CALET Instrument Scheduled for Launch to Space Station: LSU Astrophysicists Anxiously Await the Data

Professors John Wefel, Mike Cherry and Greg Guzik in the Department of Physics and Astronomy at Louisiana State University (LSU) have been searching for possible nearby sources of very high energy cosmic ray particles (e.g. from an undetected pulsar) and signatures of Dark Matter (the poorly understood component that makes up about a quarter of the mass-energy of the Universe) through high altitude balloon flights of the ATIC experiment launched from Antarctica. They are now part of a new experiment for the Space Station – CALET – which will provide a multi-year exposure in space to provide new and expanded data to continue the search.

The CALorimetric Electron Telescope (CALET) instrument is scheduled for launch to the International Space Station (ISS) aboard the HTV-5 vehicle on 19 August at about 8:50 pm JST (6:50 am CST) from the Tanegashima Space Center off the southern coast of Japan.  An H-IIB rocket will launch the H-II Transfer Vehicle, named Kounotori-5, which will dock with the ISS on 24 August. CALET will then be transferred to the Exposed Platform attached to the Japanese Experiment Module, Kibo.  There it will spend the next 2-5 years measuring very high energy cosmic ray electrons, nuclei and gamma rays. The launch and ISS rendezvous can be viewed on NASA TV, at the following website (  Prof. Cherry will represent LSU at the launch.


A Japanese led international mission, CALET involves nearly 50 researchers from Japan, Italy and the USA.  LSU leads the US Science Team consisting of LSU, Washington University in St. Louis, NASA Goddard Space Flight Center and The University of Denver and will host the US CALET Data Center. John P. Wefel, LSU Professor Emeritus of Physics and Astronomy and US Co-Principal Investigator for CALET said “This mission is a tribute to the importance of international scientific research.”  And added, “CALET is a great instrument and we expect to make new astrophysical discoveries with the rich dataset the mission will provide.  The new insights into the workings of powerful astrophysical particle accelerators can teach us how to develop better accelerating machines here on the ground.  In addition, CALET may observe a signature of the elusive dark matter.”


 CALET will measure the intensity of cosmic ray electrons, protons, and nuclei accelerated to near the speed of light, and also observe high energygamma rays. The main CALET telescope consists of an array of scintillation detectors to determine the electric charge of the incoming cosmic ray particles, an imaging calorimeter of scintillating fibers to determine the particle trajectory, and a deep lead tungstate calorimeter to measure particle and gamma ray energies up to 20 Tera-electron volts, a factor of more than three times higher than the particle beams at the largest manmade accelerator on Earth, the Large Hadron Collider in Switzerland. At such high energies, CALET may be the first experiment to observe a ‘near-by’ source of high energy radiation.


LSU scientists will operate the US CALET Data Center (USCDC) linking to Japan (and Italy), to obtain and process the flight data, distribute the results to the other US institutions, and serve as a central site for the data analysis.


Additional information on the CALET science can be found on the LSU web site at CALET is funded in the US by NASA, in Italy by the Italian Space Agency (ASI), and in Japan by the Japan Aerospace Exploration Agency (JAXA).

Mimi LaValle
LSU Physics & Astronomy
External Relations Manager

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