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NASA Wants Revolutionary Radiation Shielding Tech

Soulskill posted about 3 years ago | from the yeah-we-all-want-star-trek-shields-too dept.

NASA 160

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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160 comments

Have they considered Denial? (4, Funny)

ackthpt (218170) | about 3 years ago | (#35564924)

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

Re:Have they considered Denial? (2)

MonkWB (724056) | about 3 years ago | (#35564982)

What does Egypt have to do with Radiation?

Re:Have they considered Denial? (0)

Anonymous Coward | about 3 years ago | (#35565024)

The same thing that Tsunamis have to do with Radiation (at least according to the western media).

Re:Have they considered Denial? (1)

Tumbleweed (3706) | about 3 years ago | (#35565304)

What does Egypt have to do with Radiation?

Water, of course, is a great shielding material, if you have enough of it. Hence, de Nile.

Shields Up! (0)

Anonymous Coward | about 3 years ago | (#35564930)

Brace for impact!

Japan (0)

Anonymous Coward | about 3 years ago | (#35564972)

Perhaps we could employ the same technology around Japan?

Re:Japan (4, Informative)

Andy Dodd (701) | about 3 years ago | (#35565098)

Nope. Completely different type of radiation.

In space, the main problem (unless your spacecraft is nuclear-powered) are high energy cosmic rays.

In Japan, the issue is with radionuclide contamination.

Also, NASA's looking for a way to keep external radiation out - in Japan they're trying to contain radioactive substances within a vessel that contains superheated water that is pressurizing it, water which is unfortunately radioactive (resulting in the steam being radioactive if they vent it)

Re:Japan (2)

Phase Shifter (70817) | about 3 years ago | (#35565644)

Well, to be fair it's not the steam that's radioactive.
If they could remove the heavier elements out of the steam (perhaps by forcing it through a distillation column as it escapes?) the H2O wouldn't be an issue.

So, the (1)

Crash McBang (551190) | about 3 years ago | (#35565004)

Tinfoil Hat thing didn't play out?

Re:So, the (1)

ackthpt (218170) | about 3 years ago | (#35565062)

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.

Re:So, the (1)

vlm (69642) | about 3 years ago | (#35565206)

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.

Re:So, the (1)

bryan1945 (301828) | about 3 years ago | (#35565920)

"Hey mom, I'm going out to the vacuum to grab some taffy and get a quick suntan. Maybe say 'Hi!' to Bob the Martian."

Deflectors to full? (3, Insightful)

richdun (672214) | about 3 years ago | (#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)

Re:Deflectors to full? (3, Funny)

rossdee (243626) | about 3 years ago | (#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.

Re:Deflectors to full? (2)

Shotgun (30919) | about 3 years ago | (#35565342)

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

8*)

Re:Deflectors to full? (3, Informative)

LWATCDR (28044) | about 3 years ago | (#35565256)

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.
 

Re:Deflectors to full? (3, Informative)

Nyrath the nearly wi (517243) | about 3 years ago | (#35565388)

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.

Re:Deflectors to full? (1)

pixelpusher220 (529617) | about 3 years ago | (#35565464)

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?

Re:Deflectors to full? (1)

Amouth (879122) | about 3 years ago | (#35566282)

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

Re:Deflectors to full? (1)

richdun (672214) | about 3 years ago | (#35565416)

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 ability to use more fuel for extraplanetary maneuvers.

How about... (0)

Jeremi (14640) | about 3 years ago | (#35565080)

Employing robotics/telerobotics? That way the human operators can use Earth's atmosphere as a radiation shield. Seems to work quite well, and solves/avoids a number of other issues besides.

(ducks)

Re:How about... (0)

Anonymous Coward | about 3 years ago | (#35566068)

Seems to work quite well, and solves/avoids a number of other issues besides.

Creates a few, too. Ever tried using a mouse that took a second to start working and a second to stop?

Re:How about... (1)

couchslug (175151) | about 3 years ago | (#35566308)

This is Slashdot!

How dare you not want to send humans as soon as possible for Star Trekful fapworthy adventures despite the fact they are useless for actually "exploring" space since their function is still to operate remote systems?

Re:How about... (2)

R3d M3rcury (871886) | about 3 years ago | (#35566404)

Well, the "telerobotics" would be an issue on Mars when you figure that there will be a delay between 4 and 20 minutes. So the whole "Wait, stop! That looks interesting!" part becomes a bit trickier.

