Re: Prevention is better than cure.
"Shielding doesn't just have to be metal, we can look into the ablative, reflecting and absorbing properties of other materials like plastics or minerals."
We've already looked into such things plenty. Indeed, simple concrete is very popular for radiation shielding in places where you can just stick a big wall up and not have to worry about things like size and weight. The problem is that radiation doesn't particularly care what the material used is, it's all down to how many atoms there are in the way and how big those atoms are, ie., how likely a given particle is to actually hit something. A less dense material with smaller nuclei needs a much greater volume to give the same shielding, and the overall mass will be pretty much equivalent*.
As for magnets, there's certainly potential for shielding from lower energy particles such as those in the solar wind, but as that article notes it's really not feasible for stopping higher energy particles. Higher energies mean stronger magnets are needed to make a significant difference to a particle's direction; there's a reason the LHC is 26 km long, and that's with some of the best magnets we're capable of making. Hence the final quote:
"Getting in a tin can with a rocket on your back and flying to Mars is never going to be a safe thing to do"
* Collision cross-section doesn't scale linearly with nucleus mass, so the total mass would likely be a bit smaller.
Biting the hand that feeds IT
