Terraforming of Mars

From Wikipedia, the free encyclopedia

Artist's conception of the process of terraforming Mars.

The terraforming of Mars is the hypothetical process by which Mars's climate and surface would be deliberately changed to make large areas of the environment hospitable to humans, thus making human colonization safer and sustainable.

There are several proposed concepts, some of which present prohibitive economic and natural resource costs, and others that may be currently technologically achievable.^[1]

Motivation and ethics

Future population growth, demand for resources, and an alternate solution to the Doomsday argument may require human colonization of objects other than Earth, such as Mars, the Moon, and nearby planets. Space colonization will facilitate harvesting the Solar System's energy and material resources.^[2]

In many respects, Mars is the most Earth-like of all the other planets in the Solar System. It is thought^[3] that Mars had a more Earth-like environment early in its history, with a thicker atmosphere and abundant water that was lost over the course of hundreds of millions of years. Given the foundations of similarity and proximity, Mars would make one of the most plausible terraforming targets in the Solar System.

Ethical considerations of terraforming include the potential displacement or destruction of indigenous life, even if microbial, if such life exists.^[4][5][6][7]

Challenges and limitations

The Martian environment presents several terraforming challenges to overcome and the extent of terraforming may be limited by certain key environmental factors.

Low gravity

The surface gravity on Mars is 38% of that on Earth. It is not known if this is enough to prevent the health problems associated with weightlessness.^[8] Additionally, the lower gravity of Mars requires 2.6 times Earth’s column airmass to achieve 100 kPa pressure at the surface.^[9]
Earth and Venus^{[dubious – discuss]} are both able to sustain thick atmospheres, even though they experience more of the solar wind that is believed to strip away planetary volatiles. Continuing sources of atmospheric gases on Mars might therefore be required to ensure that an atmosphere sufficiently dense for humans is sustained in the long term.^{[citation needed]}

Countering the effects of space weather

Mars lacks a magnetosphere, which poses challenges for mitigating solar radiation and retaining atmosphere. It is thought that the localized fields detected on Mars are remnants of a magnetosphere that collapsed early in its history.
The lack of a magnetosphere is thought to be one reason for Mars's thin atmosphere. Solar-wind-induced ejection of Martian atmospheric atoms has been detected by Mars-orbiting probes. Venus, however, clearly demonstrates that the lack of a magnetosphere does not preclude a dense atmosphere.^{[citation needed]}

Earth abounds with water because its ionosphere is permeated with a magnetosphere. The hydrogen ions present in its ionosphere move very fast due to their small mass, but they cannot escape to outer space because their trajectories are deflected by the magnetic field. Venus has a dense atmosphere, but only traces of water vapor (20 ppm) because it has no magnetic field.^[10] The Martian atmosphere also loses water to space. Earth's ozone layer provides additional protection. Ultraviolet light is blocked before it can dissociate water into hydrogen and oxygen. Because little water vapor rises above the troposphere and the ozone layer is in the upper stratosphere, little water is dissociated into hydrogen and oxygen.^{[citation needed]}

The Earth's magnetic field is 31 µT. Mars would require a similar magnetic-field intensity to similarly offset the effects of the solar wind at its distance further from the Sun.

Advantages

Hypothetical terraformed Mars

According to modern theorists, Mars exists on the outer edge of the habitable zone, a region of the Solar System where life can exist. Mars is on the border of a region known as the extended habitable zone where liquid water on the surface may be supported if concentrated greenhouse gases could increase the atmospheric pressure.^{[citation needed]}

The lack of both a magnetic field and geologic activity on Mars may be a result of its relatively small size, which allowed the interior to cool more quickly than Earth's, though the details of such a process are still not well understood.^[11][12]

It has been suggested that Mars once had an atmosphere as thick as Earth's during an earlier stage in its development, and that its pressure supported abundant liquid water at the surface.^[13] Although water appears to have once been present on the Martian surface, water ice appears to exist at the poles just below the planetary surface as permafrost. The soil and atmosphere of Mars contain many of the main elements crucial to life, including sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon.^[14]

Large amounts of water ice exist below the Martian surface, as well as on the surface at the poles, where it is mixed with dry ice, frozen CO₂. Significant amounts of water are located in the south pole of Mars, which, if melted, would correspond to a planetwide ocean 11 meters deep.^[15] Frozen carbon dioxide (CO₂) at the poles sublimes into the atmosphere during the Martian summers, and small amounts of water residue are left behind, which fast winds sweep off the poles at speeds approaching 400 km/h (250 mph).^{[citation needed]} This seasonal occurrence transports large amounts of dust and water vapor into the atmosphere, forming Earth-like clouds.^[16]

Most of the oxygen in the Martian atmosphere is present as carbon dioxide (CO₂), the main atmospheric component. Molecular oxygen (O₂) only exists in trace amounts. Large amounts of elemental oxygen can be also found in metal oxides on the Martian surface, and in the soil, in the form of per-nitrates.^[17] An analysis of soil samples taken by the Phoenix lander indicated the presence of perchlorate, which has been used to liberate oxygen in chemical oxygen generators.^[18] Electrolysis could be employed to separate water on Mars into oxygen and hydrogen if sufficient liquid water and electricity were available.^{[citation needed]}

Proposed methods and strategies

Comparison of dry atmosphere

	Mars	Earth
Pressure	0.6 kPa (0.087 psi)	101.3 kPa (14.69 psi)
Carbon dioxide (CO2)	96.0%	0.04%
Argon (Ar)	2.1%	0.93%
Nitrogen (N2)	1.9%	78.08%
Oxygen (O2)	0.145%	20.94%

Artist's conception of a terraformed Mars centered on the Tharsis region

Artist's conception of a terraformed Mars. This portrayal is approximately centered on the prime meridian and 30° North latitude, and a hypothesized ocean with a sea level at approximately two kilometers below average surface elevation. The ocean submerges what are now Vastitas Borealis, Acidalia Planitia, Chryse Planitia, and Xanthe Terra; the visible landmasses are Tempe Terra at the left, Aonia Terra at the bottom, Terra Meridiani at the lower right, and Arabia Terra at the upper right. Rivers that feed the ocean at the lower right occupy what are now Valles Marineris and Ares Vallis and the large lake at the lower right occupies what is now Aram Chaos.

