[nickik]

Radiation has been studied since the 60s. Multiple Mars mission had the equipment on board to do the measurements. Nothing to surprising was measured, the same results on Curiosity and Viking.

We know a lot about both type of radiation, cosmic and solar. Why know the basic physics, and we know how to prevent it. Both types of radiation have different properties and have different levels of danger, thus need different solutions.

This had been known for a while and solutions are possible. Thus, its not the most important problem in Humans to Mars architecture, as we know much less about reusable rockets and carbon cryo tanks.