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Mars Explorers Face Huge Radiation Problem 283

Posted by timothy
from the and-not-one-zagat-rated-restaurant dept.
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."
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Mars Explorers Face Huge Radiation Problem

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  • by jellomizer (103300) on Thursday May 30, 2013 @04:06PM (#43864889)

    Radiation only has positive outcomes!

    • by rtb61 (674572) on Thursday May 30, 2013 @10:31PM (#43868643) Homepage

      So let's turn a problem into a solution. A lot of radiation, add a layered antennae tuned to the radiation to convert the energy into usable power. Nano structures can absorb and convert a lot of energy, it only remains to engineer the right one that can absorb and convert the most problematic frequencies. Often just attempting to block specific frequencies is less efficient than absorbing and converting to use full energy and then absorbing and converting to heat.

      • Has nobody read Joe Haldeman's Marsbound? Clearly the solution is to set up a camp under ground. It's obviously working well enough for the Martians.

  • by Orp (6583) on Thursday May 30, 2013 @04:06PM (#43864897) Homepage

    Piece of cake, right?

    • by Dan East (318230)

      Dig a hole in space?

      The results, based on Curiosity's 253-day, 348-million-mile cruise to Mars

      • by Orp (6583) on Thursday May 30, 2013 @04:30PM (#43865243) Homepage

        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.

        • Yes digging a hole in space is a dumb idea.

          . . . not if it's a wormhole. It would help you get there faster, and skip the long space radiation part of the trip.

          Assuming that wormholes are radiation free . . .

          • by sirsnork (530512)

            ...... and real

            • by JWSmythe (446288)

              Lets not get into semantics of fact versus fiction.. Just because we've never seen a wormhole, and have no evidence one could even exist, doesn't mean that there isn't one..

              You can replace wormhole with all kinds of things. It's a lot of fun. :)

  • To Boldly Go... (Score:5, Insightful)

    by CMYKjunkie (1594319) on Thursday May 30, 2013 @04:08PM (#43864917)
    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!!!!
    • by Orp (6583)

      I'd personally be happy with some 21st century 'tang.

    • We need 21st Century TANG!!!!

      Who needs Tang? If astronauts could somehow feed off radiation, we'd be all set, and solve the food problem, too!

      "Hello, Houston? This is Mars Sprinter 3. We're all feeling hungry, so we're going to plop ourselves into the nuclear warp drive pool for a snack. Be back in a few minutes."

    • Re:To Boldly Go... (Score:5, Insightful)

      by ebno-10db (1459097) on Thursday May 30, 2013 @05:02PM (#43865733)

      It's a shame so much of NASA's human exploration has been cut back.

      I wish I could agree, but I can't. I hate to say it because I grew up on the manned space program. As a kid I saw Neil Armstrong take the first steps on the moon (yes, that means I'm over 21) and thought what an historic moment it was. One of the things that we learned in those early days though is that people are fragile and manned space flight is horribly expensive. For a fraction of the price (10%?) you can send an unmanned mission. Frankly a lot of the support for manned space flight is that people want to see Buck Rogers, but almost all important scientific and practical work has been done by unmanned spacecraft. Please don't respond with examples of the work done in manned space flight. I know there's been some stuff, but it's tiny compared to the cost and what's been done unmanned. Also our ability to create robots (or whatever you want to call them) has increased dramatically since the early days.

      Sure we could develop some cool tech for manned missions, but there are cheaper ways to do it. We could also create some cool robotic tech for unmanned missions. Before we send anybody to Mars, let's at least do an unmanned round trip.

      Never send a man to do a robot's job.

      • Re:To Boldly Go... (Score:4, Insightful)

        by Kreigaffe (765218) on Thursday May 30, 2013 @06:14PM (#43866683)

        The things you say are true, but I still want to go to Mars. Even if being the first man on Mars means being the first man to die on Mars, that's totally fine.

        We've gotta get off this rock eventually, let's go now.

    • One can also mourn the end of steam engine tech, which died for exactly the same reasons - something better, if less "romantic", took it's place. Some people love human space travel - or at least the concept of it, given it has never really happened - for exactly the reason your title alludes to. TV taught them to think of it as the future.

      It isn't the future, of course, which is why this focus shift to what is theoretically achievable - Mars. Mars (and possibly Venus) really represent the limit of practi

  • Didn't we just have a slashdot article about how US radiation limits are ridiculously low and need to be re-assessed?

  • Hitch a ride: (Score:5, Interesting)

    by Tablizer (95088) on Thursday May 30, 2013 @04:09PM (#43864929) Homepage Journal

    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.

