600 590 [[Hydrogen]]
 +
rect 60 850 120 950 [[Mining]]
 +
rect 60 1100 120 1200 [[Mining]]
 +
rect 720 630 820 710 [[Fertilizer]]
 +
rect 720 1200 820 1280 [[Glass]]
 +
rect 60 1300 120 1380 [[Iron ore]]
 +
 
 +
</imagemap>
 +
 
 +
The use of local resources is called '''in-situ resource utilization''' or ISRU. This concept is critical to the survival of an [[Foundation of an Autonomous Colony|autonomous]] or [[Semi-autonomous colony|semi-autonomous]] [[settlement]]. The [[ISRU timeline]] is very rapid for most settlement plans since the initial Zubrin proposal of MArs Direct.
 +
 
 +
Resources(inputs) are processed to create products(outputs).  These outputs can become inputs to other processes used to create new, more complex outputs.  Eventually, the outputs can be re-used by recycling, reducing the needs for new resources. However, losses are always present is systems, making the acquisition of new resources a continuous requirement.  The presence of numerous resources on Mars is part of what makes it an interesting target for colonization and settlement.
 +
 
 +
Production processes require energy to operate and must be housed in [[Production|production facilities]].
 +
==Resources (Inputs)==
 +
 
 
===Atmosphere===
 
===Atmosphere===
 
''Main article: [[Atmospheric processing]]''
 
''Main article: [[Atmospheric processing]]''
Line 8: Line 37:
 
Many of the [[:category:elements|elements]] and molecules in the [[atmosphere]] can be utilized. Condensation, followed by distillation, are often used to extract resources. The atmosphere is first cooled to a liquid or solid state. This is distilled at precise temperatures in order to separate the elements and molecules.
 
Many of the [[:category:elements|elements]] and molecules in the [[atmosphere]] can be utilized. Condensation, followed by distillation, are often used to extract resources. The atmosphere is first cooled to a liquid or solid state. This is distilled at precise temperatures in order to separate the elements and molecules.
  
====Carbon dioxide (CO2)====
+
*[[Carbon dioxide]] (CO2) composes 96% of the martian atmosphere. Carbon dioxide is the main source of carbon, used for fuel production (CH4) and an essential element for life.  Carbon dioxide also serves as a source of oxygen for the settlement atmosphere and as the oxidizer in bi-propellant fuels.
98% of martian atmosphere
 
  
Carbon dioxide is the main source of carbon, used for fuel production (CH4) and an essential element for life.
+
*[[Nitrogen]] composes 2% of martian atmosphere.  Nitrogen is used by plants and is part of a breathable atmosphere.  Its concentration on Earth is 78% of the atmosphere.
  
====Nitrogen (N2)====
+
*[[Argon]] is an inert gas, useful in some industrial processes as an inert atmosphere and may be used as propellant in Electric Propulsion of spaceships.2% of martian atmosphere
1% of martian atmosphere
 
  
Nitrogen is used by plants and is part of a breathable atmosphere
+
*[[Water]] (H2O) is the main source of hydrogen and oxygen.  Oxygen is required for the settlement atmosphere and hydrogen is used for fuel production (CH4) and for the synthesis of hydrocarbons, the building blocks for life.
  
====Argon (Ar)====
+
===Lithosphere (surface)===
1% of martian atmosphere
+
''Main article: [[Mining]]''
  
Argon is an inert gas, useful in some industrial processes as an inert atmosphere and may be used as propellant in Electric Propulsion of spaceships.
+
Minerals in the crust of Mars must be mined and processed to be useful.  The upper layer of Mars surface is called the [[Regolith]].  It is a mixtures of materials of various interest.
  
