https://marspedia.org/api.php?action=feedcontributions&user=Multivac&feedformat=atomMarspedia - User contributions [en]2024-03-29T09:03:25ZUser contributionsMediaWiki 1.34.2https://marspedia.org/index.php?title=Biological_reactors&diff=136784Biological reactors2020-11-11T15:14:12Z<p>Multivac: /* Methanotrophs */</p>
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<div>[[Food]] and other products can be produced using industrial biological processes. This makes otherwise complex foods more accessible, it makes foods cheaper to produce and it simplifies the production of the industrial materials required for civilization.<br />
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==Methanotrophs==<br />
Methanotrophs such as [https://en.wikipedia.org/wiki/Methylococcus_capsulatus Methylococcus capsulatus] can use methane and methanol as both a source of energy as well as a carbon source<ref>https://www.genome.jp/kegg-bin/show_pathway?map00680</ref>. Using a [[Sabatier_process|sabatier reactor]], nuclear power can be used to convert [[Atmospheric_mining|atmospheric]] CO<sub>2</sub> into food or other biomass. To grow, these methanotrophs also require Nitrogen, Sulfur, Phosphorous and various trace metals. Nitrogen can be captured from the martian atmosphere, by allowing the Methanotrophs to grow in an anoxic atmosphere<ref>https://doi.org/10.1099/00221287-129-11-3481</ref> and nitrogen fix for themselves, or through a Haber reactor on refined atmospheric nitrogen producing [[ammonia]]. Sulfur and phosphorous are accessible in the regolith and will be released through metal processing. Other trace metals are only needed in minute amounts to operate enzymes and are easily recycled. These microbes are currently used on earth to produce animal feed<ref>https://web.archive.org/web/20190802163733/https://www.ntva.no/wp-content/uploads/2014/01/04-huslid.pdf</ref><ref>https://www.newscientist.com/article/2112298-food-made-from-natural-gas-will-soon-feed-farm-animals-and-us/</ref>, and their use in human food production is an active area of [[Biotechnology|biotechnological]] research<ref>https://solarfoods.fi/</ref>. The growth yields of methanotrophs have been extensively studied<ref>https://www.frontiersin.org/articles/10.3389/fmicb.2018.02947/full</ref>, with [[Methanol]]/[[Nitrate]] feedstock with trace amounts of [[Copper]] shown as an optimal point, with lower yields but higher carbon conversion efficiencies than other feedstocks<ref>https://link.springer.com/article/10.1007/BF02346062</ref>. Colonies could potentially use Methanotrophs as a [[food|foodstuff]] utilizing [[Nuclear_power|nuclear power]] in the [[nuclear food cycle]], which may be considerably more compact or easier to deploy than [[greenhouse|greenhouses]] or other conventional [[farm|farming]] methods.<br />
<br />
==Grass to glucose==<br />
Traditional hydroponic farming is complex and labor intensive. In contrast, growing and harvesting large grasses such as ''Miscanthus Giganteus'' is simple to do in a large scale and automated way through [[cellulose]] farms. These grasses can then be broken down via cellulases to provide an accessible source of glucose, along with other industrially useful compounds such as THF (a common solvent)<ref>https://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.8b00134</ref>.<br />
<br />
==Syngas to biomass==<br />
[[Syngas]], produced through either recycling carbon containing compounds through [https://en.wikipedia.org/wiki/Pyrolysis pyrolysis] or directly from [[carbon_dioxide|CO<sub>2</sub>]] and [[water]], can be used to produce biomass. Organisms such as ''Clostridium carboxidivorans''<ref>https://doi.org/10.1099/ijs.0.63482-0</ref> can directly metabolize [[syngas]] as a source of energy and [[carbon]], forming industrially useful compounds such as [[ethanol]], [[acetic acid]] along with medium chain (C<sub>4</sub>/C<sub>6</sub>) fatty acids and alcohols<ref>https://www.nature.com/articles/s41598-017-10312-2</ref><ref>https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-016-0495-0</ref>. Alternatively, syngas can also be used to produce [[methanol]] or [[methane]] which can be fed to [[Biological_reactors#Methanotrophs|Methanotrophs]].<br />
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==Xenotrophs==<br />
Some organisms, such as [https://microbewiki.kenyon.edu/index.php/Rhodopseudomonas|''Rhodopseudomonas palustris''] have a versatile metabolism, and so can consume a wide variety of chemicals both with and without sunlight in order to grow. It is capable of fixing both atmospheric CO<sub>2</sub> and N<sub>2</sub><ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940424/</ref>, and oxidising things as diverse as Iron<ref>https://www.nature.com/articles/ncomms4391</ref>, aromatic hydrocarbons or plant lignin<ref>https://en.wikipedia.org/wiki/Rhodopseudomonas_palustris</ref> as a source of energy. It has also been shown to be able to produce CH<sub>4</sub> with a modified nitrogenase when grown on acetate/carbonate and exposed to light<ref>https://www.pnas.org/content/pnas/113/36/10163.full.pdf</ref>.<br />
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==Biomass to industrial chemicals==<br />
Using GM microbes, biomass can be digested directly into a series of usable products such as Ammonia, short chain hydrocarbons<ref>https://doi.org/10.1016/j.ymben.2014.02.007</ref>, Adipic acid (a precursor to nylon)<ref>https://doi.org/10.1021/bp010179x</ref>, Phenol (a precursor to plastics) <ref>https://doi.org/10.1002/1521-3757(20010518)113:10%3C1999::AID-ANGE1999%3E3.0.CO;2-A</ref>, or converted to Benzene/Xylene/Toluene via catalytic reforming<ref>https://doi.org/10.1016/j.biortech.2019.01.081</ref>. This allows for greatly simplified industrial chemistry through a mix of careful genetic engineering and choosing biologically accessible industrial precursors.<br />
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==Biomass to engineered foods==<br />
Using genetically modified yeasts, it is also possible to directly produce proteins such as those found in eggs<ref>https://github.com/thethoughtemporium/Whose-gene-is-it-anyway/blob/master/milk-and-eggs/46815%20with%20ovalbumin%20and%20secretion%20tag.gb</ref> or milk<ref>https://github.com/thethoughtemporium/Whose-gene-is-it-anyway/blob/master/milk-and-eggs/4681%205deer%20milk%20b%20casein%20kcasein%20a%20lactalbumin%20and%20b%20lactoglobulin.gb</ref><ref>https://pubchem.ncbi.nlm.nih.gov/patent/US2017273328</ref>. It is also possible to produce various flavonoids, providing a variety of smells and flavors to artificially produced food. Vitimins and other essential nutrients can also be produced and added to ensure that foods are both tasty and nutritious.<br />
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<references /></div>Multivachttps://marspedia.org/index.php?title=Mars_cycler&diff=136782Mars cycler2020-11-11T13:11:32Z<p>Multivac: </p>
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<div>A Mars cycler, as described in <ref>https://youtu.be/42Je9Xczu0o?t=653</ref>, is a hypothetical [[Mission concepts|transportation]] system between Earth and Mars proposed by Buzz Aldrin as a way to reach Mars more economically.<ref>Wikipedia Mars Cycler https://en.wikipedia.org/wiki/Mars_cycler</ref>.<br />
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It is a vehicle on an elliptical orbit the crosses both the Earth's and Mars' orbits with transit times of about 5 month in either direction. This allows it periodically to be reached by a shuttle, either from Earth of from Mars. While moving with the cycler, no energy is expended by the shuttle. The cycler can serve as a more hospitable habitat than the shuttles: in particular it can provide better radiation protection from relatively heavy construction, artificial spin gravity and larger amounts of electricity for its [https://en.wiktionary.org/wiki/hotel_load hotel load].<br />
<br />
The shuttles require about 6km/s of [[Propulsion#Velocity_.28Rocket_equation.29|deltaV]] to reach the cycler from Earth and another 9.7km/s to slow down when they reach Mars, possibly reduced with the aid of [[skyhook|skyhooks]] or the use of aerodynamic capture. On the reverse leg of the journey, the [[Propulsion#Velocity_.28Rocket_equation.29|deltaV]] requirements would be similar.<br />
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An alternate approach would involve the cycler with a more efficient but generally mass or energy prohibitive thruster such as a [[Nuclear_thermal_propulsion|nuclear thermal]], [[Ion_thruster#Pulsed_Fission_Fusion_.28PuFF.29|Pulsed Fission Fusion(PuFF)]] or [[Ion_thruster#VASIMR|VASIMR]] thruster. This may reduce the [[Propulsion#Velocity_.28Rocket_equation.29|deltaV]] requirements for the comparably lower efficiency shuttle engines, increasing the effective mass fraction or decreasing trip time.<br />
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{{stub}}<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Perchlorate&diff=136781Perchlorate2020-11-11T12:02:13Z<p>Multivac: </p>
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<div>A '''perchlorate''' is a chemical compound containing the perchlorate ion<ref name=":0">https://en.wikipedia.org/wiki/Perchlorate#On_Mars</ref>, ClO<sub>4</sub><sup>-</sup>.<br />
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Perchlorates in the Martian soil have been identified as a significant hazard to a martian settlement plan. Perchlorate was detected in martian soil at the level of ~0.6% by weight. It is conjectured to exist as a mixture of 60% Ca(ClO<sub>4</sub>)<sub>2</sub> and 40% Mg(ClO<sub>4</sub>)<sub>2</sub><ref>https://www.space.com/21554-mars-toxic-perchlorate-chemicals.html</ref><br />
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In large amounts perchlorate interferes with iodine uptake into the thyroid gland.<ref name=":0" /> Because it is neither stored nor metabolized, the effects of perchlorate on the thyroid gland are reversible, though effects on brain development from lack of thyroid hormone in fetuses, newborns, and children are not. Perchlorate dust affects lung tissue.<br />
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==Perchlorate removal==<br />
Perchlorates are readily soluble in water and can be removed from surfaces by rinsing with water. Removing perchlorate from the settlement water supply can be done in a number of ways. Methods to remove perchlorates from water include [[Potable_water_treatment|reverse osmosis membranes]], [[Potable_water_treatment#TSSE|TSSE]], biological remediation<ref>https://pubmed.ncbi.nlm.nih.gov/25479396/</ref> or photochemically via UV light on a metallic iron catalyst<ref>https://books.google.ro/books?id=gjfSBwAAQBAJ&pg=PA106&lpg=PA106&dq=perchlorate+neutralization&source=bl&ots=ztEPz18eE-&sig=oHHZzByFHPVjYIVxbvzGl4SC_xQ&hl=en&sa=X&ved=0ahUKEwi5gpTJm_XJAhVBURoKHb3LB4o4ChDoAQguMAc#v=onepage&q=perchlorate%20neutralization&f=false</ref>.<br />
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Reducing dust intake into the settlement is a good objective. Washing vehicles, spacesuits and tool with water would reduce the intake at the source. Using [[EVA Suit|suitports]] to enter [[EVA Suit|EVA suits]] would also reduce perchlorate ingress into the settlement.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Perchlorate&diff=136780Perchlorate2020-11-11T12:00:08Z<p>Multivac: </p>
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<div>A '''perchlorate''' is a chemical compound containing the perchlorate ion, ClO<sub>4</sub><ref name=":0">https://en.wikipedia.org/wiki/Perchlorate#On_Mars</ref>.<br />
<br />
Perchlorates in the Martian soil have been identified as a significant hazard to a martian settlement plan. Perchlorate was detected in martian soil at the level of ~0.6% by weight. It is conjectured to exist as a mixture of 60% Ca(ClO<sub>4</sub>)<sub>2</sub> and 40% Mg(ClO<sub>4</sub>)<sub>2</sub><ref>https://www.space.com/21554-mars-toxic-perchlorate-chemicals.html</ref><br />
<br />
In large amounts perchlorate interferes with iodine uptake into the thyroid gland.<ref name=":0" /> Because it is neither stored nor metabolized, the effects of perchlorate on the thyroid gland are reversible, though effects on brain development from lack of thyroid hormone in fetuses, newborns, and children are not. Perchlorate dust affects lung tissue.<br />
<br />
==Perchlorate removal==<br />
Perchlorates are readily soluble in water and can be removed from surfaces by rinsing with water. Removing perchlorate from the settlement water supply can be done in a number of ways. Methods to remove perchlorates from water include [[Potable_water_treatment|reverse osmosis membranes]], [[Potable_water_treatment#TSSE|TSSE]], biological remediation<ref>https://pubmed.ncbi.nlm.nih.gov/25479396/</ref> or photochemically via UV light on a metallic iron catalyst<ref>https://books.google.ro/books?id=gjfSBwAAQBAJ&pg=PA106&lpg=PA106&dq=perchlorate+neutralization&source=bl&ots=ztEPz18eE-&sig=oHHZzByFHPVjYIVxbvzGl4SC_xQ&hl=en&sa=X&ved=0ahUKEwi5gpTJm_XJAhVBURoKHb3LB4o4ChDoAQguMAc#v=onepage&q=perchlorate%20neutralization&f=false</ref>.<br />
<br />
Reducing dust intake into the settlement is a good objective. Washing vehicles, spacesuits and tool with water would reduce the intake at the source. Using [[EVA Suit|suitports]] to enter [[EVA Suit|EVA suits]] would also reduce perchlorate ingress into the settlement.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Perchlorate&diff=136779Perchlorate2020-11-11T11:58:40Z<p>Multivac: /* Perchlorate removal */</p>
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<div>A '''perchlorate''' is a chemical compound containing the perchlorate ion, ClO−4<ref name=":0">https://en.wikipedia.org/wiki/Perchlorate#On_Mars</ref>. One Chlorine and 4 Oxygen atoms.<br />
<br />
Perchlorates in the Martian soil have been identified as a significant hazard to a martian settlement plan. Perchlorate was detected in martian soil at the level of ~0.6% by weight. It is conjectured to exist as a mixture of 60% Ca(ClO<sub>4</sub>)<sub>2</sub> and 40% Mg(ClO<sub>4</sub>)<sub>2</sub><ref>https://www.space.com/21554-mars-toxic-perchlorate-chemicals.html</ref><br />
<br />
In large amounts perchlorate interferes with iodine uptake into the thyroid gland.<ref name=":0" /> Because it is neither stored nor metabolized, the effects of perchlorate on the thyroid gland are reversible, though effects on brain development from lack of thyroid hormone in fetuses, newborns, and children are not. Perchlorate dust affects lung tissue.<br />
<br />
==Perchlorate removal==<br />
Perchlorates are readily soluble in water and can be removed from surfaces by rinsing with water. Removing perchlorate from the settlement water supply can be done in a number of ways. Methods to remove perchlorates from water include [[Potable_water_treatment|reverse osmosis membranes]], [[Potable_water_treatment#TSSE|TSSE]], biological remediation<ref>https://pubmed.ncbi.nlm.nih.gov/25479396/</ref> or photochemically via UV light on a metallic iron catalyst<ref>https://books.google.ro/books?id=gjfSBwAAQBAJ&pg=PA106&lpg=PA106&dq=perchlorate+neutralization&source=bl&ots=ztEPz18eE-&sig=oHHZzByFHPVjYIVxbvzGl4SC_xQ&hl=en&sa=X&ved=0ahUKEwi5gpTJm_XJAhVBURoKHb3LB4o4ChDoAQguMAc#v=onepage&q=perchlorate%20neutralization&f=false</ref>.<br />
<br />
Reducing dust intake into the settlement is a good objective. Washing vehicles, spacesuits and tool with water would reduce the intake at the source. Using [[EVA Suit|suitports]] to enter [[EVA Suit|EVA suits]] would also reduce perchlorate ingress into the settlement.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Silicon&diff=136778Silicon2020-11-11T11:17:07Z<p>Multivac: /* Uses */</p>
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<div>{{element|elementSymbol=Si|elementName=Silicon|protons=14|abundance=27,7% ([[regolith]])}}<br />
'''Silicon''' (''[[Elements on Mars|periodic table]] symbol:'' Si<sup>14</sup>) is a chemical element<ref>https://en.wikipedia.org/wiki/Silicon</ref> that can be found in several [[minerals]] on [[Mars]].<br />
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==Chemistry==<br />
[[File:Cyclohexasilane_cyclohexane_cyclohexasiloxane.png|frame|right|Structure of cyclohexasilane (top), cyclohexasiloxane (bottom right) and the [[hydrocarbon]] cyclohexane (bottom left).]]<br />
As a group 14 element, silicon has a chemistry similar to that of [[tin]] and [[lead]], and especially that of [[carbon]] and [[germanium]].<br /><br />
As we go down from carbon at the top of group 14, the reactivity (and electropositivity) of the elements increases. At the same time, the bond [[enthalpy]] decreases for chains of the element<ref name="Housecroft_Sharpe">C.E. Housecroft & A.G. Sharpe - ''Inorganic chemistry'' 2012. ISBN 978-0-273-74275-3 pp. 433, 444-446.</ref>. That is, C-C bonds are more stable than Si-Si bonds, which are more stable than Ge-Ge bonds, etc. The strength of their bonds with hydrogen similarly decreases. This is why, for example, [[methane]] is more stable than [[Silicon#Silanes|silane]].<br /><br />
Despite the instability of silicon chains relative to their carbon analogues, they are industrially significant.<br />
<br />
===Silanes===<br />
The silanes are acyclic chains of singly-bonded silicon atoms analogous to the [[alkanes]]. The cyclosilanes are (highly unstable) cyclic silanes.<br />
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===Silenes===<br />
The silenes are acyclic chains of doubly-bonded silicon atoms, analogous to the [[alkenes]].<br />
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===Siloxanes===<br />
Due to the instability of Si-Si bonds, longer chains of silicon atoms are often constructed with some other atom between the silicon atoms, which bonds more strongly to them. In the case of the siloxanes, this results in Si-O-Si chains. For comparison, the enthalpy of a Si-O bond is in higher than that of a C-C single bond but lower than that of a C=C double bond, and more than twice that of a Si-Si bond.<br />
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Silicones are made of polymers of siloxane.<br />
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===Silicates===<br />
Silica, SIO<sub>2</sub> ,is the most common compound found in the martian crust. Other silicates exist as well, in the general SiOx form. Quartz is pure SiO<sub>2</sub> in crystalline form.<br />
<br />
==Occurrence==<br />
Analysis of Martian soil<ref name="Pathfinder">NASA JPL - [http://mars.jpl.nasa.gov/MPF/science/apxs_elemental.html ''Mars Pathfinder: Analysis of Martian Samples by the Alpha Proton X-Ray Spectrometer: Preliminary Results''] Access 2013-04-28.</ref> shows a composition broadly similar to that of Earth, with oxygen and silicon also taking the first and second respective positions.<br />
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Silicon is the second most common element in the earth's crust (after [[oxygen]]); in fact their compound [[silica]] makes up about 60% of the crust, as on Mars.<br /><br />
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==Silica production==<br />
Silica can be obtained [[In-situ resource utilization|in-situ]] directly from the martian regolith. However is is usually mixed with contaminants and will usually require a separation process before it can be used for martian industry. There may have been geological processes that have concentrated silica into easily usable forms. Silica production for glass has en [[embodied energy]] of 6-15 MJ/kg.<br />
<br />
Silica dust is a known cancer causing agent. Dust collectors and atmospheric treatment systems will be required in production areas.<br />
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==Silicon production==<br />
Silicon production is usually a by product of steel production.<ref>https://en.wikipedia.org/wiki/Silicon#Production</ref><br />
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[[Embodied energy]] of silicon depends on its purity<ref>https://greenchemuoft.wordpress.com/2017/12/12/embodied-energy-and-solar-cells/</ref>. Solar cell grade silicon crystals have 1656 MJ/kg of embodied energy. Transforming these into solar cells adds 432 MJ/kg for a total of 2088 MJ/kg.<br />
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Clean rooms can be extremely expensive to build for production of electronic products.<br />
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==Uses==<br />
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*Silicate (or Quartz) is the main components of glass<br />
*Sand, usually composed of a large parts of silicates, is an essential construction material<br />
*Stone, concrete and bricks are largely composed of silicates. Therefore silica is a prime construction material for a martian settlement<br />
<br />
*Silicon is the main material for monocrystalline wafers, used for [[solar panel]]s and for electronics.<ref>https://en.wikipedia.org/wiki/Wafer_(electronics)</ref><br />
*Silicon can be used to produce [[phosphorus]] through neutron capture.<br />
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*Silicon is needed for [[silicone synthesis]] to produce [[synthetic materials]].<br /> High-purity silicon (produced by deposition from silanes) is used as a semiconductor in electronics (after being suitably doped). There are alternatives, such as germanium, though their exact performance characteristics vary and silicon is the obvious choice due to its abundance.<br />
*Silicon Carbide, SiC, is used in metallurgy and is an extremely hard ceramic.<br />
*Silicon is used in the production of iron.<br />
{{science question|How pure does silicon need to be? - [[User:PeterBrett|Peter]]}}<br />
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==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Oxygen&diff=136777Oxygen2020-11-11T11:10:10Z<p>Multivac: /* Production */</p>
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<div>{{element<br />
|float=right<br />
|elementName=Oxygen<br />
|elementSymbol=O<br />
|protons=8<br />
|abundance=0.15% atmosphere 46,6% crust<br />
}}<br />
<br />
<br />
'''Oxygen''' (''[[Elements on Mars|periodic table]] symbol:'' O<sup>8</sup>) is a chemical element that can be found in the [[atmosphere]] and in most [[minerals]] on [[Mars]]. Almost half of the mass of the Martian crust is Oxygen, bound up in various minerals. Oxygen is created in stars from the fusion of [[Carbon]] and [[Helium]].<br />
<br />
[[Image:alga_and_bubbles.jpg|thumb|right|200px|Alga producing oxygen]]<br />
<br />
