NASA is about to change the radiation exposure limits for astronauts. Previously, radiation levels were set on the basis of age and gender. The new proposal will simply set a lifetime radiation exposure limit. Radiation is measured in millisieverts (FYI: short form is “mSv’.) The new proposal will be 600 mSv regardless of age or gender. Statistically speaking, the new level is based on "a 3% risk of radiation exposure-induced death (REID) at the 95% confidence level.” Apparently, this will accommodate the inclusion of more female astronauts. (Not mentioned in the article, so I’m telling you … it is not understood why more women get cancer from radiation exposure than men, but they do.) Also, the new level is still too low to allow humans to be sent to, for example, Mars.