GEANT4 APPLICATIONS IN SPACE

The use of Geant4 is rapidly expanding in the domain of space applications. I try to give an overview three major application areas of Geant4 in space, which are apparatus simulation for pre-launch design and post-launch analysis, planetary scale simulation for radiation spectra and surface and sub-surface explorations, and micro-dosimetry simulation for single event study and radiation-hardening of semiconductor devices. Recently, not only the mission-dependent applications but also various multi-purpose or common tools built on top of Geant4 are also widely available. I overview some of these tools as well. The Geant4 Collaboration identifies the space applications now-as one of the major driving forces of the further developments and refinements of Geant4 toolkit. Highlights of such developments are given.