Terraforming Mars would entail three major interlaced changes: building up the atmosphere, keeping it warm, and keeping the atmosphere from being lost to outer space.^{[citation needed]} The atmosphere of Mars is relatively thin and has a very low surface pressure. Because its atmosphere consists mainly of CO₂, a known greenhouse gas, once Mars begins to heat, the CO₂ may help to keep thermal energy near the surface. Moreover, as it heats, more CO₂ should enter the atmosphere from the frozen reserves on the poles, enhancing the greenhouse effect. This means that the two processes of building the atmosphere and heating it would augment one another, favoring terraforming.^{[citation needed]}

Carbon dioxide sublimation

There is presently enough carbon dioxide (CO₂) as dry ice in the Martian south pole and absorbed by regolith (soil) on Mars that, if sublimated to gas by a climate warming of only a few degrees, would increase the atmospheric pressure to 30 kilopascals (0.30 atm),^{[19][not in citation given]} comparable to the altitude of the peak of Mount Everest, where the atmospheric pressure is 33.7 kilopascals (0.333 atm). Although this would not be breathable by humans, it is above the Armstrong limit and would eliminate the present need for pressure suits.^{[citation needed]} Phytoplankton can also convert dissolved CO₂ into oxygen. This is important because Henry's law states that a high level of atmospheric CO₂ will result in a high concentration of dissolved CO₂ in any body of liquid water (especially an ocean in the Northern Polar Basin), particularly at Mars's low temperature where gases will dissolve in liquids easily.^{[citation needed]}

Importing ammonia

Another more intricate method uses ammonia as a powerful greenhouse gas. It is possible that large amounts of it exist in frozen form on minor planets orbiting in the outer Solar System. It may be possible to move these and send them into Mars's atmosphere.^[20] Because ammonia (NH₃) is mostly nitrogen by weight, it could also supply the buffer gas for the atmosphere. Sustained smaller impacts will also contribute to increases in the temperature and mass of the atmosphere.

The need for a buffer gas is a challenge that will face any potential atmosphere builders. On Earth, nitrogen is the primary atmospheric component, making up 78% of the atmosphere. Mars would require a similar buffer-gas component although not necessarily as much.^{[citation needed]}

Importing hydrocarbons

Another way to create a martian atmosphere would be to import methane or other hydrocarbons,^[21][22] which are common in Titan's atmosphere and on its surface); the methane could be vented into the atmosphere where it would act to compound the greenhouse effect.^{[citation needed]}

Use of fluorine compounds

Because long-term climate stability would be required for sustaining a human population, the use of especially powerful fluorine-bearing greenhouse gases, possibly including sulfur hexafluoride or halocarbons such as chlorofluorocarbons (or CFCs) and perfluorocarbons (or PFCs), has been suggested.^[9] These gases are proposed for introduction because they produce a strong effect as greenhouse gases thousands of times stronger than CO₂. This can conceivably be done by sending rockets with payloads of compressed CFCs on collision courses with Mars.^[17] When the rockets crash onto the surface they release their payloads into the atmosphere. A steady barrage of these "CFC rockets" would need to be sustained for a little over a decade while Mars changes chemically and becomes warmer. However, their lifetime due to photolysis would require an annual replenishing of 170 kilotons,^[9] and they would destroy any ozone layer.^[9]

In order to sublimate the south polar CO₂ glaciers, Mars would require the introduction of approximately 0.3 microbars of CFCs into Mars's atmosphere. This is equivalent to a mass of approximately 39 million metric tons. This is about three times the amount of CFC manufactured on Earth from 1972 to 1992 (when CFC production was banned by international treaty). Mineralogical surveys of Mars estimate the elemental presence of fluorine in the bulk composition of Mars at 32 ppm by mass vs. 19.4 ppm for the Earth.^[9]

A proposal to mine fluorine-containing minerals as a source of CFCs and PFCs is supported by the belief that because these minerals are expected to be at least as common on Mars as on Earth, this process could sustain the production of sufficient quantities of optimal greenhouse compounds (CF₃SCF₃, CF₃OCF₂OCF₃, CF₃SCF₂SCF₃, CF₃OCF₂NFCF₃, C₁₂F₂₇N) to maintain Mars at 'comfortable' temperatures, as a method of maintaining an Earth-like atmosphere produced previously by some other means.^[9]

Use of orbital mirrors

Mirrors made of thin aluminized PET film could be placed in orbit around Mars to increase the total insolation it receives.^[1] This would direct the sunlight onto the surface and could increase Mars's surface temperature directly. The mirror could be positioned as a statite, using its effectiveness as a solar sail to orbit in a stationary position relative to Mars, near the poles, to sublimate the CO₂ ice sheet and contribute to the warming greenhouse effect.^[1]

Albedo reduction

Reducing the albedo of the Martian surface would also make more efficient use of incoming sunlight.^[23] This could be done by spreading dark dust from Mars's moons, Phobos and Deimos, which are among the blackest bodies in the Solar System; or by introducing dark extremophile microbial life forms such as lichens, algae and bacteria.^{[citation needed]} The ground would then absorb more sunlight, warming the atmosphere.

If algae or other green life were established, it would also contribute a small amount of oxygen to the atmosphere, though not enough to allow humans to breathe. The conversion process to produce oxygen is highly reliant upon water. The CO₂ is mostly converted to carbohydrates.^[24] On 26 April 2012, scientists reported that lichen survived and showed remarkable results on the adaptation capacity of photosynthetic activity within the simulation time of 34 days under Martian conditions in the Mars Simulation Laboratory (MSL) maintained by the German Aerospace Center (DLR).^[25][26]

Comet impact

Another way to increase the temperature could be to direct small comets onto the Martian surface.^{[citation needed]} This could be achieved through use of spaceborne lasers to alter trajectories or other methods proposed for asteroid impact avoidance.^{[citation needed]} The impact energy would be released as heat. This heat could sublimate CO₂ or, if there is liquid water present at this stage of the terraforming process, could vaporize it to steam, which is also a greenhouse gas. Comets could also be chosen for their composition, such as ammonia, which would then disperse into the atmosphere on impact, adding greenhouse gases to the atmosphere.^{[citation needed]}

Thermodynamics of terraforming

The overall energy required to sublimate the CO₂ from the south polar ice cap is modeled by Zubrin and McKay.^[1] Raising temperature of the poles by 4 K would be necessary in order to trigger a runaway greenhouse effect. If using orbital mirrors, an estimated 120 MWe-years would be required in order to produce mirrors large enough to vaporize the ice caps. This is considered the most effective method, though the least practical. If using powerful halocarbon greenhouse gases, an order of 1000 MWe-years would be required to accomplish this heating. Although ineffectual in comparison, it is considered the most practical method.^{[citation needed]} Impacting an asteroid, which is often considered a synergistic effect, would require approximately four 10-billion-tonne ammonia-rich asteroids to trigger the runaway greenhouse effect, totaling an eight degree increase in temperature.^{[citation needed]}

First baby born from IVF technique which eliminates inherited disease

A pioneering IVF technique allows babies at risk from inherited illnesses to be born free of disease

Baby Lucas with his parents Carmen and Gabriel Photo: Geoff Pugh

By Sarah Knapton, Science Editor

9:00PM GMT 28 Mar 2015

Original link:  http://www.telegraph.co.uk/news/science/science-news/11495591/First-baby-born-from-IVF-technique-which-eliminates-inherited-disease.html

The first baby has been born in Europe from a new IVF procedure that checks embryos for devastating genetic disorders.

