Chemical Composition of Galactic Cosmic Rays with Space Experiments
  The origin and properties of the cosmic radiation are one of the most intriguing question in modern astrophysics. The precise measurement of the chemical composition and energy spectra of the cosmic rays provides fundamental insight into these subjects. In this paper we will review the existing experimental data. Specifically, we will analyse results collected by space-born experiments discussing the experimental uncertainties and challenges with a focus on the PAMELA experiment. 
Mirko Boezio and Emiliano Mocchiutti
astro-ph.HE hep-ex