Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM)

The ISS-CREAM payload was launched on the SpaceX-12 Commercial Resupply Service mission to the International Space Station (ISS) from NASA’s Kennedy Space Center on August 14, 2017. It was successfully installed and activated on the ISS Japanese Experiment Module Exposed Facility as an attached payload on August 22, 2017. The ISS-CREAM instrument is configured with complementary particle detectors capable of measuring elemental spectra for Z = 1 - 26 nuclei in the energy range ~10^12 – 10^15 eV; as well as electrons at multi-TeV energies. The four layers of its finely segmented Silicon Charge Detectors provide precise charge measurements, and its ionization Calorimeter provides energy measurements. In addition, scintillator-based Top and Bottom Counting Detectors and a Boronated Scintillator Detector distinguish electrons from nuclei. The goal is to understand cosmic ray origin, acceleration and propagation by extending direct measurements of cosmic rays to the highest practical energy. On-orbit performance of the instrument and preliminary results from the ongoing analysis are presented.