Lucas Meagu was at high risk of inheriting a rare form of muscular dystrophy which would have left him with weak muscles making walking and everyday tasks difficult.

However, a ground-breaking technique which is being pioneered by fertility doctors in London has allowed Lucas to be born fit, healthy and free of disease.

Traditional embryo testing procedures require months of laboratory work but the latest technique, known as karyomapping, takes less than a fortnight and can pick up a range of diseases.

Lucas’ mother Carmen, 26, who works in recruitment, inherited Charcot-Marie-Tooth disease from her father who suffered with the illness all his life.

It causes weakness and wasting of the muscles below the knees and often those of the hands and can lead to loss of feeling in the fingers and legs.

Although Mrs Meagu only has mild symptoms, she was concerned that her children would inherit the disease and specialists warned that there was a 50 per cent chance she would pass on the illness.

“For me the risk was too high,” she said. “My dad had severe symptoms and it really got him down. He was unable to walk unaided and he always felt people were looking at him and staring. It had a massive impact on him mentally.

^{Baby Lucas Meagu was at high risk of inheriting a rare form of muscular dystrophy}
 
“I was told I could try and get pregnant and have a test at 16 weeks, but that really wasn’t an option for me because it would have been too hard to have an abortion at that stage.

“Then we were told about a clinic in London which could screen the disease out, and we felt we had to try.”
 
To isolate the genes responsible for Charcot-Marie-Tooth disease doctors took DNA swabs from Mrs Meagu, her mother and Lucas’s father Gabriel, 30, who works for Vodafone.
They then compared the gene sequences at 300,000 different points of the chromosomes to work out which section of genetic code was defective and responsible for the abnormality.

The couple then underwent a normal IVF cycle but, crucially, the embryos created from the procedure were biopsied to find out which ones were free of the genetic disease.

The test also checks that embryos have the right number of chromosomes, a common cause of miscarriage and developmental disorders, such as Down's syndrome.

The procedure started in December 2013 and Lucas was born a year later. He is now three months old, happy and healthy.

Mrs Meagu added: “Lucas is absolutely perfect. He is really big for his age, and healthy. I have peace of mind now that he is going to be ok.

“I obviously worry, like all mother’s, but now I worry about normal things. I know for sure that he is not only free of Charcot-Marie-Tooth disease but also other illnesses.

“I would recommend it to any other mother who is worried about passing on an illness.”

The procedure, which is now available on the NHS, gives renewed hope to parents who are concerned about passing on serious genetic faults to their children.

And because most people undergoing the procedure do not suffer from fertility problems, the chances of becoming pregnant are higher than usual IVF rates.

^{Mr and Mrs Meagu hope to grow their family within the next few years}

Mr and Mrs Meagu froze two more embryos during the first round of IVF and are planning to have at least one more child within the next five years.

Fertility expert Paul Serhal, the founder of Centre of Reproductive and Genetic Health, said: “Essentially, karyomapping finds a fingerprint that is unique to the chromosome that carries the defective gene.

“It is then possible to test embryos produced using IVF for this presence of this fingerprint. Whenever the fingerprint is seen in an embryo it means that it has inherited the chromosome carrying the defective gene.

“By obtaining a blood sample form Carmen, her husband and another close relative, we were able to prepare their diagnosis in a matter of weeks.

“The test checked for Charcot Marie Tooth disease and at the same time for chromosomal abnormalities, such as Down’s syndrome, enabling us to avoid inadvertently transferring an embryo which may otherwise not have been viable. We were of course delighted to hear of the safe arrival of their baby.”

Jeffrey Smith: ‘I know nothing about GMOs but that doesn’t stop me from promoting junk science’

Jon Entine | April 6, 2015 | Genetic Literacy Project

 

Original link:  http://geneticliteracyproject.org/2015/04/jeffrey-smith-i-know-nothing-about-gmos-but-that-doesnt-stop-me-from-promoting-junk-science/

 

 

Smith demonstrating “yogic flying” at Natural Law Party press conference in Springfield, Ill., Oct. 22, 1996.

Recently on the Huffington Post we came across a disturbing article – an attack by Jeffrey Smith on two respected university professors who apply a critical eye to the claims made by various advocates alleging dangers to human health linked to genetically modified organisms (GMOs.)

Smith, if you are not familiar with him, heads up a one-man band rabidly anti-GMO organization known as the Institute for Responsible Technology–he and his organization are controversial to say the least, but more on that later.

Bruce Chassy

The subject of the attack piece was co-written by University of Illinois emeritus professor Bruce Chassy and University of Melbourne geneticist David Tribe. It appears on the website of AcademicsReview, an independent non-profit set up by the scholars to address the maelstrom of misinformation that passes for debate on the GMO issue.

In one of their most pointed and heavily circulated critiques, Chassy and Tribe examine one of Smith’s two self-published books that supposedly ‘prove’ that GMO foods are reckless and dangerous. Chassy and Tribe’s critique titled “Yogic Flying and GM Foods: The Wild Theories of Jeffrey Smith,” addressed each of the 65 major

David Tribe

claims Smith makes about the safety of GMOs, using peer reviewed research and fact-based evidence to refute every one.

Smith’s response in the Huffington Post defends his claims by citing the example of the FLAVR SAVR™ tomato. Let’s take a closer look at Smith’s “new” claims.

It is not clear why, in 2015, Smith would choose to mount an argument claiming dangers from “GMOs” based on an obsolete tomato variety developed more than 25 years ago that has been off the market for two decades. But Smith chose to defend his mistaken and falsified claims that the Food and Drug Administration had botched its review of the tomato and suppressed warnings from its staff about alleged dangers.
The first thing to note is that three of Smith’s ten embedded links to
comments by FDA officials supposedly casting doubt on the safety of
the tomato or the review process don’t work. In any case, what Smith
leaves out is worth noting.

The FLAVR SAVR™ tomato, developed by Calgene, was the first “bioengineered” food ever reviewed by FDA. At that time FDA had no formalized process for such reviews, so, typically, officials bent over backwards to make sure they didn’t miss anything that might be important or relevant.

Among other things, FDA scientists did not yet have a clear view of what kind of tests were needed to ensure safety and much of the back and forth among agency scientists that Smith argues is evidence of corruption and bad faith is, in context, simply and obviously, the record of folks trying to figure out how to get it right. This is evident to those who read the documents without presupposing conspiracies and evil intent. Read through the documents Smith cites yourself and see what you think. But read them all, from beginning to end; don’t short cut. The full, boring, bureaucratic context is, in fact, the essential point.

