Radiation Exposure To Astronauts
Tim Jenkins
Idaho State University
Department of Physics

The earth’s magnetic field protects life, which is on the earth, from much of the radiation that is present in space.  Astronauts on the other hand are not protected so much, therefore their exposure to radiation is much greater.  There are three main sources of radiation that astronauts have to deal with, 1) Galactic cosmic radiation, 2) Trapped radiation, and 3) solar-particle events.  It would be impractical to shield a space craft sufficiently so that radiation was not an issue, so the amount of time that astronauts are in orbit plays a big role in radiation safety.  Dose limits are much higher for an astronaut than that of a normal radiation worker here on earth.  Limits for an astronaut, depending on age and sex, can range from 1.0 Sv to 4.0 Sv.  Much is being done in the way of radiation safety for astronauts so that things such as deep space travel may be practical one day.