    • Re:Hitch a ride: (Score:4, Informative)

      by tom17 (659054) on Thursday May 30, 2013 @04:17PM (#43865031) Homepage

      Given that attaining suitable velocity to get there in a reasonable timeframe with manageable fuel loads is probably one of the big issues of Mars travel, how does hitching a ride become advantageous? The differential velocity between you and the space rock would be way too high to dock, and even if you could 'grapple' it, you would likely slow it down too much.

      To match its speed to board it would require just as much energy as accelerating yourself to the required travelling velocity in the first place.

      Maybe a grapple with a winch could be a solution so that you can grab it while the velocity difference is high and apply a braking force to the winch mechanism until your speed matches. Then you could slowly wind yourself in. Would have to be a very long winch though. We'd probably have space elevator tech as a prerequisite to this.

      • by wagnerrp (1305589)
        It's a similar problem, but at a significantly different scale. You're probably looking at a few hundred miles worth of cable at a couple Gs, as compared to 25k miles averaging half a G. Still, if you can manage to put several hundred miles worth of high tensile cable into orbit to pull off this maneuver, surely you could just as easily use that payload for dense lead shielding on your spacecraft instead. What ever happened to the concept of lining your spacecraft with your water and waste stores to use a
      • I took the point of his post to be that sitting inside a rocky/iron asteroid, you'd be significantly more shielded from ambient radiation.

  • by Spillman (711713) <> on Thursday May 30, 2013 @04:11PM (#43864949)
    ... 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. []

    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.

    What is the protection at 180E60S, if compared to Earth?

  • by arobatino (46791) on Thursday May 30, 2013 @04:16PM (#43865023)

    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.

    • by dgatwood (11270)

      Wasn't the magnetic shielding problem basically solved [], at least in lab simulations, many years ago, using materials that are well understood and well within our ability to carry into orbit? So how is this still a "huge problem"?

    • similar shielding to Curiosityâ(TM)s

      Whyever would we limit ourselves to Curiosity's shielding? It's not like Curiosity was alive or anything?

  • Like, feed babies a diet of magnetized iron, so that they develop their own radiation shield in their blood. Or something like that. Let science fiction be your guide.

    Cockroaches can withstand radiation . . . maybe modern gene therapy could help humans to replicate that process in themselves . . . ?

    Hopefully, without turning them into cockroaches . . .

  • Shielded enclosure (Score:5, Insightful)

    by joe_frisch (1366229) on Thursday May 30, 2013 @04:41PM (#43865403)

    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.

  • by locopuyo (1433631) on Thursday May 30, 2013 @04:53PM (#43865599) Homepage
    Nothing some sunblock can't handle.
  • I wonder how it goes on the theory that asymmetric electrostatic radiation shielding could be useful for space flights.
  • "Even for the shortest of missions we are perilously close to the radiation career and health limits that we've established for our astronauts,

    Easy solution -- just raise the limits.

  • []

    I guess he has to update that chart now to account for trips to Mars...

  • use water (Score:5, Interesting)

    by wierd_w (1375923) on Thursday May 30, 2013 @05:02PM (#43865745)

    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.

    • Fill the water with oysters. Yes, Oysters. So the Scanners Live in Vain.
    • by Dzimas (547818)
      The halving-thickness of lead is approximately 1 cm. That is, it will block 50% of gamma radiation. A nice 10 cm lead plate will reduce your exposure to 1/1024th the original. Now let's try that with water, which has a halving-thickness of 18 cm. You'd need 180 cm of water to afford the same protection. I'll leave it to you to calculate the volume required to shield your craft. Once you've figured out how many thousands of liters are required, calculate the cost of lofting it into geosynchronous transfer or
      • Re:use water (Score:4, Informative)

        by wierd_w (1375923) on Thursday May 30, 2013 @11:43PM (#43869061)


        Now, calculate that your average human requires approximately 2 liters of water daily for proper renal function (though they often do drink less, and it is unhealthy.) Also factor in the scarcity of the material on mars, and the feasibility of sustainable agricultural activities without that large quantity of water.

        Now, let's also think about the secondary particles generated when heavy and complex lead neuclei are exposed to iron neculei traveling at near C, and the subsequently exponential impact that this secondary radiation will have as the shielding becomes more and more radiological from constant exposure.

        In other words, yes, water has serious issues. You still have to bring it with you if you are really serious about a martian colony. There is no discussion there. You HAVE to take it. It isn't optional. Since you already have to tae it with you, using the absurd cost to orbit it as a canard is moot. Adding the water AND the lead will always cost more than launching just the water.

