May 17, 2013 at 9:36 pm #40674
I think it would be interesting for these astronauts to return and
rehabilitate with Tao-Yin and Iron Shirt. Starting fresh. AdelMay 18, 2013 at 1:23 pm #40675
I think we will see more and more problems of this type
as the decades/centuries roll by and people start traveling
and living on places other than Earth.
It will be interesting to see what happens to the Mars group.June 10, 2013 at 12:54 pm #40677
Our Guts May Hate Mars
We can leave Earth. But will we always have to bring it with us?
By Michael Chorost|Posted Thursday, June 6, 2013, at 8:38 AM
Eighty thousand people recently applied for a trip to Mars, an excursion that will allegedly be funded by selling reality-TV show rights for the voyage. The company running this curious venture, Mars One, estimates that the price tag for an expedition of four astronautscurrently slotted for 2023would be $6 billion. But the tickets one-way: There is no budget for bringing them back.
It wouldnt be a suicide mission, though. The travelers would be going as homesteaders, intending to make Mars their permanent home. If youre going to have permanent colonies, say boosters of the idea, you might as well do it from the start.
It is not clear whether such a journey could be done safely for $6 billion, or at all. The hazards are numerous. Voyages to Mars will take anywhere between four and 10 months, depending on how much fuel you use. The lack of gravity will make the astronauts bones more brittle and prone to breakage. Zero gravity also changes the shape of the eye, harming some astronauts vision for reasons that are not fully understoodand in some cases, the changes appear to be permanent.
But thats just the start. Mars itself will be fantastically dangerous. The surface is bathed in solar and cosmic radiation. The temperature rarely gets above freezing. Theres omnipresent dust with toxic chemicals in it. Theres a total lack of breathable air. And if you have a serious medical problem, the nearest emergency room will be at least 34 million miles away.
But theres another, more subtle hazard of Martian homesteading that people have barely begun to think about: the lack of soil. It may be hard to keep people healthy in the long term on Mars without Earth-made soil. Lots of it.
During the Humans to Mars conference held in Washington, D.C., in May, several panelists suggested that colonists would grow food hydroponically, in water. That seems logical: Shipping soil from Earth would be expensive, and wed have to assume until proved otherwise that using Martian soil would be dangerous, because it has a different chemistry than Earths. (For example, it has perchlorates, chlorine-based salts that are known to harm the thyroid.) So for the foreseeable future on Mars, hydroponics seems to be the way to go.
You can grow a reasonably good tomato in water. But soil is a whole ecosystem, containing bacteria, protozoa, nematodes, insects, and much moreand it supports us in many ways.
For one thing, soil bacteria appear to be important for maintaining the proper diversity and balance of microbiota (i.e., bacteria) in the human gut. Scientists say that the bacteria and tiny insects in soil provide ecosystem services to humans and everything else on the planet. They break down the dead and the discarded, purify water, and cycle carbon dioxide into and out of the atmosphere.
Justin Sonnenburg, a microbiologist at Stanford, says that soil bacteria also enhance the quality of the foods grown in it. For instance, some of the microbes attack the plants. That may sound like a bad thing, but in fighting off those assaults, the plants generate compounds that are beneficial to human health, such as antioxidants. What it comes down to is this: Among other functions, good soil has bad bacteria that make plants do good things. We may be able to replicate some of these functions with technology, but if we dont know all of the things that soil does, we may miss something important.
Martian colonists could probably live for years on food grown without soil. The question is, could they live on it for decades? Could their children grow up on it? Are there hidden hazards that would not become apparent until much later? To put these questions another way: Can we identify and reproduce the ecosystem services of Earth for a lifetime?
Surprisingly, we may already know what some of the long-term health hazards are, and theyre alarming. Microbiologists are linking decreases in gut biodiversity to Western diseases such as allergies, asthma, irritable bowel syndrome, and colon cancer. Says Sonnenburg, [I]n the Western world, were living an existence that is somewhat Mars-like in being foreign to humans. Permanent residents of Mars, and their Mars-born children, could be even more afflicted with these problems than people on Earth. Mars may be both too dirtyin the sense of having toxic dustand too clean.
Simply put, humans need good dirt. The human body harbors 100 trillion bacteria inside and out, and their proper balance is increasingly regarded as vital to human health. But most Westerners eat factory-farm food that is doused in pesticides, antibiotics, and fertilizers. The additives may be killing off the bad bacteria (which we dont know a whole lot about) that make plants produce the stuff that is good for us (which we dont know a whole lot about, either). That, plus killing off lots of the good bacteria too. Unbalanced soil may lead to an unbalanced human gutand to allergies, asthma, and worse
Just getting to Mars could throw the bacterial balance of arriving colonists out of whack. Space does odd things to bacteria. According to Hernan Lorenzi, a biologist at the J. Craig Venter Institute, nasty bacteria like salmonella and pseudomonas become even more virulent when grown in Petri dishes in weightlessness.
But what happens inside weightless people? Forty years of research has shown that astronauts gut bacteria change during long missions. The studies have been limited, though, because most bugs in the gut cant be cultured for study. Lorenzi is using newly developed gene-sequencing machines that can identify everything in samples donated by astronauts, whether its culturable or not. If he finds a loss of biodiversity and an increase in dangerous bacteria, it will not be surprising.
To be sure, health hazards are inevitable in exploration. Sailors on long voyages suffered from scurvy until captains learned to stow limes and other foods rich in vitamin C. But wherever those sailors went, they were still in an ecosystem. For that matter, astronauts in Earth orbit still get regular shipments of food from Earth. On Mars, none of that will apply. Colonists on Mars will be pioneering a long-term experiment in human health away from the ecosystem services of Earth.
Could Earth just ship thousands of pounds of good solid Kentucky dirt to Mars, and to hell with the cost? That wouldnt necessarily solve the problem. Sonnenburg says that unless you can properly maintain a soil ecosystem, which is hard to do in a closed environment, its biodiversity will decrease. Its tendency will be to ratchet down, he says, and once that starts, its hard to stop.
Until those problems are solved, the best solution may be to send food from Earth to supplement what the colonists manage to grow on Mars. The idea is to get the colonists eating a non-Western diet, with lots of vegetables and fermented foods like yogurt, sauerkraut, kefir, and kimchi. Such foods are laden with healthy bacteria. Customized probiotic pills might also help, if they can be shown to work.
Thats going to make for an expensive cup of yogurt, though. Commercial space companies such as SpaceX are aiming to get launch costs down to a mere $1,000 per pound, and thats not even counting additional postage to Mars. Still, Sonnenburg strikes a note of optimism. If you treat Martian colonists right, he says, their gut bacteria could end up in better shape than those of most Westerners here on Earth.
But its hard to imagine that canned food and pillswhose microbial quality could decrease after months in transitwill replace all of the ecosystem services we get from Earth. In his recent novel 2312, the science fiction author Kim Stanley Robinson suggests that space colonists will have to return to Earth every seven years to replenish their internal microbiota. Robinson has thought more deeply about long-term space habitation than any other science fiction writer, stocking his novels with pages of exposition on how to create healthy bacterial ecologies on terraformed planets and hollowed-out asteroids. But even 300 years from now, Robinson suggests in 2312, we still wont fully understand the microbial genius of Earth. We will be able to leave it. But maybe not forever.
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