Well, nasa claims that they flew through the weakest part (the poles) and that the astronauts were exposed to such little radiation that it wasnt an issue.

Thing is, those belts are there for a reason, they absorb not just solar but cosmic radiation. It's possible they flew alllll the way to the moon, without getting zapped by a random radiation wave. But it just amazes me no one ended up sterile or crazy. If they made it there, it was literally by the grace of god. (They dont even mention the sparkles that many iss astronauts see when they close their eyes and cosmic radiation goes through them.)

The only reason we are not exploring space today is because there is no technology to protect us from said radiation. I believe we had/have the technology to reach low earth orbit and thats it.

One of the ways they talked about blocking some of the radiation, on say a trip to mars, is by filling the walls of the ship up with poo. No joke.

The man and woman aboard the Inspiration Mars mission set to fly-by the Red Planet in 2018 will face cramped conditions, muscle atrophy and potential boredom. But their greatest health risk comes from exposure to the radiation from cosmic rays. The solution? Line the spacecraft’s walls with water, food and their own faeces.