Plasma shields for astronauts

[5614]

Theoretically, a plasma bubble could be used to block radiation from reaching astronauts on long journeys. If so, then the heavy protective shielding currently necessary could be replaced by a lightweight plasma shield.

 

When traveling into space astronauts fight against cosmic radiation, from the sun and from outside the solar system. For current trips to the moon, the Earth's magnetic field can offer some protection. But if a journey to Mars were undertaken, the astronauts would be vulnerable to radiation, possibly causing cancer. Heavy metal plates would offer enough protection, but they're weight creates complications and makes them impractical for use with regards to take-off.

 

A few grams of plasma hydrogen could solve the problem by providing shielding equivalent to several inches of aluminum.

 

http://www.newscientistspace.com/article/dn9567-plasma-bubble-could-protect-astronauts-on-mars-trip.html

[SmallIsPower]

Is the unit (cage & power supply) going to be propibably heavy. If it does use lots of power, (ie the plasma escapes in large amounts), could plasma be shed in a direction that propels the rocket in the proper direction?

 

Maybe we should pospone this idea until there's a Space Elevator, or just go to Mars the old fashioned way (by probe).

[insane_alien]

you could always store consumables on the outside of the craft as long as they won't become radioactive if they are for human consumption.

[Cap'n Refsmmat]

Is the unit (cage & power supply) going to be propibably heavy. If it does use lots of power, (ie the plasma escapes in large amounts), could plasma be shed in a direction that propels the rocket in the proper direction?

The article mentions a cage around the field that's magnetically charged to contain the plasma effectively.

[timo]

The article mentions a cage around the field that's magnetically charged to contain the plasma effectively.

Magnetically charged?!?

 

On topic: I completely fail to understand the news (by which I mean the article linked in above, not 5614´s post). My problems start at some trivialities: What is that radiation the ionized hydrogen gas shall protect against? Assuming that the cosmic radiation does not only consist of one single particle type: Is it effective against all types or just against the most common ones or just the most unhealthy ones? Due to not knowing what the whole issue is supposed to be about at all, the next problem naturally comes quite quickly: By what mechanism shall the shielding work? I cannot really believe that the mechanism shall be the magnetic field created (by whatever means) by a current in the plasma. If it was, then I ask myself what -especially considering that superconductors are supposed to be used anyways- prevents me from simply creating these currents with wires?

[[Tycho?]]

Is the unit (cage & power supply) going to be propibably heavy. If it does use lots of power' date=' (ie the plasma escapes in large amounts), could plasma be shed in a direction that propels the rocket in the proper direction?

 

Maybe we should pospone this idea until there's a Space Elevator, or just go to Mars the old fashioned way (by probe).[/quote']

 

A space elevator would need radiation shielding as well.

[rajama]

Magnetically charged?!?

 

On topic: I completely fail to understand the news (by which I mean the article linked in above' date=' not 5614´s post). My problems start at some trivialities: What is that radiation the ionized hydrogen gas shall protect against? Assuming that the cosmic radiation does not only consist of one single particle type: Is it effective against all types or just against the most common ones or just the most unhealthy ones? Due to not knowing what the whole issue is supposed to be about at all, the next problem naturally comes quite quickly: By what mechanism shall the shielding work? I cannot really believe that the mechanism shall be the magnetic field created (by whatever means) by a current in the plasma. If it was, then I ask myself what -especially considering that superconductors are supposed to be used anyways- prevents me from simply creating these currents with wires?[/quote']

 

I think the original idea was to use plasma to contain / conduct an electric current - a 'plasma bubble' would inflate over a very large volume (much bigger than the article mentions - there was no containing mesh) and interact with the solar wind for propulsive purposes as an artificial magnetosphere... which happens to provide a radiation shield.

[calbiterol]

Rajama is mostly correct. The original concept was called Mini-Magnetospheric Plasma Propulsion, or M2P2 for short. However, the idea isn't that the plasma bubble would inflate over a large volume, but rather that it would inflate the magnetic field to a very large size. So, Atheist, what stops the magnetosphere from being made by wires or superconductors? Nothing. The plasma (IIRC) is simply to save on weight and make it practical - they were talking about simply massive magnetic fields, which would be both a power drain and an impracticality using traditional methods (even a superconductor would have to be massive for this sort of thing, which is a problem when it comes time to launch it off the ground).

[rajama]

Calbiterol, thanks, yes, a magnetic bubble, the point of the plasma was to inflate the field embedded in it… but wasn’t it also to somehow keep the power requirements low?

 

I found a popsci article from 2000 that gives some estimates:

 

http://science.nasa.gov/headlines/y2000/ast04oct_1.htm

 

The older articles made no mention of a mesh, so I assume the original schemes plasma leakage could not be tolerated by a mere shield mechanism.

 

I wonder if the mesh sphere might be used to create a ‘plasma free’ volume immediately around the spacecraft with the plasma and its embedded field attached to the outside of it – this might allow a return to the propulsion concept using the same technology as the shield…

[calbiterol]

FYI, the link to the original article (or the original article itself) is down.

 

 

...[b']ut wasn’t it also to somehow keep the power requirements low?

Yep. In this case, power is directly related to weight. I said something about that above, but I didn't make it clear that one of the purposes of it was to save on power draw, I just said that doing this conventionally would be a massive power drain. Meh, semantics. My bad.

 

 

 

 

The older articles made no mention of a mesh, so I assume the original schemes plasma leakage could not be tolerated by a mere shield mechanism.

Forgive me if I overlooked this, but what mesh?? The original articles were just as functional in radiation protection as they were in solar sailing. They had a dual purpose.

 

 

I wonder if the mesh sphere might be used to create a ‘plasma free’ volume immediately around the spacecraft with the plasma and its embedded field attached to the outside of it...

Um. Sorry, I don't think I quite understood that.

[rajama]

Forgive me if I overlooked this' date=' but what mesh?? The original articles were just as functional in radiation protection as they were in solar sailing. They had a dual purpose.

 

Um. Sorry, I don't think I quite understood that. [/quote']

 

The NewScientist article is back... as is SFN... it states:

 

There would need to be a wire mesh outside the spacecraft and enclosing the plasma cloud. Electricity supplied to the mesh would keep an electrical current running in the plasma cloud and help confined it near the spacecraft

 

Articles describing the original concept allow the bubble to expand to a huge volume to interact with the solar wind - the shield model does not in order to prevent leakage.

 

But it occurred to me that the mesh container might be be used to provide current to a plasma bubble surrounding it rather than contained by it... the system would have two operational modes, shield (contained plasma) or propulsive (anchored plasma).

 

Just a thought...