The CALorimetric Electron Telescope (CALET) is a high-energy astroparticle
physics space experiment installed on the International Space Station (ISS),
developed and operated by Japan in collaboration with Italy and the United
States. The CALET mission goals include the investigation of possible nearby
sources of high-energy electrons, of the details of galactic particle
acceleration and propagation, and of potential signatures of dark matter. CALET
measures the cosmic-ray electron + positron flux up to 20 TeV, gamma-rays up to
10 TeV, and nuclei with Z=1 to 40 up to 1,000 TeV for the more abundant
elements during a long-term observation aboard the ISS. Starting science
operation in mid-October 2015, CALET performed continuous observation without
major interruption with close to 20 million triggered events over 10 GeV per
month. Based on the data taken during the first two-years, we present an
overview of CALET observations: uses w/o major interruption 1) Electron +
positron energy spectrum, 2) Nuclei analysis, 3) Gamma-ray observation
including a characterization of on-orbit performance. Results of the
electromagnetic counterpart search for LIGO/Virgo gravitational wave events are
discussed as well.