==Relevance for life==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and various [[microbes]] depends on oxygen. The atmosphere of Mars contains only 0,15 % oxygen, which is not enough to support animal or human life.<br />
<br />
==Production==<br />
Oxygen can be produced [[Atmospheric processing|in situ]]:<br />
<br />
*in [[greenhouse]]s by plants.<br />
*in [[Photobioreactor|photobioreactors]] by algae.<br />
*by reduction of [[carbon dioxide]] from the martian atmosphere, or [[w:Carbonates_on_Mars|carbonate]] minerals via either molten salt reduction<ref>https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/57796/1/CO2OtakeREMTRev2.pdf</ref> or via [[Carbon_Dioxide_Scrubbers|MOXIE]] style solid oxide electrolysis.<br />
*by reduction of oxide minerals, either at low temperature in aqueous solution<ref>https://link.springer.com/article/10.1007/s10800-017-1127-5</ref> or at high temperature in molten salt<ref>https://link.springer.com/article/10.1007/s10800-017-1143-5</ref><br />
*by [[electrolysis]] of [[water]]<br />
*by the decomposition of [[Perchlorate|perchlorates]] in the soil.<br />
*by thermal decomposition of [[water]] through the Sulfur/Iodine<ref>https://doi.org/10.1016/j.ijhydene.2006.05.013</ref> or Zinc/Sulfur/Iodine<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref> cycles.<br />
<br />
==Uses==<br />
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*[[Propellant]]. Oxygen is often chosen as an oxidizer for chemical propulsion.<br />
*[[Air|Atmospheric component]]. Standard atmosphere contains 21% Oxygen.<br />
*Chemical reagent<br />
<br />
==Related Articles==<br />
<br />
[[lunarp:Oxygen|Oxygen<sup><b>lunarp</b></sup>]] on Lunarpedia.<br />
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[[category:Air]]</div>Multivachttps://marspedia.org/index.php?title=Thorium&diff=136776Thorium2020-11-11T11:02:04Z<p>Multivac: </p>
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<div>[[File:Th 040305 NG 5x5 SmB10 016 EQ75 with2Logos web.jpg|thumb|600x600px|Thorium concentration on Mars]]<br />
Thorium is present on [[Mars]], however, it seems to be lower concentrations than on Earth.<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> Thorium can be used to produce fuel for [[Nuclear power|nuclear reactors]] on Mars, [[Nuclear_thermal_propulsion|nuclear thermal propulsion]] and [[Ion_thruster#Pulsed_Fission_Fusion_.28PuFF.29|nuclear pulsed propulsion]]. [[Elements on Mars|Periodic table]] Th. <br />
<br />
The average concentration seems to be more than about six times lower than on Earth in the most concentrated areas<ref>https://en.wikipedia.org/wiki/Occurrence_of_thorium</ref>. Naturally concentrated deposits would need to be found to make the use of Thorium economical on Mars in the long term, or the tailings of rare earth element<ref>https://www.youtube.com/watch?v=lxwF93wnRQo</ref> or other<ref>https://www.epa.gov/radiation/tenorm-copper-mining-and-production-wastes</ref> mines could be utilized, which typically produce a waste stream enriched in thorium. <br />
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==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Oxygen&diff=136775Oxygen2020-11-11T10:41:05Z<p>Multivac: /* Production */</p>
<hr />
<div>{{element<br />
|float=right<br />
|elementName=Oxygen<br />
|elementSymbol=O<br />
|protons=8<br />
|abundance=0.15% atmosphere 46,6% crust<br />
}}<br />
<br />
<br />
'''Oxygen''' (''[[Elements on Mars|periodic table]] symbol:'' O<sup>8</sup>) is a chemical element that can be found in the [[atmosphere]] and in most [[minerals]] on [[Mars]]. Almost half of the mass of the Martian crust is Oxygen, bound up in various minerals. Oxygen is created in stars from the fusion of [[Carbon]] and [[Helium]].<br />
<br />
[[Image:alga_and_bubbles.jpg|thumb|right|200px|Alga producing oxygen]]<br />
<br />
==Relevance for life==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and various [[microbes]] depends on oxygen. The atmosphere of Mars contains only 0,15 % oxygen, which is not enough to support animal or human life.<br />
<br />
==Production==<br />
Oxygen can be produced [[Atmospheric processing|in situ]]:<br />
<br />
*in [[greenhouse]]s by plants.<br />
*in [[Photobioreactor|photobioreactors]] by algae.<br />
*by reduction of [[carbon dioxide]] from the martian atmosphere, or [[w:Carbonates_on_Mars|carbonate]] minerals via either molten salt reduction<ref>https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/57796/1/CO2OtakeREMTRev2.pdf</ref> or via [[Carbon_Dioxide_Scrubbers|MOXIE]] style solid oxide electrolysis.<br />
*by reduction of oxide minerals, either at low temperature in aqueous solution<ref>https://link.springer.com/article/10.1007/s10800-017-1127-5</ref> or at high temperature in molten salt<ref>https://link.springer.com/article/10.1007/s10800-017-1143-5</ref><br />
*by [[electrolysis]] of [[water]]<br />
*by thermal decomposition of [[water]] through the Sulfur/Iodine<ref>https://doi.org/10.1016/j.ijhydene.2006.05.013</ref> or Zinc/Sulfur/Iodine<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref> cycles.<br />
<br />
==Uses==<br />
<br />
*[[Propellant]]. Oxygen is often chosen as an oxidizer for chemical propulsion.<br />
*[[Air|Atmospheric component]]. Standard atmosphere contains 21% Oxygen.<br />
*Chemical reagent<br />
<br />
==Related Articles==<br />
<br />
[[lunarp:Oxygen|Oxygen<sup><b>lunarp</b></sup>]] on Lunarpedia.<br />
<br />
[[category:Air]]</div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136244Ion thruster2020-08-03T07:33:34Z<p>Multivac: /* Pulsed Fission Fusion (PuFF) */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
===''Pulsed Fission Fusion (PuFF)''===<br />
PuFF<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180008679.pdf</ref><ref>https://www.youtube.com/watch?v=_Ux5UpDWfEU</ref> is an experimental spacecraft propulsion system, utilizing high energy plasma produced through controlled microfusion detonations, similar to a micro scale [https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) Orion drive] with a predicted Isp of 30,000 seconds, a thrust of 29KN and an in space system weight of 240 Tons<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180006409.pdf</ref><ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140012884.pdf</ref>, allowing for theorized mission profiles of Earth to Mars in 39 days<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140008798.pdf</ref>. Electric power is collected in a [https://en.wikipedia.org/wiki/Linear_transformer_driver linear transformer driver], producing a 2MA/2MV pulse<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180006409.pdf</ref> which is discharged through a target consisting of a [[Deuterium]]/[[Tritium]] core wrapped in a <sup>235</sup>U liner encased in a lithium tamper. This forms a [https://en.wikipedia.org/wiki/Z-pinch Z pinch]<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170003402.pdf</ref> as the target is vaporized into a plasma and then crushed through lorenz forces. This crushing then increases the density of the <sup>235</sup>U plasma past supercriticality, causing it to start to rapidly fission and further heat the plasma. Once that plasma is hot enough it begins D/T fusion, producing neutrons that amplify the fission chain reaction. The hot plasma eventually eventually exits through a magnetic nozzle<ref>https://doi.org/10.2514/6.2019-4284</ref> producing thrust. The system then cycles for the next reaction, repeating ~100 times per second<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180006409.pdf</ref>. The chain reaction is overall:<br />
<br />
:<chem>^2_1H</chem> + <chem>^3_1H</chem> <chem>\to</chem> <chem>^4_2He</chem> + <chem>n</chem> + ~<chem>17MeV</chem><br />
:<chem>^235U</chem> + <chem>n</chem> <chem>\to</chem> <chem>FP</chem> + 2.5n + ~<chem>200MeV</chem><br />
<br />
With a side D/D fusion stage of:<br />
:<chem>^2_1H</chem> + <chem>^2_1H</chem> <chem>\to</chem> <chem>^3_1H</chem> + <chem>p</chem> + ~<chem>4MeV</chem><br />
:<chem>^2_1H</chem> + <chem>^2_1H</chem> <chem>\to</chem> <chem>^3_2He</chem> + <chem>n</chem> + ~<chem>3MeV</chem><br />
:<chem>^2_1H</chem> + <chem>^3_2He</chem> <chem>\to</chem> <chem>^4_2He</chem> + <chem>p</chem> + ~<chem>18MeV</chem><br />
<br />
This side reaction is important as although D/D fusion requires more heat to ignite, it leaves considerably more energy in the reaction products instead of high energy neutrons like in D/T fusion<ref>http://www.projectrho.com/public_html/rocket/fusionfuel.php</ref>. Tritium is produced in situ via neutron capture of <sup>6</sup>Li in a lithium blanket around the reaction chamber or alternatively using a solid target core of <sup>6</sup>Li[[Deuterium|D]]<ref>https://www.youtube.com/watch?v=Jm8mKo0i5YE</ref>. [[Lithium]], [[Deuterium]] and <sup>233</sup>U (via [[Thorium]]) are all reasonably common on Mars and so this system could possibly be built or refueled on Mars.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the [[Nuclear_power#LMMHD_generators|MHD generator]]. Xenon is quite expensive, at about $20 per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
[[Argon]] is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
[[Krypton]], another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
[[Water]] has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components.<br />
<br />
==='''Helium'''===<br />
[[Helium]] is fairly easy to ionize.<br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136243Ion thruster2020-08-03T06:34:48Z<p>Multivac: /* Fusion ion systems */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
===''Pulsed Fission Fusion (PuFF)''===<br />
PuFF<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180008679.pdf</ref><ref>https://www.youtube.com/watch?v=_Ux5UpDWfEU</ref> is an experimental spacecraft propulsion system, utilizing high energy plasma produced through controlled microfusion detonations, similar to a micro scale [https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) Orion drive] with a predicted Isp of 30,000 seconds, a thrust of 29KN and an in space system weight of 240 Tons<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180006409.pdf</ref><ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140012884.pdf</ref>, allowing for theorized mission profiles of Earth to Mars in 39 days<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140008798.pdf</ref>. Electric power is collected in a [https://en.wikipedia.org/wiki/Linear_transformer_driver linear transformer driver], producing a 2MA/2MV pulse<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180006409.pdf</ref> which is discharged through a target consisting of a [[Deuterium]]/[[Tritium]] core wrapped in a <sup>235</sup>U liner encased in a lithium tamper. This forms a [https://en.wikipedia.org/wiki/Z-pinch Z pinch]<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170003402.pdf</ref> as the target is vaporized into a plasma and then crushed through lorenz forces. This crushing then increases the density of the <sup>235</sup>U plasma past supercriticality, causing it to start to rapidly fission and further heat the plasma. Once that plasma is hot enough it begins D/T fusion, producing neutrons that amplify the fission chain reaction. The hot plasma eventually eventually exits through a magnetic nozzle<ref>https://doi.org/10.2514/6.2019-4284</ref> producing thrust. The system then cycles for the next reaction, repeating ~100 times per second<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180006409.pdf</ref>. The chain reaction is overall:<br />
<br />
:<chem>^2_1H</chem> + <chem>^3_1H</chem> <chem>\to</chem> <chem>^4_2He</chem> + <chem>n</chem> + ~<chem>17MeV</chem><br />
:<chem>^235U</chem> + <chem>n</chem> <chem>\to</chem> <chem>FP</chem> + 2.5n + ~<chem>200MeV</chem><br />
<br />
With a side D/D fusion stage of:<br />
:<chem>^2_1H</chem> + <chem>^2_1H</chem> <chem>\to</chem> <chem>^3_1H</chem> + <chem>p</chem> + ~<chem>4MeV</chem><br />
:<chem>^2_1H</chem> + <chem>^2_1H</chem> <chem>\to</chem> <chem>^3_2He</chem> + <chem>n</chem> + ~<chem>3MeV</chem><br />
:<chem>^2_1H</chem> + <chem>^3_2He</chem> <chem>\to</chem> <chem>^4_2He</chem> + <chem>p</chem> + ~<chem>18MeV</chem><br />
<br />
This side reaction is important as although D/D fusion requires more heat to ignite, it leaves considerably more energy in the reaction products instead of high energy neutrons like in D/T fusion<ref>http://www.projectrho.com/public_html/rocket/fusionfuel.php</ref>. Tritium is produced in situ via neutron capture of <sup>6</sup>Li in a lithium blanket around the reaction chamber. [[Lithium]], [[Deuterium]] and <sup>233</sup>U (via [[Thorium]]) are all reasonably common on Mars and so this system could possibly be built or refueled on Mars.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the [[Nuclear_power#LMMHD_generators|MHD generator]]. Xenon is quite expensive, at about $20 per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
[[Argon]] is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
[[Krypton]], another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
[[Water]] has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components.<br />
<br />
==='''Helium'''===<br />
[[Helium]] is fairly easy to ionize.<br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Geography_of_Mars&diff=136238Geography of Mars2020-07-30T07:42:03Z<p>Multivac: /* South Pole Region */</p>
<hr />
<div>{{Mars atlas}}<br />
Article written by Jim Secosky. Jim is a retired science teacher who has used the Hubble Space Telescope, the Mars Global Surveyor, and HiRISE.<br />
<br />
<br />
This article will describe the geography of Mars, starting with large features and then get more specific. Many maps will display groups of features and all can be copied and used without permission. Although there are many good maps of Martian features, most are under some sort of copyright protection. <br />
<br />
==North and South==<br />
<br />
One of the most significant aspects of Mars is the vast difference between the northern and southern hemispheres. Much of the north is smooth and of low elevation. In contrast, the southern half of the planet is rough with great numbers of craters (indicating an old age). The south is also much higher in altitude (between 1-3 km higher). The boundary between the Southern and the Northern hemispheres is called the Martian dichotomy. Although several ideas have been advanced to explain these differences, at present it is thought the northern hemisphere was struck on a low angle by an asteroid early in its history.<ref>Andrews-Hanna; et al. (2008). "The Borealis basin and the origin of the Martian crustal dichotomy". Nature. 453 (7199): 1212–1215. </ref> <ref>Marinova; et al. (2008). "Mega-impact formation of the Mars hemispheric dichotomy". Nature. 453 (7199): 1216–1219. </ref> <ref>Nimmo; et al. (2008). "Implications of an impact origin for the Martian hemispheric dichotomy". Nature. 453 (7199): 1220–1223.</ref><br />
<br />
==East and West==<br />
<br />
The Eastern hemisphere of Mars holds a small collection of volcanoes, Hellas Planitia, (a large impact crater) and a dark area that was the first feature noted on the surface by early astronomers. Studies suggest that the heat from the impact that created the Hellas Basin caused the entire surface of Mars to heat hundreds of degrees. In addition, the surface was covered with 70 meters of molted rock which fell from the sky. For a time an atmosphere of gaseous rock existed. This rock atmosphere would have been 10 times as thick as the Earth's atmosphere. In a few days, the rock would have condensed out and covered the whole planet with an additional 10 m of molten rock.<ref>Carr, Michael H. (2006). The Surface of Mars. Cambridge University Press. ISBN 978-0-521-87201-0.</ref><br />
<br />
[[File:Mars globe.png |left|thumb|px| Eastern hemisphere of Mars Syrtis Major is the dark spot in the middle. Hellas Planitia lies to the south of Syrtis Major and appears light-toned due to clouds. Southern ice cap is at the bottom.]]<br />
<br />
The HiRISE instrument onboard the Mars Reconnaissance Orbiter has discovered a strange feature on the floor of Hellas Planitia. Called "Honeycomb Terrain," it may be caused by great masses of buried water ice moving upward. <ref>Bernhardt, H.; et al. (2016). "The honeycomb terrain on the Hellas basin floor, mars: a case for salt or ice diapirism: hellas honeycombs as salt/ice diapirs". J. Geophys. Res. 121: 714–738.</ref> <ref>Weiss, D., J. Head. 2017. HYDROLOGY OF THE HELLAS BASIN AND THE EARLY MARS CLIMATE: WAS THE HONEYCOMB TERRAIN FORMED BY SALT OR ICE DIAPIRISM? Lunar and Planetary Science XLVIII. 1060.pdf</ref> <ref>Weiss, D.; Head, J. (2017). "Salt or ice diapirism origin for the honeycomb terrain in Hellas basin, Mars?: Implications for the early martian climate". Icarus. 284: 249–263.</ref> However, there are several other hypothesizes for its creation being considered.<br />
<br />
[[File: ESP_049330_1425honeycomb.jpg|thumb|px|right|Honeycomb terrain on floor of Hellas Planitia that may be caused by masses of underground ice pushing up.]]<br />
<br />
There is a big contrast between the Western and Eastern hemisphere of Mars. The Western hemisphere has the great [[Valles Marineris]], the Grand Canyon of Mars. It could stretch nearly across the continental United States. At its western end is a large group of intersecting canyons, called [[Noctis Labyrinthus]]. This hemisphere also hosts a region known as [[Tharsis]]. Tharsis is home to the largest volcanoes on Mars and in the solar system. The southern part contains Argyre Planitia, a large impact basin that probably contained a lake.<ref>Parker, T.; et al. 2000. Argyre Planitia and the Mars global hydrological cycle . LPSC. XXXI: 2033.</ref> <ref>Dohm, J.; Hare, T.; Robbins, S.; Williams, J.-P.; Soare, R.; El-Maarry, M.; Conway, S.; Buczkowski, D.; Kargel, J.; Banks, M.; Fairén, A.; Schulze-Makuch, D.; Komatsu, G.; Miyamoto, H.; Anderson, R.; Davila, A.; Mahaney, W.; Fink, W.; Cleaves, H.; Yan, J.; Hynek, B.; Maruyama, S. 201). Geological and hydrological histories of the Argyre province, Mars. Icarus. 253: 66–98.</ref> The western hemisphere also contains many outflow channels, such as [[Ares Vallis]], Ravi Vallis, Mawrth Vallis, and Kasei Valles in which giant flows of water went roaring though.<ref>Baker, V. 1982. The Channels of Mars. Austin: Texas University Press.</ref> <ref>Carr,M.H. (1979). "Formation of Martian flood features by release of water from confined aquifers". J. Geophys. Res., 84, 2995-3007.</ref> Calculations indicate that the amount of water required to erode such channels at least equals and most probably exceeds by several orders of magnitude the present discharges of the largest terrestrial rivers. These Martian floods would be comparable to the largest floods known to have ever occurred on Earth (the ones that cut the Channeled Scablands in North America).<ref>Williams, R., Phillips, R., and Malin, M. 2000. Flow rates and duration within Kasei Vallis, Mars: Implications for the formation of a Martian ocean. Geophys. Res. Lett., 27, 1073-6.</ref> <ref>Robinson, M., and Takana, K. 1990. Magnitude of a catastrophic flood event in Kasei Vallis, Mars. Geology, 18, 902-5.</ref><br />
<br />
[[File:Mars Valles Marineris.jpg |left|thumb|px| Western hemisphere of Mars Valles Marineris dominates the picture. Long channel running to the North is large outflow channel called Kasei Valles. Three volcanoes are at the left edge.]]<br />
<br />
==Volcanoes==<br />
<br />
[[File:Mars MGS colorhillshade mola 1024volcanoessyrtis.jpg |right|thumb|px|Topographic map with volcanoes labeled Tharsis volcanoes are on the left. There are no copyright restrictions on this map ]]<br />
<br />
Mars is a land of great volcanoes. [[Tharsis]] contains the largest volcano in the solar system, along with several that are about as tall as the Earth’s tallest mountains. In addition, many small ones may actually be mostly covered by ash. We may be seeing only their tips.<ref>Whitford-Stark, J. 1982. Tharsis Volcanoes: Separation Distances, Relative Ages, Sizes, Morphologies, and Depths of Burial. J. Geophys. Res. 87: 9829–9838. </ref> Tharsis covers almost 25 % of the surface of the planet.<ref>Solomon, Sean C.; Head, James W. (1982). "Evolution of the Tharsis Province of Mars: The Importance of Heterogeneous Lithospheric Thickness and Volcanic Construction". J. Geophys. Res. 87 (B12): 9755–9774. </ref> Elysium volcanic province, another smaller group of volcanoes, sits in the Eastern hemisphere; the biggest of the three is called [[ Elysium Mons]]. Apollinaris Mons is near the landing site for the Spirit Rover. This volcano may have covered over expected lake deposits in Gusev Crater. <br />
The first feature to be drawn on early maps of Mars was Syrtis Major. This dark feature is volcanic by nature with two caldera: Meroe Patera and Nili Patera. Studies involving the regional gravity field suggest a solidified magma chamber exists beneath its surface.<ref>Kiefer, W. |year=2002 |title=Under the volcano: gravity evidence for an extinct magma chamber beneath Syrtis Major, Mars |work=American Geophysical Union, Fall Meeting 2002 |at=abstract #P71B-0463 </ref> Syrtis Major is of interest to geologists because dacite and granite have been detected there from orbiting spacecraft. Dacites and granites are very common on Earth but rare on Mars.<br />
Lava sometimes forms lava tunnels. These are places in which a hard cap forms on top of a flow while the rest of the liquid lava has moved away. These tunnels can be quite large. Many have suggested that future colonists can use these tunnels for their shelters where there would be protection from radiation and meteorites, and where there would be a more constant temperature. Some pictures taken with HiRISE seem to show pits that may lead into these hollowed out places.<br />
<br />
[[Image: Mars; Arsia Mons cave entrance -MROjeanne.jpg|thumb|right|Possible cave entrance to pit]]<br />
<br />
Several old, eroded volcanoes exist near to the great impact crater Hellas Planitia. Some researchers have suggested that the location of the highland paterae around Hellas is due to deep-seated fractures caused by the impact that provided channels for magma to rise to the surface.<ref>Peterson, J. 1978. Volcanism in the Noachis-Hellas region of Mars, 2. Lunar and Planetary Science. IX: 3411–3432.</ref> <ref>Williams, D.; et al. 2009. The Circum-Hellas volcanic province, Mars: Overview. Planetary and Space Science. 57: 895–916.</ref> <ref>Rodriguez, J.; K. Tanaka. 2006. Sisyphi Montes and southwest Hellas Paterae: possible impact, cryotectonic, volcanic, and mantle tectonic processes along Hellas Basin rings. Fourth Mars Polar Science Conference. p. 8066.</ref><br />