Smith refers to a selected compilation (i.e. “cherry picked”) of FDA documents he claims supports his case. The specific “smoking gun” supposedly proving the dangers of this tomato is that in a total of 39 studies involving 456 rats, 12 animals fed the tomatoes showed “erosions” in their digestive tracts. The question is whether these were caused by eating the tomatoes, or by something else, such as the feeding procedures or stress on the animals because of their confinement, both plausible explanations. Without corroborating evidence, Smith insists the tomatoes were at fault, and he cites documents long available in the public record as evidence that facts were suppressed. But the documents, in their entirety, show the opposite of what Smith claims; the FDA reviewed all of the available data and affirmed the safety of the tomato.

One of us (Val Giddings) read these documents when they first came out as he was at the time a regulator in the biotech products division of the U.S. Department of Agriculture, and had been peripherally involved with USDA’s review of the Calgene tomato. The documents didn’t support Smith’s conspiracy theories then and that hasn’t changed in the 22 years since.

Consider item 15 on Smith’s list (chosen entirely at random as one of his few cited links that actually worked). Smith has offered it as one of many documents showing a conspiracy to suppress findings of dangers to consumers of the tomato. What does it show? Read it in its entirety for yourself and reach your own conclusions. If you do, you will find this statement, from an FDA official summarizing for his superiors:

All I can do is state my opinion that the data does not show any real toxicity. The requirements that one should have in this data (and in data generally) for a real finding [of toxicity] are:

1. A strong association between the alleged cause (treatment) and the effect. Here the association is weak and variable and the effect seems spurious and unlikely to be reproduced.
2. Specificity (One should not find the effect produced by other extraneous factors. (Here we find the effect produced in the controls.)
3. A biological gradient evidenced by a clear dose response. (This feature was not present in these studies.)
4. Consistent data shown by positive results in repeated studies. (Here a second study is negative.
5. A plausible biological mechanism for the treatment and the effect observed. (Here the tomatine levels were shown to be the same as in regular tomatoes and the acid in tomatoes is much weaker than stomach acid itself. No other likely treatment related cause is apparent.) On the other hand the stress-induced fasting is plausible.

At least two things stand out that are worth emphasizing: first, Smith claims the observed lesions were caused by the tomatoes, yet they were also seen, in the first experiment, in control rats that were not exposed; second, in the repeat experiment, no lesions at all were noted. This argues strongly against the tomatoes as the cause of the lesions seen in the first experiment, and suggests they were in fact an accidental result of the experimental procedures, which involved inserting a feeding tube down the throats of the rats – a technique that requires skill, and is easy to get wrong.

Bottom line: FDA evaluators considered all the data, compared observations to what would be expected if the tomatoes were in fact the cause of the lesions, and when things didn’t add up, they concluded, following well established principles of toxicology, that whatever caused the lesions it wasn’t the tomatoes. And they documented their analysis and conclusions for the record. End of story.

But Smith disputes FDA’s conclusion, despite the clear absence of any of the signs that would be expected if the tomatoes were in fact guilty, as enumerated above. Now Smith may sincerely believe FDA got it wrong, but there is nothing in the record to support his belief, and the science does not back him up.

Furthermore, Smith does more than just misunderstand and misrepresent ancient bureaucratic documents on obsolete products. He also writes:

To claim that there are no new potential health hazards from GMOs is absurd. Fran Sharples, the Director of the Board on Life Sciences at the US National Academy of Sciences (NAS), told me, “The academies have issued numerous reports on assessing the risks of transgenic plants. If the academy believed there were no such potential risks, why would we have delved into these matters in these reports?”

This is intriguing. Fran Sharples has been working in this area for three decades. She has a well-deserved reputation for probity and professionalism. This comment does not sound like something she would say (if only for its clumsy phrasing). So, having known Dr. Sharples for three decades, we reached out to her and asked if Smith’s quote was accurate. Her reply:

To be perfectly honest, I have no recollection of ever talking to this guy or of making such a statement. For all I know, he made it up. It’s a mystery and a bit unsettling to find my name in print in association with something I have no memory of.

It is also worth pointing out that the words Smith attributes to Dr. Sharples make no sense to anyone familiar with how the National Academy of Sciences works. The Academy generally does not pick and choose the topics of its studies, but rather responds to requests to examine issues, most often from government agencies. The Academy enlists …the aid of the nation’s most knowledgeable scientists, engineers, health professionals, and other experts who volunteer their time to produce reports that have led to some of the most significant and lasting improvements in the health, education, and welfare of all the world’s citizens.

It is commonplace for U.S. Government Agencies under assault by parties unwilling to follow where the data leads to request an impartial third party review from the Academy, which has frequently happened on GMO related issues. But as the present case demonstrates, folks unpersuaded by data are difficult to persuade by examinations of data.


One might wonder what would motivate someone to embark on a campaign of hostility toward innovations in food and agriculture that have already delivered enormous benefits around the world, particularly to small farmers in developing countries? There doesn’t appear to be anything in Smith’s previous background as an accomplished ballroom dance instructor or practitioner of yogic flying (yes, see accompanying picture) that would lead one to anticipate such an obsession.

Perhaps it is related to his membership in the Maharishi religious cult that seems to make opposition to innovation in agricultural biotechnology one of its central tenets. Whatever Smith’s motivation, the weaknesses of his claims are not repaired by his ineffective attempts in their defense.

At this point, it may be worth considering the credentials of the folks at odds here. David Tribe, a microbiology PhD, is a Senior Lecturer in microbiology, recognized around the world for his expertise in biotechnology and food safety, widely published and cited in peer-reviewed literature, and noted for his dedication to education and public service. Bruce Chassy, a biochemistry PhD, was a research chemist at the National Institutes of Health, received the Public Health Service Distinguished Service Award, served as Professor and Head of the Department of Food Science and Human Nutrition at the University of Illinois, and as a food safety expert on the FDA’s Food Advisory Committee.

Jeffrey Smith? His academic training and expertise in crop biotechnology is easily summarized: none. His credentials? He has self-published two books about the apocalyptic dangers of GM crops and foods and self-produced documentary narrated by the wife of Dr. Oz. He goes on Dr. Oz and other fringe science shows. And he travels around the world, addressing rabidly anti-GMO audiences with a the fervor of a religious fanatic.
One is free to choose who are the more credible commentators on biotechnology.

L. Val Giddings is a Senior Fellow with the Information Technology and Innovation Foundation. He is a genetics PhD with 3 decades of global experience in the science, policy, and regulation of innovations in agricultural biotechnology.

