Solar Flares Shield Astronauts from Cosmic Rays 135
It doesn't come easy writes "Considering all of the research into better shielding for astronauts, it's interesting to note that solar flares can help shield space travelers from dangerous cosmic rays. From the article: "The crew of the ISS absorbed about 30% fewer cosmic rays than usual [during this last month of high solar activity]," says Frank Cucinotta, NASA's chief radiation health officer at the Johnson Space Center. "The storms actually improved the radiation environment inside the station." Scientists have long known about this phenomenon. It's called a "Forbush decrease," after American physicist Scott E. Forbush, who studied cosmic rays in the 1930s and 40s. So, I guess it would be safer to plan a manned Mars mission to coincide with peak sunspot activity?"
Shields up (Score:5, Interesting)
How about having the spacecraft generate its own external magnetic field? How effective would that be?
Re:Shields up (Score:2, Interesting)
Eventually, when we get to the point where we're building ships in orbit (where mass will be less of an issue than it is when you're launching it all up from Earth), you'd likey be building a vehicle out of more durable materials (mmm, cermets), with a good layer of the previously mentioned hydrog
Re:Shields up (Score:1)
How about water? It's going to be important for other reasons anyway.
Re:Shields up (Score:2)
Re:Shields up (Score:2)
the long chain hydrocarbon polymers provide more hydrogen, not water.
stupid grammar.
Re:Shields up (Score:2)
Funnily enough, that's what we already use to shield ourselves from radiation, both particle (alpha, beta) and light (gamma)!
Daniel
Re:Shields up (Score:2)
Lead is used because of its density, not its effectiveness. Other than hydrogen, basically all elements cause charged particles to lose ~ 2 MeV/cm per g/cm^3 of material present. For hydrogen it's ~ 4. Gamma ray interactions are similar as well.
Of course, the problem with hydrogen is the fact that it'd take
1/r^2 kills this (Score:5, Insightful)
Even if I'm off by many orders of magnitude (IANAP), the required field strength will be unattainably high.
Re:1/r^2 kills this (Score:5, Interesting)
I've stuck the movie of the levitating frog up here [adelaide.edu.au]
Re:1/r^2 kills this (Score:2)
Re:1/r^2 kills this (Score:2)
Re:1/r^2 kills this (Score:5, Informative)
The fact that the Sun's magnetic field is large isn't what protects us from cosmic rays. The Sun's magnetic field encourages particles to orbit the Sun. That doesn't help us. What helps is when a dipole field gets closer to you - like when the Sun sloughs off a bunch of plasma that drifts near you. Hence a Forbush decrease. What protects us on Earth is the Earth's magnetic field, and the atmosphere.
Anyway, it's relatively easy to craft magnetic fields to any shape you want. So high magnetic field on the outside, zero magnetic field on the inside. We're really good at that. And 5 tesla (50,000 gauss) should be about enough [thespacereview.com]. It has been studied.
The reason it's not ideal is because cosmic rays aren't all charged. Gamma rays make up a component of solar cosmic rays, and okay, there may (should) be a few neutrons from the Sun as well (though that part is really new and not well studied).
But magnetic shielding is very actively being looked at. It's just not an easy problem - we don't have very much experience with superconducting magnets in space, for instance.
Interestingly, one of the best things about this is that you don't really have to worry about the highest energy particles which will get through. Not only is the flux far, far lower, but they deposit less energy than lower energy particles which stop in your body. So it's pretty easy to figure out how high a magnetic field you need.
And smartass comment: magnetic fields don't drop like 1/r^2. Electric fields do. For a simple magnetic dipole, the field strength drops like 1/r^3. Different configurations drop differently, as well.