====Water (H2O)====
+
*[[Water]] can be gathered in a variety of ways. It is available  in the form of [[water ice]] or as hydrated minerals.
Water is the main source of hydrogen, used for fuel production (CH4) and for the synthesis of hydrocarbons, the building blocks for life.
+
*[[Silicon|Silicates]] (SiO2) are useful for the production of glass and building materials.  It is one of the main components of the martian planetary crust.
 +
*[[Iron ore]] ( Hematite:Fe2O3) or (Magnetite: Fe3O4) is a source of iron and steel, as well as oxygen or CO2, depending on the process used.
 +
*[[Alumina]] (Al2O3) is the source of aluminium.  Processing also produces CO2, oxygen or water, depending on the process used.
 +
*[[Car|Calcium carbonate]] (CaCO3) is used for concrete production.  Carbonates are also a potential source of carbon for carbohydrates.  [[Sodium carbonates]] are used in glass production. Carbonates are available on Mars.<ref>Wikipedia Carbonates on Mars[https://en.wikipedia.org/wiki/Carbonates_on_Mars]</ref>
 +
*[[Sulfates]]
 +
*[[Nitrates]] are sources of nitrogen for plants and industrial processes, ammonia and explosives.  Nitrates were discovered on Mars by the [[Curiosity]] rover in 2015.
 +
*[[Salts]]. (Mg,Na)SO4, NaCl, and (Mg,Ca)CO3. Magnesium, Calcium, Sodium, Lithium, Chlorine.  Practically all minerals and elements can be found in the form of salts. Sodium chloride (NaCl) is the most common salt, and is essential for life.  Chlorides are likely to be abundant on Mars.<ref>Wikipedia- Chlorides on Mars[https://en.wikipedia.org/wiki/Chloride-bearing_deposits_on_Mars]</ref>
 +
*[[Thorium]] (Th) concentrations have been identified by JPL on Mars, this is the preferred fuel in a number of Molten Salt Reactor designs. <ref name=":12">Map of Martian Thorium at Mid-Latitudes,  JPL '' Map of Martian Thorium at Mid-Latitudes '', https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA04257, March 2003.</ref>
 +
*[[Fluorine]] (F) has been found in small quantities on Mars.  It is an important resource if people wish to warm Mars with [[Super Greenhouse Gases]].
  
===Lithosphere (surface)===
+
===Energy===
''Main article: [[Mining]]''
+
Main article: [[Energy]]
  
Minerals in the crust of Mars must be mined and processed to be useful.
+
Energy is required to carry out ISRU.  There are three known sources of energy on Mars: the Sun, Mars' crust and nuclear fission.  Energy may be stored in a variety of ways for when the sources are not available.
  
====Water====
+
*[[Photovoltaics|Solar energy]] is a very variable energy source on Mars, unless some form Space Solar energy is used.  It requires some form of [[Energy storage|energy storage]] in the settlement or supplementary energy sources, most likely nuclear.
[[Water]] can be gathered in a variety of ways. It is available  in the form of [[water ice]] or as hydrated minerals.  
+
*[[Nuclear power|Nuclear energy]] is a stable energy source and could be used extensively on Mars.  The availability of nuclear fuel on Mars needs to be explored and usable ore deposits found for a self sustainable settlement.
 +
*[[Geothermal energy]] may be available in some martian sites. There is evidence of Martian Vulcanism in the last 50,000 to 200,000 years, so there is almost certainly geothermal energy in some areas.
 +
*[[Wind turbine|Wind power]] has been discussed for some applications.  However, Mars' air pressure is so low that this will provide negligible power compared to other sources.  If Mars' atmosphere were to be thickened, it might become a viable energy source as solar power might then become weaker.  Note that wind energy fundamentally comes from the Sun, and Mars gets about half the solar energy than the Earth does.  So it is likely that wind power will be less useful on Mars, even if it is given a thicker atmosphere than currently.  Also note that the extremely small dust particles (fines), will be hard on mechanical moving parts.
  
====Silicates====
+
==Processes==
Silicates (SiO2) are useful for the production of glass and building materials.  It is one of the main components of the planetary crust.
+
[[File:New Essential Chemical Roadmap.jpg|thumb|By Nexus Aurora: Rider Barnum, Anna |alt=|800x800px]]Inputs need to be processed to create outputs
  
====Iron ore====
+
===Mechanical processes===
Iron ore (Fe2O3 or Fe2O4) is a source of iron and steel, as well as oxygen or CO2, depending on the process used.
 
