The solar system is awash in radiation. The second largest thing in our solar system, after the heliosphere (or area of sun’s influence) is the magnetosphere, which comes from the magnetic fields of Jupiter forming this immense penumbra or plume of radiation around it. If you design a space ship that is not shielded against radiation, you didn’t do it right. Especially if said ship has to travel through a magnetic field that causes the radiation.
Secondly, if you are designing a space suit of any kind, again, plan for radiation. Nasty stuff, that.