MOD PARENT UP (Score:2)
Re:1/r^2 kills this (Score:2)
That doesn't sound quite right. Why would free neutrons (half life 15 minutes) be an issue coming from the sun? Besides, fusion does not occur to any appreciable degree in the corona, it only occurs deep within the inside of the sun, neutrons produced this way would
Re:1/r^2 kills this (Score:2)
Re:1/r^2 kills this (Score:2, Interesting)
Re:1/r^2 kills this (Score:2)
Re:1/r^2 kills this (Score:2)
Re:1/r^2 kills this (Score:2)
Sun's only about 8 light-minutes away, so even a moderate-energy neutron - say, 1 GeV - is going to reach us well before it decays. (*) A higher-energy neutron - say, tens of GeV - with a time dilation of about a factor of 10 - won't have decayed appreciably at all before it reaches us.
This is of course akin to atmospheric muons - with a lifetime of 2.2 microseconds, they shouldn't reach the surfac
Re:1/r^2 kills this (Score:1)
Re:1/r^2 kills this (Score:1)
1.28x 10^18 Gauss is a little over the top though. But why so much? You don't need to create a field 160 million kms away, y
Re:Shields up (Score:4, Interesting)
Re:Shields up (Score:2)
Here [space.com]is a site explaining somethign simular to what i have read. Maybe i'm think of two different things. May
The fantastic four (Score:1)
Re:The fantastic four (Score:3, Informative)
Re:The fantastic four (Score:2, Funny)
(get it, it's a pun)
Re:The fantastic four (Score:1)
Spiderman (Score:2)
Oh, and we can't leave out Dr. Strange - what being smart did for Bruce Wayne.
And, finally, we don't want to forget about The Green Lantern - how being near kryptonite affects Clark Kent.
that's about once every 11 years... (Score:2, Funny)
Re:that's about once every 11 years... (Score:2)
Re:that's about once every 11 years... (Score:2)
Magnetize the hull? (Score:4, Insightful)
Might turn out Enterprise's "ionize the hull" isn't as much sci-fi nonesense as it first sounds.
Re:Magnetize the hull? (Score:2)
I think it's more like CMEs and flares (both somewhat good) protecting the guys at the ISS from cosmic rays (immensely bad). Cosmic rays, not CMEs, seem to be the problem, and CMEs sweep them away as they pass Earth (think of a flyswatter through a swarm-the flies are swept away, but not totally or permanently).
So I think, anyway. All this flare and CME talk flared up my brainand almost made my head a splode.
Re:Magnetize the hull? (Score:1, Interesting)
Re:Magnetize the hull? (Score:2)
Re:Magnetize the hull? (Score:2)
Re:Magnetize the hull? (Score:2)
What if we get stuck to a nearby asteroid with high metal concentrations? I guess the key is to latch onto one that's going the same place you are...
Re:Magnetize the hull? (Score:2)
Re:Magnetize the hull? (Score:2)
Well sorry for not realizing this beforehand. Sheeesh.
when to have space missions (Score:5, Funny)
No, the real answer is to have space missions start on Sun-days. har har har har.
Re:when to have space missions (Score:5, Funny)
In space no-one can hear your terrible puns.
Re:when to have space missions (Score:1)
Awww! And no one even made bad political puns about the "Forbush decrease" yet!
Re:when to have space missions (Score:1)
Mars trip during solar storm (Score:5, Insightful)
Well, that could be a logical conclusion from the article. BUT, what also occurs during major sunspot activity?. Mondo solar flares! Yes, they may help suppress the Cosmic Radiation. But, I sure wouldn't want to be stuck somewheres in the vast space between Mars and Earth with one of these monsters heading for me. The spaceship would be hit like a rowboat in a hurricane, in terms of solar radiation.
Re:Mars trip during solar storm (Score:5, Informative)
There may be a decrease in radiation coming from elsewhere, but the ship would still be hammered by high speed Coronal Mass Ejection particles. Radiation sheilding is essential; Bring your polyethylene, in other words.
