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Fraser
2004-Nov-17, 08:56 PM
SUMMARY: Itís the year 2027 and NASAís Vision for Space Exploration is progressing right on schedule. The first interplanetary spacecraft with humans aboard is on course for Mars. However, halfway into the trip, a gigantic solar flare erupts, spewing lethal radioactive protons directly at the spacecraft. But, not to worry. Research by former astronaut Jeffrey Hoffman and a group of MIT colleagues back in the year 2004 ensured that this vehicle has a state-of-the-art superconducting magnetic shielding system that protects the human occupants from any deadly solar emissions.

What do you think about this story? Post your comments below.

Guest_qraal
2004-Nov-17, 09:29 PM
Hi Fraser and UT

The superconducting shelter is a good idea and has been around in various forms for years. I think what really needs research is the Plasma Magnet being researched by the same group who brought us the Mini-Magnetosphere Plasma Propulsion - M2P2 - a few years ago. The Plasma Magnet is a beefier and improved version of the M2P2 system plus it can repel solar and galactic cosmic rays. Basically it generates immense magnetic fields through "captured" plasma clouds pumped up by an alternating EM field.

Because the size of the plasma cloud generated grows as solar wind density drops the sail-effect created provides continuous thrust - unlike solar sails which lose thrust inversely proportional to the square of the distance from the sun. And the power requirements are far, far less than for a rocket of the same exhaust velocity (300 - 900 km/s.) Such a system could be ramped up with a reactor for power and be used to slowly push space-station sized vehicles to other planets. Imagine one of the Space Island Group's ring-stations gliding out to Mars, the Belt or even Jupiter. That's the other advantage - Jupiter's magnetosphere is effectively an irrelevance to a shielded vehicle, if not an extra boost. And three plasma magnets in orbit of a Galilean could easily shield the surface so smaller landers can touch down safe from the radiation storm around them.

IMHO a magnificent idea that deserves a lot more research.

qraal

qraal
2004-Nov-17, 09:50 PM
Oops... forgot to add. Plasma magnets might - and I'm not sure of the power needed - be able to act as the perfect "catcher" for particle beam propulsion for interstellar flight. Winglee and colleagues have already presented their "Mag-Beam" concept for interplanetary travel, but for serious star-travel a full blown particle beam is needed. Dana Andrews has studied this concept, but using only magnetic-sails. Since these have a fixed magnetic radius the field doesn't adjust to accomodate beam spreading so has a limited range. If a suped-up plasma magnet can handle the forces involved then it may be the perfect solution.

qraal

lswinford
2004-Nov-17, 10:42 PM
I remember asking someone from a NASA presentation years ago why we didn't figure on magnetic fields to build a radiation shield. I was told (1) it would interfere with the craft's computers and electronic controls and (2) the high temperatures on the sunlit side (though he wouldn't discuss the opposite, low temperatures on the dark side) of the craft would spoil the cryogenic environment for the necessary superconductive magnetic arrays and (3) if the magnet worked then it would attract, not repell, the ionized solar radiation and (4) the extra cost in weight, power, and design considerations would be prohibative so (5) the only practical consideration for future long distance flights was to bury the crew comparments inside the array of fuel and oxidizer tanks that would be arranged to surround and shield the people sent on the trip.

Looks like someone at NASA is getting smart.

(Hmm...wonder if we could do a series of magnetic levitation rails, like that for magnetic trains, with the rails on the outside spinning a crew compartment tube inside, for the gravity mimicing centrifigal force while the primary purpose of the magnetic field is to divert and deflect solar flare energies--one feature piggybacking on the work of the other...hmm)

WendellG
2004-Nov-17, 11:23 PM
Hello all;

Ok, my question is, "In producing a man made magnetic field around a space craft would the occupants of this craft be able to wittness an Aurora Boriellis (sp) type show from a solar flare that reaches their craft?" Or do I have the concept all screwed up?

Wendell

Duane
2004-Nov-17, 11:45 PM
Aurora results from energetic particles from the solar wind striking atoms in the atmosphere. This excites the struck atoms, and they begin to glow. As there is no atmosphere around the spacecraft, this couldn't happen.

Further, the Earth's magnetic field is centred in the core. If I understand this process correctly, then the magnetic field envelopes the whole craft--there is no pole per se.

om@umr.edu
2004-Nov-18, 12:30 AM
This is an interesting story about a concept in the development stage.

It will be interesting to see what comes to fruition.

