Very false. The people who navigated the launch, which are not the astronauts, knew full well. Remember, they didn't even want the astronauts to be able to steer anything and everything was to be automated or remote. They did not fully understand the dangers but they knew enough about radiation and how to mitigate the bulk of it. Which they did. To further minimize the risk, they navigated through a smaller section (via angle/trajectory) which minimized both exposure time and peak radiation levels. The shielding used is highly effectively against this type of radition. In a nutshell, anyone who makes an issue of the Van Allen Belt and early space flights are profoundly ignorant and purposely misleading. There's no shortage of documentation and videos covering this topic in extreme detail. So it's rather disturbing it's coming up again. I believe such content has repeatedly been provided to the flatearth sub to debunk the position you offer.