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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?
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
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.
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 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.
...the future crusty old bastards are already drinking the Kool-Aid.
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.
The living have better things to do than to continue hating the dead.
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?