A Mars Mission's Greatest Challenge: Radiation 417
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."
Problems Like This (Score:5, Interesting)
I do remember from my O'Neill colony advocacy days that people who knew more about the subject than I did recommended putting heavy, static shields around the colonies. One meter or so of solid waste products (think left over materials from mineral refining) in a layer around the colony could effectively shield the inhabitants from cosmic radiation.
This, unfortunately, makes for a pretty massive structure -- difficult to move around the solar system with contemporary propulsion. Travel is possible, especially with better propulsion, but more difficult than Star Trek et al. would have you believe.
This problem also could impact those proposals for Martian bases and settlements. I think Mars doesn't provide the same protection from radiation as Earth does. So, we could build bases on Mars -- just bury them underground. That's hardly what I think Zubrin and company want.
It might be interesting to see what can be done, if anything, with some sort of magnetic shielding. Although that could be a lot trickier again than SF TV shows imply.
I think problems like this are resolvable, but it's going to take a wide variety of efforts in multiple fields and directions to come up with solutions. Is there enough interest in space currently to make that kind of effort? Or can research in various fields be done with other goals in mind to solve this specific problem?
Color me pedantic, but... (Score:2, Interesting)
I think you meant LARGE fraction of lightspeed interstellar rubbish. The spitballs my cubicle mate hurls at me are fraction-of-lightspeed rubbish. A very small fraction of lightspeed. Shielding requirements are minimal.
How, though, will we protect ourselves from the terrible secret of space?
Livin Underground (Score:4, Interesting)
NASA is addressing the problem right now... (Score:5, Interesting)
Here's the link: link [space.com]
Re:Who didn't see this coming - I did (Score:5, Interesting)
There are also hydrogen material bricks in some sleeping stations on the ISS, I think they were first used on MIR.
This low-tech shielding was the inspiration for part of the filtering my Foil Hat in my sig.
Radiation is a problem but not that big a problem (Score:5, Interesting)
- a pretty major propulsion system to get a heavy ship headed to Mars at a high rate of speed, presumably nuclear
- getting a lot of mass into LEO in the first place
It doesn't bode well for a new Moon or Mars mission that NASA can't even get mass in to orbit in a reasonable way. As I've said before throwing a bunch of money into NASA for a new space initiative is not a good idea. As the shuttle and ISS show NASA has developed fundemental institutional flaws which tend to result in large amounts of money being spent and not much being accomplished. To think you're just going to set a new goal and get a better outcome, with no structural change, is naive. Set up a new skunkworks if you want to accomplish something in space, hire the best people and reward them in a meritocracy, not a bureaucracy.
This article is also flawed in the same way as most discussions of a Mars mission. The goal SHOULD NOT be a round trip. The goal should be to start sending big unmanned cargo ships, carrying water, food, habitats, green houses and nuclear power plants to Mars and when they are arriving reliably send colonists on a fast one way trip to stay for the duration. The other major challenge finding men and women who are compatible and are willing to produce future versions of the colonists.
Spending 60 billion to send a few astronauts to pick up rocks and come back just isn't worth it. Apollo kind of proved this. As soon as landing on the moon had been done, missions to pick up rocks didn't hold public support.
A permenent colony is also kind of an underhanded way to insure long term funding for the program since once you have colonists on Mars you are going to have to do whats necessary to keep them alive, until they are self sufficient (though they may not be fully self sufficient for a long time for manufactured goods like electronics).
Once you have a self sustaining colony you are insured a perpetual mission and are free of the whims of whether Mars 18 will be funded or not.
Not a primary concern (Score:1, Interesting)
Re:How about a (Score:3, Interesting)
Re:How about a (Score:2, Interesting)
Physicists: New Radiation Shielding Materials? (Score:1, Interesting)
Obviously, one would need a way to manufacture such a sheet, but my point is, is a thin, light, radiation impermeable material technically conceivable? What are the issues?
the truth (Score:4, Interesting)
Great, space FUD.
I recommend The Case For Mars (amazon.com link) [amazon.com], by Robert Zubrin. You can also check out The Case For Mars [colorado.edu] website.
The short version is this: we have all the technology we need to safely colonize Mars right now, and with less danger and hardship than the American colonists suffered four centuries ago. If funding were allocated today, the first scientists could be on Mars in 10 years, and colonists in perhaps 20. (The money required would be a small fraction of the US civilian-bombing budget.)
Safety from radiation is easy. Zubrin points out that you can just go to the center of the ship and stack your supplies around you to reduce radiation to acceptable levels, even in the case of a powerfuil solar flare. On the surface, you just build homes underground for everyday living. People here on Earth are doing this now just for the energy-bill savings. I think we can do it in order to colonize an entire planet.
Re:Problems Like This (Score:4, Interesting)
This
One alternative that has been considered is an Apollo asteroid shuttle.
* Take one of the Apollo asteroids (which have orbits that cross that of earth).
* Modify its orbit so that it shuttles between the orbits of Earth and Mars, arriving near each when the planet is also nearby. (Use solar sails or solar-powered mass drivers or ion accellerators throwing spare mass from the asteroid for propulsion, to get your delta-v without hauling up fuel.) Takes a while, but can be automated for most of that time.
* Build a base INSIDE the asteroid.
The asteroid provides the mass of shielding, plus raw materials for buildings and a mostly-closed ecosystem. It becomes an "orbital hotel", much like an interplanetary cruise ship, making a trip every couple years.
