Hum, sorry but you are mistaken. Most of the poster are sane.
John Holtsnider, Theodore Rockwell, Michael Pepka and J. M. Wozniak all offer sane and reasonable points both biological and shielding wise in the discussion.

Radiation is a great danger and it must be dealt with. But as I pointed out before Gene Parker assumes we must stop all cosmic ray exposer instead of finding the limits we can be exposed to "safely" all from one study. The truth is even if you did nothing to protect a traveler to Mars they would not necessarily die from their exposer nor would they necessarily be disabled by the exposer. We would be raising their likelihood of death later by cancer. Do I need to point out the many people on Earth who have had higher exposers than would be that of a person traveling to Mars or camping on the Moon? We do have cataract surgery and other means to help those suffering from exposer.

Look Chang Diaz is motivated by personal reasons to reason we need his own project to go to Mars and that should have been self explanatory to you.

In Gene's reply to Chang Diaz the big issue is nine tons of hardware to protect the spacecraft. Nine tons is not a big issue with launch systems. That Gene thinks it is tells us more about how out of the loop he is than what the problems with cosmic rays exposer are.

That his biological awareness is lacking is another clue that he is wrong about the problems. Secondary exposer on the surface of Mars or the Moon are probably a bigger issue than cosmic rays are.

Anyway there are a couple replies in the middle that are nutty. But, as they actually don't attempt a reason positively toward how to effectively protect from excess exposer makes their replies just noise.