Jon Entine, executive director of the Genetic Literacy Project, is a Senior Fellow at the World Food Center Institute for Food and Agricultural Literacy, University of California-Davis. Follow @JonEntine on Twitter

Human mission to Mars

From Wikipedia, the free encyclopedia

Crewmembers setting up weather monitoring equipment on the surface of Mars (artist's concept).

A human mission to Mars has been the subject of science fiction, engineering, and scientific proposals throughout the 20th century and into the 21st century. The plans comprise proposals to land on Mars, eventually settling on and terraforming the planet, while exploiting its moons, Phobos and Deimos.

Exploration of Mars has been a goal of national space programs for decades. Preliminary work for missions that would involve human explorers has been undertaken since the 1950s, with planned missions typically being cited as taking place 10 to 30 years in the future when they are drafted. The list of manned Mars mission plans in the 20th century shows the various mission proposals that have been put forth by multiple organizations and space agencies in this field of space exploration.

In terms of the current U.S. space program, NASA's long-term program Orion has a projected pace of development such that, as of late 2014, human spaceflight to Mars is anticipated in about 2035. That mission will be preceded by shorter flights for the up to four-person capsule involved, with experiments taking place to better the technologies protecting Mars-bound astronauts from the radiation of deep space.^[1]

In fiction, the concept of humans traveling to and terraforming Mars has been explored in books, graphic novels, and films. Examples include: Kim Stanley Robinson's Mars trilogy, Total Recall, Red Planet, and Ghosts of Mars. The appeal of space-travel to the planet is a major aspect to Mars in fiction.

Travel to Mars

Closest approaches of Mars to Earth, 2014-2061. Communication times are slightly shorter when it is closest.

In interplanetary travel the energy needed for transfer between planetary orbits is lowest at intervals fixed by the synodic period. For Earth / Mars trips, this is every 26 months (2 years and 2 months),^[2] so missions are typically planned to coincide with one of these launch windows. The energy needed in the low-energy windows varies on roughly a 15-year cycle^[2] with the easiest windows needing only half the energy of the peaks.^[3] In the 20th century, there was a minimum in the 1969 and 1971 launch windows and another low in 1986 and 1988, then the cycle repeated.^[2]

Several types of mission plans have been proposed, such as the opposition class and conjunction class,^[3] or the Crocco flyby.^[4] However, typical Mars mission plans have round-trip flight times of 400 to 450 days.^[5] A fast Mars mission of 245 days round trip could be possible with on-orbit staging.^[6] Using Hohmann transfer orbits is a common plan. In 2014 Ballistic capture was proposed, which may reduce fuel cost and provide more flexible launch windows compared to the Hohmann.^[7]

Challenges

Comparison of radiation doses - includes the amount detected on the trip from Earth to Mars by the RAD inside the MSL (2011 - 2013).^[8][9][10] The vertical axis is in logarithmic scale. The dose over a Mars year is about 15 times the DOE limit, not less than twice, as a quick glance might suggest.

There are several key challenges for human missions to Mars:

1. Costs of sending people to Mars. Estimates have ranged from $6 billion to $500 billion for crewed programs.^[11][12][13]
2. Health threats from exposure to high-energy cosmic rays and other ionizing radiation.^[14][15][16] On 31 May 2013, NASA scientists reported that a possible manned mission to Mars may involve a great radiation risk based on the amount of energetic particle radiation detected by the RAD on the Mars Science Laboratory while traveling from the Earth to Mars in 2011-2012. The calculated radiation dose was 0.66 sieverts round-trip. The agency's career radiation limit for astronauts is 1 sievert.^{[8][9][10][17]}
3. Negative effects of a prolonged low-gravity environment on human health, including eyesight loss.^[18][19][20]
4. Psychological effects of isolation from Earth and, by extension, the lack of community due to impossibility of real-time connections with Earth.
5. Social effects of several humans living under crowded conditions for more than one Earth year, possibly two or three years, on the mission to Mars, and a comparable length of time on the return to Earth.
6. Inaccessibility of terrestrial medical facilities.
7. Equipment failure of propulsion or life-support systems.
8. Forward contamination of potential habitable zones.^[21]
9. Back contamination of Earth with possible Martian microbes.

Some of these issues were estimated statistically in the HUMEX study.^[22] Ehlmann and others have reviewed political and economic concerns, as well as technological and biological feasibility aspects.^[23] While fuel for roundtrip travel could be a challenge, methane and oxygen can be produced using Martian H₂O (preferably as water ice instead of liquid water) and atmospheric CO₂ with mature technology.^[24]

Mission proposals

20th century

Over the last century, a number of mission concepts for such an expedition have been proposed. David Portree's history volume Humans to Mars: Fifty Years of Mission Planning, 1950 - 2000 discusses many of these.^[2]

Wernher von Braun proposal (1947 through 1950s)

Wernher von Braun was the first person to make a detailed technical study of a Mars mission.^[2][25] Details were published in his book Das Marsprojekt (1952); published in English as The Mars Project^[26] (1962) and several subsequent works,^[27] and featured in Collier's magazine in a series of articles beginning March 1952. A variant of the Von Braun mission concept was popularized in English by Willy Ley in the book The Conquest of Space (1949), featuring illustrations by Chesley Bonestell. Von Braun's Mars project envisioned nearly a thousand three-stage vehicles launching from Earth to ferry parts for the Mars mission to be constructed at a space station in Earth orbit.^[25][28] The mission itself featured a fleet of ten spacecraft with a combined crew of 70 heading to Mars, bringing three winged surface excursion ships that would land horizontally on the surface of Mars. (Winged landing was considered possible because at the time of his proposal, the Martian atmosphere was believed to be much denser than was later found to be the case.)

In the 1956 revised vision of the Mars Project plan, published in the book The Exploration of Mars by Wernher Von Braun and Willy Ley, the size of the mission was trimmed, requiring only 400 launches to put together two ships, still carrying a winged landing vehicle.^[29] Later versions of the mission proposal, featured in the Disney "Man In Space" film series,^[30] showed nuclear-powered ion-propulsion vehicles for the interplanetary cruise.

U.S. proposals (1950s and 1960s)

Artist's conception of the Mars Excursion Module (MEM) proposed in a NASA study in 1963.