<br />
==Craters==<br />
<br />
[[File:Mars MGS colorhillshade mola 1024craters2.jpg|left|thumb|px|Map showing names and locations of quadrangles of Mars ]]<br />
Because the surface of Mars is so old, billions of years in some areas, it contains many impact craters. Basically, the more craters the older the surface. The older, southern highlands contain far more craters than the North. Craters can help us sample material under the surface because an impact event brings material from deep underground. Moreover, some material from the impactor could be gathered by automated machines in the future for use by the colonists. Our rovers have already photographed and examined meteorites sitting on Mars. Meteoritic material is more likely to come from small craters, as in large impacts the impacting body is usually vaporized. <br />
<br />
[[Image: Meteoritemars.jpg |thumb|200px|left|Meteorite found on Mars by Opportunity Rover in the Margaritifer Sinus quadrangle]]<br />
<br />
Low plains on Mars are called “Planitia.” Many of these were formed by impact events, especially Chryse, Utopia, Isidis, Argyre, and Hellas. Hellas Planitia is the deepest area on the planet.<br />
Many craters are believed to have once held lakes, including Argyre Planitia and Hellas Planitia in the South.<ref>Cabrol, N. and E. Grin (eds.). 2010. Lakes on Mars. Elsevier. NY.</ref> <ref>Voelker, M., et al. 2016. DISTRIBUTION AND EVOLUTION OF LACUSTRINE AND FLUVIAL FEATURES IN HELLAS PLANITIA, MARS, BASED ON PRELIMINARY RESULTS OF GRID-MAPPING. 47th Lunar and Planetary Science Conference (2016) 1228.pdf.</ref> <ref>arker, T.; et al. (2000). "Argyre Planitia and the Mars global hydrological cycle". LPSC. XXXI: 2033.</ref> <br />
High resolution views of many crater show that they have almost completely filled with ice which is visible as many concentric ridges. Craters begin with a bowl shape. After millions of years of collecting snow, they appear flat and shallow. Researchers have named the material “ Concentric Crater Fill .” <br />
<br />
[[File:1024px-46622 1365contextccf.jpg |thumb|200px|left|Concentric Crater Fill Many craters show these concentric ridges which are from ice moving in the crater which has almost completely filled with ice.]]<br />
The craters Milankovic, Lomonosov, Kunowsky, Lyot, and Mie are in the North and are easy to spot because there are very few features near them. The Viking 2 spacecraft landed near Mie Crater. Mariner Crater was discovered and named after the Mariner 4 spacecraft. Mariner 4’s image of Mariner Crater was the best picture returned by the Mariner 4 flyby. Nicholson and Schiaparelli Craters sit almost directly on the equator.<br />
<br />
==South Pole Region==<br />
<br />
[[File:PIA00190-MC-30-MareAustraleRegion-19980605.jpg |right|thumb|px| Region of South Pole with ice cap Southern ice cap is much smaller than the North’s.]]<br />
<br />
This region is covered in the Mare Australe quadrangle. The ice cap at the South Pole is much smaller than the one in the North. <br />
Parts of Mare Australe display pits that make the surface look like Swiss cheese.<ref>Thomas,P., M. Malin, P. James, B. Cantor, R. Williams, P. GieraschSouth polar residual cap of Mars: features, stratigraphy, and changesIcarus, 174 (2 SPEC. ISS.). 2005. pp. 535–559. http://doi.org/10.1016/j.icarus.2004.07.028</ref> <ref>Thomas, P., P. James, W. Calvin, R. Haberle, M. Malin. 2009. Residual south polar cap of Mars: stratigraphy, history, and implications of recent changes Icarus: 203, 352–375 http://doi.org/10.1016/j.icarus.2009.05.014</ref> <ref>Thomas, P., W.Calvin, P. Gierasch, R. Haberle, P. James, S. Sholes. 2013. Time scales of erosion and deposition recorded in the residual south polar cap of mars Icarus: 225: 923–932 http://doi.org/10.1016/j.icarus.2012.08.038</ref> <ref>Thomas, P., W. Calvin, B. Cantor, R. Haberle, P. James, S. Lee. 2016. Mass balance of Mars’ residual south polar cap from CTX images and other data Icarus: 268, 118–130 http://doi.org/10.1016/j.icarus.2015.12.038</ref> These pits are in a 1-10 meter thick layer of dry ice that is sitting on a much larger water ice cap<ref>Buhler, Peter, Andrew Ingersoll, Bethany Ehlmann, Caleb Fassett, James Head. 2017. How the martian residual south polar cap develops quasi-circular and heart-shaped pits, troughs, and moats. Icarus: 286, 69-9.</ref>. Some, such as [[Robert Zubrin]] have suggested craters on the south pole of mars, specifically [[Korolev|Korolev Crater]] as promising site for a [[sublake settlement]] on mars<ref>https://www.centauri-dreams.org/2020/05/29/sublake-settlements-for-mars/</ref>.<br />
<br />
[[File:South Pole Terrain.jpg |center|thumb|px| Swiss cheese terrain, as seen by HiRISE]]<br />
<br />
==North Pole Region==<br />
<br />
[[File:Mars NPArea-PIA00161.jpg |left|thumb|px| Spiral troughs in the northern ice cap]]<br />
<br />
The ice cap in the north is far larger than the one in the south. It contains a large pattern of spiral-shaped troughs. In the troughs many layers are visible in high resolution photos. The layers result from climate changes. At times the atmosphere contains more dust, consequently darker layers are formed. Sometimes thicker deposits of ice are deposited, making thicker layers. <br />
From observations with the Shallow Radar instrument (SHARAD), researchers determined that the total volume of water ice in the cap is 821,000 cubic kilometers. That is equal to 30% of the Earth's Greenland ice sheet, or enough to cover the surface of Mars to a depth of 5.6 meters<ref>http://www.spaceref.com/news/viewpr.html?pid=29211 </ref> <ref>http://spaceref.com/onorbit/radar-map-of-buried-mars-layers-matches-climate-cycles.html</ref> <ref>https://mars.nasa.gov/news/371/radar-map-of-mars-layers-matches-climate-cycles/</ref><br />
<br />
==Origin of Names==<br />
<br />
Many of the names for features on Mars are based on old classical names. Most of these names came from the names given by the astronomer G. V.Schiaparelli. A more detailed discussion of the origin of Martian nomenclature can be found in [[How are features on Mars Named?]].<br />
<br />
[[File:Karte Mars Schiaparelli MKL1888.png |left|thumb|px| Early Schiaparelli map of Mars with many of the names we use today]]<br />
[[File:Mars Viking MDIM21 ClrMosaic global 1024labeled5.jpg|left|thumb|px| Image of Mars with most major features labeled This map can be freely used because it is in the public domain]]<br />
<br />
==Quadrangles==<br />
<br />
[[File:Marspediaquadrangleoutline.jpg|left|thumb|px|Map showing names and locations of quadrangles of Mars ]]<br />
One way of locating places on Mars is with [[Mars Quadrangles|quadrangles]]. The surface of Mars is divided into 30 areas. Each quadrangle has a number and a name. Detailed descriptions and many images from each quadrangle can be found on the [[Mars atlas Quadrangles|Quadrangles page]]<nowiki/>s.[[File:MGS MOC Wide Angle Map of Mars PIA03467.jpg|left|thumb|px|Picture of Mars with quadrangles indicated. Pictures are from Mariner 9 and Viking orbiter images]]<br />
<br />
==Mission Landing Sites==<br />
<br />
We have attempted to land on the Martian surface many times. There have been many failures. However, in recent years there have been some missions that have been highly successful. The Spirit and Opportunity Rovers were only expected to last for 3 months. Both lasted for many years. As of this writing (April 2018) Opportunity is still examining the planet. These twin rovers landed in January of 2004. It might go much longer, but the government is eager to shut them down. Curiosity Rover has sent back some great pictures and science. Some believe it will be working until people land on the planet.<br />
<br />
The following map shows the landing sites and the dates of successful and unsuccessful missions.<br />
[[File:Marspedialanders.png |Landing sites and the dates of successful and unsuccessful missions]]<br />
<br />
==Locations of ice==<br />
<br />
[[File:Icemaplargelabeled454arrows.jpg|600pxr|Locations of near surface Ice]]<br />
<br />
Locations of near surface Ice<ref>Sylvain Piqueux, Jennifer Buz, Christopher S. Edwards, Joshua L. Bandfield, Armin Kleinböhl, David M. Kass, Paul O. Hayne. Widespread Shallow Water Ice on Mars at High and Mid Latitudes. Geophysical Research Letters, 2019; DOI: 10.1029/2019GL083947 </ref><br />
<br />
<br />
Data gathered from spacecraft over many years has enable scientists to construct a map showing where ice may be found under a thin cover of sand. Places where ice is found under perhaps just centimeters of sand would be idea for future colonists. They could send robotic machines to gather ice which could provide water for settlements. Places where water-ice is found under a thin soli cover can be determined because of the properties of ice. If ice abundant ice is found just under the surface, the region will take longer to heat up in the spring and longer to cool down in the fall. Thermal inertia measurements gathered with the Mars Global Surveyor were used to generate a map of underground ice.<ref>https://www.hou.usra.edu/meetings/ninthmars2019/pdf/6027.pdf</ref> <ref>Piqeux, S. et al. 2019. WIDESPREAD SHALLOW WATER ICE ON MARS AT HIGH AND MID LATITUDES. Ninth International Conference on Mars 2019 (LPI Contrib. No. 2089). 6027.pdf.</ref> <br />
<br />
A later study used two heat-sensitive instruments: MRO's Mars Climate Sounder and the Thermal Emission Imaging System (THEMIS) camera on Mars Odyssey to produce similar results to those using thermal inertia measurements from the Mars Global Surveyor.<br />
<ref>https://phys.org/news/2019-12-nasa-treasure-ice-mars.html</ref> <ref>https://www.jpl.nasa.gov/news/news.php?feature=7557&utm_source=iContact&utm_medium=email&utm_campaign=nasajpl&utm_content=daily-20191210-2</ref><br />
<br />
[[File:Waterismeniuszoom.jpg|600pxr|Locations of ice]]<br />
Locations of ice<br />
<br />
==References:==<br />
{{Reflist|2}}<br />
<br />
==Further reading==<br />
<br />
*Baker, V.R. (1982). The Channels of Mars. Austin: Texas University Press.<br />
*Carr,M.H. (1979). "Formation of Martian flood features by release of water from confined aquifers". J. Geophys. Res., 84, 2995-3007.<br />
*Carr, M.H. (2006), The Surface of Mars. Cambridge Planetary Science Series, Cambridge University Press.<br />
*Robinson, M.S., and Takana, K.L. (1990), "Magnitude of a catastrophic flood event in Kasei Vallis, Mars". Geology, 18, 902-5.<br />
<br />
==See Also==<br />
<br />
*[[Aeolis quadrangle]]<br />
<br />
*[[Cebrenia quadrangle]]<br />
<br />
*[[Diacria quadrangle]]<br />
*[[Hellas Planitia]]<br />
*[[High Resolution Imaging Science Experiment (HiRISE)]]<br />
*[[How are features on Mars Named?]]<br />
*[[How living on Mars will be different than living on Earth]]<br />
*[[Lunae Palus quadrangle]]<br />
*[[Oxia Palus quadrangle]]<br />
*[[Tharsis]]<br />
*[[Valles Marineris]]<br />
<br />
*[[What Mars Actually Looks Like!]]<br />
<br />
==External links==<br />
<br />
*[https://www.youtube.com/watch?v=JgMXPXdqJn8&t=389s Cosmic Journeys - Mars: Earth that Never Was]<br />
<br />
*[https://en.wikipedia.org/wiki/Volcanology_of_Mars Volcanology of Mars]<br />
<br />
*[https://www.youtube.com/watch?v=RYG-HLr33CM Martian Geology - Jim Secosky - 16th Annual International Mars Society Convention]<br />
<br />
*[https://www.youtube.com/watch?v=_sUUKcZaTgA Jim Secosky - Martian Ice - 16th Annual International Mars Society Convention]<br />
<br />
[[Category:Areography]]</div>Multivachttps://marspedia.org/index.php?title=Biological_reactors&diff=136215Biological reactors2020-07-27T13:03:55Z<p>Multivac: /* Methanotrophs */</p>
<hr />
<div>[[Food]] and other products can be produced using industrial biological processes. This makes otherwise complex foods more accessible, it makes foods cheaper to produce and it simplifies the production of the industrial materials required for civilization.<br />
<br />
==Methanotrophs==<br />
Methanotrophs such as [https://en.wikipedia.org/wiki/Methylococcus_capsulatus Methylococcus capsulatus] can use methane and methanol as both a source of energy as well as a carbon source. Using a [[Sabatier_process|sabatier reactor]], nuclear power can be used to convert [[Atmospheric_mining|atmospheric]] CO<sub>2</sub> into food or other biomass. To grow, these methanotrophs also require Nitrogen, Sulfur, Phosphorous and various trace metals. Nitrogen can be captured from the martian atmosphere, by allowing the Methanotrophs to grow in an anoxic atmosphere<ref>https://doi.org/10.1099/00221287-129-11-3481</ref> and nitrogen fix for themselves, or through a Haber reactor on refined atmospheric nitrogen producing [[ammonia]]. Sulfur and phosphorous are accessible in the regolith and will be released through metal processing. Other trace metals are only needed in minute amounts to operate enzymes and are easily recycled. These microbes are currently used on earth to produce animal feed<ref>https://web.archive.org/web/20190802163733/https://www.ntva.no/wp-content/uploads/2014/01/04-huslid.pdf</ref><ref>https://www.newscientist.com/article/2112298-food-made-from-natural-gas-will-soon-feed-farm-animals-and-us/</ref>, and their use in human food production is an active area of [[Biotechnology|biotechnological]] research<ref>https://solarfoods.fi/</ref>. The growth yields of methanotrophs have been extensively studied<ref>https://www.frontiersin.org/articles/10.3389/fmicb.2018.02947/full</ref>, with [[Methanol]]/[[Nitrate]] feedstock with trace amounts of [[Copper]] shown as an optimal point, with lower yields but higher carbon conversion efficiencies than other feedstocks<ref>https://link.springer.com/article/10.1007/BF02346062</ref>. Colonies could potentially use Methanotrophs as a [[food|foodstuff]] utilizing [[Nuclear_power|nuclear power]] in the [[nuclear food cycle]], which may be considerably more compact or easier to deploy than [[greenhouse|greenhouses]] or other conventional [[farm|farming]] methods.<br />
<br />
==Grass to glucose==<br />
Traditional hydroponic farming is complex and labor intensive. In contrast, growing and harvesting large grasses such as ''Miscanthus Giganteus'' is simple to do in a large scale and automated way through [[cellulose]] farms. These grasses can then be broken down via cellulases to provide an accessible source of glucose, along with other industrially useful compounds such as THF (a common solvent)<ref>https://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.8b00134</ref>.<br />
<br />
==Syngas to biomass==<br />
[[Syngas]], produced through either recycling carbon containing compounds through [https://en.wikipedia.org/wiki/Pyrolysis pyrolysis] or directly from [[carbon_dioxide|CO<sub>2</sub>]] and [[water]], can be used to produce biomass. Organisms such as ''Clostridium carboxidivorans''<ref>https://doi.org/10.1099/ijs.0.63482-0</ref> can directly metabolize [[syngas]] as a source of energy and [[carbon]], forming industrially useful compounds such as [[ethanol]], [[acetic acid]] along with medium chain (C<sub>4</sub>/C<sub>6</sub>) fatty acids and alcohols<ref>https://www.nature.com/articles/s41598-017-10312-2</ref><ref>https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-016-0495-0</ref>. Alternatively, syngas can also be used to produce [[methanol]] or [[methane]] which can be fed to [[Biological_reactors#Methanotrophs|Methanotrophs]].<br />
<br />
==Xenotrophs==<br />
Some organisms, such as [https://microbewiki.kenyon.edu/index.php/Rhodopseudomonas|''Rhodopseudomonas palustris''] have a versatile metabolism, and so can consume a wide variety of chemicals both with and without sunlight in order to grow. It is capable of fixing both atmospheric CO<sub>2</sub> and N<sub>2</sub><ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940424/</ref>, and oxidising things as diverse as Iron<ref>https://www.nature.com/articles/ncomms4391</ref>, aromatic hydrocarbons or plant lignin<ref>https://en.wikipedia.org/wiki/Rhodopseudomonas_palustris</ref> as a source of energy. It has also been shown to be able to produce CH<sub>4</sub> with a modified nitrogenase when grown on acetate/carbonate and exposed to light<ref>https://www.pnas.org/content/pnas/113/36/10163.full.pdf</ref>.<br />
<br />
==Biomass to industrial chemicals==<br />
Using GM microbes, biomass can be digested directly into a series of usable products such as Ammonia, short chain hydrocarbons<ref>https://doi.org/10.1016/j.ymben.2014.02.007</ref>, Adipic acid (a precursor to nylon)<ref>https://doi.org/10.1021/bp010179x</ref>, Phenol (a precursor to plastics) <ref>https://doi.org/10.1002/1521-3757(20010518)113:10%3C1999::AID-ANGE1999%3E3.0.CO;2-A</ref>, or converted to Benzene/Xylene/Toluene via catalytic reforming<ref>https://doi.org/10.1016/j.biortech.2019.01.081</ref>. This allows for greatly simplified industrial chemistry through a mix of careful genetic engineering and choosing biologically accessible industrial precursors.<br />
<br />
==Biomass to engineered foods==<br />
Using genetically modified yeasts, it is also possible to directly produce proteins such as those found in eggs<ref>https://github.com/thethoughtemporium/Whose-gene-is-it-anyway/blob/master/milk-and-eggs/46815%20with%20ovalbumin%20and%20secretion%20tag.gb</ref> or milk<ref>https://github.com/thethoughtemporium/Whose-gene-is-it-anyway/blob/master/milk-and-eggs/4681%205deer%20milk%20b%20casein%20kcasein%20a%20lactalbumin%20and%20b%20lactoglobulin.gb</ref><ref>https://pubchem.ncbi.nlm.nih.gov/patent/US2017273328</ref>. It is also possible to produce various flavonoids, providing a variety of smells and flavors to artificially produced food. Vitimins and other essential nutrients can also be produced and added to ensure that foods are both tasty and nutritious.<br />
<br />
<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Nuclear_food_cycle&diff=136214Nuclear food cycle2020-07-27T12:48:37Z<p>Multivac: /* Further analysis */</p>
<hr />
<div>The nuclear [[food]] cycle is a hypothetical food cycle based upon [[Bioreactor#Methanotrophs|methanotrophs]] which are fed on [[methanol]] produced in [[Nuclear_power|nuclear]] powered [[Sabatier_process|sabatier]] reactors, which are in turn fed on [[syngas]] produced from nuclear powered Zinc/Sulfur/Iodine<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref> reactors. Another product produced by the Zn/S/I reactor is breathable [[oxygen|O<sub>2</sub>]]. This then forms a loop, where people eat the methanotrophs, producing [[Carbon_dioxide|CO<sub>2</sub>]] and [[Hydrogen|H<sub>2</sub>O]] through their metabolism, which are extracted via [[atmospheric processing]] and [[Potable_water_treatment|water recycling]], processed to produce [[methanol]] which is then fed back to the methanotrophs to grow more food.<br />
== Energy analysis ==<br />
This analysis assumes that nutrients ([[nitrogen]], [[sulfur]], [[phosphorus]], etc.) are entirely recycled, in practice due to imperfect recycling or colony growth, small amounts of additional nutrients would need to be added periodically from [[mining]], [[atmospheric processing]], etc.<br />
<br />
The growth yields of methanotrophs varies considerably<ref>http://methanotroph.org/wiki/performance-and-yield/</ref><ref>https://www.che.psu.edu/faculty/wood/group/publications/pdf/Assessing%20methanotrophy%20and%20carbon%20fixation%20M.%20a.%20Microb%20Cell%20Factor%202016%20Maranas.pdf</ref><ref>https://www.doi.org/10.1007/BF02346062</ref>, but somewhere around 10-40% of the methanol used ends up as cellular mass. Methanol has an energy density of 15.6 MJ/L and a density of 792g/L<ref>https://en.wikipedia.org/wiki/Methanol</ref>. That works out to be 20 KJ per gram of methanol. Taking 20% yield as an approximation, that leads to 100KJ/g of cell mass assuming the methanol production process is 100% efficient. <br />
<br />
From animal studies, the nutritional value of [https://en.wikipedia.org/wiki/Methylococcus_capsulatus|''Methylococcus capsulatus''] is 8.96 MJ/kg<ref>https://ec.europa.eu/food/sites/food/files/safety/docs/animal-feed_additives_rules_scan-old_report_other-23.pdf</ref>, making the cycle 8.9% efficient at converting thermal energy into nutritional energy.<br />
<br />
1kg of <sup>235</sup>U contains 8.64×10<sup>13</sup> joules of energy. The average adult needs approximately 8700kj/day. That means that 1kg uranium could be converted to approximately 850,000 person days of food. Assuming that a molten salt [[Nuclear_power|reactor]] that can almost completely consume its nuclear fuel is utilized. In other words, feeding a person using the nuclear food cycle requires approximately an extra 1kw<sub>th</sub> per person.<br />
<br />
== Further analysis ==<br />
* The actual growth media is going to be [[Waste_biomass_recycling|recycled biomass]], which may contain undigested food or more complex proteins that require additional energy for catabolism. <br />
* The actual efficiency of small [[Sabatier_process|sabatier]] or Zn/S/I reactors is currently unknown.<br />
* Radiotrophic fungi have been observed<ref>https://ddd.uab.cat/pub/tfg/2014/126266/TFG_danielantoniovazquezsanchez.pdf</ref>, which may be able to more directly exploit nuclear energy.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Food&diff=136213Food2020-07-27T12:37:18Z<p>Multivac: /* Local Production Methods */</p>
<hr />
<div>[[Image:raw_food_mix.jpg|thumb|right|300px|A mix of fresh raw vegetarian food.]] <br />
<br />
The amount of '''Food''' for [[human]] beings that can be brought from [[Earth]] to [[Mars]] is limited, and the logistics of a continued food transport for the long term is [[Financial effort estimation|expensive]]. By definition, an [[autonomous colony]] needs it's own food production. Reasons for this are cost reduction and the achievement of [[independence from Earth]]. Last but not least, locally produced food can be of higher quality and fresh, including a natural mix of [[vitamins]] and [[minerals and trace elements in food|minerals]].<br />
<br />
==Food requirements==<br />
An average human requires about 2,7 kg of food per day, or 985 kg per year. A good target might be one tonne of food per year per colonist, to account for losses. Plants are composed of edible parts and non edible parts. The non edible portion is counted as biomass, and can be used for industrial production or recycled into the food production system. On average, of the solid parts of plants (not water) about 50% of a plant is edible and the rest is biomass. The following table presents a suggested diet based on the Canadian Food Guide. <br />
<br />
{| class="wikitable"<br />
|'''Food, canadian food guide'''<br />
|'''Weight of'''<br />
<br />