  
====Alumina====
+
*[[Compression]] of gases increases their density and can change conditions to allow for phase changes that can be used for gas separation.
Alumina (Al2O3) is the source of aluminium.  Processing also produces CO2 or water depending on the process used.
 
  
====Carbonates====
+
*[[Cooling|Heating and cooling]] can also be used to accomplish phase changes in various substances.
Calcium carbonate is used for concrete productionCarbonates are also a potential source of carbon for carbohydrates.
+
*[[Crushing|Crushing and milling]]. These are mechanical processes that break minerals down to individual crystals for separation and materials handlingComplex minerals such as basalts, granites or ores can be broken down for separation
 +
*Separation Mechanical, centrifugal,
 +
*[[Flotation]],
 +
*Distillation,
 +
*Condensation
  
Carbonates are available on Mars.<ref>Wikipedia Carbonates on Mars[https://en.wikipedia.org/wiki/Carbonates_on_Mars]</ref>
+
===Chemical processes===
  
====Sulfates====
+
=====Gases=====
  
====Nitrates====
+
*Gasification
Nitrates are sources of nitrogen for plants and industrial processes, ammonia and explosives.
+
*[[Reverse Water-Gas Shift Reaction]]
 +
*Haldor Topsoe CO2 electrolysis
 +
*[[Sabatier/Water Electrolysis Process]]
 +
*[[Fischer-Tropsch reaction|Fischer-Tropsch Reaction]]
 +
*[[Electrolysis]]
  
===Energy===
+
=====Alcohols=====
Energy is required to carry out ISRU.  There are two known sources of energy on Mars, the sun and nuclear fission.  Energy may be stored in a variety of ways for when the sources are not available.
 
  
====Solar energy====
+
*Methanol synthesis
 +
*[[w:Formox_process|Formox process]].  For the production of Formaldehyde
 +
*MTO process
 +
*Dehydration
  
====Nuclear energy====
+
=====Bio-oil derivatives=====
  
====Energy storage====
+
*Pyrolysis/extraction
 +
*[[Hydrodealkylation]]
 +
*Cumene process
  
====Energy distribution====
+
=====Olefin derivatives=====
  
==Processes==
+
*Wacker process
Compression
+
*Vinyl acetate monomer
 +
*[[Polymerization]]
 +
*[[Hydroformylation]]
 +
*[[Hydrogenation]]
  
Cooling
+
=====Direct ethylene glycol synthesis=====
  
Separation/crushing
+
====[[Hydrocarbon synthesis]]====
  
Flottation
+
Hydrocarbons can be manufactured by combining  and [[carbon]] through a variety of reactions
  
Distillation
+
====[[Silicone Synthesis]]====
  
Electrolysis
+
=====Reduction=====
 +
Usually, but not exclusively, a separation of a compound into individual elements.  [[Iron ore]] into iron and oxygen, for example.
  
Chemical reactions (synthesis)
+
===Biological processes===
  
==Utilization==
+
*[[Fermentation]]
{{expandsec}}
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*[[Biomethanisation]]
===Water===
 
Water is essential for life.  It is also a common process reagent, an excellent coolant for industrial processes and a source of hydrogen and oxygen using electrolysis.
 
  
On Mars it can also be used as a construction material or as radiation shielding.
+
==Products (Outputs)==
===Breathable Atmosphere===
 
A breathable atmosphere is a basic requirement for life.  It is also needed for heat transfer from people, plants and animals.
 
  
===Habitats===
+
=====Solids=====
  
===Food production===
+
*[[Sand]] is one of the most common building materials.  Composition varies greatly.
 +
*[[Gravel]]
 +
*[[Cement]]  is a binder used to link together elements such as blocks and bricks or gravel and sand to produce concrete.
 +
*[[Concrete]]
 +
*[[Compressed regolith]]
 +
*[[Glass]] is one of the most common building materials on Earth and should be common on Mars as well, since it has unique properties of low cost and transparency.  Silica (SiO2), the main component of glass, is also the most common material in the Martian crust.
  
