Observational Challenges on the ISS: A Case Study with CALET

Abstract

The International Space Station (ISS) provides an orbital platform for astrophysical missions with lower resource requirements than free-flying satellites. The many uses of the ISS, how7 keVever, can produce unique challenges to the accurate analysis of the data acquired by these instruments. In this work, we present effects observed by the Calorimetric Electron Telescope (CALET), an astroparticle physics mission installed on the Japanese Experiment Module Exposed Facility of the ISS. The CALET calorimeter is sensitive to cosmic-ray electrons and gamma rays from ~1 GeV up to above 10 TeV, and to cosmic-ray hadrons up to ~PeV total energies. The CALET Gamma-ray Burst Monitor (CGBM) is sensitive to X-rays and low-energy gamma rays from 7 keV to 20 MeV. Furthermore, ultra-heavy galactic cosmic-ray (UHGCRs) abundances are measured by CALET using a much more open geometry than is possible for events which shower in the instrument. In this work, we discuss ISS-related issues that affect the observations by CALET. Here we detail the ways these effects are accounted for in the production of scientific results. Finally, the possible impact on future missions such as TIGERISS (Trans-Iron Galactic Element Recorder for the International Space Station; planned for deployment to the ISS in 2026) and mitigation strategies are discussed.