I've heard tell that a mission to the Galilean satellites is difficult for many reasons, but radiation is one of them. Is it safe to say that above all, the worst radiation is when you are landing and have landed on the surface of the Galilean satellites, because you are in Jupiter's Van Allen belts? Or, is the nature of cosmic rays so degradative that it is the greatest risk? I'll cut to the chase. I thinkI have an idea that will help protect a lander, if we are ever crazy enough to send people to Europa. However, assuming it takes hours if not days to deorbit a lander into a plausible entry path the lander will be in Jupiter's deadly Van Allen belt for a long time before any system that is meant to protect it from Van Allen radiation is put in place. I've heard of a double wall system where the astronauts go into an extra layer of radiation protection, however they can't continue to remain in a double walled claustrophobic pod forever. That's where my system might come in, but unfortunately it is once they've landed. Does it still count by then? Do they need an all inclusive system for the duration of the flight to and back? Or is the primary concern radiation once they've landed IN the Van Allen belts on Europa?