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NASA Space Science Technology

NASA Wants Revolutionary Radiation Shielding Tech 160

Posted by Soulskill
from the yeah-we-all-want-star-trek-shields-too dept.
coondoggie writes "Long term exposure to radiation is one of the biggest challenges in long-duration human spaceflights, and NASA is now looking for what it calls 'revolutionary' technology that would help protect astronauts from harmful exposure. 'It is believed that the best strategy for radiation protection and shielding for long duration human missions is to use electrostatic active radiation shielding while, in concert, taking the full advantage of the state-of-the-art evolutionary passive (material) shielding technologies for the much reduced and weaken radiation that may escape and hit the spacecraft.'"
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NASA Wants Revolutionary Radiation Shielding Tech

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  • by ackthpt (218170) on Monday March 21, 2011 @05:18PM (#35564924) Homepage Journal

    Seems to be the first line of defence for many...

  • Tinfoil Hat thing didn't play out?
    • by ackthpt (218170)

      Tinfoil Hat thing didn't play out?

      I was fascinated to find wood is effective in blocking a stream of neutrons - how about not so much Revolutionary as trying what you have, first.

      • by vlm (69642)

        I was fascinated to find wood is effective in blocking a stream of neutrons

        Most plastics are awesome neutron shields, so if you think of wood as "naturally made plastic" then it shouldn't be too surprising.

        Carbs would make a decent neutron shield, plenty of H and low Z atoms. A giant caramel or taffy would make a decent shield. Plus you could eat it.

  • by richdun (672214) on Monday March 21, 2011 @05:28PM (#35565054)
    Active shielding could lead to some neat side techs, as with most NASA tech. But, this being what it is, I'll summarize the next few dozen comments: (insert comment here about not wasting money on NASA when we could use their budget to take care of some rounding errors in the national debt) (insert irrelevant reference to Fukushima here) (insert comment that all NASA craft would now be indestructible with the addition of something for which the polarity could be reversed and / or to which all auxiliary power could be diverted)
    • by rossdee (243626) on Monday March 21, 2011 @05:33PM (#35565110)

      Yeah, don't forget the ability for it to be reconfigured to emit a tachyon pulse. That can be very useful in many situations.

      • by Shotgun (30919)

        Fast forward to the first season of Voyager (using a tachyon pulse, of course), and it would be useful in ALL situations.

        8*)

    • by LWATCDR (28044) on Monday March 21, 2011 @05:45PM (#35565256) Homepage Journal

      Active shielding will only work for Alpha, Beta, and high energy Protons. It will do nothing for Neutron, Gamma, Xrays, and so on. For Neutron you could us a material with lots of Boron in it but I am not sure if Boron only captures some energies of Neutrons effectively or all of them. If it only captures thermal neutrons then you could combine it with carbon and have pretty efective material. But when you are talking about high energy Photons the only thing that I know works is mass.
      So pick your radiation and there will be a different way to shield it.
       

      • by Nyrath the nearly wi (517243) on Monday March 21, 2011 @05:56PM (#35565388) Homepage

        Well, not to put too fine a point on it, but NASA wants active shielding for the sorts of natural radiation astronauts encounter in space. Cosmic rays, solar flares, and the Van Allen radiation belts. All of which are charged particles.

        As a general rule, one only encounters neutrons, gamma rays, and x-rays from artificial sources, such as nuclear weapons and nuclear power plants.

        So unless NASA is contemplating starting a space war with alien invaders from another solar system, they will be well served by active shielding.

        • As a general rule, one only encounters neutrons, gamma rays, and x-rays from artificial sources, such as nuclear weapons and nuclear power plants.

          What do you think is going to be powering these space vehicles?

          • by bryan1945 (301828)

            Hamsters. On wheels. Many, many hamsters.

          • What do you think is going to be powering these space vehicles?

            Aneutronic fusion power plants, assuming Bussard was on to something. *Fingers crossed*

          • What do you think is going to be powering these space vehicles?

            Solar power arrays. The insane Luddite activists went absolutely ballistic about the Cassini space probe with its piddling 72 pounds of plutonium in a sub-critical RTGs. Do you seriously believe that the activists and the politicians they control are going to allow NASA to put an actual full-scale nuclear reactor on a booster rocket?