=====Agriculture=====
+
*[[Ceramics]]
[[Plants]] are natural factories, capable of utilizing the atmosphere and regolith to grow and reproduce.
 
  
===Manufactured Products===
+
*[[Fertilizer]] (N....)
  
====Propellant====
+
*[[Biochar]] (Cx)
Propellant is one of the main ISRU products.  It is required to make transportation less prohibitively expensive.
+
*[[Synthetic materials|Synthetic Polymers]] and [[Carbon fiber|carbon fiber]] precursors
 +
**[[Polyethylene]] (PE)
 +
**[[Polypropylene]] (PP)
 +
**[[Polyester]] (PET)
 +
**[[Polyvinyl Chloride|Polyvinyl chloride]] (PVC)
 +
**Polyamides (Nylon)
 +
**Polytetrafluoroethylene (PTFE,Teflon)
 +
*[[Biomass]]
 +
*
  
====Hydrocarbon Synthesis====
+
=====Metals=====
  
:''Main article: [[Hydrocarbon synthesis]]''
+
*[[Iron]]
 +
*[[steel]]
 +
*[[Aluminium|Aluminum]]
 +
*[[Copper]]
 +
*[[Nickel]]
 +
*[[Silicon]]
  
[[Hydrocarbons]] can be manufactured by combining [[hydrogen]] and [[carbon]] through a variety of reactions.
+
===Liquids===
====Silicone Synthesis====
 
  
:''Main article: [[Silicone synthesis ]]''
+
*[[Water]] (H<sub>2</sub>O).  Essential for life.  It is also a common process reagent, an excellent coolant for industrial processes and a source of hydrogen and oxygen using electrolysis.  On Mars it can also be used as a construction material or as radiation shielding.  It can be condensed out of the atmosphere or extracted from the regolith.
 +
*[[Ammonia]] (NH<sub>3</sub>)
 +
*[[Hydrocarbons]]
 +
**
 +
**Light olefins
 +
**Light alkenes
 +
**[[Benzene]]<nowiki/>s
 +
**[[Phenol]]
 +
**[[Acetone]]
 +
**Bio-oil
 +
*[[Alcool|Alcools]]
 +
**[[Ethanol]] (C<sub>2</sub>H<sub>5</sub>OH)
 +
**[[Methanol]] ([[Carbon|C]][[Hydrogen|H]]<sub>3</sub>[[Oxygen|O]]H)
 +
*[[Acid|Acids]]
 +
**[[Acetic acid]] (C<sub>2</sub>H<sub>4</sub>O<sub>2</sub>)
 +
**[[Sulfuric acid]] (H<sub>2</sub>SO<sub>4</sub>)
 +
**[[Aspirin|Salicylic acid]]
 +
*
 +
*
 +
*
 +
*
  
==See Also==
+
===Gases===
 +
A breathable atmosphere is a basic requirement for life.  It is also needed for heat transfer from people, plants and animals.  It is obtained by starting with oxygen and adding buffer gases to reach the desired proportions.  Humans can breath pure oxygen at 1/5 atmospheric pressure, but adding buffer gases such as nitrogen or argon is desirable.  It is likely that people will choose an air pressure less than one atmosphere for early settlements on Mars.  Carbon dioxide must be kept to trace amounts, as it rapidly becomes toxic at even low partial pressures.
  
*[[Sabatier/Water Electrolysis Process]]
+
*[[Oxygen]] (O<sub>2</sub>)
*[[Reverse Water-Gas Shift Reaction]]
+
*[[hydrogen]] (H<sub>2</sub>)
*[[Fischer-Tropsch reaction|Fischer-Tropsch Reaction]]
+
*[[Nitrogen]] (N<sub>2</sub>)
 +
*[[Argon]] (Ar)
 +
*[[Carbon dioxide|Carbon dioxide]] (CO<sub>2</sub>)
 +
*[[Carbon monoxide|Carbon monoxide]] CO)
 +
*[[Hydrocarbons]]
 +
**[[Methane]] (CH<sub>4</sub>)
 +
**[[Ethylene]] (C<sub>2</sub>H<sub>4</sub>)
 +
**[[Propane|Propane (C<sub>3</sub>H<sub>8</sub>)]]
 +
**[[Butane]] (C<sub>4</sub>H<sub>10</sub>)
 +
**[[Propylene]] (C<sub>3</sub>H<sub>6</sub>)
 +
**[[Acetylene]] (C<sub>2</sub>H<sub>2</sub>)
 +
**[[Formaldehyde]] ( CH<sub>2</sub>O)
 +
**[[Vinyl Chloride]] (C<sub>2</sub>H<sub>3</sub>Cl)
 +
*
  
