More on space radiation

I found a good detailed article on possible methods for shielding spacecraft from cosmic radiation. Unfortunately, there is no clear practical solution. The simplest idea is to be in the middle of a really big ship. But that doesn't help you while you are on Mars, say. Here's another, shorter, article that indicates this is beleived by some to be a major reason against sending humans to Mars (at least with current technology, I guess.)

"Active" shields have a lot of practical problems.

Although I find this area depressing (because it is another blow to easy exploration of space by humans) it does strike me a little as being similar to the challenges facing early maritime exploration of the earth. For example, the navigation problem of accurately determining longitude, solved by inventing an accurate transportable clock. Or perhaps there is more similarity with scurvy, suffered by sailors until they realised taking citrus juice would prevent it.

Anyway, although there are already engineers and scientists thinking deeply about it, I wonder whether this is another case (like the longitude problem) where the government ought to offer a reward for a good solution. It just seems possible to me that some sort of "new" idea for active shielding might be being overlooked.