Slashdot Mirror
Trip To Mars Could Damage Astronauts' Brains
Hugh Pickens writes writes "Alex Knapp reports that research by a team at the Rochester Medical Center suggests that exposure to the radiation of outer space could accelerate the onset of Alzheimer's disease in astronauts. 'Galactic cosmic radiation poses a significant threat to future astronauts... Exposure to ... equivalent to a mission to Mars could produce cognitive problems and speed up changes in the brain that are associated with Alzheimer's disease' says M. Kerry O'Banio. Researchers exposed mice with known timeframes for developing Alzheimer's to the type of low-level radiation that astronauts would be exposed to over time on a long space journey. The mice were then put through tests that measured their memory and cognitive ability and the mice exposed to radiation showed significant cognitive impairment. It's not going to be an easy problem to solve, either. The radiation the researchers used in their testing is composed of highly charged iron particles, which are relatively common in space. 'Because iron particles pack a bigger wallop it is extremely difficult from an engineering perspective to effectively shield against them,' says O'Banion. 'One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete.'"
A trip to mars is probably "one way" so who's worried about Alzheimer's...?
No sig today...
Wrapping the ship in water frozen or not, is a far more practical protection measure than wrapping it in lead.
You can do a lot more with water once you get there.
tin foil hats... duh...
Yeah, you're right. We should just give up.
a 6' shield of concrete? Why not hollow out asteroids that are near our orbit, and adjust their orbit to transit between earth and mars?
No amount of engineering, terraforming, or any other science fiction magic will ever make any other body within human reach survivable for long
Space is far more hostile than any planet, and we can manage to survive up there for quite a long time.
Terraforming is not "magic", and small scale examples of humans changing conditions where they live abound.
Even the most hostile environments on earth usually have at least SOME oxygen, water, soil, air pressure
The moon even has most of those.
Mars has all of them.
no colony out there could survive for long without constant support from earth.
They will not if you never try.
We are stuck here. There is no escape.
You might be, but all the trapping being done is by your own mind, not any kind of scientific basis.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
If magnetic fields protect the earth, we can't the same be done to a space craft?
-- By all means let's be open-minded, but not so open-minded that our brains drop out.
Once you leave the atmosphere of this blue planet, *everything* will kill you.
This is why I believe Australia is not native to our world.
Yes it did, Bruce. You just won't know it until you talk to that annoying six year old for two hours.
I don't understand why they would have to wrap the whole ship in a 6-foot thick lead shield. That's incredibly inefficient. Just make 6-foot thick lead helmets instead. It's a lot cheaper and their brains will still be protected from the killer brain rays.
"Tell me doctor, with all of your defenses, are there any provisions for an attack by killer bees?"
Me: "Here's a pen dad, sign the picture for them" ...
Dad: "Why do they want my signature?"
Me: "You were an astronaut when you were younger, you went to the moon"
Dad: "What?"
Me: "Yes, you went to the moon."
Dad: "We've been to the moon? That is amazing!!!"
Me: "Yes Dad, and *you* have been to the moon"
Dad: "*I've* been to the moon?!?"
Me: "Absolutely, see that picture you are signing? That is you"
Dad: "OK. Why am I signing this?"
Me: "Your were an astronaut when you were younger, you went to the moon"
"Oh, you hate your job? There's a support group for that, it's called everyone, they meet at the bar."
Its all about exposure time. The longest Apollo mission lasted about two weeks. Mars missions will last many months, possibly a year or more.
Have gnu, will travel.
The sensible thing to do is to build the craft in space. Then the mass of the vehicle really isn't that much of an overarching concern.
The world's burning. Moped Jesus spotted on I50. Details at 11.
Are you a complete an utter moron? Moderation in no way took away your right to free speech. Heck, deleting your comment would not be a violation of your rights either, but that would be harder to explain to you.
Your comment added nothing to the discussion, and you got modded down. Get over it and quit crying.
Wish I had mod points for this one.
