[geoschmo]

I suspect that it's less a problem with being outside of the reach of earth's magnetosphere and more of a problem of being exposed to those nasty things that the magnetosphere normally protects us from. There are types of radiation out there that our little aluminium foil space ships don't protect us from very well. We will probably find ways to shield agaisnt it, but it's not easy.

As far as the Lunar astronauts medical records being classified, I wouldn't be so quick to ascribe it to conspiracy theories. Medical records are personal information afterall. It's bad enough those guys couldn't take a pee for years without filling out a report in triplicate listing the quantity, temperature and color. Would you want all that info turned over to the kooks and curiosity seekers if you were an astonaut or one of his family members?