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Mars Explorers Face Huge Radiation Problem
astroengine writes "A radiation sensor inside NASA's Curiosity Mars rover shows that even under the best-case scenario and behind shielding currently being designed for NASA's new deep-space capsule, future travelers will face a huge amount of radiation. The results, based on Curiosity's 253-day, 348-million-mile cruise to Mars, indicate an astronaut most likely would exceed the current U.S. lifetime radiation exposure limit during one round trip mission. "Even for the shortest of missions we are perilously close to the radiation career and health limits that we've established for our astronauts," NASA's chief medical officer Richard Williams told a National Academy of Sciences' medical committee on Thursday."
Radiation only has positive outcomes!
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
It's a shame so much of NASA's human exploration has been cut back. It's awesome scientific challenges like protecting astronauts on such a mission that would create untold breakthroughs in shielding tech and other fields. We need these challenges to advance our society! We need to reap the benefits. We need 21st Century TANG!!!!
Just find a small periodic asteroid going approx. the same way, or make one go the same way using the slingshot affect, bore a hole into it via robots and explosives, and then the "roidnauts" and their ship could hop in the hole when it passes by Earth.
Table-ized A.I.
... it's not going to be much better. Mars does not have a spinning core so no radiation belts to deflect evil radiation on the surface either. Surface exposure would have to be limited.
http://mars-one.com/en/faq-en/19-faq-health/185-will-the-astronauts-suffer-from-radiation
However, I would still go. I mean, if we can actually get people to Mars, we shoudl have no problem getting around the radiation problem.
sig?
Won't this just turn people into mutants like in Total Recall?
That's once they get their asses to Mars! Before that, they'll be in space, and they'll be more like the Fantastic 4.
"For every expert, there is an equal and opposite expert"
No. We read an article about how US limits on radioactivity at Superfund sites are ridiculously low compared to the allowable exposure limits.
From the article:
Current U.S. standards limit an astronaut’s lifetime radiation exposure to 1 Sievert, or 1,000 milliSieverts, which equates to about a five percent chance increase in developing a fatal cancer.
A new study shows that with currently available propulsion technologies and similar shielding to Curiosity’s, astronauts on even the shortest roundtrips to Mars would get radiation doses of about 662 millisieverts and that doesn’t include radiation dosages for any time spent on the Martian surface.
Sounds like a rather low risk compared to that of the mission as a whole.
Well, you're already over your limit then.
Best source I can find is this article, which lists the surface radiation as around .7 millisieverts a day, or around the same as low Earth Orbit (Mars atmosphere is extremely thin, so it doesn't give as much protection as Earth's does from cosmic rays). This is vastly more than people are exposed to on Earth, and could definitely pose long-term health risks for a colony or other one-way mission.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Uh oh. You're breathing in radioactive Carbon-14 right now. You better hold your breath...
What, you expect me to RTFA?
Yes digging a hole in space is a dumb idea.
I have noting further of value to add to this conversation.
A squid eating dough in a polyethylene bag is fast and bulbous, got me?
So limit outdoor activity, and bury the colony shelters so that you can leverage inxpensive dirt for shielding.
Say, with sandbags packed with martian regolith.
(With a solar sintering machine, and "refined 19th century tech*", you could produce all the glass fiber sandbags you could possibly ever want on mars.)
* 19th century version
*refined modern and cheap consumer version
[For the imagination impaired, you use the solar sintering machine to produce a small, stationary bead of melted glass from abundant martian regolith, use a steel mandril to pull several glass fiber pulls off that bead, thread them through some eye-hooks in a halfcircle around the bead, then thread them through one last eye-hook as a bundle, and then feed the bundle into the knitting machine. Turn the crank, and a continuous tube of knitted glass fiber gets pooped out. Cut the "sock" at desired lengths, and use more glass fiber in a handheld bag stitcher to close the end, and stuff them with martian regolith. You can then stack them up to make 1950s style bunkers around the the habitat structures, which will not only keep the wind off of them, but also provide radiation shielding on the cheap for the colony. The total equipment needed would be well under 20kg, and would allow unlimited sandbag production at the colony site.]
To get that, you'd need to be surrounded by a substance that was so black that you'd think to yourself "How much more black could this be? And the answer is none. None more black."
I am officially gone from
The heaviest material? Really compatible with space travel fuelled by some of the world's most expensive fuel at great expense. Part of the problem of space is not that "we can't do that", it's that "it's so FECKING expensive to do it the way we would on Earth".