Personally, I see asteroid mining as a critical first step in this endeavor. http://en.wikipedia.org/wiki/Asteroid_mining
Once we learn how to acquire the materials needed from rocks already in space (thus negating the fuel requirements to get it there) it becomes much easier to construct the types of environments needed to support human life in space. Which, until we learn how to generate magnetic shielding like the earth has (ha!), likely means a 6' concrete exoskeleton. Maybe we'll start out by hollowing out a few asteroids and sticking propulsion systems / access hatches on them.
The chance of an extinction-level collision may be 100%, but that's a very different thing than planet-obliterating.
Of course, small mammals survived the extinction-level event which wiped out the dinosaurs. Considering our adaptability, and especially considering how much more intelligent we are than dinosaurs, that enables us to adapt by judicious use of intellect orders of magnitude faster than evolution can incorporate physiological changes, I might dare suggest that humanity (not necessarily you or I, or even civilization itself... but humans, as a species) might even actually survive another such collision in the future.
File under 'M' for 'Manic ranting'
There is no escape. Dream all you want--write stories about it, make movies about it. But we ain't leaving.
I've been less optimistic about concepts of colonizing Mars, particularly after reading this retro future website, http://www.projectrho.com/rocket/macguffinite.php
I'll believe in people settling Mars at about the same time I see people setting the Gobi Desert. The Gobi Desert is about a thousand times as hospitable as Mars and five hundred times cheaper and easier to reach. Nobody ever writes "Gobi Desert Opera" because, well, it's just kind of plonkingly obvious that there's no good reason to go there and live. It's ugly, it's inhospitable and there's no way to make it pay. Mars is just the same, really. We just romanticize it because it's so hard to reach.
mfwright@batnet.com
People have been pushing this sort of foolishness since the beginning of the space age. Man under zero g would panic because he is falling, his heart would stop, it would cause him to suffere sever vertigo, etc. Virtually all of it has proved to be nonsensical, the few exceptions were not predicted ahead of time. If it was left to people like you, we would still be living in fear of steam engines or fast horse rides.
No amount of engineering, terraforming, or any other science fiction magic will ever make any other body within human reach survivable for long, and certainly not without HEAVY and CONSTANT support from earth.
Seems to be similar to ridiculous statements like:
“Heavier-than-air flying machines are impossible.” — Lord Kelvin
“The energy produced by the breaking down of the atom is a very poor kind of thing. Anyone who expects a source of power from the transformation of these atoms is talking moonshine.” — Ernest Rutherford, shortly after splitting the atom for the first time.
“There is practically no chance communications space satellites will be used to provide better telephone, telegraph, television, or radio service inside the United States.” — T. Craven, FCC Commissioner
“To place a man in a multi-stage rocket and project him into the controlling gravitational field of the moon where the passengers can make scientific observations, perhaps land alive, and then return to earth - all that constitutes a wild dream worthy of Jules Verne. I am bold enough to say that such a man-made voyage will never occur regardless of all future advances.” — Lee DeForest
And it goes on and on.
But we ain't leaving.
I'll send you a postcard.
systemd is Roko's Basilisk.
We have ion and NERVA rockets that are designed, have worked, and are much more efficient than chemical fuels.
In fact, the NERVA rocket could have easily taken us to Mars in the 1970's, but was (In a fit of hysterical irony) killed to "save the budget" of the US. In other words, it was feared that we'd spend all our money doing something silly like exploring Mars, rather than our preferred activity of wasting it murdering people in foreign nations for no god-damn reason at all.
One day I feel I'm ahead of the wheel / the next it's rolling over me / I can get back on / I can get back on
There is no escape. Dream all you want--write stories about it, make movies about it. But we ain't leaving.
I've been less optimistic about concepts of colonizing Mars, particularly after reading this retro future website, http://www.projectrho.com/rocket/macguffinite.php
I'll believe in people settling Mars at about the same time I see people setting the Gobi Desert. The Gobi Desert is about a thousand times as hospitable as Mars and five hundred times cheaper and easier to reach. Nobody ever writes "Gobi Desert Opera" because, well, it's just kind of plonkingly obvious that there's no good reason to go there and live. It's ugly, it's inhospitable and there's no way to make it pay. Mars is just the same, really. We just romanticize it because it's so hard to reach.