In 1962, Aeronutronic Ford,^[31] General Dynamics and the Lockheed Missiles and Space Company made studies of Mars mission designs as part of NASA Marshall Spaceflight Center "Project EMPIRE".^[25] These studies indicated that a Mars mission (possibly including a Venus fly-by) could be done with a launch of eight Saturn V boosters and assembly in low Earth orbit, or possibly with a single launch of a hypothetical "post Saturn" heavy-lift vehicle. Although the EMPIRE missions were only studies, and never proposed as funded projects, these were the first detailed analyses of what it would take to accomplish a human voyage to Mars using data from the actual NASA spaceflight, and laid much of the basis for future studies, including significant mission studies by TRW, North American, Philco, Lockheed, Douglas, and General Dynamics, along with several in-house NASA studies.^[25]

Following the success of the Apollo Program, von Braun advocated a manned mission to Mars as a focus for NASA's manned space program.^[32] Von Braun's proposal used Saturn V boosters to launch nuclear-powered (NERVA) upper stages that would power two six-crew spacecraft on a dual mission in the early 1980s. The proposal was considered by (then president) Richard Nixon but passed over in favor of the Space Shuttle.

Soviet mission proposals (1956 through 1970)

The Martian Piloted Complex or "'MPK'" was a proposal by Mikhail Tikhonravov of the Soviet Union for a manned Mars expedition, using the (then proposed) N-1 rocket, in studies from 1956 to 1962.

Artist's depiction of TMK-MAVR

Heavy Interplanetary Spacecraft (known by the Russian acronym TMK) was the designation of a Soviet Union space exploration proposal in the 1960s to send a manned flight to Mars and Venus (TMK-MAVR design) without landing. The TMK spacecraft was due to launch in 1971 and make a three-year-long flight including a Mars fly-by at which time probes would have been dropped. The TMK project was planned as an answer from the Soviet Union to the United States manned moon landings. The project was never completed because the required N1 rocket never flew successfully.

The Mars Expeditionary Complex, or "'MEK"' (1969) was another Soviet proposal for a Mars expedition that would take a crew from three to six to Mars and back with a total mission duration of 630 days.

Case for Mars (1981–1996)

Following the Viking missions to Mars, between 1981 and 1996 a series of conferences named The Case for Mars were held at the University of Colorado at Boulder. These conferences advocated human exploration of Mars, presented concepts and technologies, and held a series of workshops to develop a baseline concept for the mission.
The baseline concept was notable in that it proposed use of In Situ Resource Utilization to manufacture rocket propellant for the return trip using the resources of Mars. The mission study was published in a series of proceedings volumes^[33][34] published by the American Astronautical Society. Later conferences in the series presented a number of alternative concepts, including the "Mars Direct" concept of Robert Zubrin and David Baker; the "Footsteps to Mars" proposal of Geoffrey A. Landis,^[35] which proposed intermediate steps before the landing on Mars, including human missions to Phobos; and the "Great Exploration" proposal from Lawrence Livermore National Laboratory, among others.

NASA Space Exploration Initiative (1989)

Artist's conception of a human mission on the surface of Mars
1989 painting by Les Bossinas of Lewis Research Center for NASA

In response to a presidential initiative, NASA made a study of a project for human lunar- and Mars exploration as a proposed follow-on to the International Space Station project. This resulted in a report, called the 90-day study,^[36] in which the agency proposed a long-term plan consisting of completing the Space Station as "a critical next step in all our space endeavors," returning to the moon and establishing a permanent base, and then sending astronauts to Mars. This report was widely criticized as too elaborate and expensive, and all funding for human exploration beyond Earth orbit was canceled by Congress.^[37]

Mars Direct (early 1990s)

Because of the distance between Mars and Earth, the Mars mission would be much more risky and more expensive than past manned flights to the Moon. Supplies and fuel would have to be prepared for a 2-3 year round trip and the spacecraft would have to be designed with at least partial shielding from intense solar radiation. A 1990 paper by Robert Zubrin and David A. Baker, then of Martin Marietta, proposed reducing the mission mass (and hence the cost) with a mission design using in situ resource utilization to manufacture propellant from the Martian Atmosphere.^[38][39] This proposal drew on a number of concepts developed by the former "Case for Mars" conference series. Over the next decade, this proposal was developed by Zubrin into a mission concept, Mars Direct, which he developed in a book, The Case for Mars (1996). The mission is advocated by the Mars Society, which Zubrin founded in 1998, as a practical and affordable plan for a manned Mars mission.

International Space University (1991)

In 1991 in Toulouse, France, the International Space University studied an international human Mars mission.^[40] They proposed a crew of 8 traveling to Mars in a nuclear-powered vessel with artificial gravity provided by rotation.^[40] On the surface, 40 tonne habitats pressurized to 10 psi were powered by a 40 kW photovoltaic array.^[40]

NASA Design reference missions (1990s)

NASA Mars habitat concept for DRA 1.0, derived from the Mars Direct Architecture. (1995)

In the 1990s NASA developed several conceptual level human Mars exploration architectures. One of these was NASA Design reference mission 3.0 (DRM 3.0). It was a study performed by the NASA Mars Exploration Team at the NASA's Johnson Space Center (JSC) in the 1990s. Personnel representing several NASA field centers formulated a "Reference Mission" addressing human exploration of Mars. The plan describes a human mission to Mars with concepts of operations and technologies to be used as a first cut at an architecture. The architecture for the Mars Reference Mission builds on previous work, principally on the work of the Synthesis Group (1991) and Zubrin's (1991) concepts for the use of propellants derived from the Martian atmosphere. The primary purpose of the Reference Mission was to stimulate further thought and development of alternative approaches, which can improve effectiveness, reduce risks, and reduce cost. Improvements can be made at several levels; for example, in the architectural, mission, and system levels.

Selected other US/NASA plans (1988–2009):^[41]

1) 1988 "Mars Expedition"

2) 1989 "Mars Evolution"

3) 1990 "90-Day Study"

4) 1991 "Synthesis Group"

5) 1995 "DRM 1"

6) 1997 "DRM 3"

7) 1998 "DRM 4"

8) 1999 "Dual Landers"

21st Century

NASA Design reference missions (2000+)

Concept for NASA Design Reference Mission Architecture 5.0 (2009)

Development of reference missions continued in the 21st century Selected other US/NASA plans (1988–2009):^[41]

11) 2000 SERT (SSP)

12) 2002 NEP Art. Gravity

13) 2001 DPT/NEXT

14) 2009 DRA 5

MARPOST (2000/2005)

The Mars Piloted Orbital Station (or MARPOST) is a Russian proposed manned orbital mission to Mars, using a nuclear reactor to run an electric rocket engine. Proposed in October 2000 by Yuri Karash from the Russian Academy of Cosmonautics as the next step for Russia in space along with the Russian participation in the International Space Station, a 30-volume draft project for MARPOST has been confirmed as of 2005.^[42] Design for the ship proposed to be ready in 2012, and the ship itself in 2021.^[43]

ESA Aurora programme (2001+)

The European Space Agency had a long-term vision of sending a human mission to Mars in 2033.^[44] Laid out in 2001, the project's proposed timeline would begin with robotic exploration, a proof of concept simulation of sustaining humans on Mars, and eventually a manned mission; however, objections from the participating nations of ESA and other delays have put the timeline into question.