'''food (gram)'''<br />
|'''kiloCalorie/kg'''<br />
|'''Calories'''<br />
per day<br />
|-<br />
|Fruit<br />
|500<br />
|500<br />
|250<br />
|-<br />
|Vegetables<br />
|750<br />
|300<br />
|225<br />
|-<br />
|Protein (meat and beans)<br />
|200<br />
|4 000<br />
|800<br />
|-<br />
|Dairy<br />
|750<br />
|420<br />
|315<br />
|-<br />
|Grains<br />
|240<br />
|2 100<br />
|504<br />
|-<br />
|Oils<br />
|40<br />
|5 000<br />
|200<br />
|-<br />
|'''Total'''<br />
|'''2 480'''<br />
|'''925'''<br />
|'''2 294'''<br />
|}<br />
Note: Calories as expressed in food guides and nutritional documents are actually kiloCalories. so the Calories of column 4 in this table are actually kiloCalories.<br />
<br />
==Food that can be brought from Earth==<br />
<br />
*Several varieties of dehydrated food.<br />
*Food that contains large amounts of fat and [[carbohydrate]]s, such as nuts and dried meats.<br />
*Concentrated fruit juice.<br />
*Lightweight, high energy foods with a long shelf-life.<br />
<br />
==Local Production Methods== <br />
<br />
*[[:category:plants|Vegetable]] can be grown in [[greenhouse]]s, grow rooms or on [[green wall|green walls]] in order to close the [[carbon cycle]].<br />
*[[Protein|Proteins]], fat and carbohydrates can be produced by a [[biotechnology|biotechnological factory]] also known as [[biological reactors]].<br />
*[[:category:animals|Animals]], such as chicken or [[fish]], may be raised in sections of greenhouses.<br />
*It takes 2000 to 3000 liters of [[water]] to produce 1 kg of meat, it takes 100 liters of water to grow 1 kg of grain. Water will be a very valuable commodity on Mars, so the first generation of settlers may well be vegetarian by necessity. This may be mitigated by water recycling.<br />
<br />
*Growing [[insects]] and their larvae (e.g. flour worms or [[flies|fly maggots]]) can provide valuable proteins and might consume mostly [[waste biomass recycling|waste biomass]]. Pigs might be a more palatable alternative, of fish.<br />
*[[Algae]] can produce large amount of food and oil. However, is is impossible to survive only on algae alone in the long term(reference needed).<br />
*Some food (possibly [[Genetic engineering|genetically modified]]) may be grown in the Martian atmosphere. Results from the Phoenix lander indicate that some vegetables may be grown in caves safe from radiation(ref needed).<br />
*The [[nuclear food cycle]] could produce food and [[oxygen]] using [[nuclear power]]<br />
<br />
==Nutrition and Energy Calculations==<br />
{| class="wikitable"<br />
|+Calorie calculation<br />
|<br />
|Unit<br />
|1 person<br />
|1000 persons<br />
|-<br />
|Human calorie intake<br />
|kilocalorie/day<br />
|2300<br />
|2300000<br />
|-<br />
|Days per year<br />
|<br />
|365<br />
|365<br />
|-<br />
|Energy per year<br />
|kiloca<br />
|839500<br />
|839,500,000<br />
|-<br />
|Yearly energy production<br />
|kilocal/m2<br />
|4700<br />
|4700<br />
|-<br />
|'''Area to feed humans'''<br />
|'''m2'''<br />
|'''179'''<br />
|'''178,617'''<br />
|}<br />
<br />
==Food and crop energy and yields==<br />
The following table has been compiled from various sources. The values are high but remain bellow record yields and are usually for open field intensive agriculture unless otherwise noted. Most of the energy in plants is stored in the form of [[carbohydrates]], that store about 4000 kilo-calories per kg.<br />
<br />
On Mars, these crops could be grown year round, with supplemental artificial lighting, no weather, extra CO2 concentration and optimum irrigation and fertilization. Some Yields might then be significantly higher.<br />
{| class="wikitable"<br />
|+Food and crop yields<br />
|'''Food type'''<br />
|<br />
|'''Tonnes'''<br />
'''/ha/y'''<br />
|'''kg'''<br />
'''/m2/y'''<br />
|'''kilocalorie'''<br />
'''/kg'''<br />
|'''kilocalorie'''<br />
'''/m2/y'''<br />
|'''Notes'''<br />
|-<br />
|Apples, pears<br />
|Australia<br />
|65<br />
|6.5<br />
|571<br />
|3714<br />
|<nowiki>https://www.goodfruit.com/calculate-target-yield/</nowiki><br />
|-<br />
|<br />
|Ontario<br />
|25<br />
|2.5<br />
|580<br />
|1450<br />
|<br />
|-<br />
|Oranges, citrus<br />
|Florida<br />
|130<br />
|13<br />
|470<br />
|6110<br />
|<nowiki>https://www.hort.purdue.edu/newcrop/morton/orange.html#Yield</nowiki><br />
|-<br />
|<br />
|Israel<br />
|50<br />
|5<br />
|470<br />
|2350<br />
|<nowiki>https://www.haifa-group.com/citrus-tree-fertilizer/crop-guide-growing-citrus-trees</nowiki><br />
|-<br />
|Banana<br />
|Puerto Rico<br />
|70<br />
|7<br />
|1000<br />
|7000<br />
|<nowiki>https://www.hort.purdue.edu/newcrop/morton/banana.html#Yield</nowiki><br />
|-<br />
|Strawberries<br />
|England<br />
|30<br />
|3<br />
|330<br />
|990<br />
|<nowiki>https://vegetablegrowersnews.com/article/tunnels-varieties-double-uk-berry-yields/</nowiki><br />
|-<br />
|<br />
|California<br />
|90<br />
|9.0<br />
|330<br />
|2970<br />
|Hydroponic <nowiki>https://cals.arizona.edu/strawberry/Hydroponic_Strawberry_Information_Website/Costs.html</nowiki><br />
|-<br />
|<br />
|Australia<br />
|150<br />
|15.0<br />
|330<br />
|4950<br />
|<nowiki>http://www.nuffieldinternational.org/rep_pdf/1450740021NickyMannFinalReport.pdf</nowiki><br />
|-<br />
|Dwarf fruit trees<br />
|California<br />
|72<br />
|7.2<br />
|<br />
|<br />
|<br />
|-<br />
|Potato<br />
|UK<br />
US<br />
|50<br />
70<br />
|5.0<br />
7<br />
|850<br />
|4250<br />
5950<br />
|<nowiki>https://potatoes.ahdb.org.uk/sites/default/files/GB%20Potatoes%202016-2017.pdf</nowiki><br />
These are for 1 crop per year, 120 days per crop. So it might be possible to reach 200 tonnes/ha for 3 crops per year in intensive agriculture. So 17 000 kilocalories/m2.<br />
|-<br />
|<br />
|Sweden<br />
|26 <ref>[http://www.scb.se/templates/pressinfo____220855.asp Press release from Statistics Sweden and Swedish Board of Agriculture]</ref><br />
|2.6<br />
|<br />
|<br />
|<br />
|-<br />
|Sweet potato<br />
|california<br />
|27<br />
|2.7<br />
|860<br />
|2346<br />
|<nowiki>https://ucanr.edu/repository/fileaccess.cfm?article=54045&p=%20MKCWZJ</nowiki><br />
|-<br />
|Tomatoes<br />
|<br />
|150<br />
|15.0<br />
|180<br />
|2700<br />
|<br />
|-<br />
|Water melon<br />
|<br />
|36<br />
|3.6<br />
|300<br />
|1071<br />
|<br />
|-<br />
|Cabbage<br />
|<br />
|90<br />
|9.0<br />
|250<br />
|2250<br />
|<nowiki>https://www.kzndard.gov.za/images/Documents/Horticulture/Veg_prod/expected_yields.pdf</nowiki><br />
|-<br />
|Beans<br />
|<br />
|20<br />
|2.0<br />
|3470<br />
|6940<br />
|Hydroponic : <nowiki>https://uponics.com/hydroponics-yield/</nowiki><br />
|-<br />
|watercress<br />
|<br />
|25<br />
|2.5<br />
|110<br />
|275<br />
|<nowiki>https://ipmdata.ipmcenters.org/documents/cropprofiles/HIwatercress.pdf</nowiki><br />
|-<br />
|Lettuce<br />
|hydroponic<ref>Comparison of Land, Water, and Energy Requirements of Lettuce Grown Using Hydroponic ''vs.'' Conventional Agricultural Methods<br />
Guilherme Lages Barbosa,1 Francisca Daiane Almeida Gadelha,1 Natalya Kublik,1 Alan Proctor,1 Lucas Reichelm,1 Emily Weissinger,1 Gregory M. Wohlleb,1 and Rolf U. Halden1,2,*</ref><br />
|400<br />
|40<br />
|150<br />
|6000<br />
|<br />
|-<br />
|<br />
|US<br />
|40<br />
|4<br />
|150<br />
|600<br />
|Typical field grown<br />
|-<br />
|Alfafla (luzerne)<br />
|Jordan<br />
|180<br />
40<br />
|18<br />
4<br />
|230<br />
290<br />
|4140<br />
1160<br />
|Hydroponic : https://www.hindawi.com/journals/isrn/2012/924672/<br />
Soil grown : https://wikifarmer.com/alfalfa-harvest-yield-per-acre/<br />
|-<br />
|canola<br />
|<br />
|3<br />
|0.3<br />
|8840 ?<br />
|2652<br />
|<br />
|-<br />
|Rice<br />
|China<br />
|17<br />
|1.7<br />
|1300<br />
|2210<br />
|<nowiki>http://www.xinhuanet.com//english/2017-10/16/c_136683786.htm</nowiki><br />
|-<br />
|Wheat<br />
|US-Europe<br />
|10<br />
|1.0<br />
|3400<br />
|3400<br />
|Two crops per year, summer and winter. Often another crop (oats, maize, barley) and wheat<br />
|-<br />
|<br />
|US<br />
|150<br />
|15<br />
|3400<br />
|50 000<br />
|Maximum theoretical, hydroponic in lab conditions, Bugbee_Monje_LimitsCropProductivity_BioScience_1992.pdf<br />
|-<br />
|<br />
|US<br />
|80<br />
|8<br />
|3400<br />
|27 000<br />
|NASA<ref>Continuous Hydroponic Wheat Production Using A Recirculating System C. L. Mackowiak L. P. Owens C. R. Hinkle The Bionetics Corporation, Kennedy Space Center, Florida</ref> This test cites the Bugbee study. Main difference is lower lighting levels. Doubling the lighting increases yields by about 80%.<br />
|-<br />
|<br />
|Canada<ref name=":0">https://ourworldindata.org/yields-and-land-use-in-agriculture</ref><br />
|5.9<br />
|<br />
|<br />
|<br />
|<br />
|-<br />
|<br />
|<br />
|6<ref>[http://www.ienica.net/reports/swedenupdate.pdf Report from State of Sweden]</ref><br />
|0.6<br />
|<br />
|<br />
|<br />
|-<br />
|Oats<br />
|<br />
|4.3<br />
|0.4<br />
|3890<br />
|1673<br />
|<br />
|-<br />
|<br />
|<br />
|3.2<br />
|<br />
|<br />
|<br />
|<br />
|-<br />
|Barley<br />
|<br />
|7<br />
|0.7<br />
|3540<br />
|2478<br />
|<br />
|-<br />
|soya<br />
|<br />
|3<br />
|0.3<br />
|4460<br />
|1338<br />
|<br />
|-<br />
|Corn<br />
|<br />
|12<br />
|1.2<br />
|960<br />
|1152<br />
|<br />
|-<br />
|Fodder Corn<br />
|Canada<ref name=":0" /><br />
|50<br />
|5<br />
|<br />
|<br />
|<br />
|-<br />
|Bamboo<ref>http://afribam.com/index.php?option=com_content&view=article&id=49:bamboo-for-plantations&catid=22&Itemid=116</ref><br />
|<br />
|4<br />
|<br />
|<br />
|<br />
|For wood type products<br />
|}<br />
Many of the higher yield in this table are the result of multiple crops per year.<br />
<br />
These a edible food crop yields. the actual biomass crop yields are about double these. Potatoes are about 80% edible yield while most plants are between 35% and 50%.<br />
<br />
==Meat production==<br />
Meat production may someday be artificial, but may for some time come from [[animals]]. Vegetable alternatives exist for meat, and usually require less energy for their production. Therefore producing meat may be a question of demand and opportunity, rather than a question of need. Animals can produce meat from unused biomass, but the demand for other uses may be higher than the demand for meat production. <br />
{| class="wikitable"<br />
|+Energy in meat and meat products and dairy products.<br />
|'''Food type'''<br />
|'''kg'''<br />
'''/m2'''<br />
|'''kilocalorie'''<br />
'''/kg'''<br />
|'''kilocalorie'''<br />
'''/m2'''<br />
|Notes<br />
|-<br />
|Meat<br />
|<br />
|5000<br />
|<br />
|<br />
|-<br />
|fat<br />
|<br />
|9000<br />
|<br />
|<br />
|-<br />
|protein<br />
|<br />
|4000<br />
|<br />
|<br />
|-<br />
|Salmon<br />
|<br />
|2080<br />
|<br />
|<br />
|-<br />
|Tilapia<br />
|<br />
|1290<br />
|<br />
|<br />
|-<br />
|chicken<br />
|<br />
|2390<br />
|<br />
|<br />
|-<br />
|milk<br />
|<br />
|420<br />
|<br />
|<br />
|-<br />
|Eggs<br />
|<br />
|1550<br />
|<br />
|<br />
|}<br />
[[w:Feed_conversion_ratio|Feed conversion ratio]] (FCR) is a measure of efficiency. It is the ratio between the mass of feed and the mass of product output. For dairy cows, for example, the output is milk, whereas in animals raised for meat (such as beef cows, pigs, chickens, and fish) the output is the flesh, that is, the body mass gained by the animal, represented either in the final mass of the animal or the mass of the dressed output (from Wikipedia). <br />
{| class="wikitable"<br />
|+<br />
Feed conversion ratios<br />
!Livestock<br />
!FCR<br />
!<br />
|-<br />
|Beef<br />
|4.5–7.5<br />
|calculated on live weight gain<ref>Beef production feed rate https://web.archive.org/web/20190805235813/https://lib.dr.iastate.edu/cgi/viewcontent.cgi?referer=https://en.wikipedia.org/&httpsredir=1&article=1027&context=driftlessconference</ref><br />
|-<br />
|Dairy<br />
|<br />
|<br />
|-<br />
|Pigs<br />
|3.8-4.5<br />
|About 1 for piglets, grows higher and higher with time<ref>Pig FCR<nowiki/>https://web.archive.org/web/20150917051750/http://www.pigprogress.net/Breeding/Sow-Feeding/2009/4/Taking-control-of-feed-conversion-ratio-PP005927W/</ref><br />
|-<br />
|Sheep<br />
|4-6, 40<br />
|4-6 on grain, 40<ref>Cronjé. P. B. and E. Weites. 1990. Live mass, carcass and wool growth responses to supplementation of a roughage diet with sources of protein and energy in South African Mutton Merino lambs. S. Afr. J. Anim. Sci. 20: 141-168</ref> on straw. This is an example of the difference between the production from high value food and the production<br />
from lower value biomass.<br />
|-<br />
|Poultry<br />
|1.6-2<br />
|A hen can lay up to 330 eggs per year. Maturation is about 40 days. <br />
Note than hens and many birds may require gravity for feeding/drinking, and transportation to Mars may be a problem.<ref>https://finchwench.wordpress.com/2011/09/06/cosmoquails/</ref><br />
|-<br />
|Criquets<br />
|0,9-1.0<br />
|Seems unlikely to be below 1....<ref>http://buglady.dk/wp-content/uploads/2015/02/van-Huis-2013-Potential-of-insects-as-food-and-feed.pdf</ref><br />
|-<br />
|Fish<br />
|1-1.5<br />
|Tilapia is 1<ref>https://web.archive.org/web/20151106233121/http://www2.ca.uky.edu/wkrec/TilapiaTankCulture.pdf</ref>. Salmon about 1,3<ref>http://www.fao.org/fishery/culturedspecies/Salmo_salar/en</ref>. Higher for fish to fish conversion, almost 4 in many piscicultures.<br />
|-<br />
|Rabbits<br />
|2.5-3<br />
|<br />
|}<br />
<br />
==Artificial food==<br />
There is no existing complete food than might be considered artificial. <br />
<br />
*See [[vitamins]] for the basic vitamin requirements that need to be obtained from food.<br />
*Industrial proteins and carbohydrates are not produced directly from base chemicals but require [[biological reactors]]. There are a number of experiments being done to produce artificial food from the output of biological reactors, but these have not, to this time(2019), been proven to be more economical that naturally produced food.<br />
*[[w:Beyond_Meat|Beyond meat]], a vegetable meat substitute, may be considered as artificial in some ways, but is more a modified food. Entirely vegetarian diets are possible.<br />
*[[In-vitro meat]] is possible, but requires large amounts of energy for its production. Modified vegetables, such as Beyond Meat might produce a better substitute.<br />
<br />
==See also==<br />
<br />
*[[Food preservation]]<br />
<br />
==References==<br />
<references /><br />
<br />
[[Category: Agriculture]]</div>Multivachttps://marspedia.org/index.php?title=Nuclear_food_cycle&diff=136212Nuclear food cycle2020-07-27T12:36:05Z<p>Multivac: Created page with "The nuclear food cycle is a hypothetical food cycle based upon methanotrophs which are fed on methanol produced in Nuclear_power|nuclear..."</p>
<hr />
<div>The nuclear [[food]] cycle is a hypothetical food cycle based upon [[Bioreactor#Methanotrophs|methanotrophs]] which are fed on [[methanol]] produced in [[Nuclear_power|nuclear]] powered [[Sabatier_process|sabatier]] reactors, which are in turn fed on [[syngas]] produced from nuclear powered Zinc/Sulfur/Iodine<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref> reactors. Another product produced by the Zn/S/I reactor is breathable [[oxygen|O<sub>2</sub>]]. This then forms a loop, where people eat the methanotrophs, producing [[Carbon_dioxide|CO<sub>2</sub>]] and [[Hydrogen|H<sub>2</sub>O]] through their metabolism, which are extracted via [[atmospheric processing]] and [[Potable_water_treatment|water recycling]], processed to produce [[methanol]] which is then fed back to the methanotrophs to grow more food.<br />
== Energy analysis ==<br />
This analysis assumes that nutrients ([[nitrogen]], [[sulfur]], [[phosphorus]], etc.) are entirely recycled, in practice due to imperfect recycling or colony growth, small amounts of additional nutrients would need to be added periodically from [[mining]], [[atmospheric processing]], etc.<br />
<br />
The growth yields of methanotrophs varies considerably<ref>http://methanotroph.org/wiki/performance-and-yield/</ref><ref>https://www.che.psu.edu/faculty/wood/group/publications/pdf/Assessing%20methanotrophy%20and%20carbon%20fixation%20M.%20a.%20Microb%20Cell%20Factor%202016%20Maranas.pdf</ref><ref>https://www.doi.org/10.1007/BF02346062</ref>, but somewhere around 10-40% of the methanol used ends up as cellular mass. Methanol has an energy density of 15.6 MJ/L and a density of 792g/L<ref>https://en.wikipedia.org/wiki/Methanol</ref>. That works out to be 20 KJ per gram of methanol. Taking 20% yield as an approximation, that leads to 100KJ/g of cell mass assuming the methanol production process is 100% efficient. <br />
<br />
From animal studies, the nutritional value of [https://en.wikipedia.org/wiki/Methylococcus_capsulatus|''Methylococcus capsulatus''] is 8.96 MJ/kg<ref>https://ec.europa.eu/food/sites/food/files/safety/docs/animal-feed_additives_rules_scan-old_report_other-23.pdf</ref>, making the cycle 8.9% efficient at converting thermal energy into nutritional energy.<br />
<br />
1kg of <sup>235</sup>U contains 8.64×10<sup>13</sup> joules of energy. The average adult needs approximately 8700kj/day. That means that 1kg uranium could be converted to approximately 850,000 person days of food. Assuming that a molten salt [[Nuclear_power|reactor]] that can almost completely consume its nuclear fuel is utilized. In other words, feeding a person using the nuclear food cycle requires approximately an extra 1kw<sub>th</sub> per person.<br />
<br />
== Further analysis ==<br />
* The actual growth media is going to be [[Waste_biomass_recycling|recycled biomass]], which may contain undigested food or more complex proteins that require additional energy for catabolism. <br />
* The actual efficiency of small [[Sabatier_process|sabatier]] or Zn/S/I reactors is currently unknown<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Helium&diff=136211Helium2020-07-27T09:56:14Z<p>Multivac: Created page with "Helium is a noble gas. It can be ionized and used as fuel for an ion drive, as well as a coolant for high temperature gas core Nuclear_power|nuclear rea..."</p>
<hr />
<div>[[Helium]] is a noble gas. It can be ionized and used as fuel for an [[Ion_thruster|ion drive]], as well as a coolant for high temperature gas core [[Nuclear_power|nuclear reactors]] and as a cryogenic coolant.<br />
<br />
{{stub}}</div>Multivachttps://marspedia.org/index.php?title=Nuclear_thermal_propulsion&diff=136210Nuclear thermal propulsion2020-07-27T09:51:32Z<p>Multivac: </p>
<hr />
<div>Nuclear thermal propulsion uses a nuclear core to heat a propellant and provide propulsion to a space vehicle.<br />
<br />
Liquid hydrogen is usually used as the propellant as it has a higher velocity for the same input power, and therefore produces a faster final velocity according to the [[Propulsion|rocket equation]]. An animated illustration of nuclear thermal rockets can be found at <ref>https://www.youtube.com/watch?v=3aBOhC1c6m8</ref>.<br />
<br />
__NOTOC__<br />
==History of nuclear thermal propulsion==<br />
<br />
===American===<br />
Nerva<ref>Nerva on Wikipedia: https://en.wikipedia.org/wiki/NERVA</ref> <br />
{| class="wikitable"<br />
!Propellant<br />
|Liquid hydrogen<br />
|-<br />
! colspan="2" |Performance<br />
|-<br />
!Thrust (vac.)<br />
|246,663 N (55,452 lb<sub>f</sub>) <br />
|-<br />
!Chamber pressure<br />
|3,861 kPa (560.0 psi)<br />
|-<br />
!''I''<sub>sp</sub> (vac.)<br />
|841 seconds (8.25 km/s)<br />
|-<br />
!''I''<sub>sp</sub> (SL)<br />
|710 seconds (7.0 km/s)<br />
|-<br />
!Burn time<br />
|1,680 seconds<br />
|-<br />
!Thrust to weigh ratio<br />
!1.36<br />
|-<br />
!Restarts<br />
|24<br />
|-<br />
! colspan="2" |Dimensions<br />
|-<br />
!Length<br />
|6.9 meters (23 ft)<br />
|-<br />
!Diameter<br />
|2.59 meters (8 ft 6 in)<br />
|-<br />
!Dry weight<br />
|18,144 kilograms (40,001 lb)<br />
|}<br />
<br />
*<br />
<br />
*<br />
<br />
===Russian===<br />
<br />
==Analysis of use==<br />
<br />
===Advantages===<br />
<br />
*Higher ISP than chemical<br />
*Higher power energy source<br />
*Shorter travel time<br />
*Oberth effect<br />
*Self cooling<br />
<br />
===Disadvantages===<br />
<br />
*Cost<br />
*Cost of development<br />
*Risk of accident<br />
*Lower ISP than electric<br />
*Low public trust<br />
*Thrust to weight ratio close to 1 (cannot take off from Earth with a significant payload)<br />
<br />
===Types===<br />
<br />
*Solid core<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960001947.pdf</ref><br />
*Gas core<ref>https://deepblue.lib.umich.edu/bitstream/handle/2027.42/87734/585_1.pdf</ref><br />
*Nuclear light bulb, open and closed<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690014077.pdf</ref><br />
*Nuclear salt water rockets<ref>http://www.path-2.narod.ru/design/base_e/nswr.pdf</ref><br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Nuclear_thermal_propulsion&diff=136209Nuclear thermal propulsion2020-07-27T09:50:17Z<p>Multivac: /* Types */</p>
<hr />
<div>Nuclear thermal propulsion uses a nuclear core to heat a propellant and provide propulsion to a space vehicle.<br />
<br />
Liquid hydrogen is usually used as the propellant as it has a higher velocity for the same input power, and therefore produces a faster final velocity according to the [[Propulsion|rocket equation]].<br />
<br />
__NOTOC__<br />
==History of nuclear thermal propulsion==<br />
<br />
===American===<br />
Nerva<ref>Nerva on Wikipedia: https://en.wikipedia.org/wiki/NERVA</ref> <br />
{| class="wikitable"<br />
!Propellant<br />
|Liquid hydrogen<br />
|-<br />
! colspan="2" |Performance<br />
|-<br />
!Thrust (vac.)<br />
|246,663 N (55,452 lb<sub>f</sub>) <br />
|-<br />
!Chamber pressure<br />
|3,861 kPa (560.0 psi)<br />
|-<br />
!''I''<sub>sp</sub> (vac.)<br />
|841 seconds (8.25 km/s)<br />
|-<br />
!''I''<sub>sp</sub> (SL)<br />
|710 seconds (7.0 km/s)<br />
|-<br />
!Burn time<br />
|1,680 seconds<br />
|-<br />
!Thrust to weigh ratio<br />
!1.36<br />
|-<br />
!Restarts<br />
|24<br />
|-<br />
! colspan="2" |Dimensions<br />
|-<br />
!Length<br />
|6.9 meters (23 ft)<br />
|-<br />
!Diameter<br />
|2.59 meters (8 ft 6 in)<br />
|-<br />
!Dry weight<br />
|18,144 kilograms (40,001 lb)<br />
|}<br />
<br />
*<br />
<br />
*<br />
<br />
===Russian===<br />
<br />
==Analysis of use==<br />
<br />
===Advantages===<br />
<br />
*Higher ISP than chemical<br />
*Higher power energy source<br />
*Shorter travel time<br />
*Oberth effect<br />
*Self cooling<br />
<br />
===Disadvantages===<br />
<br />
*Cost<br />
*Cost of development<br />
*Risk of accident<br />
*Lower ISP than electric<br />