Once it's established you only need enough delta-v to get your passengers and freight between the planets at the end of the trip and the asteroid. This is the same amount of fuel as shipping them and their docking shuttle to Mars or back by the same orbit - but you DON'T need to ship their well-shielded vehicle or most of their consumables. MUCH cheaper. Radiation exposure in the hypothetically less-shielded shuttle is for a few hours at the ends of the trip, rather than for a couple years during the trip.
Re:Radiation is a problem but not that big a probl (Score:3, Interesting)
- a pretty major propulsion system to get a heavy ship headed to Mars at a high rate of speed, presumably nuclear - getting a lot of mass into LEO in the first place
Actually right now the future seems to be ion engines, not nuclear, for long-term missions because it is lighter and far more feul efficient. Light reading: http://www.bbc.co.uk/science/space/exploration/fut urespaceflight/ionengines.shtml [bbc.co.uk].
The goal SHOULD NOT be a round trip. The goal should be to start sending big unmanned cargo ships, carrying water, food, habitats, green houses and nuclear power plants to Mars and when they are arriving reliably send colonists on a fast one way trip to stay for the duration.
I've always been fascinated by the idea of colonizing other planets. However, to say that should be the first manned mission to a planet seems foolish to me. At the very least I would think we would need to send a sort of "exploratory mission" to make sure things exist on the planet the way we think they exist.
Preferably on whatever planet we one day colonize, we find a source of fresh water. Colonizing a planet without that seems counter-productive except for long-term research. The vast amount of water that even a single city on Earth uses makes it impractical and insanely expensive to set up a system in which water must be constantly delivered, at least in order to maintain any sort of lifestyle we're used to. And really, if we can't provide something resembling a "normal" life on a colonized planet, and the "colonization" amounts to only a scientific outpost, we have to weigh the costs of that colony against its benefits. Is the extra benefit of living there for a while worth the extra money it would take compared to occasional visits to pick up something to research?
And what of biological entities? As you probably know, the NASA folks are put through an extremely rigorous quarantine and "cleaning" (I can't think of the word right now) to ensure we neither bring any of our bacteria and such to another planet nor bring any from there back with us, if any such exist. Assuming we can say with any certainty that no life of any kind exists on Mars (or any planet) is a dangerous assumption. It is, after all, one of the questions that drives space exploration.
It seems that all of your ideas hinge upon a self-sustaining colony. We'd certainly better send some folks to investigate whether or not that is ever possible before we start sending settlers. I agree with you that our long term goal should be colonization of a planet (not Mars necessarily if it is not adequate), but that's a goal that should be significantly farther down the road. It might not ever be possible. Between the extreme temperatures, lack of water, etc, we might never find a planet we can colonize that is within our reach.
Not the only issue (Score:4, Interesting)
Human bones become brittle in less than 1G environments, after extended time. The time it would take for a mars mission, given current technology, the damage to astronauts would probably be irreversible for all but a short-stay mars mission.
Bone loss in zero G is about 10% per year. 10% is a lot of bone loss.
A short-stay mars mission is where you only stay on mars 30-90 days, and total mission time runs between 400 and 650 days. This may be long enough to do permanent damage.
A long-stay mars mission has a round-trip time of about 900 days. Even with half of that spent on mars, the combination of the extended stay in low G combined with the other half in zero G will turn most people to jelly. You're probably looking at around 25% bone loss here.
Not just the bones you normally think of, but your teeth will rot and fall out as well with these kinds of trips.
Even with exercise, muscles, ligaments, and tendons will atrophy significantly.
The plain fact is, human beings weren't built for space travel. By providing an artificial gravity (which would therefore mean a larger ship to shield), you can get by this, but then you're adding weight, which adds fuel and time, and so forth.
I personally don't think we're ready for a mars mission any time soon. Probably not in my lifetime. We ought to concentrate on closer targets until we have the technology to send people to mars safely.
How about borrowing... (Score:3, Interesting)
from that kook, Erik Von Daniken of Ancient Astronauts fame? In one of his interpretations of a Mayan carven rock image, he sees an astronaut in a reclined position operating instruments. Outside the "vehicle" he sees a rocket plume, etc. The thing is, and I always wondered about the possibility of this working, he produced an "engineered" drawing of the "spacecraft" and added annotations. One of them indicated a magnetic shield around the spacecraft.
Since way back when Ancient Astronauts was new and I saw that drawing, I have wondered about that idea. Could you not generate a magnetic field around your spacecraft so as to deflect charged high speed particles? You could also use water shielding. Water tanks could be placed to completely encircle the crew compartment(s)/living quarters and act as shielding as well. So...what about combining an artificial ship's magnetic field and water shielding?
Re:Mars Missions? ...No Way! (Score:3, Interesting)
If we had the technology to send people off to colonize a barren place like Mars, wouldn't we also be able to use the tech (and more easily) to keep a colony of people alive on earth after an asteroid impact? (assuming the colony isn't close to the impact point or the coasts, and you can tolerate the intense guilt of hanging out while everyone else dies a la Dr. Strangelove's plan)
Why don't we make our own magnetic field? (Score:3, Interesting)
Zubrin's gravity plan (Score:1, Interesting)
Re:Not the only issue (Score:3, Interesting)
It would be interresting to see how this went.
Re:Comparing Price (Score:3, Interesting)
Sir, I believe that nothing is more important than space exploration. The only chance for life to survive in the universe is for use to colonize other planets/moons/rocks. No single life is as important as the survival of the species, nay the survival of LIFE ITSELF. Eventually, the Earth will be destroyed, and if we haven't spread by then, life in the universe will die with the Earth. The ultimate goal of all life is to spread. If you don't, you die.