            • Solar panels won't work very well far out in the solar system and not at all in deep space. Even if they would, the size you'd need to power 'active' shielding would be prohibitive to actually getting stuff into orbit.
        • by Unkyjar (1148699)

          Wait, no Gamma in space? What about the gamma ray bursts? Too far away?

          • Wait, no Gamma in space? What about the gamma ray bursts? Too far away?

            You might say that. Gamma ray burst occur in other galaxies. Way to far away to be harmful.

            Such a burst inside our galaxy would probably be strong enough to cause a mass-extinction event on the entire Earth, so any astronauts who were killed would have plenty of company.

        • by Amouth (879122)

          last time i checked our sun put out a fairly decent amount of gamma and x-rays .. and i don't think it is artificial

          • by tehcyder (746570)

            last time i checked our sun put out a fairly decent amount of gamma and x-rays ..

            and i don't think it is artificial

            Jeez, I suppose you think they really landed men on the moon too? And that JFK wasn't an alien lizard?

        • by EdIII (1114411)

          So unless NASA is contemplating starting a space war with alien invaders from another solar system, they will be well served by active shielding.

          You mean like an ant hill would be well served by putting up a layer of leaves and debris? Cuz it would be about the same thing I think.

        • by LWATCDR (28044)

          True the majority are charged particals but you do also have hard X-Ray as well. Some of which could be caused by your own shielding.

      • by richdun (672214)
        I'd think one of the key interests in new active shielding techniques is weight. As you said, some things as we know them now just require more mass or relatively light material in rather thick shielding. Assuming this tech doesn't come with a revolutionary mining of asteroids or a revolutionary construction in space, we still have to get the stuff up there. Maybe impossible, but if some kind of generator(s) could replace a few inches of metal / ceramic, that could mean big savings in launch costs and the a
      • by loufoque (1400831)

        There is no need to pick, mass works for everything.

        • by LWATCDR (28044)

          Actually Mass can make it worse. Comic rays can cause more radiation when they hit a high mass shield then when there is no shielding. That is unless you have a LOT of mass.

  • by Quiet_Desperation (858215) on Monday March 21, 2011 @05:36PM (#35565154)

    Just move the Earth wherever you want to go.

  • by dmgxmichael (1219692) on Monday March 21, 2011 @05:42PM (#35565222) Homepage

    The reason, even 1st generation ones will be able to lift 2 to 3 times as much weight in orbit as the chemical rockets we have now. This is the difference between orbiting the earth with substantial protection in an overbuilt craft and orbiting with tin foil.

    The simple act of wrapping the crew quarters with water tanks for one. Water, when exposed to vacuum, freezes. It expands when it freezes, sealing any holes made by micro meteorites or space junk. It absorbs radiation somewhat readily, meaning you'd have to purify it before putting it to its most common use - drinking it.

    But building a spacecraft or spaceship with such a concept in place will take a monumental increase in lifting capacity. We've taken chem rockets about as far as they are going to go - nuclear is the way if we can ever get over our irrational fear of the stuff.

    • The one downside of nuclear rockets is that if we had another Challenger-esque disaster, this time with, say, plutonium fuel, the repercussions would be much, much, much more immense. Just to be sure, we'd have to launch all rockets from tiny little atolls in the middle of the ocean.
      • by 0123456 (636235) on Monday March 21, 2011 @06:10PM (#35565568)

        The one downside of nuclear rockets is that if we had another Challenger-esque disaster, this time with, say, plutonium fuel, the repercussions would be much, much, much more immense. Just to be sure, we'd have to launch all rockets from tiny little atolls in the middle of the ocean.

        Except you wouldn't use plutonium for fuel.

        When NASA were planning to launch NERVA rockets the flight path would have been south from California so that any launch failure would either dump the NERVA into the ocean or the Antarctic. And since it would have been boosted by a conventional Saturn V, there wouldn't be any really nasty radioactivity until the NERVA started firing late in the launch.

        That said, using nuclear fission rockets for launch from Earth still seems pretty optimistic to me.

        • [...] the flight path would have been south from California so that any launch failure would either dump the NERVA into the ocean or the Antarctic.

          And it's not like anything we eat actually comes from the ocean, so it's a great place to dump stuff.