But... (0)

vell0cet (1055494) | about 3 years ago | (#35565088)

Radiation is good for you! Ann Coulter says so!

http://www.youtube.com/watch?v=FXFUUGeV1DI

Re:But... (0)

Anonymous Coward | about 3 years ago | (#35566314)

I don't what Ann Coulter says, but I believe the hormetic effect of low-level radiation is real -- why, because the best scientific evidence supports it. Ann Coulter happens to cite a few of those studies. What, you think it is wrong because she said it? I read the studies year ago and drew this conclusion. I personally would gladly live in an area having 10 times the normal background radiation found in this country.

The straight-line radiation dosage / radiation damage assumption is just that, an assumption -- the evidence seems to indicate this assumption is not valid. I could point you to additional studies of low-level radiation, but somehow, if you look these up yourself you may be more likely to consider the studies valid -- i.e., not biased by my selectivity.

Am I being naieve... (0)

Anonymous Coward | about 3 years ago | (#35565102)

Or does an electrostatic shield not really help.

There are 3 types of radiation in high-school physics.

Alpha particles are blocked by a thin sheet of paper, so no risk to astronautics as long as the alpha particle producers stay outside the craft.

Beta particles are neutrons, so with no electric charge, and unaffected by an electrostatic field.

Gamma rays are an electromagnetic wave, like light, and hence also can't be deflected by an electric field.

There are other types of radiation, but I got the feeling they were rare (ie. not found except in particle accelerators) - can someone correct me?

Re:Am I being naieve... (1)

0123456 (636235) | about 3 years ago | (#35565142)

As far as I remember the biggest threat to astronauts is from cosmic rays, which are charged particles and require shedloads of shielding if you want to stop them with a passive shield.

Re:Am I being naieve... (1)

Relic of the Future (118669) | about 3 years ago | (#35565228)

Beta radiation is high speed electrons (or positrons, AKA anti-electrons). Most can be stopped with a thin sheet of metal.

Neutron radiation is neutrons. The #1 neutron-stopper in use is water (or other stuff high in hydrogen).

Re:Am I being naieve... (3, Informative)

vlm (69642) | about 3 years ago | (#35565250)

Alpha particles are blocked by a thin sheet of paper, so no risk to astronautics as long as the alpha particle producers stay outside the craft

Secondary gammas release on impact. Ouch.

Beta particles are neutrons

No electrons.

Gamma rays are an electromagnetic wave, like light, and hence also can't be deflected by an electric field.

There are other types of radiation, but I got the feeling they were rare (ie. not found except in particle accelerators) - can someone correct me?

Not really. nuke radiation is pretty much defined as alpha beta and gamma "waves/particles" plus our mostly artificially generated pal, the neutron. If we could make muons or other particles in bulk we'd probably add those. Delta waves and stuff are only found in star trek technobabble.

The concept of "rare" is kind of vague in particle physics.

Re:Am I being naieve... (2)

Phase Shifter (70817) | about 3 years ago | (#35565772)

Not really. nuke radiation is pretty much defined as alpha beta and gamma "waves/particles" plus our mostly artificially generated pal, the neutron. If we could make muons or other particles in bulk we'd probably add those. Delta waves and stuff are only found in star trek technobabble.

The concept of "rare" is kind of vague in particle physics.

Don't forget the odd decay by positron emission. (and subsequent annihilation radiation when that hits your passive shielding)

Re:Am I being naieve... (1)

mbone (558574) | about 3 years ago | (#35566384)

I think what they are really worried about are very high energy cosmic rays, can be protons, but also can be atomic nuclei (I believe that Iron nuclei have been detected in UHECR's, for example). If these hit shielding, they will cause a shower of secondaries that would be quite dangerous (on the Earth, this happens many km up, so it's not dangerous here on the ground). It might be possible to use multiple shield with a gap, but that make for a big structure. Deflecting these away from the spacecraft would be a good idea, if it can be done.

Re:Am I being naieve... (1)

ceoyoyo (59147) | about 3 years ago | (#35565316)

The universe is a big particle accelerator. Cosmic rays are one of the biggest dangers and they're mostly protons or helium nuclei, which can certainly be deflected by electric or magnetic fields. Likewise, the solar wind is mostly protons and electrons, both of which are charged and can be deflected.

Not nuclear radiation (2)

pavon (30274) | about 3 years ago | (#35565686)

I'm taking a course right now about how to predict and mitigate space radiation effects in electronics. We may have skipped over radiation that harms humans but not electronics, but here is what I know.