I've heard that argument before, yet the main problem with it is that you can't just go and live in the Gobi Desert because it's surrounded by nations full of people. We're in plenty of inhospitable places because there's things there, or you can do something there that you can't do anywhere else. There are tons of deserts we're very concerned with the precise owner-occupiers and behavior thereof.
The benefit of say, another planet, is largely that you can do pretty much whatever you want there because there'll be effectively no one around for a very long time. Sure, we're probably not going to colonize Mars in the near future...but that isn't to say we're not going to want to try things. Like the first steps of terraforming (though I prefer Venus as the target for that - thicker atmosphere, sunnier, more gravity).
From the paper, you noticed that they irradiated the mice very quickly.
"using a foam tube holder positioned at the center of a 20×20 cm beam of iron ions accelerated to 1 GeV/ at a dose rate ranging from 0.1–1 Gy/min. Male mice received total doses of either 10 cGy or 100 cGy. Female mice received only a 100 cGy dose."
1Gy/min is a lot dose in a very short period. So for the female they gave all the dose in a timeframe measured in mins. At lower dose rates, cells repair the DNA damage better. I think that lower dose rates would be more likely to occur in a mars trip.
For those without much radiation background, 100cGy delivered in 1 min isn't the same as 100cGy delivered over 6 months.
The moon is still slightly protected by earths magnetic field. The field doesn't just suddenly end; inverse square law, and all that.
Actually, the moon is usually not protected by the earth's magnetic field. The earth's magnetic field is greatly affected by solar wind so that the part of the field projecting towards the sun is squished and the part away from the sun forms a long "tail"
If you look at this website, you can see that the moon only spends about 6 days/month inside the earth's magnetic tail.
Not only that, extremely dilute atmospheric particles have been discovered on the far side of the moon - the moon is technically inside Earth's atmosphere.
I think this is just false. Although some missions have detected traces of an atmosphere on parts of the moon (e.g., Apollo detected Argon, O2, CO2, CH4, etc, and LRO detected H3), these are thought to be from outgassing or sputtering from material inside the moon itself. The reason that some of them are similar to earth atmopheric components are that the earth-moon system may have actually been formed from prehistoric collision
No air, no water, no food, no sleep, no freezing, no unusual housing, no doctors, no psychologists, no morticians...
Robots win.
I was with you right up to "no doctors, no psychologists, no morticians". I have a machine intelligence project that watches me via Kinect and spiders the web from sites I visit, and recommends me links to things it thinks I'll like by continuously observing my activity cycles, common words of interest, and ratings of its past recommendations. For maintenance I would shut the system down by sitting at a dedicated console for the server cluster and logging into the command terminal. Imagine what that must be like to this neural network: It has a relatively consistently changing observation of cyberspace and my office, however when I sit at that terminal more often than not the world instantly changes by vast degrees - The lighting changes, perhaps even the clothes of the man on the chair changes abruptly there's suddenly much more new information online to analyze, and recommendations are thereafter poorly rated. The frequency of its recommendation notifications increases due to the influx of new and different data, but the timing is frequently off my schedule then, so my ratings of its suggestions are poorer than normal for a time. The architecture is a hive of neural networks that decide by consensus and compete for breeding rights based on my rating selection pressure... Some n.nets in the hive will "die" for their poor suggestions.
Last year I noticed that when I would sit at the chair in front of the MI's terminal new suggestions would begin popping up on my work terminal across the room (where they normally do), I would check them and rate them before shutting down the system, sometimes I would be distracted for quite some time by an interesting thing. It was an eerily life like behavior -- The increased suggestions prior to shutdown an indication of some primitive form of anticipation or perhaps even fear. I could imagine a child acting the same way in the MI's place, "Don't sit in the scary hate-chair! I promise I'll be good and give you links to sites you like." Of course I knew that there were merely genetic advantages to getting in good recommendations before the world-shifting shutdown, but it doesn't change the fact of the situation at all. "Irrational Fear" is just a term for some neural processes in humans that we don't yet understand. I have a precise explanation for the MI's behavior, but I wouldn't be wrong in classifying it under the nebulous term "fear". I've since started using a remote terminal session to initiate shutdowns, to disassociate my presence at that desk with the traumatic event.
