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A Mars Mission's Greatest Challenge: Radiation
daSeiz writes "A New York Times article explores the possible effects of prolonged radiation exposure in deep space. Surprisingly, very little is known about the subject. We'll need to find innovative new ways of shielding spacecraft from fraction-of-lightspeed interstellar rubbish if we're ever to spend much time outside our own magnetosphere."
By the lack of consistent success in getting small probes to the red planet, I'd have to say that rushing out a manned mission should NOT be a priority.
Conformity is the jailer of freedom and enemy of growth. -JFK
Others include price, estimated at $30 billion to $60 billion, and launching enough food, supplies and fuel for a round trip. Any one of these could make the project impractical.
Well, not to sound too bitter, but going to Mars seems like a much better way to spend billions than going to Iraq.
Who said Freedom was Fair?
Ummm... Actually, wouldn't the worst problem be bone density loss. That's one of the main problems on the ISS (International Space Station). Without the effect of gravity, bone density decreases. From what I understand it's a pretty nasty recovery. The time required to go to and from Mars plus mission time would require much more time in space than any ISS mission to date.
Ok, IANAP, but what would be the requirements to build a device capable of generating a magnetic field similar to the earth's magnetosphere? I would imagine that it's more efficient to generate a powerful magnetic field around a spaceship than it would be to line the whole thing with lead bricks...
/.s out there who may be able to answer this.
Would the energy requirements be far to high, or maybe the diameter has to be a certain size to deflect solar radiation around the ship? This is all pure non-researched speculation of course, but I know that there's more than a few intelligent
- sig? who is this sig of which you speak?
Water is one of the best radiation protectors. By filling the double hull with water (and compartmentalizing against breaches) you could effectively shield an entire crew. Some form of EM "bubble" technology would also work, but it would be much more difficult to implement.
Oh, and they should use nuclear engines like NERVA or Orion. That way the extra weight of the water is less important, not to mention that the craft may be able to reserve enough fuel for emergency maneuvers.
Javascript + Nintendo DSi = DSiCade
What you really have to worry about is mid-energy stuff coming from the sun during a flare; that will bake you in a couple of hours. Luckily you just need a meter of water or so and you're good, so you can have a hidey-hole in the core of the ship to duck into for a few hours during flares, which you can get a warning of.
There's not much you can do about cosmic rays in a ship; you can't economically carry that much shielding, but luckily it's pretty low flux; a Mars mission would, by the estimates I've seen, raise a participant's lifetime chance of dying of cancer by 2%.
If we do go ahead with the administration's somewhat-ridiculous moon base idea, we could just launch some carved lunar rock shields -- perhaps encased in a polymer to prevent micrometeor-induced fractures. Throw those off the surface of the moon for much less energy and attach them to the mars craft at Lagrange or in orbit. Get a slow but steady start helped by some gravity slingshotting and you're on your way to mars.
I'm sure there are slashdotters with a stronger grip on rocket science than I have (which is basically limited to F=ma). Is this feasible? Or would it make more sense to just pay for firing lead/water into space from earth?
Seems to me it would make sense to return to the moon and establish a base there. Practice mining for materials, building a liveable environment, grow food. Basically set up a biosphere type environment on the moon, then worry about Mars. Next, I would imagine launching a mission to mars could be in some cases easier from the moon. Less gravity, tested equipment, people used to the idea of living off earth. And to echo another poster, why not send robots for a couple of missions well in advance to set up stuff, start mining, building shelters so when the people get there they don't have to cart a ton of stuff with them.
One thing that would helps is to only build the minimum necessary on the surface. Build the rest deep underground. Not great shielding, but better than sticking tin cans on the surface.
Why not wall paper the inside of the ship with Demron [sciam.com] for the outside use a the foam/armid lamiante process developed for the Cassini probe for the outer shell. All of it could be made out of plyable frabrics and assempled in space. No metal, so its easy to bring up on ship rolled up in bolts of cloth, the foam can come up as a liquid. Just a big ass micrometor and radiation proof ball with a truster on one end. Let it spin and even hav a parital G for the ride.
Right. Let's put all of humanity's other efforts on the back burner until your pet causes have been resolved. Tomorrow we'll all drop everything until we've got breast cancer figured out. After that we can work on AIDS, SARS, malaria, TB, and influenza; in that order. Once these pressing issues are out of the way we can lat NASA go back to playing with their rockets.
"Prefiero morir de pie que vivir siempre arrodillado!"
What's the point of: Publicly Funded Art? Big Science? Pure Science? Exploration? Going to the Moon? Going to Mars? SETI? Falling in love? Climbing a Mountain? (last one's a clue)
You will find many "justifications" for such endeavors--many of which are to the scale that they must be publicly supported (funded) if they are to happen at all.
They are just that. Justifications. Rationalizations of a decision after the fact. All the justifications offered for these acts are BULLSHIT.
The reason we do these things is "because". Peroid. This is the concept of intrinsic value.
Think about this for a moment. If we do something--anything, we give a reason. I go to work to make money. I make money to buy things. I bought a car to go to work. But what do all these things get me? In the free time that I have when I'm done working, when I'm done driving, what do I do?
Love? Learn? Raise children? Why? What do these things get me?
Nothing except themselves. They have value because I say they do. Nothing more. There is no "purpose" for love. There is no purpose for "Going to Mars".
Sure, we got useful stuff--national pride (some think that has value), new technologies, etc. from our trip to the moon.
But that's not why we did it.
We did it because it was hard. And it would be cool to have done it.
That's what makes us what we are. The things we do "just because". Not because we have to or because they are a means to an end. Just because we think they would be cool to do.
Intrinsic value is by definition subjective. If there's no justification, then there's no logical argument I can provide that says the things I value are the things you value.
But, as a society, there are some "great things" we can do.
The challenge of doing a "great thing" is not the doing of the thing (solving the radiation problem). The challenge is getting enough committed people together--through social imperatives (taxes, congress) or consensus--to actually get up and do it
Why do you climb a mountain?
Becuase it's there.
"Reality is that which, when you stop believing in it, it doesn't go away." - Philip K. Dick
All the diseases the poster mentioned are preventable: AIDS (safe sex, use clean needles, etc), SARS (everyone washing their hands properly being much more effective than face masks), malaria (sanitation), TB (sanitation), influenza (wash your hands, don't share telephones, keyboards, mice, etc., improved ventilation).
As for weaponized smallpox - I was vaccinated against smallpox as a kid. It's not like we don't have the technology to do this...
As for breast cancer - heart disease is still the #1 killer of women. And both heart disease and breast cancer are, to a certain extent, preventable as well, (diet, exercise, not smoking all improve your odds against both diseases, and breast-feeding also reduces the odds of breast cancer).
Overweight has just recently replaced smoking as the #1 health risk in the United States, and both these risks are totally preventable. We already have the cure. It's just that the majority are too fat, lazy, selfish, and stupid. So we're going to see the first generation where the children don't live as long as their parents. Not because of AIDS, or SARS, or an exotic disease, but because they choose not to exercise self-control over what they put in their fat, nicotine-stained mouths.
The answer is to design the Mars transit vehicle to carry its own magnetic field. Superconductors allow us to create fields of such strength that just about any cosmic ray will be bent to miss the spacecraft. Also, we can inject some local ions into that magnetic field, trapping them, and they in turn act as a partial shield against electromagnetic radiation (charged particles and photons have a nice high interaction probability). For more, and on even using such magnetic fields as a modest propulsion mechanism (interacting with Solar Wind), see this.