Re:Mars trip during solar storm (Score:2)
Re:Mars trip during solar storm (Score:2)
Re:Mars trip during solar storm (Score:2, Interesting)
Re:Mars trip during solar storm (Score:1, Insightful)
Shields up!! (Score:2)
Re:Shields up!! (Score:2)
Re:Shields up!! (Score:2)
ISS is inside the van allens/earh's magnetic field (Score:4, Insightful)
No protection from death rays! (Score:4, Funny)
Re:No protection from death rays! (Score:1)
trip to the sun... (Score:1)
NASA source (Score:4, Informative)
Another source:
Strange, but true: Solar flares can be good for astronauts. [nasa.gov]
Re:NASA source (Score:3, Interesting)
Re:NASA source (Score:2)
aha! (Score:1)
Nothing is more... (Score:1)
Except that... (Score:2, Interesting)
I don't think that it matters much to an astr
Re:Except that... (Score:1)
The ISS is in Low Earth Orbit, deep inside the Earth's magnetic field. Solar flares dump huge amounts of energy into the Earth's magnetic field. The more engergy, the further south the Aurora Borealis appears, as the magnetic field pulls particles from the solar wind to larger circles further away from the poles. The temporary increase in the strength of the Earth's magnetic field protects astronauts in the ISS; astronauts on their way to Mars, unprotected by the Earth's magnetic field, would have both t
Re:Except that... (Score:2, Interesting)
Not exactly. What happens is that with the increased solar wind pressure the magnetosphere becomes distorted, the auroral oval expands equatorwards, and electric currents start flowing. "Magnetic reconnection" events in the magnetotail energize magnetospheric (not so
A ForBush Decrease? (Score:1)
I always knew I was special (Score:2)
Great, but... bone loss still a problem (Score:2, Informative)
A simplistic source, (http://www.factmonster.com/ipka/A0778174.html [factmonster.com]) has this easy to digest quote
"... And because the gravity on Mars is only 38% of Earth's, ways to counteract any damaging effects of the weak gravity on their bodies, such as progressive bone loss and muscle atrophy, will have to be found. Currently, there is no fully effectiv
The Ultimate Solution!!!! Maybe. (Score:1)
Use magnetic fields to shield the ship from plasma by funneling it into a reactor rather than repelling it.
The solar flare blocks radiation, fuels the ship, and could potentially provide enough fuel to solve the bone mass issue.
The bone mass issue is caused by being in zero G, but if you're constantly under acceleration, you don't suffer from being in zero G. You also go places much faster than if you allow yourself to travel in free fall.
Accelerate th
Re:Great, but... bone loss still a problem (Score:1)
Not an obvious extrapolation... (Score:2)
There are any number of possible models for bone loss on partial gravity. It might be that there's no accelerated bone loss at all once gravity is above some minimum value. It might be a linear relationship. Or something more complex again.
The MarsGravity biosatellite [marsgravity.org] will hopefully provid
MarsGravity Biosatellite (Score:2)
Why don't they just develop the little spinny thing to hold and feed the mice and send it up on the next Progress Drone to the ISS? Why are they developing their own satellite with it's own life-support system when we have a perfectly good space station that has a life-support system, as well as a couple of guys to monitor the experiment and the mice and potentially fix anything that goes wrong.
And rather than developing the heat sh
Some possible reasons... (Score:2)
Re:Some possible reasons... (Score:2)
Heck, even if it goes outside ISS, I imagine there's some way to get oxygen and power out there for experiments. I know they can do
Budget cuts... (Score:2)
Re:Budget cuts... (Score:2)
A solar physicist speaks... (Score:5, Informative)
The energetic protons are a real problem for man and machine. They arrive minutes to hours after the flare itself is seen. They have a high "quality factor", meaning they do a lot more biological damage than an equivalent ionizing dose of X-rays or gamma rays; and they tend to embed themselves in insulators, developing a humongous static charge that screws with electronic circuits and can burn out components. The clouds are more of a problem for planet-sized bodies (like the Earth) than for astronauts, but they do have some potential health consequences. They travel at "only" 1-4 million miles per hour, arriving at Earth about 1-4 days after the solar event.