The radiation you are talking about are the all result of nuclear decay. In science/engineering the word radiation can refer to any type of electromagnetic or energetic particle which is radiating from an object. Nuclear radiation generally isn't a concern in the space environment (unless you are carrying some nuclear material yourself).

The types radiation that we are primarily concerned about in space are charged particles: electrons, protons, and heavy ions (any ionized atom). Those all interact with electromagnetic fields. The fact that the earth's magnetic field has such a profound affect on radiation is why terrestrial radiation is at a much lower level than space radiation.

But while it makes the terrestrial environment nicer, the earth's magnetic shield makes the orbital environment worse, as all those charged particles that would have hit the earth either get deflected or trapped where they travel back and forth along the magnetic field lines (see Van Allen Belts) which is of course worst at the poles (see South Atlantic Anomaly).

Neutrons are also a concern, as are X-Rays/Gamma-Rays (especially during solar flares), and even UV. But the vast majority of radiation effects are caused by charged particles.

huh? (1)

slew (2918) | about 3 years ago | (#35565800)

Alpha particles = helium nucelus
Beta particles = electrons and positrons (not neutrons)
Gamma rays being EM waves, might be deflected by electro magnetics...

Some others common forms of ionizing radiation...
Neutron radiation = neutrons (you got that mixed up with beta), basically how current fission nuclear reactors chain and how C14 carbon dating works.
Proton radiation = mostly cosmic rays, but also used for cancer treatment

The problem with cosmic rays which are mostly proton radiation (but also include all the above mentioned forms of radiation and all sorts of other charged ions of various heavier nucleic isotopes and vanilla uncharged neutron radiation) is that they are HIGHLY energetic (e.g, from 10^7 up to 10^20 eV) compared the usual sources of radiation. This makes them exceptionally hard to stop or deflect. Even cosmic alpha particles won't be stopped by a thin sheet of paper.

It seems unlikely that an electro-static shield configuration would stop this stuff (from an strictly energy point of view). But maybe a "startrek" like dynamically modulated shield would have a better chance to deflect the radiation around a small volume of space where people might be located in a ship. Still, it seems unlikley that would work either (even though it would probably take less energy to diffract the radiation than to cancel/stop the stream of radio active particles, it still seems like a lot to ask).

For example, I don't think they have even solved this problem for the moon or mars where we would get protected from about 1/2 of the radiation by being on the ground (since cosmic rays from the other side have to go through the celetial object to get to us) and there isn't that much of a weight problem. In outerspace, it's coming from all sides and would be twice as bad and we have to carry it with us.

Solved problem (1)

Anonymous Coward | about 3 years ago | (#35565134)

A few thousand kilometers radius magnetic field and about 70 Kg/m^2 mass does the trick nicely.

Just crew the ship with Japanese astronauts (0)

WillAffleckUW (858324) | about 3 years ago | (#35565144)

Just crew the ship(s) with Japanese astronauts. ...

What? Too soon?

I mean, their nuclear regulatory agency says they can take 10 to 20 times the exposure levels for radiation as any other human, so they must be better!

Re:Just crew the ship with Japanese astronauts (2)

pixelpusher220 (529617) | about 3 years ago | (#35565502)

Just crew the ship(s) with Japanese astronauts. ... What? Too soon?

Yes, this rare situation is much to serious to be made light of.

Wait till it's well done before making such jokes!

The Best Solution Ironically is Nuclear Rockets (2, Insightful)

dmgxmichael (1219692) | about 3 years ago | (#35565222)

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.

Re:The Best Solution Ironically is Nuclear Rockets (0)

Anonymous Coward | about 3 years ago | (#35565452)

It would also very nicely boil the crew on their way down if you had any of those pesky microfractures.
Oh and it would send hot radioactive steam into teh atmosphere.

Re:The Best Solution Ironically is Nuclear Rockets (1)

bennomatic (691188) | about 3 years ago | (#35565462)

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.

Re:The Best Solution Ironically is Nuclear Rockets (4, Interesting)

0123456 (636235) | about 3 years ago | (#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.

Re:The Best Solution Ironically is Nuclear Rockets (1)

R3d M3rcury (871886) | about 3 years ago | (#35566430)

[...] 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.

Re:The Best Solution Ironically is Nuclear Rockets (2)

dmgxmichael (1219692) | about 3 years ago | (#35566802)

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 with any one of the 200 or so / year 50's bomb tests. But I don't foresee more than 1 failure a decade - and that amount of release, on a global scale, is acceptable in my mind. At least there'd be a point to it other than foolish sabre rattling with the Russians.

