Scientist develop shielding for spaceships

[The Big I]

Humans may soon visit Mars

SCIENTISTS believe they have found a way of protecting astronauts from a dangerous source of space radiation, thus lifting a major doubt clouding the dream to send humans to Mars.
Their breakthrough takes forward ideas born in the golden age of science fiction, including a proton shield used in the TV show Star Trek, says one of the researchers.
Space weather is one of the greatest challenges facing Mission Red Planet sketched by the United States and Europe for some three decades from now.
Even the shortest round trip would take at least 18 months.
During this time, the crew would be exposed to sub-atomic particles that whizz through space, capable of slicing through DNA like a hot knife through butter and boosting the risk of cancer and other disorders.
The peril has been known for nearly half a century but has seemed insoluble because costs and technological difficulty.
Some experts have toyed with the idea of shielding the crew with lead or massive tanks of water, but the price of lifting this load into orbit from Earth is mind-spinning.
Another idea, born in the 1960s, would be to swathe the spaceship with a replica of Earth's own magnetic field.
According to these calculations, the spacecraft would have to generate a magnetic field hundreds of kilometres across.
But such equipment would be huge and drain the ship's energy supply and its powerful field could well harm the crew.
British and Portuguese scientists have taken a fresh look at this old concept and say the magnetic field does not, in fact, have to be huge - just a "bubble'' a few hundred metres across would suffice.
"The idea is really like in Star Trek, when Scottie turns on a shield to protect the starship Enterprise from proton beams - it's almost identical really,'' Bob Bingham of the Rutherford Appleton Laboratory near Oxford told said.
Their study, published today in a specialist journal by Britain's Institute of Physics, draws on numerical simulation that is also used by experts in nuclear fusion, in which a hot plasma is kept in place by a powerful magnetic field.

http://www.news.com.au/story/0,27574,24 ... 09,00.html

Very interesting hopefully this theory works in practise.

[Solauren]

Interesting, but I'll stay cautious until I see a working model.

[dragon]

These ideas have been floating around for a while now. There are several other versions of this idea as well. Inclding one that will allow the used plasma to be directed out the back providing extrta thrust.

Space-borne protective energy systems, like the deflector shields on the fictional starship U.S.S. Voyager, are on the drawing board of real-world scientists.

These "cold plasmas" -- analogs to the sophisticated defensive grids envisioned by Star Trek's creators -- are ambient-temperature, ionized gases related to those found deep within the sun’s core.

Such plasmas are capable of shielding satellites and other spacecraft, making them invisible to radars, or both. Nor will they fry electronics or melt metal.

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Plasma: What is it?
Plasma is the fourth state of matter, prevalent in the interstellar medium and in stars. Want to learn more?


On Earth, cold plasmas should permit rapid, room-temperature sterilization of food, medical equipment and contaminated civilian and military gear. Low-temperature plasmas could one day also make possible an entire new generation of miniature lasers and ultra-low-energy fluorescent light tubes.

While scientists have known of low-temperature plasmas since at least the end of the 19th century, only within the past several years have techniques emerged to make cold plasma generation practical

link
an updated version

Using fields of force to accomplish goals in space is a favorite device of science fiction authors. In Larry Niven's award-winning 1970 novel Ringworld, protection against the harsh environmental hazards of space is provided by a hybrid system consisting of a General Products hull and the Slaver stasis field. The General Products hull is an example of a "passive" or material shielding; the hull is transparent to visible light and impervious to electromagnetic energy and matter in any form. The Slaver stasis field creates an area in which time does not pass; since time stands still, no damage can be done to the material occupying the space protected by the field.

Former astronaut Jeffery Hoffman is proposing a different sort of hybrid system to protect future astronauts; on long voyages through the solar system they will be exposed to lethal doses of radiation from cosmic rays. He has recieved funding from NASA through NIAC (NASA Institute for Advanced Concepts) to research the idea of a superconducting magnetic radiation shielding system to supplement (or replace) traditional passive shielding.