Over the last three years we've had six or seven large flares that could have caused radiation sickness or death for Apollo astronauts (or Mars-bound astronauts with similar amounts of shielding to a mere Apollo capsule). That's enough that you'd have to expect at least one such event during a Hohmann transfer orbit to Mars, if you travelled at this phase of the solar cycle (declining).
The space station is largely shielded from the energetic protons, because it stays in low Earth orbit, underneath the Van Allen radiation belts -- Earth's magnetosphere diverts the protons away from the station. But the high energy galactic cosmic rays have no trouble passing through and hitting the station. So station astronauts are (probably somewhat) safer during solar maximum, but interplanetary astronauts are (probably) safer during solar minimum. Either way the radiation dose is a problem that has to be designed around.
Incidentally, the largest effect of solar activity on the space station is orbital decay! During solar maximum, the increased far-ultraviolet brightness of the Sun heats the outer layers of the atmosphere (the "thermosphere"), making them expand significantly -- that increases orbital drag a LOT. It's one reason (the other being delays in the Shuttle program) that Skylab re-entered the atmosphere before the Shuttle came on-line to provide additional boost. Skylab was launched during solar minimum in the mid 1970s, and the orbital decay projections were based on solar minimum conditions. It re-entered several years earlier than initially expected, because the atmosphere (and hence orbital drag) got larger in the solar maximum period of the late 1970s. The space station has similar orbital-decay issues; if you Google for the altitude-versus-time plots, you'll see that at its chosen altitude, the ISS needs to be boosted every six months or so, or it will spiral in and re-enter the atmosphere.
Solar Flare or Cosmic Ray (Score:1)
hmm.. did I just invented a new way to execute people?
Re:Solar Flare or Cosmic Ray (Score:2)
No, you just invented a new language and field for psychologial study.
Fantastic! (Score:1)
Safer? No. (Score:2)
Peak sunspot activity means peak coronal mass ejection (solar flare) activity. A really large solar flare can inflict thousands of rems in a short period of time, while you'd be reducing cosmic ray exposure by tenths of a rem per week. Even smaller flares will influct tens or hundreds, and at any reasonable interplanetary speed, you'll get hit by several during a sunspot peak.
If you've got the Van Allen belt
SPF! (Score:1)
Speaking of astronauts..... (Score:3, Informative)
Some of the things they are talking about(from the official program):
The Genesis of Cooperation in Space: The Apollo-Soyuz Program
Tom Stafford
Panel Discussion (ASE Founders)
Loren Acton, Bertalan Farkas, Georgi Ivanov, Alexei Leonov, Vladimir Lyakhov, Dorin Prunariu, Rusty Schweickart, Vitaly Sevastyonov
Technical Session: International Space Programs Review
Chairs: Chris Hadfield, Leroy Chiao
NASA Headquarters Update: The ISS Program and Future Issues
Bill Readdy, NASA
Life on Station
Leroy Chiao, NASA
Report on the Canadian Space Program
Chris Hadfield, CSA
Report on the Russian Space Program
Yuri Usachev, RSC Energia
Technical Session: Crew Safety & Technical Issues
Chairs: Sergei Avdeev, Charlie Precourt
Shuttle Derived Vehicles
Mike Conn, ATK Thiokol
Maintaining On-Orbit Crew Proficiency
Chris Hadfield, CSA
Electromagnetic Radiation and Crew Health
Alexander Serebrov
Technical Session: Future Programs
Chairs: Michel Tognini, Yuri Usachev
Beyond the Moon: The Asteroid Option
Tom Jones
Kliper
Yuri Usachev, RSC Energia
Russia's Future in Space
Georgi Grechko
The Aurora Program
Piero Messina, ESA
There's some pretty big names in there, also note that they are talking about astronaut safety with regard to electromagnetic radiation.
