Posted on 08/01/2005 1:19:26 PM PDT by LibWhacker
"Which is equal to 33 feet of water or 3 feet of lead."
Or somewhere inbetween for fused lunar rock!
The problem can be solved. We can go to Mars if we want to!
People have posted about solar sails and bringing back Orion (yay for Orion and hang the Limited Test ban Treaty!) to cut the transit time.
There are lots of ways!
I will volunteer for a manned mission to Mars.
So what if I die from cancer in 20 or so years.
My name would become immortal as the first man on Mars.
We are all born terminally ill anyway, so might as well make something of the life we have.
If I can get a cool superpower, I'd do it!
Hell, even unfit, 59, and asthmatic, I would still risk it just to get to the moon, let alone Mars.
A whole new meaning to "once in a lifetime". Some things are worth whatever the cost.
Cosmic rays are killing all of us ... right now. The human body is self repairing. It just can't keep up with the ray bombardment.
Back when the 'firmament' was still in place folks lived hundreds of years.
Wouldn't want to be confusing comic rays with cosmic rays, now would we?
Tinfoil hats, "sunglasses", and lead jockstraps for the crew.
Why in the world would you even think of trying to shield the entire ship?
Hey, Einstein. Over here.
First step, a political campaign to get us out of the Space Treaty so that there can be extra-terrestrial private property.
Not yet. They are still 30 years behind. But seeing that we haven't done much in 30 years, we might as well be 30 years behind ourselves. Still, they have nothing to match the throw weight of the Space Shuttle. They will have to develop the BDB if they expect to compete or even to meet the goals they have laid out for themselves. It's still Long March over there.
At that level, do we absorb?
As far as shielding, if radiation occurs within the shielding, then it seems obvious that spaced shielding would work better than just more thickness, where you have an open buffer zone before reaching the inner shielding.
No biggie in the long run. If we can't solve the problem from one direction - properly shielding the spaceships - then we'll eventually solve it from the other: repairing the physical damage. Everyone seems to be fixated on the former, but the latter would be far more widely useful in any event.
Ping to myself
Yes, we absorb energy from these hot nuclei. We are thick slabs of water that can slow a cosmic ray, and that means it deposits energy in us. If you look at the chart from the transport calculator, you see the flux is not high, but it is constant. Also the transport calculator does not include secondaries like mesons and neutrons or brems photons that come from the shielding itself. You need to use a code like MCNP for that, and that's not free on the web. So the transport calculator does not do doses, just attenuation of the incident without considering secondaries or absorption in people.
Why put a space? The particle will just cross that space.
Shielding is done in layers, though. Typically a plastic layer for real light stuff and to slow neutrons, an aluminum shield to stop light particles, then a denser shield to stop more particles and the bremstrahlung radiation, then sometimes a plastic type again for neutrons. It cuts weight; the low-Z materials stop the light particles OK. For electronics there are very small very dense shields (like the tantalum Rad_Pak) that are small. You could not make a personnel shield.
On the lighter side, a few years ago National Geographic had a shot of NASA's Janet Barth, from the "Living With A Star" program, wearing corrugated plastic sleeves filled with water for a wearable shield. Actually it was a bunch of gadjets for making tubular ice in your freezer stapled together but it sure looked cool.
If we had wanted to, we could have launched the Shuttle with the main tank attached and leave it up there, so that now we'd have a bunch of big empty cylinders in orbit. Tie them together and fill them with water and you have a big habitat and shield. It would help to find water on the Moon, but if we wanted to we could boost a couple tons a year, if we had a good ongoing space program.
I am wondering if lead would protect them. Certainly though, by the time we develop a ship that can make the journey, a shielding material will have been invented. Human ingenuity. Of course, the space program being turned over to the private sector would make it happen faster.
Well that sounds right but the question we were originally addressing was whether this is a net increase in the hazard of the cosmic rays themselves. That is still not clear.
And I'm still not convinced that you are right (although I'm leaning in your direction.) What you are saying is that as I increase my velocity I will see a different spectrum when I look at the cosmic ray environment. It seems to me that this violates the principle that the laws of physics are the same in all inertial reference frames. There just seems to be a conflict here. I understand that relative motion between you and a source will redshift or blueshift the energy. When there are thousands or millions of surces of the cosmic rays and you must be looking at averages it just seems to me that you cannot equate this to what would happen between you and a single source. The rules just have to be different. If not, it seems like the measurment of the cosmic ray spectrum would provide a universal speedometer and I don't think there is such a thing.
Or is there?
Please enlighten me. This is a very interesting subject.
Cosmic rays will keep democrats from thinking
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