*Low public trust<br />
*Thrust to weight ratio close to 1 (cannot take off from Earth with a significant payload)<br />
<br />
===Types===<br />
<br />
*Solid core<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960001947.pdf</ref><br />
*Gas core<ref>https://deepblue.lib.umich.edu/bitstream/handle/2027.42/87734/585_1.pdf</ref><br />
*Nuclear light bulb, open and closed<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690014077.pdf</ref><br />
*Nuclear salt water rockets<ref>http://www.path-2.narod.ru/design/base_e/nswr.pdf</ref><br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Nuclear_thermal_propulsion&diff=136208Nuclear thermal propulsion2020-07-27T09:47:35Z<p>Multivac: /* Types */</p>
<hr />
<div>Nuclear thermal propulsion uses a nuclear core to heat a propellant and provide propulsion to a space vehicle.<br />
<br />
Liquid hydrogen is usually used as the propellant as it has a higher velocity for the same input power, and therefore produces a faster final velocity according to the [[Propulsion|rocket equation]].<br />
<br />
__NOTOC__<br />
==History of nuclear thermal propulsion==<br />
<br />
===American===<br />
Nerva<ref>Nerva on Wikipedia: https://en.wikipedia.org/wiki/NERVA</ref> <br />
{| class="wikitable"<br />
!Propellant<br />
|Liquid hydrogen<br />
|-<br />
! colspan="2" |Performance<br />
|-<br />
!Thrust (vac.)<br />
|246,663 N (55,452 lb<sub>f</sub>) <br />
|-<br />
!Chamber pressure<br />
|3,861 kPa (560.0 psi)<br />
|-<br />
!''I''<sub>sp</sub> (vac.)<br />
|841 seconds (8.25 km/s)<br />
|-<br />
!''I''<sub>sp</sub> (SL)<br />
|710 seconds (7.0 km/s)<br />
|-<br />
!Burn time<br />
|1,680 seconds<br />
|-<br />
!Thrust to weigh ratio<br />
!1.36<br />
|-<br />
!Restarts<br />
|24<br />
|-<br />
! colspan="2" |Dimensions<br />
|-<br />
!Length<br />
|6.9 meters (23 ft)<br />
|-<br />
!Diameter<br />
|2.59 meters (8 ft 6 in)<br />
|-<br />
!Dry weight<br />
|18,144 kilograms (40,001 lb)<br />
|}<br />
<br />
*<br />
<br />
*<br />
<br />
===Russian===<br />
<br />
==Analysis of use==<br />
<br />
===Advantages===<br />
<br />
*Higher ISP than chemical<br />
*Higher power energy source<br />
*Shorter travel time<br />
*Oberth effect<br />
*Self cooling<br />
<br />
===Disadvantages===<br />
<br />
*Cost<br />
*Cost of development<br />
*Risk of accident<br />
*Lower ISP than electric<br />
*Low public trust<br />
*Thrust to weight ratio close to 1 (cannot take off from Earth with a significant payload)<br />
<br />
===Types===<br />
<br />
*Solid core<br />
*Gas core<ref>https://deepblue.lib.umich.edu/bitstream/handle/2027.42/87734/585_1.pdf</ref><br />
*Nuclear light bulb, open and closed<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690014077.pdf</ref><br />
*Nuclear salt water rockets<ref>http://www.path-2.narod.ru/design/base_e/nswr.pdf</ref><br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Nuclear_thermal_propulsion&diff=136207Nuclear thermal propulsion2020-07-27T09:44:10Z<p>Multivac: /* Types */</p>
<hr />
<div>Nuclear thermal propulsion uses a nuclear core to heat a propellant and provide propulsion to a space vehicle.<br />
<br />
Liquid hydrogen is usually used as the propellant as it has a higher velocity for the same input power, and therefore produces a faster final velocity according to the [[Propulsion|rocket equation]].<br />
<br />
__NOTOC__<br />
==History of nuclear thermal propulsion==<br />
<br />
===American===<br />
Nerva<ref>Nerva on Wikipedia: https://en.wikipedia.org/wiki/NERVA</ref> <br />
{| class="wikitable"<br />
!Propellant<br />
|Liquid hydrogen<br />
|-<br />
! colspan="2" |Performance<br />
|-<br />
!Thrust (vac.)<br />
|246,663 N (55,452 lb<sub>f</sub>) <br />
|-<br />
!Chamber pressure<br />
|3,861 kPa (560.0 psi)<br />
|-<br />
!''I''<sub>sp</sub> (vac.)<br />
|841 seconds (8.25 km/s)<br />
|-<br />
!''I''<sub>sp</sub> (SL)<br />
|710 seconds (7.0 km/s)<br />
|-<br />
!Burn time<br />
|1,680 seconds<br />
|-<br />
!Thrust to weigh ratio<br />
!1.36<br />
|-<br />
!Restarts<br />
|24<br />
|-<br />
! colspan="2" |Dimensions<br />
|-<br />
!Length<br />
|6.9 meters (23 ft)<br />
|-<br />
!Diameter<br />
|2.59 meters (8 ft 6 in)<br />
|-<br />
!Dry weight<br />
|18,144 kilograms (40,001 lb)<br />
|}<br />
<br />
*<br />
<br />
*<br />
<br />
===Russian===<br />
<br />
==Analysis of use==<br />
<br />
===Advantages===<br />
<br />
*Higher ISP than chemical<br />
*Higher power energy source<br />
*Shorter travel time<br />
*Oberth effect<br />
*Self cooling<br />
<br />
===Disadvantages===<br />
<br />
*Cost<br />
*Cost of development<br />
*Risk of accident<br />
*Lower ISP than electric<br />
*Low public trust<br />
*Thrust to weight ratio close to 1 (cannot take off from Earth with a significant payload)<br />
<br />
===Types===<br />
<br />
*Solid core<br />
*Gas core<br />
*Nuclear light bulb, open and closed<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690014077.pdf</ref><br />
*Nuclear salt water rockets<ref>http://www.path-2.narod.ru/design/base_e/nswr.pdf</ref><br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Nuclear_thermal_propulsion&diff=136206Nuclear thermal propulsion2020-07-27T09:42:58Z<p>Multivac: /* Types */</p>
<hr />
<div>Nuclear thermal propulsion uses a nuclear core to heat a propellant and provide propulsion to a space vehicle.<br />
<br />
Liquid hydrogen is usually used as the propellant as it has a higher velocity for the same input power, and therefore produces a faster final velocity according to the [[Propulsion|rocket equation]].<br />
<br />
__NOTOC__<br />
==History of nuclear thermal propulsion==<br />
<br />
===American===<br />
Nerva<ref>Nerva on Wikipedia: https://en.wikipedia.org/wiki/NERVA</ref> <br />
{| class="wikitable"<br />
!Propellant<br />
|Liquid hydrogen<br />
|-<br />
! colspan="2" |Performance<br />
|-<br />
!Thrust (vac.)<br />
|246,663 N (55,452 lb<sub>f</sub>) <br />
|-<br />
!Chamber pressure<br />
|3,861 kPa (560.0 psi)<br />
|-<br />
!''I''<sub>sp</sub> (vac.)<br />
|841 seconds (8.25 km/s)<br />
|-<br />
!''I''<sub>sp</sub> (SL)<br />
|710 seconds (7.0 km/s)<br />
|-<br />
!Burn time<br />
|1,680 seconds<br />
|-<br />
!Thrust to weigh ratio<br />
!1.36<br />
|-<br />
!Restarts<br />
|24<br />
|-<br />
! colspan="2" |Dimensions<br />
|-<br />
!Length<br />
|6.9 meters (23 ft)<br />
|-<br />
!Diameter<br />
|2.59 meters (8 ft 6 in)<br />
|-<br />
!Dry weight<br />
|18,144 kilograms (40,001 lb)<br />
|}<br />
<br />
*<br />
<br />
*<br />
<br />
===Russian===<br />
<br />
==Analysis of use==<br />
<br />
===Advantages===<br />
<br />
*Higher ISP than chemical<br />
*Higher power energy source<br />
*Shorter travel time<br />
*Oberth effect<br />
*Self cooling<br />
<br />
===Disadvantages===<br />
<br />
*Cost<br />
*Cost of development<br />
*Risk of accident<br />
*Lower ISP than electric<br />
*Low public trust<br />
*Thrust to weight ratio close to 1 (cannot take off from Earth with a significant payload)<br />
<br />
===Types===<br />
<br />
*Solid core<br />
*Gas core<br />
*Nuclear light bulb, open and closed<br />
*Nuclear salt water rockets<ref>http://www.path-2.narod.ru/design/base_e/nswr.pdf</ref><br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ammonia&diff=136205Ammonia2020-07-27T09:29:20Z<p>Multivac: </p>
<hr />
<div>'''Ammonia''' is a chemical compound composing of one [[nitrogen]] atom and three [[hydrogen]] atoms NH<sub>3</sub>. Ammonia is foul smelling and is toxic to humans. However, ammonia is often used as an artificial [[fertilizer]] for plants to provide [[nitrogen]]. Ammonia could be used as a coolant or refrigerant and is useful in industry. Ammonia can be [[Waste biomass recycling|generated]] from human and animal waste, but first, the Nitrogen needs to be extracted from the Martian atmosphere by [[atmospheric processing]].<br />
<br />
== Production ==<br />
* Ammonia can be created through nitrogen fixing microbes in [[greenhouse|greenhouses]] and [[photobioreactor|photobioreactors]], as well as some [[Bioreactor#Methanotrophs|methanotrophs]].<br />
* Ammonia can be created industrially by combining [[nitrogen]] with [[hydrogen]] in an optimized low pressure<ref>https://www.ammoniaenergy.org/wp-content/uploads/2019/11/20191112.1043-Ammonia-Talk-NH3-Fuel.pdf</ref> low temperature <ref>https://www.ammoniaenergy.org/wp-content/uploads/2019/08/20191114.0826-AIChE_CSM_Final.pdf</ref> [https://en.wikipedia.org/wiki/Haber_process Haber reactor].<br />
* Ammonia can be produced from protein and other biomass using microbes<ref>https://doi.org/10.1016/j.ymben.2014.02.007</ref><br />
<br />
== Uses ==<br />
* It can be a non cryogenic storage of [[hydrogen]] as it can be split through catalytic decomposition<ref>https://pubs.acs.org/doi/pdfplus/10.1021/ja5042836</ref>.<br />
* It can be used as [[fertilizer]], or can be used to produce [[urea]] and other more effective fertilizers.<br />
* It can be used as a feedstock in industrial chemistry<br />
<br />
<br />
[[Category:Materials]]<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Nitrogen&diff=136204Nitrogen2020-07-27T09:19:08Z<p>Multivac: /* Uses */</p>
<hr />
<div>{{element|elementName=Nitrogen|elementSymbol=N|protons=7|abundance=2.7%}} <br />
'''Nitrogen''' (''chemical symbol: N, molecule'' N<sub>2</sub>) is the most abundant atmospheric element in the [[Earth]]'s atmosphere, making up 78% of the total atmospheric gas. [[Mars]], however, has less nitrogen in it's [[atmosphere]], only 3% of the total atmospheric gas. This relative scarcity of nitrogen will cause an expense for colonists on Mars as the existing atmosphere must be processed to separate out [[Carbon_dioxide|CO<sub>2</sub>]]. As the CO<sub>2</sub> is required for propellant production, the concentration of Nitrogen to breathable levels becomes part of the propellant production cycle. <br />
<br />
Producing [[In-situ resource utilization|in-situ]] nitrogen from the martian atmosphere by [[atmospheric processing]] will be an important process for a martian settlement. For a stand-alone nitrogen production process, where the nitrogen is separated by cooling, the cooling needed to liquefy the carbon dioxide is mainly provided by evaporating the liquid carbon dioxide after the nitrogen has been removed. Likewise the power for compressing the carbon dioxide is partially provided by expanding the output waste through a turbine with a common shaft with the compressor. Some energy is required to offset system losses and the Carnot cycle is not perfectly reversible. However, for a system that also compressed the atmosphere to produce CO<sub>2</sub> for propellant production, the energy to compress the CO2 will not be available. <br />
<br />
<br />
The "[[nitrogen cycle]]" is an essential terrestrial process that produces organic compounds intrinsic to life on Earth. "Fixing" by [[lightning]] strikes or [[bacteria|bacterial]] processes combine atmospheric nitrogen with other elements (such as hydrogen, producing [[ammonia]]) producing organic compounds required for plants ([[fertilizer|sustaining growth]] and used in [[photosynthesis]]), thereby supporting [[ecosystem]]s. Nitrogen can be found in [[amino acids]], proteins and DNA, making it an essential component of life as we know it. <br />
<br />
==Storage== <br />
Nitrogen from [[atmospheric processing]] will probably be used immediately to create the settlement atmosphere. If any excess nitrogen is produced it can be stored in some form of containment, or pressure vessel. The boiling point of nitrogen is -195.79 °C at atmospheric pressure. Unless the nitrogen is actively cooled by a refrigeration system, it will eventually heat up to ambient temperatures and the pressure will increase. If the nitrogen is obtained though CO<sub>2</sub> compression to 520 kPa (about 5 atmosphere, or 75 psi) it can remain a liquid if cooled to about -170°C. To keep the nitrogen liquid at a room temperature of 23°C requires a pressure of about 1500 kPa (220 psi). This can be easily maintained in small pressure vessels but requires extremely strong and heavy vessels in large volumes. <br />
<br />
It is likely that all the nitrogen obtain through atmospheric processing will become part of the colony atmosphere, at least in the early stages. So large scale storage is not an immediate problem. In all cases nitrogen can be stored at lower pressures when cooled bellow ambient temperatures. However, a refrigeration system is required to do this. If there is sufficient insulation, the heat gain can be quite small and the refrigeration system will also be minimum. <br />
<br />
The surface temperature of Mars aids for refrigeration as the average global temperature is approximately -63&deg;C. So the storage location for liquid nitrogen would not be inside [[settlement|habitats]] (where the average temperature should be as close to 23 &deg;C as possible), but outside, on the cooler surface. Or preferably underground in pressure vessels. '''''{{PersPosSection}} [[User:Ioneill|Ioneill]]'''''<br />
<br />
==Uses== <br />
<br />
*[[Air|Settlement atmosphere]] (main usage).<br />
*Fertilizer, when combined with [[hydrogen]] to form [[ammonia]] or [[urea]] as part of the nitrogen cycle.<br />
**Nitrogen is an essential element of all the amino acids in plant structures which are the building blocks of plant proteins, important in the growth and development of vital plant tissues and cells like the cell membranes and chlorophyll.<br />
**Nitrogen is a component of nucleic acid that forms DNA a genetic material significant in the transfer of certain crop traits and characteristics that aid in plant survival. It also helps hold the genetic code in the plant nucleus.<br />
**Chlorophyll being an organelle essential for carbohydrate formation by photosynthesis and a substance that gives the plant their green color, nitrogen is a component in it that aids in enhancing these features.<br />
**Nitrogen is essential in plant processes such as photosynthesis. Thus, plants with sufficient nitrogen will experience high rates of photosynthesis and typically exhibit vigorous plant growth and development.<br />
*Inert gas for certain industrial processes.<br />
*Explosives component (nitrates).<br />
*May be used to [[funeral|prepare dead bodies]] prior to disposal. Freezing bodies with liquid nitrogen and then powdering the remains (through vibration) may be a viable means to reuse valuable biomass (in [[greenhouse]]s etc.).<br />
<br />
==External links== <br />
<br />
*[http://en.wikipedia.org/wiki/Nitrogen_cycle The nitrogen cycle on Wikipedia.] <br />
<br />
[[category:Air]]</div>Multivachttps://marspedia.org/index.php?title=Nitrogen&diff=136203Nitrogen2020-07-27T09:18:29Z<p>Multivac: </p>
<hr />
<div>{{element|elementName=Nitrogen|elementSymbol=N|protons=7|abundance=2.7%}} <br />
'''Nitrogen''' (''chemical symbol: N, molecule'' N<sub>2</sub>) is the most abundant atmospheric element in the [[Earth]]'s atmosphere, making up 78% of the total atmospheric gas. [[Mars]], however, has less nitrogen in it's [[atmosphere]], only 3% of the total atmospheric gas. This relative scarcity of nitrogen will cause an expense for colonists on Mars as the existing atmosphere must be processed to separate out [[Carbon_dioxide|CO<sub>2</sub>]]. As the CO<sub>2</sub> is required for propellant production, the concentration of Nitrogen to breathable levels becomes part of the propellant production cycle. <br />
<br />
Producing [[In-situ resource utilization|in-situ]] nitrogen from the martian atmosphere by [[atmospheric processing]] will be an important process for a martian settlement. For a stand-alone nitrogen production process, where the nitrogen is separated by cooling, the cooling needed to liquefy the carbon dioxide is mainly provided by evaporating the liquid carbon dioxide after the nitrogen has been removed. Likewise the power for compressing the carbon dioxide is partially provided by expanding the output waste through a turbine with a common shaft with the compressor. Some energy is required to offset system losses and the Carnot cycle is not perfectly reversible. However, for a system that also compressed the atmosphere to produce CO<sub>2</sub> for propellant production, the energy to compress the CO2 will not be available. <br />
<br />
<br />
The "[[nitrogen cycle]]" is an essential terrestrial process that produces organic compounds intrinsic to life on Earth. "Fixing" by [[lightning]] strikes or [[bacteria|bacterial]] processes combine atmospheric nitrogen with other elements (such as hydrogen, producing [[ammonia]]) producing organic compounds required for plants ([[fertilizer|sustaining growth]] and used in [[photosynthesis]]), thereby supporting [[ecosystem]]s. Nitrogen can be found in [[amino acids]], proteins and DNA, making it an essential component of life as we know it. <br />
<br />
==Storage== <br />
Nitrogen from [[atmospheric processing]] will probably be used immediately to create the settlement atmosphere. If any excess nitrogen is produced it can be stored in some form of containment, or pressure vessel. The boiling point of nitrogen is -195.79 °C at atmospheric pressure. Unless the nitrogen is actively cooled by a refrigeration system, it will eventually heat up to ambient temperatures and the pressure will increase. If the nitrogen is obtained though CO<sub>2</sub> compression to 520 kPa (about 5 atmosphere, or 75 psi) it can remain a liquid if cooled to about -170°C. To keep the nitrogen liquid at a room temperature of 23°C requires a pressure of about 1500 kPa (220 psi). This can be easily maintained in small pressure vessels but requires extremely strong and heavy vessels in large volumes. <br />
<br />
It is likely that all the nitrogen obtain through atmospheric processing will become part of the colony atmosphere, at least in the early stages. So large scale storage is not an immediate problem. In all cases nitrogen can be stored at lower pressures when cooled bellow ambient temperatures. However, a refrigeration system is required to do this. If there is sufficient insulation, the heat gain can be quite small and the refrigeration system will also be minimum. <br />
<br />
The surface temperature of Mars aids for refrigeration as the average global temperature is approximately -63&deg;C. So the storage location for liquid nitrogen would not be inside [[settlement|habitats]] (where the average temperature should be as close to 23 &deg;C as possible), but outside, on the cooler surface. Or preferably underground in pressure vessels. '''''{{PersPosSection}} [[User:Ioneill|Ioneill]]'''''<br />
<br />
==Uses== <br />
<br />
*[[Air|Settlement atmosphere]] (main usage).<br />
*Fertilizer, when transformed into ammonia as part of the nitrogen cycle.<br />
**Nitrogen is an essential element of all the amino acids in plant structures which are the building blocks of plant proteins, important in the growth and development of vital plant tissues and cells like the cell membranes and chlorophyll.<br />
**Nitrogen is a component of nucleic acid that forms DNA a genetic material significant in the transfer of certain crop traits and characteristics that aid in plant survival. It also helps hold the genetic code in the plant nucleus.<br />
**Chlorophyll being an organelle essential for carbohydrate formation by photosynthesis and a substance that gives the plant their green color, nitrogen is a component in it that aids in enhancing these features.<br />
**Nitrogen is essential in plant processes such as photosynthesis. Thus, plants with sufficient nitrogen will experience high rates of photosynthesis and typically exhibit vigorous plant growth and development.<br />
*Inert gas for certain industrial processes.<br />
*Explosives component (nitrates).<br />
*May be used to [[funeral|prepare dead bodies]] prior to disposal. Freezing bodies with liquid nitrogen and then powdering the remains (through vibration) may be a viable means to reuse valuable biomass (in [[greenhouse]]s etc.).<br />
<br />
==External links== <br />
<br />
*[http://en.wikipedia.org/wiki/Nitrogen_cycle The nitrogen cycle on Wikipedia.] <br />
<br />
[[category:Air]]</div>Multivachttps://marspedia.org/index.php?title=Hydrogen&diff=136202Hydrogen2020-07-27T09:16:52Z<p>Multivac: /* Use */</p>
<hr />
<div>{{element<br />
|float=right<br />
|elementName=Hydrogen<br />
|elementSymbol=H<br />
|protons=1<br />
|abundance=0.03% (as [[water|H<sub>2</sub>O]])<br />
}}<br />
<br />
'''Hydrogen''' (''periodic table symbol:'' H<sup>1</sup>) is a chemical element that can be found in the [[atmosphere]] and in frozen [[water]] on [[Mars]].<br />
<br />
Liquid hydrogen has a density of 70 kg/m3. Gaseous hydrogen at standard atmospheric pressure and temperature has a density of 0,089 kg/m3.<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and [[microbes]] depends on water, composed of hydrogen and [[oxygen]]. The human body contains about 70% water. Human beings need about 2 liters water per day for drinking, hard working people need even more. Some organisms, [[Bioreactor#Xenotrophs|Xenotrophs]], can directly metabolize hydrogen as a source of energy.<br />
<br />
==Production==<br />
Hydrogen can be produced by [[electrolysis]] of [[water]], thermally via the Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2006.05.013</ref> or with [[Carbon_monoxide|CO]] to produce [[syngas]] in the Zinc/Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref>. Thermal production of hydrogen can be achieved using [[nuclear_power|nuclear]] heat, enhanced with a turboinductor<ref>http://www.academia.edu/download/48701931/ACT-RPR-PRO-1107-LS-NTER.pdf</ref> to achieve the high required operating temperatures. Hydrogen can also be produced through the catalytic decomposition of [[ammonia]]<ref>https://pubs.acs.org/doi/pdfplus/10.1021/ja5042836</ref>, allowing for the non cryogenic storage of bulk hydrogen.<br />
<br />
==Use==<br />
<br />
*Hydrogen may be used directly as a [[fuel]] for a propulsion system, or, through the [[Sabatier process|sabatier]] reaction, in the form of [[methane]] for the same purpose.<br />
*Hydrogen can be used to react with [[iron ore]] or [[Aluminum|aluminium]] ore to create metals and water.<br />
*Hydrogen can be combined with carbon to form [[methane]] or [[methanol]] to feed [[Biological_reactors#Methanotrophs|methanotrophs]], creating [[carbohydrates]], [[amino acids]] and [[hydrocarbons]], the building blocks of all living organisms.<br />
<br />
[[Category:Materials]]<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Hydrogen&diff=136201Hydrogen2020-07-27T08:48:25Z<p>Multivac: </p>
<hr />
<div>{{element<br />
|float=right<br />
|elementName=Hydrogen<br />
|elementSymbol=H<br />
|protons=1<br />
