It's more along the lines because the semi conductors they're made out of can't be affected by radiation, as I said exposure to ionizing radiation (ion implantation) is actually one method used for modern micro processor manufacturing, these methods can't be used in radiation hardened designs, you have to use manufacturing methods often many years older that don't have all the benefits of modern processes.
Space is orders of magnitude more difficult to exist in than most people think. On some of the first orbits man took into space flashes of light were noticed, it took a while to figure out but cosmic radiation entering the eye actually excited the eyes receptors to pick up bursts of light.
If it can do that to the human eye, what do you think it can do to the delicate matrix in modern cmos device? A single photon generated at the wrong time can lead to total system failure, at least in the long term.