I don't think we have a choice though. We've pushed chem rockets as far as the tech can go. Just as, 100 years ago, we'd pushed steam as far as it can go. Either we change techs or we make no progress - pretty simple really.

Huh? (4, Insightful)

StefanJ (88986) | about 3 years ago | (#35565522)

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? (4, Informative)

Phase Shifter (70817) | about 3 years ago | (#35565862)

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)..

Re:Huh? (1)

Chris Burke (6130) | about 3 years ago | (#35565888)

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 instead you could just launch two regular rockets?

Re:The Best Solution Ironically is Nuclear Rockets (0)

Anonymous Coward | about 3 years ago | (#35565540)

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.

Ideally, this water would not be used for drinking, but instead be a part of the vehicle's thermal management system, which would conveniently double as added radiation protection. You'd need to take the hit of the extra mass for having two water supplies, but you'd drastically cut down on the tech needed for the potable water recycling systems (along with the increased chance of failure that goes with having the more complex system).

Re:The Best Solution Ironically is Nuclear Rockets (1)

AK Marc (707885) | about 3 years ago | (#35565560)

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, then it would be a bad thing.

Re:The Best Solution Ironically is Nuclear Rockets (3, Informative)

treeves (963993) | about 3 years ago | (#35566112)

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.

Re:The Best Solution Ironically is Nuclear Rockets (1)

dmgxmichael (1219692) | about 3 years ago | (#35566744)

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?

Re:The Best Solution Ironically is Nuclear Rockets (1)

Chris Burke (6130) | about 3 years ago | (#35565632)

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 improved safety in rockets and in nuclear power before anyone becomes comfortable with combining them, and I don't think that's an entirely irrational position.

Re:The Best Solution Ironically is Nuclear Rockets (1)

Jartan (219704) | about 3 years ago | (#35565924)

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.

Re:The Best Solution Ironically is Nuclear Rockets (1)

mbone (558574) | about 3 years ago | (#35566306)

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.

Re:The Best Solution Ironically is Nuclear Rockets (1)

somersault (912633) | about 3 years ago | (#35565646)

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

Re:The Best Solution Ironically is Nuclear Rockets (1)

Mascot (120795) | about 3 years ago | (#35565656)

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?

Water doesn't freeze. (1)

Anonymous Coward | about 3 years ago | (#35565778)

Water, when exposed to a vacuum, boils. (Slowly.)

Re:The Best Solution Ironically is Nuclear Rockets (1)

Phase Shifter (70817) | about 3 years ago | (#35565802)

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.

Re:The Best Solution Ironically is Nuclear Rockets (1)

mywhitewolf (1923488) | about 3 years ago | (#35566002)

the fallout from a nuclear powered rocket would cause a massive amount of fallout sprayed from the ground to the upper atmosphere, the fear is far from irrational. there is talk however of using a nuclear powered rocket as a means of interplanetary / interstellar travel where fallout isn't such an issue.

Passive shielding has diminishing returns. (1)

pavon (30274) | about 3 years ago | (#35566124)

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 distribution of particle energies, then additional shielding may block the lower energy ones, but slow down the higher energy ones to take their place, leaving you with a similar distribution of particles as you began with. One of my professors told me that she has even heard of rare situations where additional shielding actually made things worse through that substitution effect. Normally, after about 20-50mm of aluminum, it helps some but not enough to justify the additional launch costs.

Re:The Best Solution Ironically is Nuclear Rockets (1)

mbone (558574) | about 3 years ago | (#35566204)

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.

Re:The Best Solution Ironically is Nuclear Rockets (0)

Anonymous Coward | about 3 years ago | (#35566292)

Wouldn't water evaporate in a vacuum?

This is easy... (1)

97cobra (89974) | about 3 years ago | (#35565224)

Just go at night.

Re:This is easy... (1)

roman_mir (125474) | about 3 years ago | (#35565280)

And how do you suppose they'd see where they are going then? Ha? Ha? Have you thought about that?

Re:This is easy... (0)

Anonymous Coward | about 3 years ago | (#35565406)

Yeah, and since space is way out in the middle of nowhere it's run by country folk. Everything is closed after 6 and on Sundays. Where are they going to get burgers? Where???

ICE (1)

scharkalvin (72228) | about 3 years ago | (#35565246)

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

Re:ICE (1)

ackthpt (218170) | about 3 years ago | (#35565378)

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.

Re:ICE (0)

Anonymous Coward | about 3 years ago | (#35565530)

I believe you're referring to _Songs of a Distant Earth_.