|abundance=0.03% (as [[water|H<sub>2</sub>O]])<br />
}}<br />
<br />
'''Hydrogen''' (''periodic table symbol:'' H<sup>1</sup>) is a chemical element that can be found in the [[atmosphere]] and in frozen [[water]] on [[Mars]].<br />
<br />
Liquid hydrogen has a density of 70 kg/m3. Gaseous hydrogen at standard atmospheric pressure and temperature has a density of 0,089 kg/m3.<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and [[microbes]] depends on water, composed of hydrogen and [[oxygen]]. The human body contains about 70% water. Human beings need about 2 liters water per day for drinking, hard working people need even more. Some organisms, [[Bioreactor#Xenotrophs|Xenotrophs]], can directly metabolize hydrogen as a source of energy.<br />
<br />
==Production==<br />
Hydrogen can be produced by [[electrolysis]] of [[water]], thermally via the Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2006.05.013</ref> or with [[Carbon_monoxide|CO]] to produce [[syngas]] in the Zinc/Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref>. Thermal production of hydrogen can be achieved using [[nuclear_power|nuclear]] heat, enhanced with a turboinductor<ref>http://www.academia.edu/download/48701931/ACT-RPR-PRO-1107-LS-NTER.pdf</ref> to achieve the high required operating temperatures. Hydrogen can also be produced through the catalytic decomposition of [[ammonia]]<ref>https://pubs.acs.org/doi/pdfplus/10.1021/ja5042836</ref>, allowing for the non cryogenic storage of bulk hydrogen.<br />
<br />
==Use==<br />
<br />
*Hydrogen may be used directly as a [[fuel]] for a propulsion system, or, through the [[Sabatier process|sabatier]] reaction, in the form of [[methane]] for the same purpose.<br />
*Hydrogen can be used to react with [[iron ore]] or [[Aluminum|aluminium]] ore to create metals and water.<br />
*Hydrogen can be combined with carbon to create [[carbohydrates]], [[amino acids]] and [[hydrocarbons]], the building blocks all all living organisms.<br />
<br />
[[Category:Materials]]<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Hydrogen&diff=136200Hydrogen2020-07-27T08:47:45Z<p>Multivac: /* Production */</p>
<hr />
<div>{{element<br />
|float=right<br />
|elementName=Hydrogen<br />
|elementSymbol=H<br />
|protons=1<br />
|abundance=0.03% (as [[water|H<sub>2</sub>O]])<br />
}}<br />
<br />
'''Hydrogen''' (''periodic table symbol:'' H<sup>1</sup>) is a chemical element that can be found in the [[atmosphere]] and in frozen [[water]] on [[Mars]].<br />
<br />
Liquid hydrogen has a density of 70 kg/m3. Gaseous hydrogen at standard atmospheric pressure and temperature has a density of 0,089 kg/m3.<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and [[microbes]] depends on water, composed of hydrogen and [[oxygen]]. The human body contains about 70% water. Human beings need about 2 liters water per day for drinking, hard working people need even more. Some organisms, [[Bioreactor#Xenotrophs|Xenotrophs]], can directly metabolize hydrogen as a source of energy.<br />
<br />
==Production==<br />
Hydrogen can be produced by [[electrolysis]] of [[water]], thermally via the Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2006.05.013</ref> or with [[Carbon_monoxide|CO]] to produce [[syngas]] in the Zinc/Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref>. Thermal production of hydrogen can be achieved using [[nuclear_power|nuclear]] heat, enhanced with a turboinductor<ref>http://www.academia.edu/download/48701931/ACT-RPR-PRO-1107-LS-NTER.pdf</ref> to achieve the high required operating temperatures. Hydrogen can also be produced through the catalytic decomposition of [[ammonia]]<ref>https://pubs.acs.org/doi/pdfplus/10.1021/ja5042836</ref>, allowing for the non cryogenic storage of bulk hydrogen.<br />
<br />
==Use==<br />
<br />
*Hydrogen may be used directly as a [[fuel]] for a propulsion system, or, through the [[Sabatier process|sabatier]] reaction, in the form of [[methane]] for the same purpose.<br />
*Hydrogen can be used to react with [[iron ore]] or [[Aluminum|aluminium]] ore to create metals and water.<br />
*Hydrogen can be combined with carbon to create [[carbohydrates]], [[amino acids]] and [[hydrocarbons]], the building blocks all all living organisms.<br />
<br />
[[Category:Materials]]</div>Multivachttps://marspedia.org/index.php?title=Hydrogen&diff=136199Hydrogen2020-07-27T08:46:20Z<p>Multivac: /* Production */</p>
<hr />
<div>{{element<br />
|float=right<br />
|elementName=Hydrogen<br />
|elementSymbol=H<br />
|protons=1<br />
|abundance=0.03% (as [[water|H<sub>2</sub>O]])<br />
}}<br />
<br />
'''Hydrogen''' (''periodic table symbol:'' H<sup>1</sup>) is a chemical element that can be found in the [[atmosphere]] and in frozen [[water]] on [[Mars]].<br />
<br />
Liquid hydrogen has a density of 70 kg/m3. Gaseous hydrogen at standard atmospheric pressure and temperature has a density of 0,089 kg/m3.<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and [[microbes]] depends on water, composed of hydrogen and [[oxygen]]. The human body contains about 70% water. Human beings need about 2 liters water per day for drinking, hard working people need even more. Some organisms, [[Bioreactor#Xenotrophs|Xenotrophs]], can directly metabolize hydrogen as a source of energy.<br />
<br />
==Production==<br />
Hydrogen can be produced by [[electrolysis]] of [[water]], thermally via the Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2006.05.013</ref> or with [[Carbon_monoxide|CO]] to produce [[syngas]] in the Zinc/Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref>. Thermal production of hydrogen can be achieved using [[nuclear_power|nuclear]] heat, enhanced with a turboinductor<ref>http://www.academia.edu/download/48701931/ACT-RPR-PRO-1107-LS-NTER.pdf</ref> to achieve the high required operating temperatures.<br />
<br />
==Use==<br />
<br />
*Hydrogen may be used directly as a [[fuel]] for a propulsion system, or, through the [[Sabatier process|sabatier]] reaction, in the form of [[methane]] for the same purpose.<br />
*Hydrogen can be used to react with [[iron ore]] or [[Aluminum|aluminium]] ore to create metals and water.<br />
*Hydrogen can be combined with carbon to create [[carbohydrates]], [[amino acids]] and [[hydrocarbons]], the building blocks all all living organisms.<br />
<br />
[[Category:Materials]]</div>Multivachttps://marspedia.org/index.php?title=Hydrogen&diff=136198Hydrogen2020-07-27T08:40:52Z<p>Multivac: /* Biological significance */</p>
<hr />
<div>{{element<br />
|float=right<br />
|elementName=Hydrogen<br />
|elementSymbol=H<br />
|protons=1<br />
|abundance=0.03% (as [[water|H<sub>2</sub>O]])<br />
}}<br />
<br />
'''Hydrogen''' (''periodic table symbol:'' H<sup>1</sup>) is a chemical element that can be found in the [[atmosphere]] and in frozen [[water]] on [[Mars]].<br />
<br />
Liquid hydrogen has a density of 70 kg/m3. Gaseous hydrogen at standard atmospheric pressure and temperature has a density of 0,089 kg/m3.<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and [[microbes]] depends on water, composed of hydrogen and [[oxygen]]. The human body contains about 70% water. Human beings need about 2 liters water per day for drinking, hard working people need even more. Some organisms, [[Bioreactor#Xenotrophs|Xenotrophs]], can directly metabolize hydrogen as a source of energy.<br />
<br />
==Production==<br />
Hydrogen can be produced by [[electrolysis]] of [[water]].<br />
<br />
==Use==<br />
<br />
*Hydrogen may be used directly as a [[fuel]] for a propulsion system, or, through the [[Sabatier process|sabatier]] reaction, in the form of [[methane]] for the same purpose.<br />
*Hydrogen can be used to react with [[iron ore]] or [[Aluminum|aluminium]] ore to create metals and water.<br />
*Hydrogen can be combined with carbon to create [[carbohydrates]], [[amino acids]] and [[hydrocarbons]], the building blocks all all living organisms.<br />
<br />
[[Category:Materials]]</div>Multivachttps://marspedia.org/index.php?title=Xenon&diff=136197Xenon2020-07-27T08:26:55Z<p>Multivac: Created page with "Xenon is a noble gas, much like krypton and argon. It is the most efficient choice for the fuel of most types of ion engines and may be used as well as an ionizing..."</p>
<hr />
<div>[[Xenon]] is a noble gas, much like [[krypton]] and [[argon]]. It is the most efficient choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in a [[Nuclear_power|nuclear]] [[Nuclear_power#LMMHD_generators|MHD]] generator. Xenon is quite expensive, at about $20 per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, [[argon]] may be a more practical choice than Xenon.<br />
<br />
{{stub}}</div>Multivachttps://marspedia.org/index.php?title=Krypton&diff=136196Krypton2020-07-27T08:20:12Z<p>Multivac: Created page with "Krypton is a noble gas, much like xenon and argon. It is useful as propellant for ion drives, and an isotope of krypton, <sup>79</sup>Kr, has been..."</p>
<hr />
<div>[[Krypton]] is a noble gas, much like [[xenon]] and [[argon]]. It is useful as propellant for [[Ion_thruster|ion drives]], and an isotope of krypton, <sup>79</sup>Kr, has been proposed as a positron source in an experimental [[Ion_thruster#Scaled_radioisotope_positron_propulsion|radioisotope positron propulsion system]]. Krypton is also used by SpaceX for the thrusters in its Constellation project. <br />
<br />
{{stub}}</div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136195Ion thruster2020-07-27T08:14:45Z<p>Multivac: /* Xenon */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the [[Nuclear_power#LMMHD_generators|MHD generator]]. Xenon is quite expensive, at about $20 per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
[[Argon]] is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
[[Krypton]], another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
[[Water]] has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components.<br />
<br />
==='''Helium'''===<br />
[[Helium]] is fairly easy to ionize.<br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136194Ion thruster2020-07-27T08:09:00Z<p>Multivac: /* Helium */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
[[Argon]] is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
[[Krypton]], another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
[[Water]] has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components.<br />
<br />
==='''Helium'''===<br />
[[Helium]] is fairly easy to ionize.<br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136193Ion thruster2020-07-27T08:08:50Z<p>Multivac: /* Water */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
[[Argon]] is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
[[Krypton]], another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
[[Water]] has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components.<br />
<br />
==='''Helium'''===<br />
Helium is fairly easy to ionize. <br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136192Ion thruster2020-07-27T08:08:40Z<p>Multivac: /* Krypton */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
[[Argon]] is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
[[Krypton]], another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
Water has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components. <br />
<br />
==='''Helium'''===<br />
Helium is fairly easy to ionize. <br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136191Ion thruster2020-07-27T08:08:29Z<p>Multivac: /* Argon */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
[[Argon]] is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
Krypton, another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
Water has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components. <br />
<br />
==='''Helium'''===<br />
Helium is fairly easy to ionize. <br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136190Ion thruster2020-07-27T08:08:20Z<p>Multivac: /* Xenon */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
[[Xenon]] is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
Argon is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
Krypton, another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
Water has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components. <br />
<br />
==='''Helium'''===<br />
Helium is fairly easy to ionize. <br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136189Ion thruster2020-07-27T08:07:25Z<p>Multivac: /* Hydrogen */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
[[Hydrogen]] is an effective propellant, very appropriate for high ISP thrusters. Some have suggested extracting hydrogen from the [[Interplanetary_commerce|Lunar poles]].<br />
<br />
==='''Xenon'''===<br />
Xenon is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
Argon is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
Krypton, another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
Water has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components. <br />
<br />
==='''Helium'''===<br />
Helium is fairly easy to ionize. <br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136188Ion thruster2020-07-27T06:10:47Z<p>Multivac: /* Propellants */</p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
==='''Interstellar plasma'''===<br />
The Dipole Drive<ref>https://www.youtube.com/watch?v=93pX9_7vYb0</ref><ref>https://doi.org/10.2514/6.2019-1122</ref> by [[Robert_Zubrin|Robert Zubrin]] utilizes charged particles in free space to produce thrust via a set of external electrostatic grids. These grids extend outwards like a solar sail, and accelerate charged particles that pass through them via the electric field between them.<br />
<br />
==='''Hydrogen'''===<br />
Hydrogen is an effective propellant, very appropriate for high ISP thrusters. <br />
<br />
==='''Xenon'''===<br />
Xenon is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
Argon is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
Krypton, another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
Water has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components. <br />
<br />
==='''Helium'''===<br />
Helium is fairly easy to ionize. <br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Ion_thruster&diff=136187Ion thruster2020-07-27T05:53:52Z<p>Multivac: </p>
<hr />
<div>Ion thrusters require power sources, either [[Nuclear power|nuclear]] or [[Photovoltaics|solar]].<br />
<br />
Electrical drives are not new technology. They have been available for many years. However, lack of a suitable mission and, in particular, lack of an adequate power source has hampered their development. Although electrical [[propulsion]] is not very powerful, it is exceptionally efficient and can be applied for very long periods. So despite tiny accelerations, a vehicle with ion thrusters can eventually reach very high speeds.<br />
<br />
==Electrothermal Propulsion Systems==<br />
<br />
===Resistojets===<br />
<br />
==='''Arcjets'''===<br />
An arcjet heats a propellant using an electric arc rather than a chemical reaction. It is therefore a thermal engine. The ISP from an arcjet can be higher than for a chemical rocket, but remains at around 500s, one order of magnitude less than what is required for systems more efficient that standard chemical rockets.<br />
<br />
===Microwave & ECR thrusters===<br />
<br />
==Electromagnetic Propulsion Systems==<br />
<br />
==='''Magnetoplasmadynamic (MPD) Thrusters'''<ref>http://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster</ref>===<br />
In a MPD thruster a gas is ionised, turned into a plasma and fed into a acceleration chamber, where the interaction between an electrical current in the plasma and the magnetic field produced by electromagnets pushes the plasma up to high speeds. Vasimir is an application of this principle.<br />
<br />
This is one of the best candidates for the Interplanetary propulsion. However, since it is more efficient at larger sizes, the lack of a suitable power source to test the principle in space has hampered the development of this technology. Thrusters with thrust up to 500 N and more are possible. SUPREME<ref>https://www.youtube.com/watch?v=Au54kj-qkpg</ref>, an advanced MPD thruster utilizing high temperature superconductors, has been proposed for use in Earth/Luna missions and may also improve payload capacity for Earth/Mars missions.<br />
<br />
==='''VASIMR'''===<br />
The Vasimr (Variable Specific Impulse Magnetoplasma rocket) engine, as per 2011, has an optimum specific impulse of 5000s. The required power is 200 kW, with an efficiency of 60%, for a thrust of 6 N. The fuel is argon, but other gases can be used. The concept should be scalable up to 500N per unit. <br />
<br />
==='''[http://en.wikipedia.org/wiki/Pulsed_plasma_thruster Pulsed Plasma Thrusters]'''===<br />
A material is transformed into a burst of plasma by a short lived electric arc (think of a spark plug), and the plasma is accelerated by the electric field between an anode and a cathode. This is a simple but inefficient type of thruster that, at 10% efficiency, is not suitable for Mars transportation. <br />
<br />
However, in <ref>http://alfven.princeton.edu/papers/tem_jpc2002.pdf</ref> a proposal is made for a much more powerful version, that, although still only 50% efficient, might be further upgraded to provide the required thrust. The proposed fuel would be lithium. The design is very simple, and might be very light.<br />
<br />
==Electrostatic Propulsion Systems==<br />
<br />
==='''Hall effect'''===<br />
The Hall effect thruster is a (mostly) Russian technology. Over 200 units have been flown. Engine performances are comparable to ion grid. Hall effect thrusters are physically smaller than ion grid thrusters. This is a distinct advantage for some configurations. Wikipedia cites efficiencies up to 75%<br />
<br />
==='''Ion grid'''===<br />
The ion grid thruster is a mature technology that has performances very close to the Interplanetary transportation mission requirements. <br />
<br />
The current NASA model is the NEXT thruster. The engine thrust is very small, at 0,2 N per motor, with 6,9 kW and 70% efficiency. The fuel is Xenon gas. With a size of about 600mm wide per unit, they are physically large.<br />
<br />
The Hipep Ion engine has an efficiency of 80% and similar characteristics than the NEXT. The HIPEP is rectangular and can be assembled in tight grids. The model tested was 600mm x 1200mm (approx, to be confirmed).<br />
<br />
==='''Colloidal Accelerators & FEEP'''===<br />
<br />
==='''NanoFET'''===<br />
This is a technology in the very early stages of development. The fuel is composed of tiny droplets of semi conductors, encased in a shell of protein. The propulsion method uses electric fields to accelerate the particles. Efficiencies may be very high. The envisioned market is micro satellites, but it might be possible to 'print out' large boards of these micro thrusters using micropressor production technologies and eventually reach the required thrust (with millions of thrusters).<br />
<br />
== Fusion ion systems ==<br />
<br />
==='''Scaled radioisotope positron propulsion'''===<br />
An experimental system described in <ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190018063.pdf</ref> showcased in <ref>https://www.youtube.com/watch?v=HH70-FdP-os</ref> and animated in <ref>https://www.youtube.com/watch?v=EBjt2CgZACU</ref> from the company Positron Dynamics<ref>http://www.positrondynamics.com</ref> builds upon earlier work on coupling the energy produced from electron/positron annihilation into [[Deuterium]] <ref>https://doi.org/10.1063/1.5127534</ref>, forming a possible design for a high performance rocket engine. In this design <sup>79</sup>Kr is frozen on a cold plate, forming a positron source as it naturally decays. Those positrons are then moderated, formed into a pulse train and then focused through a set of ion beam optics on to deuterium contained on a metal tape. Those positrons then annihilate electrons in the deuterium, rapidly releasing energy and igniting fusion. The fusing deuterium then forms an expanding ball of hot plasma that exits through a magnetic nozzle providing thrust. It also releases neutrons, breeding <sup>79</sup>Kr from <sup>78</sup>Kr stored in tanks around the reaction chamber. The <sup>79</sup>Kr is then enriched from the Kr tanks via an enrichment process proposed by Mills et al<ref>https://link.springer.com/content/pdf/10.1393/ncr/i2011-10064-5.pdf</ref>.<br />
<br />
==Propellants==<br />
<br />
==='''Hydrogen'''===<br />
Hydrogen is an effective propellant, very appropriate for high ISP thrusters. <br />
<br />
==='''Xenon'''===<br />
Xenon is an inert gas that is relatively easy to ionise and denser that other inert gases. It is the best choice for the fuel of most types of ion engines and may be used as well as an ionizing agent in the coolant system, to provide the required plasma for the MHD generator. Xenon is quite expensive, at about 20$ per liter (6g). There are about 45 billions tons of Xenon in Earth's atmosphere. Due to cost and availability concerns, argon may be a better choice that Xenon.<br />
<br />
==='''Argon'''===<br />
Argon is a inert gas that composes almost 1% of Earths atmosphere. It can be used instead of Xenon as propellant for electric propulsion. It should also be possible to use it as the ionising agent in the cooling system for a MHD generator operation. The Vasimir engine can use argon as propellant. Argon is available in the Martian atmosphere and might be an in-situ resource for space electric propulsion.<br />
<br />
===Krypton===<br />
Krypton, another inert gas, is used by SpaceX for the thrusters in its Constellation project.<br />
<br />
==='''Water'''===<br />
Water has been proposed for some kinds of thermal rockets. The high temperatures and the need for ionisation in electrical engines would probably dissociate water its components. <br />
<br />
==='''Helium'''===<br />
Helium is fairly easy to ionize. <br />
<br />
==='''Liquid metals'''===<br />
Sodium, Lithium, lead, lead bismuth, mercury have all been proposed for electric propulsion. Concerns with toxicity during testing has led to the the abandonment of a number of these metals.<br />
<br />
Liquid salts<br />
<br />
==='''Nanofluids'''===<br />
Nanoparticles in suspension in a carrier fluid can have interesting propulsive properties.<br />
<br />
==References==<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Carbon_dioxide&diff=136180Carbon dioxide2020-07-26T09:41:33Z<p>Multivac: /* Settlement atmosphere */</p>
<hr />
<div>'''Carbon dioxide'''<ref>https://en.wikipedia.org/wiki/Carbon_dioxide</ref> (''chemical formula:'' CO<sub>2</sub>) is a chemical substance that occupies about 96 % of the [[Mars|Martian]] [[atmosphere]].<br />
