There are two types of cosmic rays traveling through space: neutral cosmic rays (light rays and neutrinos) which have been studied extensively by Hubble telescope, by PLANCK satellites and many other space-born and ground and underground experiments such as AUGER, HESS and IceCube. These studies have contributed greatly to our understanding of the Universe.
The second types of cosmic carry charge and mass. They are absorbed in Earth atmosphere. To study the original properties of charged cosmic rays, one needs a precision magnetic spectrometer in space to identify the charge and the mass.
The Alpha Magnetic Spectrometer (AMS) is a precision particle physics detector deployed on the International Space Station in May 2011. In five years, 80 billion cosmic rays have been measured. The precision of the detector and its ability to measure and distinguish charged nuclei at extremely at high energy have changed our understanding of properties of charged cosmic rays.