There are obviously many challenges:

1. The weight of the superconducting magnet.

2. Maintaining the low temperature required for superconductivity.

Does anyone know the range of values of the neutron/proton ratio in solar flare eruptions and the ability of a superconducting magnetic shielding system to deflect neutrons?

With knid regards,

Oliver
http://www.umr.edu/~om

WendellG
2004-Nov-18, 12:43 AM
Thanks Duane. I appreciate your answer.

Wendell

antoniseb
2004-Nov-18, 12:50 AM
Originally posted by om@umr.edu@Nov 18 2004, 12:30 AM
Does anyone know the range of values of the neutron/proton ratio in solar flare eruptions and the ability of a superconducting magnetic shielding system to deflect neutrons?
At Earth's distance from the Sun, the ratio is zero, since neutron's have a ten minute half-life and a several thousand minute flight time. That's good, because the system will not deflect neutrons at all.

qraal
2004-Nov-18, 02:42 AM
Hi Antoniseb

Neutrons do respond to magnetic fields, but reluctantly. There's some quantum effect that causes them to be deflected in a field. A strong field, mind.

qraal

antoniseb
2004-Nov-18, 03:34 AM
Originally posted by qraal@Nov 18 2004, 02:42 AM
There's some quantum effect that causes them to be deflected in a field.
OK, I'll change that last line to:

That's good, because the system will not deflect neutrons significantly.

om@umr.edu
2004-Nov-18, 03:10 PM
Originally posted by antoniseb@Nov 18 2004, 12:50 AM
At Earth's distance from the Sun, the ratio is zero, since neutron's have a ten minute half-life and a several thousand minute flight time.
That's about right, Anton.

However, high energy protons (primaries) produce neutrons (secondaries) when they strike matter.

With kind regards,

Oliver
http://www.umr.edu/~om

John L
2004-Nov-18, 05:26 PM
I agree with qraal that the M2P2 guys already have3 a working system that would provide this protection, and apparently are working on more advanced versions now. I'm fairly certain their system doesn't require exotic superconducting magnets, either, but then the benefit of the SC magnets is low power consumption.

Bridh Hancock
2004-Nov-19, 04:00 AM
Hi-ho, everybody!
I never thort I would be reading this in a discussion on Magnetic Bubbles. I had no idea what a magnetic bubble might be. Well!
Concerning the space-ships I am designing for traveling in the Solar System, and for going to and coming back from Apha Huotzitzname: Do I now make the outsides of the vessels out of black PVC over white styrofoam over 9-ply marine ply-wood?, and should they have windows any where? What is a space-ship without windows, what ever it is made from?
Power is another question for another topic. Needless to say, I do not propose putting out garbage before zooming or whoosing off anywhere thru space.
Right-oh!
Bright-oh!

Essel
2004-Nov-19, 12:38 PM
Hey Guys,

How does such a powrful magnetic field interact with human body in close proximity? We could be damaging ourselves more than the protections offered by such a strong magnetic field produced by a superconductor.

If Magneto-therapy exisits so could Magneto-sickness.

Any Views?

Cheers

antoniseb
2004-Nov-19, 02:53 PM
Originally posted by om@umr.edu@Nov 18 2004, 03:10 PM
That's about right, Anton. However, high energy protons (primaries) produce neutrons (secondaries) when they strike matter.

There are some neutrons in interplanetary space, but not many, and probably not caused by solar-wind and flare protons colliding with neutron-rich species in dust and asteroids. These protons don't have enough kinetic energy to penetrate the coulomb field around these nuclei; their energies are a few KeV. Any free neutrons come from interactions between dust and cosmic rays. So the answer to your original question is still zero.

John L
2004-Nov-19, 08:22 PM
Essel,

Every study I've seen shows no damage to a person from EM fields. There were theories that things like high-tension power lines, which produce EM fields, could be damageing, but no study has ever proven that.

zephyr46
2004-Nov-20, 05:41 AM
Good luck Bright :)

I thought the temperature difference would be an asset, ie solar thermal power or basic temperature management by having surrounding pipes that allow a liquid to circulate and provide power or transfer heat to the cooler areas and vice versa.

I saw in a documentary on water that 'heavy water' (D2O) is the 2 neutron isotope of hydrogen. So if water was used in such insulating plumbing, you might also produce heavy water? Would this add to the sheild against radiation?