<br />
Molar Mass of 12(C)+32(O<sub>2</sub>)=44<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and various [[microbes]] depends on the oxidation of [[carbohydrate]]s, resulting in carbon dioxide and water exhalation. [[:Category:Plants|Plants]] use the [[carbon]] from carbon dioxide to produce [[carbohydrates]] and release the [[oxygen]] back to the [[atmosphere]], completing the cycle. <br />
<br />
:The reaction is: CO<sub>2</sub>(carbon dioxide) + 2H<sub>2</sub>O (water) + photons (light energy) → C<sub>(n)</sub>H<sub>2</sub>O<sub>(m)</sub> (carbohydrate) + O<sub>2</sub>(oxygen)+ H<sub>2</sub>O (water)<ref>[[w:Photosynthesis|Photosynthesis- https://en.wikipedia.org/wiki/Photosynthesis]]</ref><br />
<br />
==Production==<br />
CO2 will be extracted [[In-situ resource utilization|in-situ]] by [[atmospheric processing]], or from carbonate rocks to provide larger industrial quantities to feed industry<ref>https://www.nature.com/articles/ngeo971</ref><br />
<br />
==Settlement atmosphere==<br />
[[File:Colony CO2 treatment.png|thumb|600x600px]]<br />
Carbon dioxide is required in the [[Air|settlement atmosphere]] for plant metabolism. Standard concentration on Earth is increasing, so the value is a moving target. However, a concentration between 300ppm (0,03%) and 1000ppm (0,1%) is considered acceptable<ref>Carbon dioxyde concentrations<nowiki/>https://www.nap.edu/read/11170/chapter/5</ref>. Nuclear submarines have varying carbon monoxide levels that can reach 9000 ppm in normal operations. A CO<sub>2</sub> enriched environment may be beneficial for the growth of plants in [[greenhouse|greenhouses]] or [[photobioreactor|photobioreactors]].<br />
<br />
The Sabatier process can be used in place of photosynthesis to complete the atmospheric part of the carbon cycle. [[Bioreactor#Methanotrophs|Methanotrophic]] synthesis of carbohydrates from [[methane]] would be required to complete the carbon metabolic cycle without the use of plants. Or food can be supplied from Earth or Mars for a partial cycle, where [[Methane]] from the Sabatier process can be stored for use as a propellant.<br />
<br />
==Concentration==<br />
Concentration of CO2 on Earth is about 400 ppm. Increasing concentration improves plan production rates, however the effect is non linear and reaches a peak of 20% improvement in yields at about 1200 ppm.<ref>University of California, Agriculture and Natural ressources https://ucanr.edu/blogs/NurseryFlower/</ref><br />
[[File:CO2 concentration.jpg|thumb|Effect of CO2 concentration on plant production]]<br />
<br />
==Uses==<br />
<br />
*[[Food preservation|Food Preservation]]<br />
<br />
*[[Photosynthesis]] by plants in [[greenhouse]]s to create [[carbohydrates]] for plant metabolism.<br />
*[[Synthetic materials]], [[Hydrocarbons|hydrocarbon]]<nowiki/>s using the [[Fischer-Tropsch reaction|Fischer Tropsch]] reaction process.<br />
*[[Propellant]] production. Methane (CH<sub>4</sub>) and Oxygen (O<sub>2</sub>), through [[In-situ resource utilization|ISRU]] using the [[Sabatier process]]. The hydrogen comes from Electrolysis of water or is brought from Earth.<br />
*[[Carbon]] using the [[Bosch reaction]] process. The Bosch reaction consumes hydrogen to produce carbon and water. The [[hydrogen]] can come from [[electrolysis]] of water.<br />
<br />
==References==<br />
[[Category: Biospherics]]<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Carbon_dioxide&diff=136179Carbon dioxide2020-07-26T09:14:46Z<p>Multivac: /* Production */</p>
<hr />
<div>'''Carbon dioxide'''<ref>https://en.wikipedia.org/wiki/Carbon_dioxide</ref> (''chemical formula:'' CO<sub>2</sub>) is a chemical substance that occupies about 96 % of the [[Mars|Martian]] [[atmosphere]].<br />
<br />
Molar Mass of 12(C)+32(O<sub>2</sub>)=44<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and various [[microbes]] depends on the oxidation of [[carbohydrate]]s, resulting in carbon dioxide and water exhalation. [[:Category:Plants|Plants]] use the [[carbon]] from carbon dioxide to produce [[carbohydrates]] and release the [[oxygen]] back to the [[atmosphere]], completing the cycle. <br />
<br />
:The reaction is: CO<sub>2</sub>(carbon dioxide) + 2H<sub>2</sub>O (water) + photons (light energy) → C<sub>(n)</sub>H<sub>2</sub>O<sub>(m)</sub> (carbohydrate) + O<sub>2</sub>(oxygen)+ H<sub>2</sub>O (water)<ref>[[w:Photosynthesis|Photosynthesis- https://en.wikipedia.org/wiki/Photosynthesis]]</ref><br />
<br />
==Production==<br />
CO2 will be extracted [[In-situ resource utilization|in-situ]] by [[atmospheric processing]], or from carbonate rocks to provide larger industrial quantities to feed industry<ref>https://www.nature.com/articles/ngeo971</ref><br />
<br />
==Settlement atmosphere==<br />
[[File:Colony CO2 treatment.png|thumb|600x600px]]<br />
Carbon dioxide is required in the [[Air|settlement atmosphere]] for plant metabolism. Standard concentration on Earth is increasing, so the value is a moving target. However, a concentration between 300ppm (0,03%) and 1000ppm (0,1%) is considered acceptable<ref>Carbon dioxyde concentrations<nowiki/>https://www.nap.edu/read/11170/chapter/5</ref>. Nuclear submarines have varying carbon monoxide levels that can reach 9000 ppm in normal operations.<br />
<br />
The Sabatier process can be used in place of photosynthesis to complete the atmospheric part of the carbon cycle. Synthesis of carbohydrates from methane would be required to complete the carbon metabolic cycle without the use of plants. Or food can be supplied from Earth or Mars for a partial cycle, where Methane from the Sabatier process can be stored for use as a propellant.<br />
<br />
==Concentration==<br />
Concentration of CO2 on Earth is about 400 ppm. Increasing concentration improves plan production rates, however the effect is non linear and reaches a peak of 20% improvement in yields at about 1200 ppm.<ref>University of California, Agriculture and Natural ressources https://ucanr.edu/blogs/NurseryFlower/</ref><br />
[[File:CO2 concentration.jpg|thumb|Effect of CO2 concentration on plant production]]<br />
<br />
==Uses==<br />
<br />
*[[Food preservation|Food Preservation]]<br />
<br />
*[[Photosynthesis]] by plants in [[greenhouse]]s to create [[carbohydrates]] for plant metabolism.<br />
*[[Synthetic materials]], [[Hydrocarbons|hydrocarbon]]<nowiki/>s using the [[Fischer-Tropsch reaction|Fischer Tropsch]] reaction process.<br />
*[[Propellant]] production. Methane (CH<sub>4</sub>) and Oxygen (O<sub>2</sub>), through [[In-situ resource utilization|ISRU]] using the [[Sabatier process]]. The hydrogen comes from Electrolysis of water or is brought from Earth.<br />
*[[Carbon]] using the [[Bosch reaction]] process. The Bosch reaction consumes hydrogen to produce carbon and water. The [[hydrogen]] can come from [[electrolysis]] of water.<br />
<br />
==References==<br />
[[Category: Biospherics]]<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Carbon_dioxide&diff=136178Carbon dioxide2020-07-26T09:13:48Z<p>Multivac: /* Production */</p>
<hr />
<div>'''Carbon dioxide'''<ref>https://en.wikipedia.org/wiki/Carbon_dioxide</ref> (''chemical formula:'' CO<sub>2</sub>) is a chemical substance that occupies about 96 % of the [[Mars|Martian]] [[atmosphere]].<br />
<br />
Molar Mass of 12(C)+32(O<sub>2</sub>)=44<br />
<br />
==Biological significance==<br />
The metabolism of [[human|human beings]], [[:category:animals|animals]] and various [[microbes]] depends on the oxidation of [[carbohydrate]]s, resulting in carbon dioxide and water exhalation. [[:Category:Plants|Plants]] use the [[carbon]] from carbon dioxide to produce [[carbohydrates]] and release the [[oxygen]] back to the [[atmosphere]], completing the cycle. <br />
<br />
:The reaction is: CO<sub>2</sub>(carbon dioxide) + 2H<sub>2</sub>O (water) + photons (light energy) → C<sub>(n)</sub>H<sub>2</sub>O<sub>(m)</sub> (carbohydrate) + O<sub>2</sub>(oxygen)+ H<sub>2</sub>O (water)<ref>[[w:Photosynthesis|Photosynthesis- https://en.wikipedia.org/wiki/Photosynthesis]]</ref><br />
<br />
==Production==<br />
CO2 will be extracted [[In-situ resource utilization|in-situ]] by [[atmospheric processing]], or from carbonate rocks to provide larger industrial quantities to feed industry<ref>https://www.researchgate.net/profile/Paul_Niles/publication/47374184_Deep_crustal_carbonate_rocks_exposed_by_meteor_impact_on_Mars/links/004635143366fdd629000000/Deep-crustal-carbonate-rocks-exposed-by-meteor-impact-on-Mars.pdf</ref><br />
<br />
==Settlement atmosphere==<br />
[[File:Colony CO2 treatment.png|thumb|600x600px]]<br />
Carbon dioxide is required in the [[Air|settlement atmosphere]] for plant metabolism. Standard concentration on Earth is increasing, so the value is a moving target. However, a concentration between 300ppm (0,03%) and 1000ppm (0,1%) is considered acceptable<ref>Carbon dioxyde concentrations<nowiki/>https://www.nap.edu/read/11170/chapter/5</ref>. Nuclear submarines have varying carbon monoxide levels that can reach 9000 ppm in normal operations.<br />
<br />
The Sabatier process can be used in place of photosynthesis to complete the atmospheric part of the carbon cycle. Synthesis of carbohydrates from methane would be required to complete the carbon metabolic cycle without the use of plants. Or food can be supplied from Earth or Mars for a partial cycle, where Methane from the Sabatier process can be stored for use as a propellant.<br />
<br />
==Concentration==<br />
Concentration of CO2 on Earth is about 400 ppm. Increasing concentration improves plan production rates, however the effect is non linear and reaches a peak of 20% improvement in yields at about 1200 ppm.<ref>University of California, Agriculture and Natural ressources https://ucanr.edu/blogs/NurseryFlower/</ref><br />
[[File:CO2 concentration.jpg|thumb|Effect of CO2 concentration on plant production]]<br />
<br />
==Uses==<br />
<br />
*[[Food preservation|Food Preservation]]<br />
<br />
*[[Photosynthesis]] by plants in [[greenhouse]]s to create [[carbohydrates]] for plant metabolism.<br />
*[[Synthetic materials]], [[Hydrocarbons|hydrocarbon]]<nowiki/>s using the [[Fischer-Tropsch reaction|Fischer Tropsch]] reaction process.<br />
*[[Propellant]] production. Methane (CH<sub>4</sub>) and Oxygen (O<sub>2</sub>), through [[In-situ resource utilization|ISRU]] using the [[Sabatier process]]. The hydrogen comes from Electrolysis of water or is brought from Earth.<br />
*[[Carbon]] using the [[Bosch reaction]] process. The Bosch reaction consumes hydrogen to produce carbon and water. The [[hydrogen]] can come from [[electrolysis]] of water.<br />
<br />
==References==<br />
[[Category: Biospherics]]<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Greenhouse&diff=136177Greenhouse2020-07-26T08:45:54Z<p>Multivac: /* Underground Greenhouse Concept (Grow room) */</p>
<hr />
<div>[[File:Greenhouse_tile.JPG|link=Create_a_settlement|alt=|border|right|frameless|100x100px|[[Create a settlement]]]]<br />
[[image:Eden_project.jpg|thumb|right|300px|[[The Eden Project]]] (near St Austell, Cornwall, UK) is a terrestrial example of the possible use of large ''biomes'' as greenhouses and life support for Mars colonies. ''Image credit: Jürgen Matern'']] <br />
Greenhouses and grow rooms are types of agricultural facilities. Growing [[:category:plants|plants]] in a '''Greenhouse''' delivers [[oxygen]] and [[food]]. It can play an important part in human recreation ([[Mars Garden Wins Gold at London’s Chelsea Flower Show (MarsHome.org)|Mars Garden]]) and may be the place for [[funeral]]s. The [[sunlight]] is not bright enough on Mars to allow most terrestrial plants to thrive, but it provides a valuable part of light energy for plants. Additional [[energy]] is necessary for [[lighting]] and [[heating]]. [[Food|Food production]] [[Settlement facilities|facilities]] may include biological reactors for bulk protein and carbohydrates production, sidestepping plant production altogether. <br />
<br />
[[image:TropicalIslandsInside.jpg|thumb|right|300px|The Tropical Islands (Germany) is a terrestrial example of a huge dome to create an inhouse habitat.]]<br />
The greenhouse may be constructed from transparent material, allowing maximum sunlight to pass, generating an artificial "[[greenhouse effect]]". This effect may be enhanced by filling the greenhouse with potent greenhouse gasses such as [[sulfur hexafluoride]] The spectral properties of the material should be optimized to match the absorption characteristics of chlorophyll, maximizing the energy gain, possibly using a layer of quantum dots<ref>http://dx.doi.org/10.33383/2017-084</ref>. <br />
<br />
Plants need a mix of air pressure and temperature. The greenhouse must be strong enough to hold that air pressure, and it must be [[insulation|insulated]] to hold the temperature inside. Photosynthesis works only at fairly high temperatures.<br />
<br />
==Side-lit Greenhouse Concept== <br />
<br />
[[Image:Greenhouse_marsfoundation.jpg|thumb|left|300px|The [[Mars Foundation]] concept for a side-lit greenhouse.]] <br />
The [[Mars Foundation]] concept for a greenhouse involves the maximum use of local materials to avoid waste, maximize energy input and optimize space. Spawned from the [[Hillside settlement]] design, the greenhouse would most likely be located inside/next to a hill side (possibly in the location of [[Candor Chasma]]). Therefore [[regolith]] or some other absorbent material could be suspended above the greenhouse to protect occupants and plants from [[solar radiation|harmful radiation]]. The source of light would therefore be directed from the side, via an array of adjustable mirrors. A system of vents and ducts would allow warm air to circulate, perhaps even used to heat the main habitat.<br />
<br />
==Underground Greenhouse Concept (Grow room)==<br />
[[Image:Underground Greenhouse.png|thumb|right|300px|Underground Greenhouse Concept]] <br />
<br />
If geothermal energy or [[nuclear power]] is not available the [[heating]] will consume large amounts of electrical energy. In this case the sum of energy used for [[lighting]] and heating must be considered. An underground greenhouse is easier to insulate to hold warmth inside. On the other hand the effort of lighting is higher, since no direct sunlight is used. This concept has some additional advantages: It is [[meteorites|meteorite]]-safe and [[radiation]]-safe.<br />
<br />
[[caves|Natural caves]] and [[artificial cave]]s can be utilized to build such an underground greenhouse, which requires a preparation with high effort in either case. The maintenance is quite cheap, for the ambient temperatures are steady and the radiation levels are low, so it is a good long term solution. A combination of greenhouse and living space for the settlers is suggested.<br />
<br />
The [[Mars One]] concept for the initial settlement is an inflatable greenhouse with a thick cover of [[regolith]].<br />
<br />
==Water-shield Greenhouse Concept==<br />
<br />
[[Image:WaterShieldGreenhouse.png|thumb|right|300px|Water-shield Greenhouse Concept]] <br />
[[Hydrogen]] does a good job absorbing [[cosmic radiation]]. [[Water]] contains highly concentrated hydrogen, and hence serves as a good radiation shield. On the other hand it is highly transparent for visible light and UV. The combination of both makes it an interesting material for greenhouse shielding.<br />
<br />
Under a strong pressure resistent housing the water is placed in a thick layer. It absorbes the dangerous parts of cosmic radiation and [[sunlight]] and passes most of the spectral parts needed by [[human]]s and plants. Additionally, it helps to buffer daily temperature variations because of its high specific heat capacity.<br />
<br />
The layering could be as follows: The outer layer is a construction of [[steel]] and [[glass]], providing enough strength for the difference in [[atmosphere|atmospheric pressure]]. It also serves as insulation for [[temperature]] differences. Additional sheets of glass or [[Synthetic materials|plastics]] improve the insulation effect. A [[self-healing puncture protection]] should be considered. The innermost layer is the water. It can be held by transparent canisters.<br />
<br />
==Multiplying Sunlight==<br />
[[Image:MultipleMirrorsForGreenhouse.png|thumb|left|300px|Multiple Mirrors for Greenhouse]] <br />
<br />
A [[solar concentrator]] is a set of mirrors that can be used to bring more sunlight into the greenhouse than the base area of the greenhouse receives directly from the sun. Three times the amount of Martian sunlight should be enough to serve terrestrial plants. During good weather periods this allows growing vegetables without additional energy.<br />
<br />
However, 40% or more of martian light is diffuse light. This light cannot be focused by a mirror and therefore the surface required may be much larger.<br />
<br />
==Flora and fauna==<br />
Plants can be grown either in liquid fertilizer ([[hydroponics]]) or in [[soil]]. Many plants live in symbiosis with [[microbes]] and [[insects]]. [[Bee]]s can be used to pollinate the blossoms for fruit plants. Probably, the greenhouse is less labor-intensive with as many natural processes as possible, including decay of dead parts of plants to [[compost]]. The growth of flora and fauna under the low Martian [[gravity]] bears some uncertainties.<br />
<br />
==Nutrition and Energy Calculations==<br />
Based upon the figures in the [[food]] and [[sunlight]] articles the following calculations can be carried out for an artificially lit greenhouse:<br />
<br />
The minimum size of cropland per person is about 365 m<sup>2</sup>. The needed [[lighting|light energy]] can be assumed with 1000 kWh per m<sup>2</sup> and year. The result is an annual amount of 365 MWh per person. In other words: An average illumination power of 41,67 kW per person is required.<br />
<br />
The usage of fluorescent lamps with an efficiency factor of 30% results in a requirement of about 140 kW per person in electrical energy. The overall efficiency of food production with artificially lit greenhouses is less then 1 permille, or in other words, to produce food with a content of 1 kWh the amount of more than 1 MWh in electricity must be spent.<br />
<br />
Parts of the required light can possibly be provided by direct or indirect sunlight. [[Heating]] the greenhouse will require additional energy.<br />
<br />
==Open Issues== <br />
<br />
*How long can plants survive without sunlight (e.g. during a dust storm)?<br />
*How many persons are needed to work in the greenhouse to produce enough food for a hundred persons?<br />
*How much energy is required for heating, especially during long lasting dust storms? This question can not be answered without an [[experimental setup#greenhouse heating|experimental setup]].<br />
*What temperature and air pressure do plants need?<br />
*What air pressure is needed for persons to work in the greenhouse?<br />
*What transparent materials match the absorption characteristics of chlorophyll?<br />
*Do plants need wind? How can it be provided?<br />
*What is known about radiation tolerance of food crop?<br />
<br />
==See Also== <br />
<br />
*[[Research on greenhouses & assumptions]]<br />
*[[Experimental setup]]<br />
<br />
==External links==<br />
<br />
*[http://www.marshome.org/archives/2007/03/sidelit_greenho.php The Mars Foundation Side-lit Greenhouse design.]<br />
<br />
{{SettlementIndex}}<br />
<br />
{{Featured_red_ring}}<br />
<br />
[[category:Growing Methods]]</div>Multivachttps://marspedia.org/index.php?title=Greenhouse&diff=136176Greenhouse2020-07-26T07:09:06Z<p>Multivac: </p>
<hr />
<div>[[File:Greenhouse_tile.JPG|link=Create_a_settlement|alt=|border|right|frameless|100x100px|[[Create a settlement]]]]<br />
[[image:Eden_project.jpg|thumb|right|300px|[[The Eden Project]]] (near St Austell, Cornwall, UK) is a terrestrial example of the possible use of large ''biomes'' as greenhouses and life support for Mars colonies. ''Image credit: Jürgen Matern'']] <br />
Greenhouses and grow rooms are types of agricultural facilities. Growing [[:category:plants|plants]] in a '''Greenhouse''' delivers [[oxygen]] and [[food]]. It can play an important part in human recreation ([[Mars Garden Wins Gold at London’s Chelsea Flower Show (MarsHome.org)|Mars Garden]]) and may be the place for [[funeral]]s. The [[sunlight]] is not bright enough on Mars to allow most terrestrial plants to thrive, but it provides a valuable part of light energy for plants. Additional [[energy]] is necessary for [[lighting]] and [[heating]]. [[Food|Food production]] [[Settlement facilities|facilities]] may include biological reactors for bulk protein and carbohydrates production, sidestepping plant production altogether. <br />
<br />
[[image:TropicalIslandsInside.jpg|thumb|right|300px|The Tropical Islands (Germany) is a terrestrial example of a huge dome to create an inhouse habitat.]]<br />
The greenhouse may be constructed from transparent material, allowing maximum sunlight to pass, generating an artificial "[[greenhouse effect]]". This effect may be enhanced by filling the greenhouse with potent greenhouse gasses such as [[sulfur hexafluoride]] The spectral properties of the material should be optimized to match the absorption characteristics of chlorophyll, maximizing the energy gain, possibly using a layer of quantum dots<ref>http://dx.doi.org/10.33383/2017-084</ref>. <br />
<br />
Plants need a mix of air pressure and temperature. The greenhouse must be strong enough to hold that air pressure, and it must be [[insulation|insulated]] to hold the temperature inside. Photosynthesis works only at fairly high temperatures.<br />
<br />
==Side-lit Greenhouse Concept== <br />
<br />
[[Image:Greenhouse_marsfoundation.jpg|thumb|left|300px|The [[Mars Foundation]] concept for a side-lit greenhouse.]] <br />
The [[Mars Foundation]] concept for a greenhouse involves the maximum use of local materials to avoid waste, maximize energy input and optimize space. Spawned from the [[Hillside settlement]] design, the greenhouse would most likely be located inside/next to a hill side (possibly in the location of [[Candor Chasma]]). Therefore [[regolith]] or some other absorbent material could be suspended above the greenhouse to protect occupants and plants from [[solar radiation|harmful radiation]]. The source of light would therefore be directed from the side, via an array of adjustable mirrors. A system of vents and ducts would allow warm air to circulate, perhaps even used to heat the main habitat.<br />
<br />
==Underground Greenhouse Concept (Grow room)==<br />
[[Image:Underground Greenhouse.png|thumb|right|300px|Underground Greenhouse Concept]] <br />