There's nothing stopping us shipping an entire biodome up to Mars, with enough food for a million people. It's just a question of weight (and, thus, cost). The point of the very first manned Mars mission is going to be to get there, not to prove we can start industry there. As such, things like huge amounts of lead are a luxury we can ill afford.
That, and most of the radiation that's damaging can actually be stopped by a bit of aluminium foil. The problem isn't that we *couldn't* shield from it, it's that we can't afford to. And pioneers often have to suffer for the title of being "first", I'm afraid (e.g. Madame Curie).
The bigger problem is the legality over what is basically a health and safety issue that, if we'd worried about it in the past, we'd never have let anyone go up Everest, fly to the Moon, etc. etc. etc.
These people are going to get irradiated. There's nothing practical that we can do to stop that. Many of the Apollo astronauts had eye problems related to radiation exposure in later life, it's just a simple fact of going outside the Van Allen belts (and, hell, flight attendants probably get more radiation in a year than ANYONE who works in a radiology department).
We just have to make sure they understand the risk. But I'm sure that Scott understood the risk of the Antarctic, that Hillary understood the risk of Everest, and so on. There will be people more than willing to do it. And in 100 years time, in any luck, space travel could be commonplace to the point where we finally do "solve" most of those problems through finally getting the money / incentive to actually prevent them. But at the moment, it's just a legal issue to make sure these people understand just how much simple things (like invisible radiation) can scupper their lives on a remote planet.
I don't think this is new - surely we have enough data to know the interplanetary radiation levels. In some of the old Mars mission designs there was a shielded "shelter" on the spacecraft that could be used during times of high radiation from solar activity. This of course adds weight - but if its located in the center of the spacecraft, or maybe shielded by fuel it might not be too bad.
On the martian surface it would seem fairly straightforward to make a covered trench. Most of the work could be done by robotic equipment before the manned mission arrived.
Putting people on mars isn't easy - if it were, much of the point would be lost.
Cockroaches can withstand radiation . . . maybe modern gene therapy could help humans to replicate that process in themselves . . . ?
Hopefully, without turning them into cockroaches . . .
Too late. We call them lawyers
I'm a consultant - I convert gibberish into cash-flow.
Seriously, they already know how to deal with this, and discovered that hydrogen neuclei are ideal for absorbing high energy cosmic rays, since they produce a minumum of secondary high energy particles from the interaction. This means a substance with lots of hydrogen in a small volume makes the best shielding.
This leads us to the most abundant, hydrogen dense material available, which would also be necessary for the trip, and colony operations: water.
Basically, put the crew capsule inside the water storage tank. Radiation problem solved. You have to send the water anyway. Make the most of it.
Solar sintering machine.
http://www.markuskayser.com/work/solarsinter/
Instead of attempting to use it as a 3d printer, you keep a fixed focal point, and simply melt the regolith into a small (US quarter sized) bead of hot glass.
You use a small metal mandril to pull glass fiber pulls off of that. The drawing of the glass shrinks the bead, but the sinter just makes more to replace it. Multiple pulls are made from the same bead, at different angles, then combined into a bundle.
Note how the 3d printer version fits in a suitcase.
Mars has 1/2 the solar irradiation as earth, so it will need a larger fresnel lens. Otherwise, same setup, minus the build table mechanics.
I don't care. Put me on that rock. Hell, I'll go tonight. Let's do this.
Get me there, let me walk on Mars. The rest is details, nothing that happens after taking a step on another planet could possibly ever matter to me ever again, and whatever was done, whatever was sacrificed, whatever the cost, it would be worth it. I don't care. Let's go.
... still waiting for this free-as-in-beer free beer I keep hearing about.
Ya, there's something that can be done. The government is being very hush-hush about it. Until now, only those "in the know" have been told.
Just under the surface of Mars is a vast quantity of water ice.
In the Cydonia region of mars, there is an ancient pyramid. Deep within the pyramid is an alien device which will turn the water ice into a Earth-like breathable atmosphere.
There is a catch though. There are agents already on-planet who will stop at nothing to keep you from activating the machine.
It would take a madman to even consider it. More specifically, a madman who's mind has already been scrambled by a dramatically failed lobotomy. That man may be you.
Serious? Seriousness is well above my pay grade.
No need to fill sand bags or dig holes. Mars has big lava tubes and other caves that could be put to the task. It would probably be possible to take advantage of the cave walls themselves when building the habitat.