          • by 0123456 (636235)

            And it's not like anything we eat actually comes from the ocean, so it's a great place to dump stuff.

            The impact on sea life of a few tons of uranium on the seabed would be practically zero.

          • by Tim C (15259)

            See, the thing about the ocean is that in general, it's very, very deep, while our nets are very, very small, and the fish we eat tends to stay relatively near the surface.

        • I wasn't thinking NERVA - but Gaseous Diffusion rockets which use Uranium Hexafluoride gas as the reactant. A lot more kick to those, but admittedly if we start today they're still 30 years away.

          And yes, it is overly optimistic. Even the educated public here is scared of the things not to mention the 4th grade reading level challenged common public that believes the lies CNN and Faux News cook up for them. When such a rocket goes bad (it will happen, Murphy's law) the radiation release would be on par wi

      • by AJWM (19027)

        if we had another Challenger-esque disaster, this time with, say, plutonium fuel, the repercussions would be much, much, much more immense

        Oh, we've had one. The vehicle blew up (a Titan, if I recall correctly) shortly after launch, and the plutonium fuel canister (in an RTG, for the space probe) fell into the ocean ... where it was recovered, cleaned off, and used in the backup spacecraft.

        Want to argue that that was an RTG and not a NERVA-type engine? Okay. Rocket engines are designed to withstand thousa

    • Huh? (Score:5, Insightful)

      by StefanJ (88986) on Monday March 21, 2011 @06:05PM (#35565522) Homepage Journal

      With the exception of Project Orion, all of the nuclear propulsion concepts I've read about, and even the actual trials made in the 1960s, have much lower thrust than chemical fueled rockets. In the case of ion and plasma thrusters, vanishingly little thrust. Even in the case of fission/thermal rockets (e.g., NERVA), only about a third of the thrust of chemical rockets. They are less suitable for getting stuff into orbit than chemical rockets.

      Once you're in orbit (or beyond), thrust counts for much less than exhaust velocity.

      And as for Project Orion: Yeah, some of the proposed designs could heave a pretty damn big ship into orbit, But the fear of fallout from hundreds of little atomic bombs going off in the atmosphere is anything but irrational. One of the principles of the project, Freeman Dyson, specifically stated that the risk wasn't worth it. (I mean, maybe if there was a big asteroid on the way . . .)

      And . . . jeeze:
      "Water, when exposed to vacuum, freezes."

      No, it evaporates.

      • Re:Huh? (Score:5, Informative)

        by Phase Shifter (70817) on Monday March 21, 2011 @06:35PM (#35565862) Homepage

        And . . . jeeze: "Water, when exposed to vacuum, freezes."

        No, it evaporates.

        Or to be more precise, it evaporates, and the loss of heat due to the latent heat of vaporization results in cooling, which in turn results in freezing when the temperature gets sufficiently low (after which point you will still have some cooling due to sublimation of solid ice)..

      • by Chris Burke (6130)

        Even in the case of fission/thermal rockets (e.g., NERVA), only about a third of the thrust of chemical rockets. They are less suitable for getting stuff into orbit than chemical rockets.

        The thrust is lower, but so is the mass of the engine and fuel. When used in second or subsequent stages this means you can be carrying a bigger payload and still be traveling faster after the first-stage burn, meaning less thrust is needed from subsequent stages to reach orbit.

        However it's hardly a revolution in lift capacity given the revolution in power source. Doubling the payload is an impressive gain, but is it impressive enough to actually build and operate and fight the political battles when inst

    • by AK Marc (707885)

      Water, when exposed to vacuum, freezes. It expands when it freezes, sealing any holes made by micro meteorites or space junk.

      Water freezes. Ice sublimates. Water would make a very poor hull material because it would quickly evaporate into space. Having it fill small holes may work, or it may just allow the precious water supply to leak through those tiny holes.

      I also thought of keeping the water on the outside, but the question I have is whether the water will become radioactive itself. The coolant used in nuclear plants becomes radioactive. I haven't looked into the process, but if your water supply became radioactive, the

      • by treeves (963993) on Monday March 21, 2011 @07:01PM (#35566112) Homepage Journal

        The coolant in nuclear power plants is radioactive *mainly* because it has small amounts of insoluble stuff (commonly called "crud") suspended in it and soluble stuff dissolved in it that are radioactive, mostly Na-24 and Cl-38. Just a teeny little bit of cobalt from alloys in valves and pumps getting into the coolant and getting activated to Co-60 contributes a majority of the long-lived radioactivity of reactor coolant. There are some water activation products but they are smaller contributors and have short half-lives.