<br />
If geothermal energy is not available the [[heating]] will consume large amounts of electrical energy. In this case the sum of energy used for [[lighting]] and heating must be considered. An underground greenhouse is easier to insulate to hold warmth inside. On the other hand the effort of lighting is higher, since no direct sunlight is used. This concept has some additional advantages: It is [[meteorites|meteorite]]-safe and [[radiation]]-safe.<br />
<br />
[[caves|Natural caves]] and [[artificial cave]]s can be utilized to build such an underground greenhouse, which requires a preparation with high effort in either case. The maintenance is quite cheap, for the ambient temperatures are steady and the radiation levels are low, so it is a good long term solution. A combination of greenhouse and living space for the settlers is suggested.<br />
<br />
The [[Mars One]] concept for the initial settlement is an inflatable greenhouse with a thick cover of [[regolith]].<br />
<br />
==Water-shield Greenhouse Concept==<br />
<br />
[[Image:WaterShieldGreenhouse.png|thumb|right|300px|Water-shield Greenhouse Concept]] <br />
[[Hydrogen]] does a good job absorbing [[cosmic radiation]]. [[Water]] contains highly concentrated hydrogen, and hence serves as a good radiation shield. On the other hand it is highly transparent for visible light and UV. The combination of both makes it an interesting material for greenhouse shielding.<br />
<br />
Under a strong pressure resistent housing the water is placed in a thick layer. It absorbes the dangerous parts of cosmic radiation and [[sunlight]] and passes most of the spectral parts needed by [[human]]s and plants. Additionally, it helps to buffer daily temperature variations because of its high specific heat capacity.<br />
<br />
The layering could be as follows: The outer layer is a construction of [[steel]] and [[glass]], providing enough strength for the difference in [[atmosphere|atmospheric pressure]]. It also serves as insulation for [[temperature]] differences. Additional sheets of glass or [[Synthetic materials|plastics]] improve the insulation effect. A [[self-healing puncture protection]] should be considered. The innermost layer is the water. It can be held by transparent canisters.<br />
<br />
==Multiplying Sunlight==<br />
[[Image:MultipleMirrorsForGreenhouse.png|thumb|left|300px|Multiple Mirrors for Greenhouse]] <br />
<br />
A [[solar concentrator]] is a set of mirrors that can be used to bring more sunlight into the greenhouse than the base area of the greenhouse receives directly from the sun. Three times the amount of Martian sunlight should be enough to serve terrestrial plants. During good weather periods this allows growing vegetables without additional energy.<br />
<br />
However, 40% or more of martian light is diffuse light. This light cannot be focused by a mirror and therefore the surface required may be much larger.<br />
<br />
==Flora and fauna==<br />
Plants can be grown either in liquid fertilizer ([[hydroponics]]) or in [[soil]]. Many plants live in symbiosis with [[microbes]] and [[insects]]. [[Bee]]s can be used to pollinate the blossoms for fruit plants. Probably, the greenhouse is less labor-intensive with as many natural processes as possible, including decay of dead parts of plants to [[compost]]. The growth of flora and fauna under the low Martian [[gravity]] bears some uncertainties.<br />
<br />
==Nutrition and Energy Calculations==<br />
Based upon the figures in the [[food]] and [[sunlight]] articles the following calculations can be carried out for an artificially lit greenhouse:<br />
<br />
The minimum size of cropland per person is about 365 m<sup>2</sup>. The needed [[lighting|light energy]] can be assumed with 1000 kWh per m<sup>2</sup> and year. The result is an annual amount of 365 MWh per person. In other words: An average illumination power of 41,67 kW per person is required.<br />
<br />
The usage of fluorescent lamps with an efficiency factor of 30% results in a requirement of about 140 kW per person in electrical energy. The overall efficiency of food production with artificially lit greenhouses is less then 1 permille, or in other words, to produce food with a content of 1 kWh the amount of more than 1 MWh in electricity must be spent.<br />
<br />
Parts of the required light can possibly be provided by direct or indirect sunlight. [[Heating]] the greenhouse will require additional energy.<br />
<br />
==Open Issues== <br />
<br />
*How long can plants survive without sunlight (e.g. during a dust storm)?<br />
*How many persons are needed to work in the greenhouse to produce enough food for a hundred persons?<br />
*How much energy is required for heating, especially during long lasting dust storms? This question can not be answered without an [[experimental setup#greenhouse heating|experimental setup]].<br />
*What temperature and air pressure do plants need?<br />
*What air pressure is needed for persons to work in the greenhouse?<br />
*What transparent materials match the absorption characteristics of chlorophyll?<br />
*Do plants need wind? How can it be provided?<br />
*What is known about radiation tolerance of food crop?<br />
<br />
==See Also== <br />
<br />
*[[Research on greenhouses & assumptions]]<br />
*[[Experimental setup]]<br />
<br />
==External links==<br />
<br />
*[http://www.marshome.org/archives/2007/03/sidelit_greenho.php The Mars Foundation Side-lit Greenhouse design.]<br />
<br />
{{SettlementIndex}}<br />
<br />
{{Featured_red_ring}}<br />
<br />
[[category:Growing Methods]]</div>Multivachttps://marspedia.org/index.php?title=Sulfur_hexafluoride&diff=136175Sulfur hexafluoride2020-07-26T07:04:25Z<p>Multivac: Created page with "Sulfur hexafluoride is an dense, incredibly potent, long lived greenhouse gas, with a greenhouse potency of over 23,900 times that of CO<sub>2</sub><ref..."</p>
<hr />
<div>[[Sulfur hexafluoride]] is an dense, incredibly potent, long lived greenhouse gas, with a greenhouse potency of over 23,900 times that of [[Carbon_dioxide|CO<sub>2</sub>]]<ref>http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10-2.html</ref>, an atmospheric lifetime of 800–3,200 years<ref>http://www.sciencemag.org/content/259/5092/194.abstract</ref>, and a density almost 6x that of Air. It is useful in [[greenhouse|greenhouses]] and other structures as a buffer gas, and to help maintain habitable temperatures. It has also been suggested as a means to terraform areas on mars<ref>https://www.youtube.com/watch?v=9Ot32cwr9ww</ref>, although using it at small scale to microterraform craters is more feasible.<br />
<br />
SF<sub>6</sub> can be created readily using S and NaF, which are common byproducts of mining.<br />
<br />
#S + (2 + ''x'') Br<sub>2</sub> + 4 KF → SF<sub>4</sub>↑ + ''x'' Br<sub>2</sub> + 4 KBr (~20-80C) <ref>https://en.wikipedia.org/wiki/Sulfur_tetrafluoride</ref><br />
#2&nbsp;CoF<sub>3</sub> + SF<sub>4</sub> + [Br<sub>2</sub>] → SF<sub>6</sub> + 2&nbsp;CoF<sub>2</sub> + [Br<sub>2</sub>] (~100C) <ref>https://en.wikipedia.org/wiki/Sulfur_hexafluoride</ref><br />
<br />
With a theorized step to regenerate the CoF<sub>3</sub> from HF or F<sub>2</sub> as needed, forming a loop.</div>Multivachttps://marspedia.org/index.php?title=Terraforming&diff=136174Terraforming2020-07-26T06:40:10Z<p>Multivac: /* Methods */</p>
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<div>[[File:Logo-Mars-in-a-shell.jpg|thumb|The planet Mars under a global glas dome. This is certainly not an idea of terraforming, but it gives an idea of the dimensions of the topic.]]<br />
'''Terraforming''', or ''Earth-shaping'', is a theoretical process of modifying a planet's atmosphere to make it habitable for humans. In the case of Mars, terraforming would require artificial thickening of the atmosphere to intensify the process of [[greenhouse effect|greenhouse warming]] (heating the frozen landscape), [[water|ice]] melting to increase the H<sub>2</sub>O content of the atmosphere (creating [[clouds|water clouds]]) and greatly increasing the [[oxygen|O<sub>2</sub>]] density to ultimately make the atmosphere breathable. <br />
<br />
==Mars and the "Triple Point" of water== <br />
<br />
[[Image:Phase_diagram_water.png|thumb|right|200px|The phase diagram for water, clearly displaying water's [[triple point]].]] <br />
<br />
Presently, [[water|ice]] on Mars [[sublimation|sublimes]] as the atmospheric pressure is so low, ice bypasses the liquid phase when heated. Sublimation occurs allowing ice to turn directly into gas (steam). One of the main challenges for future terraforming efforts would be to increase the atmospheric pressure significantly so water can exist as a liquid on the surface of Mars. The atmospheric pressure and ambient temperature will therefore need to be greater than the [[triple point]] of water (thereby existing as ice, liquid and gas). This is just above 0C and 600 Pa. Mars atmospheric pressure is already above 600 Pa. However, close to the triple point, water takes very little energy to turn into a gas, so higher pressures would be required in practice. <br />
<br />
==Methods==<br />
A life supporting atmosphere needs to contain a "buffer gas", such as nitrogen. Mars is currently lacking in nitrogen, but nitrogen could be sourced from Venus, Saturn's moon Titan, or from comets.<br />
Mars could be warmed up using greenhouse gases such as perfluorocarbons, which are stable in the atmosphere for long periods of time. Mirrors could be placed in orbit to increase the amount of insolation Mars receives. <br />
<br />
Other greenhouse gasses include [[sulfur hexafluoride]] and 1,1,1-Trichloro ethane. These are very stable and highly effective greenhouse gasses. Use of such gasses to warm the atmosphere would allow the Carbon dioxide frozen into the polar caps and some of the water to evaporate adding to the mass of the atmosphere.If 4 hundredths of a microbar of manufactured greenhouse gas is needed to warm Mars to the point of runaway greenhouse effect, then a mass of manufactured greenhouse gasses equal to about 5.73 times the cargo capacity of the Edmund Fitzgerald (26 000 tonnes) every week for twenty years ( about 150 million tonnes) would be required for the project.<br />
<br />
==Pioneer Organisms==<br />
Certain organisms, such as [[archaea]], [[lichen]], and [[tardigrades]] have been proven capable of surviving extreme environments, such as the vacuum of space. They could gain a foothold on the martian surface after minimal terraforming. The byproducts of their metabolism would contribute to the terraforming efforts.<br />
<br />
==Long term prospects==<br />
<br />
The ultimate results of terraforming are disputed. Terraforming may have only a temporary effect, even if the effect lasts for some hundred or thousand years. Eventually, the [[solar wind]] may carry away most of the new atmosphere due to the insufficient [[magnetosphere|magnetic field]]s of Mars. It has been suggested that the cost of terraforming a planet would be prohibitive, however to a growing population on the surface of that planet it would most likely be considered a normal colonial function to ensure that daily colonial endeavours have a positive effect on the atmosphere. Artificial magnetic fields might also be created around Mars to reduce atmospheric losses to space. And the solar system contains sufficient resources to replenish martian atmosphere indefinitely, but at a significant energy cost. Building space habitats might be a more practical long term objective for human occupation of space.<br />
<br />
==Partial terraforming==<br />
<br />
{| class="wikitable" align="right" style="margin-left:1em;"<br />
|+Present gas abundance on Mars and required limits for plants and humans<br />
|-<br />
!Parameter!!Mars<ref name="Abundance">Mahaffy, P. R.; Webster, C. R.; Atreya, S. K.; Franz, H.; Wong, M.; Conrad, P. G.; Harpold, D.; Jones, J. J.; Leshin, L. A.; Manning, H.; Owen, T.; Pepin, R. O.; Squyres, S.; Trainer, M.; Kemppinen, O.; Bridges, N.; Johnson, J. R.; Minitti, M.; Cremers, D.; Bell, J. F.; Edgar, L.; Farmer, J.; Godber, A.; Wadhwa, M.; Wellington, D.; McEwan, I.; Newman, C.; Richardson, M.; Charpentier, A. - ''Abundance and Isotopic Composition of Gases in the Martian Atmosphere from the Curiosity Rover'', Nature 341, pp. 263-266. DOI:10.1126/science.1237966</ref>, mbar!!Plants<ref name="Making_Mars_habitable">Christopher P. McKay, Owen B. Toon & James F. Kasting - ''Making Mars habitable'', Nature 352, pp. 489-496. DOI:10.1038/352489a0</ref>, mbar!!Humans, mbar<br />
|-<br />
|Total pressure||0.30-11.55 (6 average)||>10||>250<br />
|-<br />
|Carbon dioxide (CO<sub>2</sub>)||0.29-11.09 (5.76 average)||>0.15||<10<br />
|-<br />
|Nytrogen (N<sub>2</sub>)||0.01-0.22 (0.114 average)||>1-10||-<br />
|-<br />
|Oxygen (O<sub>2</sub>)||<0.015||1||>130<br />
|}<br />
<br />
While full terraforming to make Mars atmosphere suitable for breathable condition for humans can take around 100,000 years, transformations to the atmosphere suitable for plants could take from 100 to several thousands years. Current requirements for plants to grow on Mars are based on atmospheric pressure. Mars polar caps have enough CO<sub>2</sub> to provide 100 mbar (10 kPa) additional atmospheric pressure to the existing 6 millibars. This would be enough to create sustainable growth condition for plants.<br />
<br />
To make using pressure suit unnecessary for humans, atmospheric pressure needs to rise to at least 250 mbar (25 kPa) or 25% of Earth atmospheric pressure. This might be composed of 50 mbar of CO<sub>2,</sub> 60 mbar of water vapour and 130 mbar of Oxygen (minimal requirement oxygen pressure).<br />
<br />
This would require extraction some part of the regolith deposits of CO<sub>2</sub> which are estimated to be able to contribute 300 mbar of additional pressure, but require significantly greater time to extract. A 550 mbar atmosphere composed primarily of CO2 with a high fraction of oxygen would have then been achieved.<br />
<br />
==References==<br />
<references /><br />
<br />
[[category:Terraforming]]</div>Multivachttps://marspedia.org/index.php?title=Biological_reactors&diff=136173Biological reactors2020-07-26T05:03:22Z<p>Multivac: /* Syngas to biomass */</p>
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<div>[[Food]] and other products can be produced using industrial biological processes. This makes otherwise complex foods more accessible, it makes foods cheaper to produce and it simplifies the production of the industrial materials required for civilization.<br />
<br />
==Methanotrophs==<br />
Methanotrophs such as [https://en.wikipedia.org/wiki/Methylococcus_capsulatus Methylococcus capsulatus] can use methane and methanol as both a source of energy as well as a carbon source. Using a [[Sabatier_process|sabatier reactor]], nuclear power can be used to convert [[Atmospheric_mining|atmospheric]] CO<sub>2</sub> into food or other biomass. To grow, these methanotrophs also require Nitrogen, Sulfur, Phosphorous and various trace metals. Nitrogen can be captured from the martian atmosphere, by allowing the Methanotrophs to grow in an anoxic atmosphere<ref>https://doi.org/10.1099/00221287-129-11-3481</ref> and nitrogen fix for themselves, or through a Haber reactor on refined atmospheric nitrogen producing [[ammonia]]. Sulfur and phosphorous are accessible in the regolith and will be released through metal processing. Other trace metals are only needed in minute amounts to operate enzymes and are easily recycled. These microbes are currently used on earth to produce animal feed<ref>https://web.archive.org/web/20190802163733/https://www.ntva.no/wp-content/uploads/2014/01/04-huslid.pdf</ref><ref>https://www.newscientist.com/article/2112298-food-made-from-natural-gas-will-soon-feed-farm-animals-and-us/</ref>, and their use in human food production is an active area of [[Biotechnology|biotechnological]] research<ref>https://solarfoods.fi/</ref>. The growth yields of methanotrophs have been extensively studied<ref>https://www.frontiersin.org/articles/10.3389/fmicb.2018.02947/full</ref>, with [[Methanol]]/[[Nitrate]] feedstock with trace amounts of [[Copper]] shown as an optimal point, with lower yields but higher carbon conversion efficiencies than other feedstocks<ref>https://link.springer.com/article/10.1007/BF02346062</ref>.<br />
<br />
==Grass to glucose==<br />
Traditional hydroponic farming is complex and labor intensive. In contrast, growing and harvesting large grasses such as ''Miscanthus Giganteus'' is simple to do in a large scale and automated way through [[cellulose]] farms. These grasses can then be broken down via cellulases to provide an accessible source of glucose, along with other industrially useful compounds such as THF (a common solvent)<ref>https://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.8b00134</ref>.<br />
<br />
==Syngas to biomass==<br />
[[Syngas]], produced through either recycling carbon containing compounds through [https://en.wikipedia.org/wiki/Pyrolysis pyrolysis] or directly from [[carbon_dioxide|CO<sub>2</sub>]] and [[water]], can be used to produce biomass. Organisms such as ''Clostridium carboxidivorans''<ref>https://doi.org/10.1099/ijs.0.63482-0</ref> can directly metabolize [[syngas]] as a source of energy and [[carbon]], forming industrially useful compounds such as [[ethanol]], [[acetic acid]] along with medium chain (C<sub>4</sub>/C<sub>6</sub>) fatty acids and alcohols<ref>https://www.nature.com/articles/s41598-017-10312-2</ref><ref>https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-016-0495-0</ref>. Alternatively, syngas can also be used to produce [[methanol]] or [[methane]] which can be fed to [[Biological_reactors#Methanotrophs|Methanotrophs]].<br />
<br />
==Xenotrophs==<br />
Some organisms, such as [https://microbewiki.kenyon.edu/index.php/Rhodopseudomonas|''Rhodopseudomonas palustris''] have a versatile metabolism, and so can consume a wide variety of chemicals both with and without sunlight in order to grow. It is capable of fixing both atmospheric CO<sub>2</sub> and N<sub>2</sub><ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940424/</ref>, and oxidising things as diverse as Iron<ref>https://www.nature.com/articles/ncomms4391</ref>, aromatic hydrocarbons or plant lignin<ref>https://en.wikipedia.org/wiki/Rhodopseudomonas_palustris</ref> as a source of energy. It has also been shown to be able to produce CH<sub>4</sub> with a modified nitrogenase when grown on acetate/carbonate and exposed to light<ref>https://www.pnas.org/content/pnas/113/36/10163.full.pdf</ref>.<br />
<br />
==Biomass to industrial chemicals==<br />
Using GM microbes, biomass can be digested directly into a series of usable products such as Ammonia, short chain hydrocarbons<ref>https://doi.org/10.1016/j.ymben.2014.02.007</ref>, Adipic acid (a precursor to nylon)<ref>https://doi.org/10.1021/bp010179x</ref>, Phenol (a precursor to plastics) <ref>https://doi.org/10.1002/1521-3757(20010518)113:10%3C1999::AID-ANGE1999%3E3.0.CO;2-A</ref>, or converted to Benzene/Xylene/Toluene via catalytic reforming<ref>https://doi.org/10.1016/j.biortech.2019.01.081</ref>. This allows for greatly simplified industrial chemistry through a mix of careful genetic engineering and choosing biologically accessible industrial precursors.<br />
<br />
==Biomass to engineered foods==<br />
Using genetically modified yeasts, it is also possible to directly produce proteins such as those found in eggs<ref>https://github.com/thethoughtemporium/Whose-gene-is-it-anyway/blob/master/milk-and-eggs/46815%20with%20ovalbumin%20and%20secretion%20tag.gb</ref> or milk<ref>https://github.com/thethoughtemporium/Whose-gene-is-it-anyway/blob/master/milk-and-eggs/4681%205deer%20milk%20b%20casein%20kcasein%20a%20lactalbumin%20and%20b%20lactoglobulin.gb</ref><ref>https://pubchem.ncbi.nlm.nih.gov/patent/US2017273328</ref>. It is also possible to produce various flavonoids, providing a variety of smells and flavors to artificially produced food. Vitimins and other essential nutrients can also be produced and added to ensure that foods are both tasty and nutritious.<br />
<br />
<br />
<references /></div>Multivachttps://marspedia.org/index.php?title=Syngas&diff=136172Syngas2020-07-26T04:09:01Z<p>Multivac: Created page with "Syngas is an industrially useful chemical mixture of CO and H<sub>2</sub>. It is used in the production of methanol, methane and o..."</p>
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<div>[[Syngas]] is an industrially useful chemical mixture of [[Carbon_monoxide|CO]] and [[Hydrogen|H<sub>2</sub>]]. It is used in the production of [[methanol]], [[methane]] and other [[Hydrocarbon_synthesis|hydrocarbon synthesis]]. It can also be used to feed [[Biological_reactors#Methanotrophs|Methanotrophs]] to produce food and other industrially useful products.<br />
<br />
== CO production ==<br />
CO and H<sub>2</sub> can be produced from [[methane]] and [[water]]:<br />
:CH<sub>4</sub> + H<sub>2</sub>O → CO + 3 H<sub>2</sub><br />
<br />
CO can also be produced from CO<sub>2</sub> via high temperature electrolysis in a [[Atmospheric_processing|MOXIE]] or chemically using the [https://en.wikipedia.org/wiki/Bosch_reaction Bosch reaction]:<br />
:CO<sub>2</sub> + H<sub>2</sub> → H<sub>2</sub>O + CO<br />
<br />
or from the thermal decomposition of [[biomass]], [[plastic|plastics]] and other carbon containing compounds through [https://en.wikipedia.org/wiki/Pyrolysis pyrolysis]. <br />
<br />
== H<sub>2</sub> production ==<br />
H<sub>2</sub> can also be obtained through the catalytic splitting of [[ammonia]]:<br />
:2NH<sub>3</sub> → 3H<sub>2</sub> + N<sub>2</sub> (Catalyst: Na+NaNH<sub>2</sub>)<ref>https://pubs.acs.org/doi/pdfplus/10.1021/ja5042836</ref><br />
<br />
H<sub>2</sub> can also be obtained from the splitting of [[water]]:<br />
:2H<sub>2</sub>O → 2H<sub>2</sub> + O<sub>2</sub><br />
Either through [[electrolysis]] or thermally through the Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2006.05.013</ref>. The expanded Zinc/Sulfur/Iodine cycle<ref>https://doi.org/10.1016/j.ijhydene.2015.11.049</ref> produces both CO and H<sub>2</sub>, along with O<sub>2</sub>, which makes it very well suited for this process. The energy for these thermal cycles is likely to come from [[nuclear power]], utilizing a turboinductor<ref>http://www.academia.edu/download/48701931/ACT-RPR-PRO-1107-LS-NTER.pdf</ref> to convert the large amounts of lower temperature heat produced by the reactor to smaller quantities of much higher temperature heat required to run the hottest parts of the cycles.<br />
<br />
== References ==<br />
<references /></div>Multivac