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

The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) instrument is designed and built to measure elemental spectra of cosmic-ray nuclei (1 ≤ Z ≤ 26) and electrons. It will measure energy of incident cosmic rays from 1011 to 10^15 eV with a tungsten/scintillator sampling calorimeter and densified carbon target with an interaction length of ~ 1 λL. A finely segmented, four-layer silicon charge detector will identify the elemental composition with a resolution of ~ 0.15e. The instrument is triggered by selectable, independent, and combined algorithms from the calorimeter and a scintillator-based counting detector on the top and bottom of the calorimeter. The counting detectors also provide separation of protons and electrons using differences in the shower shapes. A boronated scintillator detector provides additional e/p separation by looking at late scintillation light produced by a particle interacting in the calorimeter system. ISS-CREAM underwent vibrational, electromagnetic, thermal/vacuum, and telemetry systems tests at various NASA f acilities to qualify for rocket transportation and space operations. All testing and integration were completed and ISS-CREAM was delivered to NASA. It is now flight ready and waiting for launch on SpaceX-12 in 2017. ISS-CREAM integration, environmental qualification, and instrument performance will be presented.