 
==References==
 
==References==
 
[[Category:In-situ Resource Utilization]]
 
[[Category:In-situ Resource Utilization]]
 
<references />
 
<references />

Latest revision as of 07:58, 24 February 2022

Dust collectorCompressionCarbon monoxideCompressionCarbon dioxideNitratesAtmospheric processingNitrogenOxygenSabatier processMethaneWaterElectrolysisHydrogenMiningMiningFertilizerGlassIron ore
In Situ resources Utilisation. Copyright R. Heidmann

The use of local resources is called in-situ resource utilization or ISRU. This concept is critical to the survival of an autonomous or semi-autonomous settlement. The ISRU timeline is very rapid for most settlement plans since the initial Zubrin proposal of MArs Direct.

Resources(inputs) are processed to create products(outputs). These outputs can become inputs to other processes used to create new, more complex outputs. Eventually, the outputs can be re-used by recycling, reducing the needs for new resources. However, losses are always present is systems, making the acquisition of new resources a continuous requirement. The presence of numerous resources on Mars is part of what makes it an interesting target for colonization and settlement.

Production processes require energy to operate and must be housed in production facilities.

Resources (Inputs)

Atmosphere

Main article: Atmospheric processing

Many of the elements and molecules in the atmosphere can be utilized. Condensation, followed by distillation, are often used to extract resources. The atmosphere is first cooled to a liquid or solid state. This is distilled at precise temperatures in order to separate the elements and molecules.

  • Carbon dioxide (CO2) composes 96% of the martian atmosphere. Carbon dioxide is the main source of carbon, used for fuel production (CH4) and an essential element for life. Carbon dioxide also serves as a source of oxygen for the settlement atmosphere and as the oxidizer in bi-propellant fuels.
  • Nitrogen composes 2% of martian atmosphere. Nitrogen is used by plants and is part of a breathable atmosphere. Its concentration on Earth is 78% of the atmosphere.
  • Argon is an inert gas, useful in some industrial processes as an inert atmosphere and may be used as propellant in Electric Propulsion of spaceships.2% of martian atmosphere
  • Water (H2O) is the main source of hydrogen and oxygen. Oxygen is required for the settlement atmosphere and hydrogen is used for fuel production (CH4) and for the synthesis of hydrocarbons, the building blocks for life.

Lithosphere (surface)

Main article: Mining

Minerals in the crust of Mars must be mined and processed to be useful. The upper layer of Mars surface is called the Regolith. It is a mixtures of materials of various interest.

  • Water can be gathered in a variety of ways. It is available in the form of water ice or as hydrated minerals.
  • Silicates (SiO2) are useful for the production of glass and building materials. It is one of the main components of the martian planetary crust.
  • Iron ore ( Hematite:Fe2O3) or (Magnetite: Fe3O4) is a source of iron and steel, as well as oxygen or CO2, depending on the process used.
  • Alumina (Al2O3) is the source of aluminium. Processing also produces CO2, oxygen or water, depending on the process used.
  • Calcium carbonate (CaCO3) is used for concrete production. Carbonates are also a potential source of carbon for carbohydrates. Sodium carbonates are used in glass production. Carbonates are available on Mars.[1]
  • Sulfates
  • Nitrates are sources of nitrogen for plants and industrial processes, ammonia and explosives. Nitrates were discovered on Mars by the Curiosity rover in 2015.
  • Salts. (Mg,Na)SO4, NaCl, and (Mg,Ca)CO3. Magnesium, Calcium, Sodium, Lithium, Chlorine. Practically all minerals and elements can be found in the form of salts. Sodium chloride (NaCl) is the most common salt, and is essential for life. Chlorides are likely to be abundant on Mars.[2]
  • Thorium (Th) concentrations have been identified by JPL on Mars, this is the preferred fuel in a number of Molten Salt Reactor designs. [3]
  • Fluorine (F) has been found in small quantities on Mars. It is an important resource if people wish to warm Mars with Super Greenhouse Gases.