      • Yes, ice sublimates. But it's a relatively slow process, one that allows for patching. If the hull breach leads straight to air on the other hand you have explosive decompression. So which would you rather have, a slow sublimating ice leak that will leak out your water supply in about 7 days or an explosive decompression that kills you in 7 seconds unless you're fortunate enough to have a bulkhead between you and the strike?

    • by Chris Burke (6130)

      But building a spacecraft or spaceship with such a concept in place will take a monumental increase in lifting capacity. We've taken chem rockets about as far as they are going to go - nuclear is the way if we can ever get over our irrational fear of the stuff.

      Or we could give up on the idea of lifting entire spacecraft and every component on them in a single launch. Think less like Apollo and more like the ISS. Lift components separately on cheap, commodity rockets, assemble in space, lift water and fuel in separate launches.

      It's not as sexy as the giant launcher, but much more flexible. Also more attainable.

      We're quite a ways from nuclear rockets even if the environment were politically amenable. I think we'll need quite a while of demonstrating vastly impr

      • by Jartan (219704)

        Well said. I think we should also point out that there are many possible lift technologies that generate acceleration a human could not possibly live through. Those same technologies could be very cheap though.

        The idea of one giant rocket pushing the crew and everything they need into space all at once should of been abandoned long ago.

      • by mbone (558574)

        We had a nuclear rocket, NERVA. It worked quite well, had a number of successful ground tests with no failures IIRC, and was ready for a flight test. It was killed for political reasons in 1972 during the Nixon administration, along with Apollo and all Apollo follow-ons.

    • Eh, I don't think our fear of radiation poisoning is that irrational. Nuclear powered rockets do sound pretty useful though.

      • by dpilot (134227) on Monday March 21, 2011 @09:23PM (#35567418) Homepage Journal

        Check out "Project Pluto" some time. It was a nuclear-powered ramjet cruise missile. At some point they realized that simply flying the dirty engine at low-altitude mach 3 over anything was about as bad as actually bombing the target. The stuff the engine spewed out the back was so bad that there was no safe way to flight test it, and you could never fly it over a friendly nation on its way to a target.

        • by jgtg32a (1173373)
          To be fair Pluto's reactor core was directly exposed to the air.
          • by dpilot (134227)

            That's true, but by the time you add the weight of a heat exchanger to a nuclear ramjet, I suspect the best you'll do is a nuclear-ramjet-powered car or boat.

    • by Mascot (120795)

      Water, when exposed to vacuum, freezes. It expands when it freezes, sealing any holes made by micro meteorites or space junk

      Unless the idea was that the water should be frozen to begin with, I don't get this. To remain liquid in order to later be frozen, it would have to be kept pressurized and heated, right? Exposing it to vacuum would then at least involve a short period of boiling?

    • Actually I thought about circulating human waste between an inner and outer hull.
      It would absorb the same types of radiation as other organic matter (Like human tissue), and as a bonus the radiation would tend to kill off any lurking pathogens.
    • Shielding is primarily used to take care of the low-hanging fruit when dealing with space radiation. There are some really high energy particles out there which are simply impractical to completely block with passive shielding.

      Furthermore, energetic particles do the most damage when they are low-enough energy that object they hit can just barely stop them (at the Bragg Peak [wikipedia.org]), whereas very high energy particles are more likely to pass right through without interacting. If you have a relatively uniform distri

    • by mbone (558574)

      At the Target NEO [targetneo.org] meeting, "thermal nuclear" was one of the propulsion types on the table. It's only been

      By the way, "primordial" asteroids contain water, and one of the ideas we discussed at lunch at that meeting was to stick down a pipe to get water to fill those shielding tanks, which would really cut down on the lift required. This would make a very interesting target for a NEO mission.

      It's only been 39 frakking years since NERVA was canceled.

  • IIRC there was an SF story by A.C. Clark where a space craft used a huge block of ice as a radiation shield.

    • by ackthpt (218170)

      IIRC there was an SF story by A.C. Clark where a space craft used a huge block of ice as a radiation shield.