Oh, I would feel more comfortable if the magfeild was external to the living quarters, speaking for myself.

qraal, those plasma magnets sound amazing. With these 'beam' technologies, could you create a 'highway' with two beams creating two directions of travel and multiple craft using a beam at the same time?

blueshift
2004-Nov-20, 10:22 PM
Originally posted by Essel@Nov 19 2004, 12:38 PM
Hey Guys,

How does such a powrful magnetic field interact with human body in close proximity? We could be damaging ourselves more than the protections offered by such a strong magnetic field produced by a superconductor.

If Magneto-therapy exisits so could Magneto-sickness.

Any Views?

Cheers
Hello..I think humans are frequency sensitive to fields....

As long as we don't move relative to a field....or vice versa...I would think we
would be out of harm's way....

Many someone has a better grip on this but that's the way this amateur sees it.

blueshift

Guest_Neil
2004-Nov-22, 09:13 AM
Originally posted by Essel@Nov 19 2004, 12:38 PM
Hey Guys,

How does such a powrful magnetic field interact with human body in close proximity? We could be damaging ourselves more than the protections offered by such a strong magnetic field produced by a superconductor.

If Magneto-therapy exisits so could Magneto-sickness.

Any Views?

Cheers
People in MRI machines seem to do alright. Also, I'm fairly certain that magneto-therapy has been pretty thorougly debunked.

lswinford
2004-Nov-23, 08:09 PM
Zephyr's comments gave me an interesting idea.

Picture a space craft getting its power from a fusion reactor (obvious not in the very near future). It has a magnetic bubble to protect the crew and sensitive payload areas. This slows and captures neutrons, which though are ionicly neutral they are negatively charged particles relative to magnetism, if I recall right. So placing an insulating layer of water (which would have to be in constant and quick pressure flow else the extreme cold of the shadow side would flash freeze what the extreme heat of the sunlit side would flash vaporize) and this water would then be a neutron receptical, making heavy water. Then you have some fuel for the fusion reactor.

Naw, too far away. But still Zephyr's observation is interesting in this, has anyone ever checked the water on space missions, whether from the Gemini, Apollo, Spacelab, and Space Station, to see if the water they used up there is getting any "heavier"? :huh:

kjargirl
2004-Nov-25, 04:05 PM
I had a request from Rigel to add something to the discussion going on about the magnetic field's effects on humans. In interviewing Dr. Jeffrey Hoffman for the article about using superconducting magnet technology for protecting spacecraft from cosmic radiation, I asked him about what effects this would have on the humans inside the spacecraft.

He said, "There would be no magnetic field inside the spacecraft, just around the spacecraft. In that sense it is not the equivalent of the Earth's (magnetic field). The inside would be a ďFaraday cageĒ where the magnetic field would be constrained to go in circles around the spacecraft, but would not go inside the spacecraft. You donít want to be living inside of a 7 tesla magnetic field. That would upset a lot of your bodily functions."

To clarify, a tesla is defined as the field intensity generating one newton of force per ampere of current per meter of conductor, (and one tesla equals 10,000 gauss for you old-schoolers). A field of one tesla is quite strong: the strongest fields available in laboratories are about 20 teslas, and the Earth's magnetic flux density, at its surface, is about 50 microteslas (ĶT).

A Faraday Cage is an electrical device designed to prevent the passage of electromagnetic waves, either containing them in or excluding them from its interior space. It is named for physicist Michael Faraday, who built the first one in 1836.

In talking about the magnetic field strength that his research is trying to obtain, Hoffman said, "Weíre talking about a magnetic field strength of 7-10 teslas. It is hundreds of thousand of times stronger than the earthís magnetic field. Itís not out of line with some of the strongest fields that have been created in laboratories on Earth with superconducting magnets. They typically made fields of several teslas. Itís a very strong magnetic field. But getting that field to work with a spacecraft, thatís the tricky part."

The Earth's magnetic field is very large, and therefore, doesn't have to be as strong to offer protection for us humans, while a spacecraft is small, and would need a stronger field to be able to "turn" or deflect the cosmic rays. As Hoffman told me, "If you are a spacecraft the volume is smaller. But for a given magnetic field you can only turn the cosmic ray so rapidly, and if you canít turn it rapidly enough youíre not going to be protected. So what you really want to do is turn it around so it goes back out. Given the small volume that youíre dealing with, you need a short turning radius. And that means you need a high magnetic field. The only way that we can create that is with superconducting magnets."

I was also asked to comment on the question about heavy water, but I'll have to defer that to someone else.

