Comment on Moon Landing Hoax Proof by jfb.

X-rays aren’t the problem in the Van Allen belts; high-energy charged particles (protons and electrons) are the issue (which makes sense, since charged particles can be easily trapped in a magnetic field, as opposed to high-frequency EM radiation like X- or gamma rays). As such, the shielding requirements aren’t quite so severe (charged particles are more easily blocked than EM radiation).

And since the transit times through the belts were so short, the total exposure was kept around 5 REM.