There are many possible CR accelerators in the Universe, such as supernovae, massive stars with high speed winds, pulsars, blazars, and cannabilistic black holes, to name a few, however the extent of their contributions to the CR population is presently unknown. In addition, as CRs propogate through space, they interact with the galactic interstellar medium (ISM). Precision energy spectra of CR nuclei of all types will lead to an improved understanding of CR sources and propagation throughout the galaxy.