I submitted this to
Yes, AND... (Score:2)
Re:hmmm, matter absorbing energy? (Score:2, Interesting)
Re:hmmm, matter absorbing energy? (Score:1)
The people looking into it have already noticed the field is weakening and has been for hundreds of years. The rate at which it gets weaker will also get faster and faster until it collapses entirely.
I think it's due to completely collapse in 500-1000 years or so, before growing again but the other way around.
You're right about deflecting t
Re:hmmm, matter absorbing energy? (Score:1)
Turns out that the last time was 780000 years ago. It's not very precise but they usually happen every 250000 years so we're *long* overdue for it. And it does appear to be happening now, so the flip will slowly happen over the next couple of millenia.
Some scientists aren't so sure it is going to flip though, as the past 2000 years have seen it just about the highest it's ever been, so it might just be returning to a reasonably normal level.
The reason it flucuates so much by the wa
Re:hmmm, matter absorbing energy? (Score:2)
Djing! Incorrect physics alert! Target located. Engaging.
There are no magnetic monopoles in the universe -- or at least we have yet to find one, though they have been postulated to possibly exist. All sources of a magnetic field are dipoles (ie they have a "North" side and a "South" side). Additionally, all sources of a magnetic field are moving electric charges. Atoms produce magnetic fields (thank
Re:hmmm, matter absorbing energy? (Score:2, Informative)
Looking on Google again I found what I'd been think of. It's the Geodynamo if anyone want to look for it.
"Currents flowing in giant loops through the earth's core."
You're pretty much correct there on how they think it happens.
Basically the guy noticed that the direction the molton core convects is different in some places than others. And it changes the way the magnetic flux acts.
When the convects in one direction, the flux goings in one direction; when it conv
Re:hmmm, matter absorbing energy? (Score:1)
Oh and just to clarify, I hadn't meent these were monopoles although I do see why it reads that way.
Each convection hotspot creates its own magnetic field. Thus has a North and South pole and flux lines between them.
There are many hotspots, hence many North&South pole pairs. They move around as the hotspots move around.
They all add up when combined in the core to produce one large magnet with a sin
Depends what you mean by "radiation" (Score:2)
The Earth's magnetic field deflects charged particles from the Sun or in cosmic rays. These particles are sometimes called "radiation," but that may be a little bit misleading as they're not at all like light or X-rays.
That being said, it is indeed
Re:hmmm, matter absorbing energy? (Score:1)
I've had that idea in the back of my mind for a while now too. Thing is i've done various google searches for data on the output of the sun over the last few decades and haven't found anything yet - i can't help but feel howevewr
Re:hmmm, matter absorbing energy? (Score:2)
Re: (Score:1)
Re:Danger Level (Score:1)
Re:Danger Level (Score:4, Informative)
Of course, these same cosmic rays will also destroy cells in the brain and fragment DNA, potentially generating damage which could either lead to cancer or lead to genetic problems which could be passed on to future generations.
Although I can't quantify the risk associated with the latter phenomena, knowing that every time I see a little flash I have suffered a small but permanent loss of vision would make space travel less appealing.
Re:Danger Level (Score:1, Funny)
Duude, you're full of crap! My cellphone does the same thing, and they say it's perfectly safe. Can you hear me now? Can you hear me meow? What?
Re:Danger Level (Score:1)
Re:Danger Level (Score:1)
Re:Can we get that down here??? (Score:1)
Well, I certainly won't deny it was Bush bashing, but "idiotic" is definitely a bit harsh. They put the phrase in quotes right in the post, for Pete's sake. That's not idiotic, that's taking advantage of a perfect lay-up.
Talk about being kept down by the man. Geesh!
Re:Forbush decrease? (Score:2, Insightful)
Well, at least your karma didn't spanked for it like mine did...
</whine>