ISO 15390:2004 specifies a model for estimating the radiation impact of galactic cosmic rays (GCR) on hardware and on biological and other objects when in space. ISO 15390:2004 can also be used in scientific research to generalize the available experimental evidence for GCR fluxes. ISO 15390:2004 establishes the model parameters and characteristics of variations in the 101 MeV to 105 MeV GCR particles (electrons, protons, and Z = 2 to 92 nuclei in the near-Earth space beyond the Earth's magnetosphere).