"We'd better develop mature gene therapy soon". Cancers, aging, congenital defects, HIV, Lupus, psoriatic eczema... the list goes on and on.
Effective medicine will open the cosmos to post-humans. It's just silly to pretend we have to leave our little egg before we've developed enough to survive in the outside world.
My eyes just popped.
With that kind of negativity, of couse you won't look for sensible options.
Like, using marsian weather to deposit the dirt for you, or noting that martian surface gravity is 1/3 that of earth, and that a "50lb bag of sand" will weigh only 16.6lbs on mars.
Don't let those little things trouble your already made up mind though. (Like how at that kind of mechanical strain reduction, glass fiber tethers can hold up loads that you need high grade steel cables for on earth, and all the engineering tricks this simple fact would let you get away with on mars, that you simply would be unable to do on earth in any of the other harsh environments you cited, especially the ocean floor, where you would need a habitat made of pure premium unobtanium to hold back the hundreds of tons of pressure per square meter of water overhead.)
If you approach your problems with the preconception of "Its hard, and can't be done, and isn't worth the time!", then it will never be done, even when conditions have changed, and it most certainly can be done.
The purpose of building a colony outside of the earth is NOT to solve word overpopulation. The purpose is to put our eggs in many baskets. Or did you learn nothing from the celybinsk(sp?) Meteor incident?
Life doesn't have to be fun, glamorous, easy, or desirable there. The reason for putting life there isn't to crow about accomplishments, to solve some "overpopulation problem", or due to some science fiction fantasy utopian ideology or dream. Those are all popular canards used by people who hold your viewpoint, but none of them are the reasons why we should build a martian colony.
So, why then? Ask Mr Sagan. The basic gist is that keeping all the humans in one basket (earth) is a recipie for extinction on the long term. We have had at least one mass extinction event on this world. (And likely many others.) If it has happened once, it can and eventually will happen again. Refusal to accept this as a rational reason to expand our holdings as a species in favor of petty indulgences and empty arguments about difficulty are not founded on reason. Or did the recent russian meteor event not provide enough impetus for you?
No-one is saying a martian colony will be anything but a torturous, inhospitable, and eternally drudge-infused effort to barely survive. We are saying that the adversities that would be present are not insurmountable, and that you only truly fail when you fail to try, and are offing suggestions on how those adversities could be effectively overcome.
Take your recent one: moving hundreds of tons of dirt on top of the habitat's dome of sandbags.
Here's an inexpensive way to do it, that makes use of the martian environment, rather than fighting it:
Mars has seasonal winds that blow the powder fine regolith all over the place, and routinely move huge dunes of the stuff around. You build a wind control wallaround the leeward sides of the dome, so that the dust carried by the winds gets dropped. Mars itself willdump the dirt you want if you are patient.
You can test this out in earth based deserts right now if you want. It's how lost cities in the sahara from antiquity get buried over.
When faced with a very daunting engineering challenge, don't work hard and go nowhere; work smart, and get shit done.
The "avoid mass extinction event" reasoning is basically rubbish. If we have the technology to survive on the surface of Mars --- no water, air, or food except what you bring and raise in your sealed habitats; open a window and you die --- then we can survive the very worst planetary extinction events right here on Earth. Giant meteor smashes into the planet; toxic dust cloud blocks out 50% of sunlight; ecosystems thrown into havoc; flaming ashy death raining down from the skies for decades? *Still* easier to survive than Mars. The engineering know-how to create sustainable human habitats on Mars could do much more on Earth, even in such a worst-case scenario.
All the recent Russian meteor did was remind me of how gigantic a panic is made over extremely rare events, causing very little harm, while millions of people are dying from much easier to fix problems. We can start worrying about once-in-a-million-years vague possibilities after we've solved the issue of murdering each other for profit on a daily basis.
The simplest solution is to use astronauts who are immune to lifetime radiation exposure.
I am serious.
An astronaut who is 65 years old is safe from radiation damage that will kill him 40 years later. He or she is relatively immune to radiation damage that would be a threat to their health 20 years down the road. Not only that, but the corps of potential astronauts is expanded to include all the women who are post menopause.
I doubt that there would be much problem recruiting astronauts from the pool of USA retirees. Since computerization has also pretty much eliminated the need for astronauts with fast reflexes, there is no reason at all not to do this.
As a possibly major fringe benefit, the possibility of aging into the USA Astronaut Corps would encourage a lot of the middle aged to fight harder against that midriff bulge. We would have a much healthier populace.
Will