ESA/Russia plan (2002)

Another proposal for a joint ESA mission with Russia is based on two spacecraft being sent to Mars, one carrying a six-person crew and the other the expedition's supplies. The mission would take about 440 days to complete with three astronauts visiting the surface of the planet for a period of two months. The entire project would cost $20 billion and Russia would contribute 30% of these funds.^[45]

USA Vision for Space Exploration (2004)

Project Constellation included an Orion Mars Mission. United States President George W. Bush announced an initiative of manned space exploration on January 14, 2004, known as the Vision for Space Exploration. It included developing preliminary plans for a lunar outpost by 2012^[46] and establishing an outpost by 2020. Precursor missions that would help develop the needed technology during the 2010-2020 decade were tentatively outlined by Adringa and others.^[47] On September 24, 2007, Michael Griffin, then NASA Administrator, hinted that NASA may be able to launch a human mission to Mars by 2037.^[48] The needed funds were to be generated by diverting $11 billion^[49] from space science missions to the vision for human exploration.

NASA has also discussed plans to launch Mars missions from the Moon to reduce traveling costs.^[50]

Mars Society Germany - European Mars Mission (EMM) (2005)

The Mars Society Germany proposed a manned Mars mission using several launches of an improved heavy-lift version of the Ariane 5.^[51] Roughly 5 launches would be required to send a crew of 5 on a 1200 days mission, with a payload of 120,000 kg (260,000 lb).^[51]

China National Space Administration (CNSA) (2006)

Sun Laiyan, administrator of the China National Space Administration, said on July 20, 2006 that China would start deep space exploration focusing on Mars over the next five years, during the Eleventh Five-Year Plan (2006–2010) Program period.^[52] The first uncrewed Mars exploration program could take place between 2014–2033, followed by a crewed phase in 2040-2060 in which crew members would land on Mars and return home.^[53] The Mars 500 study of 2011 prepared for this manned mission.

The One-Way Trip Option (2006); Mars to Stay (2006)

The idea of a one-way trip to Mars has been proposed several times. Space activist Bruce Mackenzie, for example, proposed a one-way trip to Mars in a presentation "One Way to Mars - a Permanent Settlement on the First Mission" at the 1998 International Space Development Conference,^[54] arguing that since the mission could be done with less difficulty and expense if the astronauts were not required to return to Earth, the first mission to Mars should be a settlement, not a visit. In 2006, former NASA engineer James C. McLane III proposed a scheme to initially colonize Mars via a one way trip by only one human. Papers discussing this concept appeared in The Space Review,^[55] Harper's Magazine,^[56] SEARCH Magazine^[57] and The New York Times.^[58]
Mars to Stay proposes that astronauts sent to Mars for the first time should stay there indefinitely, both to reduce mission cost and to ensure permanent settlement of Mars. Among many notable Mars to Stay advocates, former Apollo astronaut Buzz Aldrin is a particularly outspoken promoter who has suggested in numerous forums "Forget the Moon, Let's Head to Mars!"^[59] In June 2013, Aldrin wrote an opinion published in The New York Times supporting a manned mission to Mars and views the moon "not as a destination but more a point of departure, one that places humankind on a trajectory to homestead Mars and become a two-planet species."^[60]

NASA Design Reference Mission 5.0 (2007)

NASA released initial details of the latest version conceptual level human Mars exploration architecture in this presentation. The study further developed concepts developed in previous NASA DRM and updated it to more current launchers and technology.

MarsDrive mission design (2008)

The MarsDrive Organization has been working at a series of new human mission designs starting with Mars for Less. Their current design program under Director of Engineering Ron Cordes has discarded many of the Mars for Less elements and was reviewed as MarsDrive DRM 2.5 in June 2008. Some of their design philosophy is focused on using current or near term existing launch vehicle systems, permanent human settlement, conceptual EDL systems and enhanced surface ISRU. Their current design in 2012 is titled "Ready For Mars" and focuses on use of small Viking heritage landers to solve the Entry, Descent and Landing challenge. Their proposed methods of funding the mission are also an alternative to the current government funded plans with a private consortium approach being investigated.

NASA Design Reference Mission Architecture 5.0 (2009)

DRMA 5.0 "commuter" Mars base, Chemical Propulsion Option (2009)

NASA released an updated version of NASA DRM 5.0 in early 2009, featuring use of the Ares V launcher, Orion CEV, and updated mission planning. In this document.^[61]

NASA Austere Human Missions to Mars (2009)

Extrapolated from the DRMA 5.0, plans for a manned Mars expedition with chemical propulsion. Austere Human Missions to Mars

USA's Mars orbit by the mid-2030s (2010)

In a major space policy speech at Kennedy Space Center on April 15, 2010, U.S. President Barack Obama predicted a manned Mars mission to orbit the planet by the mid-2030s, followed by a landing:

By the mid-2030s, I believe we can send humans to orbit Mars and return them safely to Earth. And a landing on Mars will follow. And I expect to be around to see it.

The United States Congress has mostly approved a new direction for NASA that includes canceling Bush's planned return to the Moon by 2020 and instead proposes asteroid exploration in 2025 (Asteroid Redirect Mission) and orbiting Mars in the 2030s.^[62]

Russian mission proposals (2011)

A number of Mars mission concepts and proposals have been put forth by Russian scientists. Stated dates were for a launch sometime between 2016 and 2020. The Mars probe would carry a crew of four to five cosmonauts, who would spend close to two years in space.^{[citation needed]}

In late 2011, Russian and European space agencies successfully completed the ground-based MARS-500.^[63] The biomedical experiment simulating manned flight to Mars was completed in Russia in July 2000.^[64]

2-4-2 concept (2011-2012)

In 2011, Jean-Marc Salotti published a new proposal for a manned Mars mission, with a release in 2012.^[65][66] The 2-4-2 concept is based on a reduction of the crew size to only 2 astronauts and the duplication of the entire mission. There are 2 astronauts in each space vehicle, there are 4 on the surface of Mars and there are 2 once again in each return vehicle. In addition, at every step of the mission, there are 2 astronauts ready to help the 2 others (2 for 2).
This architecture simplifies the entry, descent and landing procedures, which are known to be very risky, thanks to a significant reduction of the size of the landing vehicles. It also avoids the assembly of huge vehicles in LEO. The author claims that his proposal is much cheaper than the NASA reference mission without compromising the risks and can be undertaken before 2030.