Energy

Main article: Energy

Energy is required to carry out ISRU. There are three known sources of energy on Mars: the Sun, Mars' crust and nuclear fission. Energy may be stored in a variety of ways for when the sources are not available.

  • Solar energy is a very variable energy source on Mars, unless some form Space Solar energy is used. It requires some form of energy storage in the settlement or supplementary energy sources, most likely nuclear.
  • Nuclear energy is a stable energy source and could be used extensively on Mars. The availability of nuclear fuel on Mars needs to be explored and usable ore deposits found for a self sustainable settlement.
  • Geothermal energy may be available in some martian sites. There is evidence of Martian Vulcanism in the last 50,000 to 200,000 years, so there is almost certainly geothermal energy in some areas.
  • Wind power has been discussed for some applications. However, Mars' air pressure is so low that this will provide negligible power compared to other sources. If Mars' atmosphere were to be thickened, it might become a viable energy source as solar power might then become weaker. Note that wind energy fundamentally comes from the Sun, and Mars gets about half the solar energy than the Earth does. So it is likely that wind power will be less useful on Mars, even if it is given a thicker atmosphere than currently. Also note that the extremely small dust particles (fines), will be hard on mechanical moving parts.

Processes

By Nexus Aurora: Rider Barnum, Anna

Inputs need to be processed to create outputs

Mechanical processes

  • Compression of gases increases their density and can change conditions to allow for phase changes that can be used for gas separation.
  • Heating and cooling can also be used to accomplish phase changes in various substances.
  • Crushing and milling. These are mechanical processes that break minerals down to individual crystals for separation and materials handling. Complex minerals such as basalts, granites or ores can be broken down for separation
  • Separation Mechanical, centrifugal,
  • Flotation,
  • Distillation,
  • Condensation

Chemical processes

Gases
Alcohols
  • Methanol synthesis
  • Formox process. For the production of Formaldehyde
  • MTO process
  • Dehydration
Bio-oil derivatives
Olefin derivatives
Direct ethylene glycol synthesis

Hydrocarbon synthesis

Hydrocarbons can be manufactured by combining and carbon through a variety of reactions

Silicone Synthesis

Reduction

Usually, but not exclusively, a separation of a compound into individual elements. Iron ore into iron and oxygen, for example.

Biological processes

Products (Outputs)

Solids
  • Sand is one of the most common building materials. Composition varies greatly.
  • Gravel
  • Cement is a binder used to link together elements such as blocks and bricks or gravel and sand to produce concrete.
  • Concrete
  • Compressed regolith
  • Glass is one of the most common building materials on Earth and should be common on Mars as well, since it has unique properties of low cost and transparency. Silica (SiO2), the main component of glass, is also the most common material in the Martian crust.
Metals

Liquids

Gases

A breathable atmosphere is a basic requirement for life. It is also needed for heat transfer from people, plants and animals. It is obtained by starting with oxygen and adding buffer gases to reach the desired proportions. Humans can breath pure oxygen at 1/5 atmospheric pressure, but adding buffer gases such as nitrogen or argon is desirable. It is likely that people will choose an air pressure less than one atmosphere for early settlements on Mars. Carbon dioxide must be kept to trace amounts, as it rapidly becomes toxic at even low partial pressures.

References

  1. Wikipedia Carbonates on Mars[1]
  2. Wikipedia- Chlorides on Mars[2]
  3. Map of Martian Thorium at Mid-Latitudes, JPL Map of Martian Thorium at Mid-Latitudes , https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA04257, March 2003.