Isn't this cozy: Magnetic fields protect astronauts while supplying drive.



The idea of using a magnetic field to shield a craft from radiation is not new; as Dr. Hoffman points out "the Earth has been doing it for billions of years!" Using magnetic shielding was proposed in the late 1960's, but not pursued after plans for further space exporation were scrapped.

Two types of radiation need to be addressed, according to William S. Higgins, an engineering physicist who works on radiation safety at Fermilab, the particle accelerator near Chicago, IL:

Solar flare protons (which would come in bursts following a solar flare)
Galactic cosmic rays (a continuous background radiation)
The easiest way to protect against this radiation is to absorb it. However, such shielding can be massive, and cosmic rays can interact with the shielding and create secondary charged particles, worsening the situation. The primary benefit of using magnetic shielding is to save on the mass required for traditional absorption technologies. The mass of the spacecraft, which must be lifted off from the Earth and placed in orbit, directly drives the cost of space systems. Reducing the amount of mass would make space exploration more affordable and therefore more sustainable over the long term.
Hoffman believes that the best solution may be a hybrid system using both a magnetic field and some passive absorbtion shielding. "That's the way the Earth does it," Hoffman explained, "and there's no reason we shouldn't be able to do that in space."

A related experiment, the Alpha Magnetic Spectrometer (AMS), is scheduled to be attached to the outside of the International Space Station and search for different types of cosmic rays. This experiment will be a practical test of maintaining the magnetic field strength and the near-absolute zero temperatures of this kind of system in space.

Phase I research studies the shielding efficiency of the baseline design, and would begin conceptual systems design. Phase II would provide a detailed comparison of magnetic shielding with traditional passive absorption technologies, and detail how to integrate the magnetic shield into a spacecraft.

link

[TithonusSyndrome]

"The idea is really like in Star Trek, when Scottie turns on a shield to protect the starship Enterprise from proton beams - it's almost identical really,''

GAAAAH! SHUT UP! Do you have any idea how much harder an offhand comment like that makes it for us to tolerate Trektards?!? Stop encouraging them!

[Samuel]

Eh- it doesn't affect lasers, missles or mass drivers. Only charged particles. A poor warship shield. Maybe good against radiation, but it probably is better to make thincker hulls.

[Ender]

Eh- it doesn't affect lasers, missles or mass drivers. Only charged particles. A poor warship shield. Maybe good against radiation, but it probably is better to make thincker hulls.

Definitely not. Thicker hulls means more mass.

[Samuel]

Yes, but the system they are proposing requires a shitload of power... which means more fuel, machinery, etc. In addition, it is an active system which means that it can fail- not something you want 1.5 years from home.

Of course, that depends on how much they can miniturize it.

[Patrick Degan]

Eh- it doesn't affect lasers, missles or mass drivers. Only charged particles. A poor warship shield. Maybe good against radiation, but it probably is better to make thincker hulls.

Forget it —any space warships which might ever be developed are never going to have armour thick enough to withstand even slugs because of the aforementioned mass penalties, and KE-resistant energy shields are a pipe dream. It's going to be a given that, despite what SF has to say, a single hit on a real space warship with a kinetic impactor will as likely kill the ship.

[Dartzap]

http://news.bbc.co.uk/1/hi/sci/tech/7706844.stm

Magnetic shield for spacefarers




Future astronauts could benefit from a magnetic "umbrella" that deflects harmful space radiation around their crew capsule, scientists say.

The super-fast charged particles that stream away from the Sun pose a significant threat to any long-duration mission, such as to the Moon or Mars.

But the research team says a spaceship equipped with a magnetic field generator could protect its occupants.

Lab tests are reported in the journal Plasma Physics and Controlled Fusion.

The approach mimics the protective field that envelops the Earth, known as the magnetosphere.

Astronauts' risk

Our star is a constant source of charged particles, and storms that arise on the Sun's surface result in huge numbers of these particles spilling into space.

