Outside the protective barrier of the Earth's atmosphere, space radiation can pose significant health and safety challenges. Primarily comprised of galactic cosmic rays, solar particle events, and heavy ions, space radiation may cause radiation sickness, nervous system disturbances, cataracts and vision impairment, increased risk of cancer, and other health problems. In addition, space radiation may also be responsible for adverse changes in the cells and genes.
For nearly 40 years, NASA scientists have collected radiation exposure data from crewmembers who have returned from space flight missions. Radiation scientists have used these findings to develop current exposure guidelines and basic safety procedures. However, more research is necessary to understand fully the health impacts of space radiation exposure. Additional research will also explore the unique challenges associated with higher levels of space radiation that astronauts may encounter during the extended missions that are planned for the future.