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NASA Wants Revolutionary Radiation Shielding Tech
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.'"
Seems to be the first line of defence for many...
A feeling of having made the same mistake before: Deja Foobar
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)
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)
retrorocket.o not found, launch anyway?
Just move the Earth wherever you want to go.
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.
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.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
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.
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
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
That was the turning point of my life--I went from negative zero to positive zero.
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!
People in cars cause accidents....accidents in cars cause people
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.
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.
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.
The Songs of Distant Earth, 1986
http://en.wikipedia.org/wiki/The_Songs_of_Distant_Earth
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.
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)
All de water in Denial?
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
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.
Your mindless trashing of NASA is revolting. The people at NASA are dedicated professionals. I doubt you have the qualifications to mow the lawn at a NASA facility, given the shear ignorance of your statement. I assume that you trash talk you betters because you are both stupid and vile. You are most likely incapable of tying you own shoes, so your only response is to slander people who have real accomplishments.
Why is Snark Required?