As well as this plasma, or "solar wind", high velocity particles known as cosmic rays also flood through our galaxy.

The Earth's magnetosphere deflects many of these particles that rain down on the planet, and our atmosphere absorbs most of the rest.

International space agencies acknowledge that astronauts face a significant risk of ill health and even death if they experience major exposure to this harsh environment.

And even the spacecraft themselves are not immune to the effects. A solar flare crippled the electronics on Japan's mission to Mars, Nozomi, in 2002, for example.

But researchers from the Rutherford Appleton Laboratory (RAL), the Universities of York and Strathclyde, and IST Lisbon have shown how it might be possible to create a portable mini-magnetosphere for spaceships.

People scale

In its experimental set-up, the team simulated the solar wind in the laboratory and used magnetic fields to isolate an area inside the plasma, deflecting particles around the "hole".

It was not initially clear the idea would work, said Ruth Bamford, who led the research.

"There was a belief that you couldn't make a little hole in the solar wind small enough to do this at all," Dr Bamford, from RAL, told BBC News.

"It was believed that you had to have something very large, approaching planetary scale, to work in this way."

The team has had to take into account the physics of plasmas at the comparatively tiny human scale. To create its metre-sized trial, the team used a plasma jet and a simple $20 magnet.

"The first time we switched it on, it worked," said Dr Bamford.

What is more, the trial field seems to adjust itself automatically. "It does have the capacity to be somewhat self-regulating, just like the Earth's magnetosphere is," Dr Bamford explained.

"When it gets a strong push from the solar wind, the bubble gets smaller. The video shows us increasing the pressure of the solar wind, and the shield gets smaller but brighter."

Power issues

Many more experiments are needed, Dr Bamford admits, to understand how best to harness the effect; and a practical implementation is probably 15 to 20 years away.

To protect a spaceship and its crew, she said, the craft itself might carry the magnetic field generator. Alternatively, it was possible to envisage a constellation of accompanying ships dedicated to the purpose of providing the umbrella where it was needed most.

The approach will probably also work with a field that is not on constantly, but cycles on and off - conserving the power that is precious on long-term missions. The details of how to cycle the field and control its shape must be hammered out, however.

"There're a lot of things to work out, like control, reliability, weight to launch, and so on," said Dr Bamford.

"I don't think it'll come down to as little as sticking fridge magnets on the outside of the spacecraft."

There is, infact, a video of it doing the buisiness on the very top of the linked page

[GrandMasterTerwynn]

Eh- it doesn't affect lasers, missles or mass drivers. Only charged particles. A poor warship shield. Maybe good against radiation, but it probably is better to make thincker hulls.

Forget it —any space warships which might ever be developed are never going to have armour thick enough to withstand even slugs because of the aforementioned mass penalties, and KE-resistant energy shields are a pipe dream. It's going to be a given that, despite what SF has to say, a single hit on a real space warship with a kinetic impactor will as likely kill the ship.

Indeed, and even if we managed to somehow invent inertial mass masking, a real "inertial compensator" or "mass-lightener" isn't going to work like it does in the minds of TV writers with no grasp of science. The real beast will only be able to screen a certain fraction of the ship's mass (not to exceed 100% of the energy put into them, unlike Star Trek tech, which are perpetual-motion machines.) Like everything else, our magic compensator will also have a finite response to changes in the ship's inertia, and this finite response will occur over some arbitrary value of time n, which is non-instantaneous.

The end result of all that technical verbiage is that the designers of a space warship, even with such technologies, are going to design them as low-mass as possible. And since any missile with the range to hit another space warship will be able to defeat any armor of feasible thickness constructible from non-unobtanium materials . . . armor will be the first thing on the designer's chopping block.

[Samuel]

I was suggesting the armor to defeat radiation, not to defeat weapons fire.

I was disappointed by the shields lack of usefulnes in that regard.