        The water does not have the same problem with producing dangerous secondary radiation, and does not become radioactive itself at near the same rate as will the lead rad shield. The water is already required, and is not optional.

        Why not just use the water, then?

        You can resolve the "water expands, dumbass!" Problem by freezing it already prior to launch. This also makes it much safer to transport in the event of a micrometeorite puncturing the containment vessel, and believe it or not, ice can be quite insulating, and can serve other functions for regulating the capsule's environment.

  • ...said a million Slashdotters sporting Tinfoil hats.

  • by Ultra64 (318705) on Thursday May 30, 2013 @05:12PM (#43865885)

    Do normal size radiation protection methods not work against Huge Radiation?

  • If it's close to lifetime exposure limits, that means it's still fairly safe, since our limits are very conservative. Astronauts might have a slightly elevated risk of cancer and probably shouldn't have kids, but they are still much more likely to die during takeoff and landing.

  • Not a surprise. This is not the only hard show-stopper. Fantasy alone is not enough to make something difficult a reality, it must at least me feasible in some real sense as well.

    • by iggymanz (596061)

      solar radiation is not a hard show stopper, we know how to shield against radiation

    • You are right that space is hard. Flight was hard, many of the early pioneers of flight died in the attempt. Crossing oceans was hard, climbing mountains was hard, exploring the poles was hard. It is in the nature of exploration that it is difficult, otherwise it would have already been done.

      In the end though you are right - going into space doesn't get us anything. Unless you see it as a goal, rather than a means, there is no point. There are plenty of resources here on earth for hundreds of millions of hu

  • with TFS is that they assume a round trip right off the bat. How bad is it if we send people one-way?

  • by Odonian (730378) on Thursday May 30, 2013 @05:45PM (#43866331)
    If the spacecraft and habitat had some abundant source of energy (fission or fusion reactor for instance) could the power be used to generate a magnetic field to provide shielding the way it does on earth? Or is the amount of radiation / power required an insurmountable problem with our near-future technology?
  • All I'm hearing is (Score:4, Interesting)

    by Anonymous Coward on Thursday May 30, 2013 @05:48PM (#43866347)

    "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.

  • by Hartree (191324) on Thursday May 30, 2013 @05:48PM (#43866351)

    You're telling me that you got 660mSieverts behind shielding designed to protect a nonliving robot with at least somewhat rad hardened electronics? (And was traveling in a fairly quiet solar period.)

    And (though I don't see the specifics to back up the shielding info for the deep space capsule in TFA) that a capsule that's largely a follow on from Orion that was mostly designed for a few day trip for a return to the moon provides inadequate shielding for deep space or Mars missions? Especially when they're limited in speed because they're only powered by chemical rockets?

    Who'da thunk it.

    This is why I'd rather go back to the moon to learn how to run space bases only a couple days away from home where there's lots of nice lunar soil to hide from the radiation under.

    Then, design much larger more heavily shielded Mars and deep space craft once we have the easier challenges of lunar operations understood.

  • I can just see the brochures.
    Go to Mars on a one way trip.
    Live in close proximity with the same few people for the rest of your life.
    Never again feel real sun or wind on your skin or swim on a natural body of water.
    Spend most of your life underground.
    Continually hope that funding does not get cut and the supplies keep coming from earth.
    Hope that there are no problems with the shipments or you may starve.
    Never be able to touch most of the people you love.
    Probably die of cancer due to radiation.
    Realize that t

  • "astronauts on even the shortest roundtrips to Mars would get radiation doses of about 662 millisieverts"

    That is simply *not* the "huge amount of radiation" the article claims. It won't even cause any effects that can be tied to the'll increase the long-term risk of fatal cancer by a few percent (for the 1000 mSv, 5% increase in cancer risk limit, that means you're still 20 times more likely to die of cancer from something else), provided the models are even accurate for such low exposures. R

    • by Shimbo (100005)

      "astronauts on even the shortest roundtrips to Mars would get radiation doses of about 662 millisieverts"

      That is simply *not* the "huge amount of radiation" the article claims. It won't even cause any effects that can be tied to the'll increase the long-term risk of fatal cancer by a few percent (for the 1000 mSv, 5% increase in cancer risk limit, that means you're still 20 times more likely to die of cancer from something else), provided the models are even accurate for such low exposures.

      The problem is that the radiation levels can vary by several orders of magnitude depending on what the sun is up to. If you're unlucky, you get 10 or 100 times that; if you're really unlucky, lethal levels. It's a significant problem even if most of the time you aren't getting much of a dose.

It is not every question that deserves an answer. -- Publilius Syrus