The belt would have to behave differently (which is possible because space changes how things works, but would require experimentation than 99.9999999999999999999999999% of the world's historical population would never be able to perform) than any other radioactive particles for metal not to deflect it.
We already deflect radioactive particles on the surface of the planet using thin foil.
Additionally, the belt(s, plural) are not static, and do not cover the same vast differences at all times. It is very thin around the poles.
Further, you have to consider what an unprotected Van Allen Belt puts into humans; you can survive for a short time, but you are just taking more rads than is normal by a significant margin.
E.g. (arbitrary numbers) a month in the Van Allen Belt could be equal to about a year's worth of background radiation.
There is a lot of technical and scientifically understandable reasoning for why we could get to and from the moon safely.
The more curious thing is how the extremely fast moving space particles didn't tear the foil, and even more curious thing is why we still haven't gone back with better cameras and technology.
All you have to do is take a closer look at the lunar module and imagine if it can withstand exiting and reentering the Van Allen belt.
The belt would have to behave differently (which is possible because space changes how things works, but would require experimentation than 99.9999999999999999999999999% of the world's historical population would never be able to perform) than any other radioactive particles for metal not to deflect it.
We already deflect radioactive particles on the surface of the planet using thin foil.
Additionally, the belt(s, plural) are not static, and do not cover the same vast differences at all times. It is very thin around the poles.
Further, you have to consider what an unprotected Van Allen Belt puts into humans; you can survive for a short time, but you are just taking more rads than is normal by a significant margin.
E.g. (arbitrary numbers) a month in the Van Allen Belt could be equal to about a year's worth of background radiation.
There is a lot of technical and scientifically understandable reasoning for why we could get to and from the moon safely.
The more curious thing is how the extremely fast moving space particles didn't tear the foil, and even more curious thing is why we still haven't gone back with better cameras and technology.