[Sea Skimmer]

Eh- it doesn't affect lasers, missles or mass drivers. Only charged particles. A poor warship shield. Maybe good against radiation, but it probably is better to make thincker hulls.

Forget it —any space warships which might ever be developed are never going to have armour thick enough to withstand even slugs because of the aforementioned mass penalties, and KE-resistant energy shields are a pipe dream. It's going to be a given that, despite what SF has to say, a single hit on a real space warship with a kinetic impactor will as likely kill the ship.

That kind of depends on the nature of the KE impact. Very high velocity, very low mass projectiles for example (like projectiles in the grams range fired from 8km/s railguns) could well be defeated by spaced armor. Because they have high energy but low momentum, on impact with the spaced plate the tendency would be for the projectile to explode in an omnidirectional manner. That means the second layer of armor could be a reasonable thickness and yet stop a very high power hit. NASA is currently investigating various combinations of spaced armor to protect satellites and future Mars probes from space debris and meteorites

Lower speed higher mass projectiles would be less likely to shatter/explode, and most of the mass would retain the original direction of travel if they did so, but since they go slower that reduces the odds of being hit at all. Even if a spaced plate doesn’t damage the projectile at all, it will induce yaw which reduces penetration. If that will be enough to matter is an issue of details. It would help that in space the volume of the armor package doesn't matter a great deal, unlike earthly applications. As long as you can keep it attached to the engine it can use all the volume it wants. Spaced armor would also be highly useful against lasers, since vaporizing a path through the outer plate would likely break up the beams coherence and ability to solidly hit the inner plate.

I doubt anyone will ever build anything you could really call space warships at all though. I mean you look at how hard pressed nations are to compete with naval power today because of costs, the odds of multiple nations ever being able to afford space going warships and having reason to build them seem slim to none. Even if space colonies began popping up, well, if you want a war you’ll just attack the owners on earth. Control of earth orbit will mean control of the colonies unless they can reach economic independence which his just damn unlikely. In earth orbit meanwhile, I can’t see any need for anything you’d really call a warship as opposed to a more focused ASAT interceptor rocket plane or similar concepts.

The current direction of military space capabilities in any case is aimed at smaller, cheaper but more usable systems.

[Ender]

Yes, but the system they are proposing requires a shitload of power... which means more fuel, machinery, etc.

All of which will mass less then the shielding required to protect the same volume.

In addition, it is an active system which means that it can fail- not something you want 1.5 years from home.

Of course, that depends on how much they can miniturize it.

If you are toting that much mass instead of the active system you are going to be too heavy to get 1.5 lightyears from home in the first place. The math on this is real clear - save all the mass you can. This is a system that lets us do that.

[Samuel]

Yes, but the system they are proposing requires a shitload of power... which means more fuel, machinery, etc.

All of which will mass less then the shielding required to protect the same volume.

In addition, it is an active system which means that it can fail- not something you want 1.5 years from home.

Of course, that depends on how much they can miniturize it.

If you are toting that much mass instead of the active system you are going to be too heavy to get 1.5 lightyears from home in the first place. The math on this is real clear - save all the mass you can. This is a system that lets us do that.

It is that small?

[Ender]

Yes, but the system they are proposing requires a shitload of power... which means more fuel, machinery, etc.

All of which will mass less then the shielding required to protect the same volume.

In addition, it is an active system which means that it can fail- not something you want 1.5 years from home.

Of course, that depends on how much they can miniturize it.

If you are toting that much mass instead of the active system you are going to be too heavy to get 1.5 lightyears from home in the first place. The math on this is real clear - save all the mass you can. This is a system that lets us do that.

It is that small?

It is a geometry problem. Coating the entire exterior of the ship with an equivalent thickness of shielding will out mass it. The surface area of an object goes up with the square of the change in its dimensions. While it is true that the volume goes up with the cube of the change, the internal volume is going to be far less dense - most of it will be air or machinery whereas the shielding will be solid slabs of material.