NASA/SpaceX 'Red Dragon' (2012)

Red Dragon is a proposed concept for a low-cost Mars lander mission that would use a SpaceX Falcon Heavy launch vehicle, and a modified Dragon capsule to enter the Martian atmosphere. The concept was slated to be proposed for funding in 2012/2013 as a NASA Discovery mission, for launch in 2018.^[67][68] However, it was never proposed for that funding. The primary objective would be the search for evidence of life on Mars (biosignatures), past or present; a substantially unmodified version of the crewed Dragon capsule could be used for payload transport to Mars, and would be a precursor to the ambitious long-term plans of a manned mission to Mars.^[67][68]

Conceptual Space Vehicle Architecture for Human Exploration of Mars (2012)

In 2012, Conceptual Space Vehicle Architecture for Human Exploration of Mars, with Artificial Gravity and Mini-Magnetosphere Crew Radiation Shield was released, outlaying a possible design for a human Mars mission.^[69] Components of the architecture include various spacecraft for the Earth-to-Mars journey, landing, and surface stay as well as return.^[69] Some features include a several unmanned cargo landers assembled into a base on the surface of Mars.^[69] The crew would land at this base in the "Mars Personnel Lander", which could also take them back into Mars orbit.^[69] The design for the manned interplanetary spacecraft included artificial-gravity and an artificial magnetic field.^[69] Overall, the architecture was modular and to allow for incremental R&D.^[69]

Mars One (2012)

In 2012, a Dutch entrepreneur group revealed plans of a fund-raising campaign for a human Mars base to begin in 2023.^[70] One difference from other projects is that 'Mars One' is organized as a not-for-profit organization, strives to use worldwide suppliers, with no politics involved. It would be a "one-way" mission, i.e., there will be no return trip to Earth. Astronaut applications are invited from the public all over the world.
In 2018, a telecom orbiter would be sent, a rover in 2020, and after that the base components and its settlers.^[70] The base would be powered by 3,000 square meters of solar panels.^[71] The SpaceX Heavy rocket would launch flight hardware.^[70] The first crew of 4 astronauts would land on Mars in 2025. Then, every two years, a new crew of 4 astronauts would arrive. Current plans specify that the entire mission is to be filmed and broadcast back to Earth as a media event, revenues from which would help fund the program.

Inspiration Mars Foundation (2013)

In 2013, the Inspiration Mars Foundation founded by Dennis Tito revealed plans of a manned mission to fly by Mars in 2018 with support from NASA.^[72][73]

Boeing Affordable Mission (2014)

On December 2, 2014, NASA's Advanced Human Exploration Systems and Operations Mission Director Jason Crusan and Deputy Associate Administrator for Programs James Reuthner announced tentative support for the Boeing "Affordable Mars Mission Design" including radiation shielding, centrifugal artificial gravity, in-transit consumable resupply, and a lander which can return.^[74][75] Reuthner suggested that if adequate funding was forthcoming, the proposed mission would be expected in the early 2030s.^[76]

Current intentions

A number of nations and organisations have long-term intentions to send humans to Mars.

Planting a U.S. flag on Mars

Artist's rendering of the planned Orion/DSH/Cryogenic Propulsion Module assembly.

• The United States has a number of robotic missions currently exploring Mars, with a sample-return planned for the future. On December 5, 2014 NASA successfully launched and tested the Orion Multi-Purpose Crew Vehicle (MPCV), the first component of NASA's planned Mars mission program. The Orion MPCV will serve as the launch/ splashdown crew delivery vehicle, in combination with a Deep Space Habitat module, which will provide additional living-space for the crew on the 16-month-long journey from Earth to Mars and back. The first manned Mars Mission, which will include sending astronauts to Mars, orbiting Mars, and a return to Earth, is currently scheduled for the 2030s.^[77][78][79] One possible means of propulsion for such interplanetary transport ships has been proposed by New Scientist. In its proposal, New Scientist outlines an argon plasma-based VASIMR rocket which the group claims could reduce the interplanetary transit time.^[80] As a training venue for future Mars missions, NASA has used the Haughton impact crater on Devon Island due to the crater's similarity with Martian geology.^[81]
• The European Space Agency has sent robotic probes, and has long-term plans to send humans but has not yet built a manned spacecraft. It plans to launch an unmanned mission to Mars, ExoMars, in 2016.
• Russia (and previously the Soviet Union) has sent a large number of probes. It can send humans into Earth orbit and has extensive experience with long-term manned orbital space flight due to its space station programs. A simulation of a manned Mars mission, called Mars-500, was completed in Russia in November 2011.
• India successfully placed an unmanned Mars Orbiter Mission (also called Mangalyaan) satellite in Mars orbit on 23 September 2014.^[82]
• Japan has sent one robotic mission to Mars, the Nozomi, but it failed to achieve Mars orbit.
• China's mission to Mars, the Yinghuo-1 space probe, was lost with Russia's sample return mission to Phobos, Fobos-Grunt. China claims to have built and tested a functioning EmDrive prototype, which could reduce Mars' interplanetary transit time. The EmDrive spacecraft propulsion technology is also being investigated in the United States,^[83][84] despite it being criticized as pseudoscience.^[85][86][87]

Technological innovations and hurdles

Fuel is mined from Phobos with the help of a nuclear reactor.^[88]

Various technologies may aid a human mission to Mars.

One of the medical supplies that may be needed is intravenous fluid, which is mostly water but contains other things so it can be added directly to the human blood stream. If it can be created on the spot from existing water then it could spare the weight of hauling earth-produced units, whose weight is mostly water.^[89] A prototype for this capability was tested on the International Space Station in 2010.^[89]

While it is possible for humans to breathe pure oxygen, a pure oxygen atmosphere was implicated in the Apollo 1 fire. As such, Mars habitats may have a need for additional gases. One possibility is to take nitrogen and argon from the atmosphere of Mars; however, they are hard to separate from each other.^[90] As a result, a Mars habitat may use 40% argon, 40% nitrogen, and 20% oxygen.^[90]

Precursor missions

Mars sample return missions

Sample return mission concept

An unmanned Mars sample return mission (MSR) is often considered to be an essential precursor to crewed missions to Mars' surface.

Crewed orbital missions

Landis^[91] and Lupisella proposed to explore Mars via telepresence from human astronauts in orbit.^[92]

A similar idea, was the proposed "Human Exploration using Real-time Robotic Operations" (HERRO) mission.^[93][94]

Another proposed mission was the Russian Mars Piloted Orbital Station.

Lockheed Martin as part of their "Stepping stones to Mars" project, called the "Red Rocks Project" proposed to explore Mars robotically from Deimos.^[35][95][96]

Mars analogs

Crew for a Mars research mission practice techniques on Devon Island, in the Canadian arctic

Mars analogs are experiments that often use environments that simulate aspects of the conditions people could experience during a hypothetical mission to Mars. These efforts have received interest by non-governmental organizations interested in spaceflight as well as notable media coverage.