      Probably work great until the thing has totally sublimated.

      They'll probably develop something which captures it in a magnetic envelope or has a game of kick about with particles and nano-tubes, then find the composite material of a standard childrens rain coat works just as well.

      Radiation is funny that way.

      • IIRC there was an SF story by A.C. Clark where a space craft used a huge block of ice as a radiation shield.

        Probably work great until the thing has totally sublimated.

        I've followed most of this whole freeze vs. sublimate thread thus far, but your comment raises what should be an obvious question: if ice sublimates so readily and quickly in space that it's not considered suitable as a shielding material, how do things like the rings of Saturn continue to exist? Last I heard, the rings are thought to be composed of various ices, some of which is likely water ice.

        The rings have been there a long, long, *long* time and haven't sublimated away, yet they don't appear to be c

    • by DeCappa (651304)

      The Songs of Distant Earth, 1986

      http://en.wikipedia.org/wiki/The_Songs_of_Distant_Earth [wikipedia.org]

      Blocks of ice were frozen on-planet and then lifted with a space elevator to create a shield. The shield was there to protect against micrometeorites and other space debris though, not radiation.

  • by Shotgun (30919) on Monday March 21, 2011 @05:59PM (#35565444)

    Is it possible that an active magnetic envelope could be devised that would capture radiation and particles at the front of the craft and accelerate it to the rear. There is not a lot of interplanetary debris, but what is there would be devastating as the craft approaches a significant fraction of c. Shielding would be necessary for both radiation and particulate matter. If the particles and ionized radiation could be harnessed, the craft could move through space much like a jelly fish.

  • by Billy the Mountain (225541) on Monday March 21, 2011 @06:01PM (#35565480) Journal
    Well, I guess if you are somehow able to set up a magnetic field that circles the craft then charged particles heading towards the craft could possibly be bent around the craft without making contact. This is due to a magnetic field causing Lorentz forces on the incoming particles. However, this only takes care of particles that are heading right for the craft, i.e. normal to the body. Particles moving parallel to the body might well be snagged and sucked into the body due to the same Lorentz forces.

    The other issue is generating magnetic fields is non-trivial and usually requires heavy equipment, i.e. permanent magnets, coils and iron cores. Any workarounds on this?

    I think gamma rays might still be a significant problem.

    BTM
  • This is just a random thought that I had, and I'll admit I know jack about physics. But from my understanding high energy electromagnetic radiation needs to be block by rather dense things because it increase the chance that the electromagnetic wave will collide with the atoms and be absorbed instead of pass through it.

    What if there was a superconductor that was saturated with electrons, would that be effective at blocking electromagnetic radiation? I'm asking at more of a theoretical level, and I am ign
    • by sFurbo (1361249)
      Heavy things are good at blocking photons, as photons interact most strongly with electrons (highest charge/mass ratio). The amount of electrons in a substance is roughly proportional to its weight (one electron for each proton, one to two neutrons per proton in normal substances). So, X-rays and gamma-rays are blocked better by heavy substances. The state of the electrons doesn't matter much, so superconductivity won't make much of a change.

      Radiation consisting of heavier particles, such as protons or nu
  • The good old MIR had a much better shielding than the Internationale Space Station. The simple reason: It was so massive with so much junk around the module. Now they want to be fancy, light, and efficient.

    Fools, I say!

    Once the space elevator is finally running, we might be able to go back to nice and heavy, with a lead, paraffin, moon-rock mixture.- Who knows, the first interplanetary cruiser might look like Red Dwarf.

  • People in Hell want iced water. But that ain't gonna happen either.
    • by ThosLives (686517)

      I'm pretty sure people that live here [hell2u.com] get plenty of iced water. It tends to freeze over every single year, actually.

  • (a) Polarize the hull plating

    (b) If that doesn't work, I recommend bypassing the quantum phase-modulator arrays in the plasma conduits, thereby frequency-limiting the gravimetric fluctuations in the warp nacelles and hopefully inducing a soliton static-warp shield-harmonic attenuation grid over the triassic subresonance field.

  • Burns: What will you demand next? Real *lead* in the radiation shields?!
  • Just supply the crew with enough Rad-X and Rad-Away.
    And don't forget some extra water chips, just in case.

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