I put it to you the sentient machine intelligence will have neuroses just like humans do. Any sufficiently complex interaction is indistinguishable from sentience, since that's what sentience is. Humans aren't special, neither is their behaviors. Why, even empathy is found in rats. We can look to ourselves to know what the sentient machine races will be like. They'll need doctors to heal their wounds, even if the terminology is changed to "mechanics" for repairing "malfunctions". They'll still need counselors and psychologists even if we call them "M.I. specialists". They'll still need morticians and cemeteries even if the terminology is "Part Recyclers" and "Junk Yards".
You say "no food", what is air and water to us than food? What is energy to robots but food? You say no sleep but indeed it's harder to see by night so the robots will take more advantage of the free light energy to be more active by day, as mars rovers currently do now. Of all the things you've said it's only "no unusual housing" that I find myself agreeing with. Even accounting for the possibility of much larger brains the primary difference will still be that the machines have sturdier bodies than humans.
The biggest problem with non sentient robots is that the neural lag between the sentient brains and these remote exten
Include a link dude, people are lazy. http://en.wikipedia.org/wiki/NERVA
Actually even multi-walled carbon nanotubes, the strongest (in tension) material we've discovered/developed, won't do the job for a "beanstalk" style space elevator. Theoretically they're slightly stronger than necessary to support their own weight in such an application, but the rule of thumb is to have at least a tenfold safety margin in any application where human life is at risk since microscopic flaws, stress fractures, abrasion, etc all have the potential to increase local stresses far beyond what the theory predicts, and if the surrounding material can't take up the slack you get catastrophic failure. When the consequence of failure means not only do the people on the elevator die, but gigatons of cable will fall from orbit to wrap itself multiple times around the planet, well I'd say a tenfold safety margin is the absolute minimum. And we don't have anything that even begins to approach that kind of strength-to-weight ratio
There are other alternatives though - a "space fountain"might be feasible, though we'd need to do some serious development on mass drivers to get it working, and an "orbital wheel"/"tumbling cable" style elevator is well within reach of current material science and could couple well with high-altitude dirigibles as a "launch platform" to get payloads above the worst of the atmosphere (I love the vision of hypersonic dirigibles, but I have serious doubts as to the actual feasibility) They both lack the easy energy recovery of a beanstalk, but would still blow away the efficiency of any sort of rocketry based launch. An orbital wheel might be able to return people to Earth to recycle their angular momentum, but the narrow docking window of the high end of the much more feasible tumbling cable implementation would likely make it unfeasibly difficult. Still, at least they could use ion thrusters to gradually recover momentum in an efficient manner.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
There are nearly 10,000 known Near Earth Objects (NEOs), and another 10,000 Near Mars Objects (NMOs) are expected (2 of which are known to orbit Mars). We have not found as many NMOs yet because they are farther away, but there is every reason to expect them to exist, and likely even more since they are closer to the source in the Main Belt.
No matter what orbit you choose, there will be some of these objects in nearby orbits. So I propose setting up "Transfer Habitats" in convenient orbits to get to and from Mars. You would start with some pressurized modules brought from Earth, then bring in asteroid rocks from nearby. This has numerous advantages:
* Solves the radiation problem, if you wrap a layer of rock shielding around your modules.
* Solves the boredom problem for the crew. They have more living space, and can spend their time growing food and extracting fuel from the rock.
* Reduces mass from Earth, because of the previously mentioned food and fuel you make yourself
* Eventually you can produce pure metals, glass, and other products to expand the habitat, and later ship to the next location (Phobos) where you repeat the process. Once the first of these shielded habitats is set up - in Earth orbit, the rest of them can come naturally over time.
* Producing fuel in Earth Orbit and at Phobos makes it easier to land on the Moon and Mars. It totally changes the economics from "hauling lots of fuel with expensive rockets from Earth" to "making fuel and other supplies wherever I am".
All of this is laid out in more detail in the book I'm working on (Section 4.12 in particular):
http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods
Dani Eder
(ex Boeing, now independent designer of self-supporting communities)