Space Radiation Exposures for Manned Polar Missions: A Parametric Study

Abstract

Manned operations in low-earth, polar orbit will increase the risk of space radiation exposures to astronauts. The three sources of naturally-occurring space radiation are the geomagnetically-trapped Van Allen belt protons and electrons, galactic cosmic radiation, and solar flare-related particles. To date, the majority of the Space Shuttle missions have flown at low inclinations (28.5 deg). Five Shuttle missions were flown at inclinations greater than 49 deg. Measurements obtained from onboard radiation dosimeters from these five high latitude missions showed an increase in dose due to galactic cosmic radiation. The geomagnetic field offers less protection from both solar and galactic particles as the orbital inclination increases with polar missions being the worst.