Thanks,
Nancy Atkinson
free-lance writer
NASA Solar System Ambassador

Guest
2004-Nov-25, 11:57 PM
A problem might exist based upon the size of the magnet. The earth has a relatively low intensity magnetic field, but it is many thousands of miles in size. A smaller magnet would require a higher field.

After a point, conventional magnets will self-destruct due to magnetic force. A magnet a few thousand miles in size will be fine and need not be very high strength to protect a ship - but try and launch (or propel) something that big!

With much smaller magnets (something that might fit into a building), then problems exist. A stong enough field can actually affect the electon's orbits around an atom. A stong enough field (I think it is around 10^9 gauss) will distort atoms into a cylinder - enough distortion that biological functions can no longer work. I.E., you will die.

Another order of 10 (10^11 gauss) and an atom is stretched into a needle. Its' diameter is about 1% of its' lenght.

For a bit more information (not all of which I mentioned as I'd have to look further), check this URL:
http://solomon.as.utexas.edu/~duncan/magne...Magnetic_Fields (http://solomon.as.utexas.edu/~duncan/magnetar.html#Strong_Magnetic_Fields)


Best regards from Rochester, NY
Jim

kdhrocks
2004-Nov-26, 01:27 AM
I have no idea how strong the magnetic field would be, however we already know what MRI fields do to your body, Would that be a starting place for discussion?
Dave

DC2Mars
2004-Nov-26, 06:52 AM
The only problem I have with the concept is that it takes place in 2027, to long to wait. Let's get a move on folks, gee, the Moon only took a couple of years, and we know far more now that we did then.

We need to have humans on Mars in 10 years. Let's get serious about this. It's more boring than knitting a mile long scarf.

{;^))))

Dave
Mars Scoiety Australia.
http://www.marssociety.org.au

antoniseb
2004-Nov-26, 01:24 PM
Originally posted by DC2Mars@Nov 26 2004, 06:52 AM
it takes place in 2027, to long to wait.
Aside from impatience, what's the rush?

ddl9
2006-Sep-26, 03:19 PM
Electrostatic fields would be a easier solution to the shielding problem.
Compared to magnets, electrodes would not need cryogenics or massive coils so they can be relatively lightweight. The electronic interference problem can be solved by faraday shielding. For a magnetic radiation shield, such shielding would be impossible because no material can "reroute" a >2 tesla magnetic field. Problems with stray ions and electrons or photoelectrons would still need to be solved though, but with enough distance between electrodes this would present less of a barrier.

antoniseb
2006-Sep-26, 03:31 PM
Hi ddl9, welcome to the BAUT forum.

I'm not sure how you'd impliment electrostatic shielding with enough capability to stop particles from a solar storm.

Of course the more recent study showing that the high energy cosmic rays alone (which any shielding less than a meter or two of water thick will not stop sufficiently) are enough to cripple astronauts on year long missions.

ddl9
2006-Sep-28, 02:37 PM
I've read that physicists have seen stars by moving their heads in between cyclotron magnets. The induced currents interferes with neurons in the brain. If you were flying in a magnetic bubble you would have to sit very still:dance:



Hey Guys,

How does such a powrful magnetic field interact with human body in close proximity? We could be damaging ourselves more than the protections offered by such a strong magnetic field produced by a superconductor.

If Magneto-therapy exisits so could Magneto-sickness.

Any Views?

Cheers

ddl9
2006-Sep-28, 02:47 PM
I would imagine you would build a large inflatable gossamer structure(0.5-1.0km) charged to about 1e9 volts. Some serious engineering is needed but at least it might be able to solve weight problems. I read a NASA(?) article on electrostatic cosmic ray shielding for astronauts stationed on the moon. It involved placing balloon charged to 150-200 MV along the periphery of working areas.
If all else fails, you can travel in a city sized water balloon;)



Hi ddl9, welcome to the BAUT forum.

I'm not sure how you'd impliment electrostatic shielding with enough capability to stop particles from a solar storm.

Of course the more recent study showing that the high energy cosmic rays alone (which any shielding less than a meter or two of water thick will not stop sufficiently) are enough to cripple astronauts on year long missions.

publiusr
2006-Oct-06, 07:17 PM
This is an interesting story about a concept in the development stage.

It will be interesting to see what comes to fruition.

There are obviously many challenges:

1. The weight of the superconducting magnet.

Oliver
http://www.umr.edu/~om

One more reason for Ares V