Personally, I'm more amused by _A Prelude to Space_, in which Clarke directly asserted that a chemical rocket could never reach the moon.

radiation required to quell revolution, raise fear (0)

Anonymous Coward | about 3 years ago | (#35565334)

as the old standbys; murder&mayhem, traditional poisoning, pandering, media mindphuking, sex etc... does not seem to be keeping us natives down as it once (2 months ago) did?

Biotech (1)

Anonymous Coward | about 3 years ago | (#35565422)

Find out how radiation damages cells and find out how to repair it. Awww, too hard? Better get that shit figured out before dreaming about long term human spaceflight, eh?

Harness the energy (2)

Shotgun (30919) | about 3 years ago | (#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.

Ion deflection (2)

Billy the Mountain (225541) | about 3 years ago | (#35565480)

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

Re:Ion deflection (0)

Anonymous Coward | about 3 years ago | (#35566678)

The simplest way to do this I can think of is to use superconducting coils. The issue is that you need giant fields, fields which will wreck electronics inside the ship, so you have to shield the ship from the fields too. This can be done, though.

Stick a coil of superconducting wire around the craft, then another coil located 10m outside it or so. To keep the superconductors superconducting, use a solar shade; as long as you're far enough away from a planet a layered solar shade should be enough to keep you cool. Once you get cold enough that the coils start superconducting, ramp up the current in the outside one; this will induce a current in the inner one sufficient to keep the total magnetic flux within that inner coil constant. Any fluctuations in the field due to the outer coil will be compensated for by changes in the current in the inner coil, and the folks inside will be shielded (modulo edge effects).

Another option is to land a nuclear reactor on a small asteroid somewhere, and then over the course of several decades use power from the reactor and reaction mass from the asteroid to steer the asteroid into a transfer orbit. If you use an asteroid that contains the right chemistry (water ice comes to mind) you could use more power from the reactor to make chemical fuel (by hydrolysis, or whatever) that can be burned later -- fuel that doesn't have to be boosted out of Earth's gravity well.

Ready to go to Mars, just stick your people on the dark side of that asteroid and ride it to Mars. The only trouble is that it has to be timed pretty carefully, since that transfer orbit has to be planned for particular launch/return times.

Random thought from an ignorant person (1, Insightful)

jgtg32a (1173373) | about 3 years ago | (#35565494)

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 ignoring all of the engineering problems.

Be nice, I haven't taken physics since high-school.
-An Inquisitive Idiot

Re:Random thought from an ignorant person (1)

Anonymous Coward | about 3 years ago | (#35565768)

I am a PhD student in Materials Eng, and that idea sounds reasonable actually... if you can make a thin film of superconducting material and encased a space ship in it, then the cold vacuum of space would keep things cool and superconducting... wow that idea could actually get funding! You should contact some local Universities that are doing superconductor research and email them. Don't just let your idea die on a /. forum! Go be an active participant in society... Here's a link to get you started: http://web.mst.edu/~umrr/cf004.pdf

Re:Random thought from an ignorant person (0)

Anonymous Coward | about 3 years ago | (#35565932)

To the GP, and if you get funding, and if its used on a space ship you should demand the first ride. I would.

Why bother? (1)

davev2.0 (1873518) | about 3 years ago | (#35565520)

We don't have a manned spaceflight program anymore, so why bother with it? We should just slide into insignificance the way the current plan has us doing?

Russian technology! (1)

formfeed (703859) | about 3 years ago | (#35565688)

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.

Taking advantage of the situation (0)

DaveWick79 (939388) | about 3 years ago | (#35565856)

Frankly I just think NASA is taking advantage of the situation in Japan to beg for funding. Since they have been defunded so much in recent years, this is their window of opportunity to get Congress thinking about them again and sending a few more billion bucks their way.

In other news ... (1)

517714 (762276) | about 3 years ago | (#35565868)

People in Hell want iced water. But that ain't gonna happen either.

Re:In other news ... (0)

Anonymous Coward | about 3 years ago | (#35566250)

And I'd like to be king of all Londinum and wear a shiny hat.

Re:In other news ... (1)

ThosLives (686517) | about 3 years ago | (#35566342)

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

Agnihotra (1)

Anonymous Coward | about 3 years ago | (#35566236)

Silly "experts! The Hindus have had active technology for a long time now.
Agnihotra: The solution to prevent effect of nuclear radiation.
http://www.hindujagruti.org/news/11560.html

Can't they just...?? (1)

cstacy (534252) | about 3 years ago | (#35566508)

(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.

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