Japanese Experiment Module Exposed Facility Research Articles

The Calorimetric Electron Telescope (CALET) on the International Space Station: Results from the first eight years on orbit

The Calorimetric Electron Telescope, CALET, is an astroparticle physics mission installed on the International Space Station, ISS. The primary objective of the mission is studying the details of galactic cosmic-ray acceleration and propagation, and searching for the possible nearby sources of high-energy electrons and dark matter signatures. The CALET experiment measure the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma-rays to 10 TeV and nuclei to 1000 TeV. The detector is an all-calorimetric instrument with a total vertical thickness of 30 radiation lengths and fine imaging capability, optimized for the measurement of the electron and positron (all-electron) spectrum well into the TeV energy region. It consists of a charge detector (CHD) with two layers of segmented plastic scintillators for the identification of cosmic-rays via a measurement of their charge over the range Z=1∼40, a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). The instrument was launched on August 19, 2015 to the ISS and installed on the Japanese Experiment Module-Exposed Facility. Since the start of operation in October, 2015, CALET has been collecting scientific data without any major interruption for more than eight years. The number of triggered events over 10 GeV is nearly 1.97 billion events as of November 30, 2023. In this paper, we present the results of the CALET mission so far, including the all-electron energy spectrum, the spectra of protons and other nuclei, gamma-ray observations, as well as the characterization of on-orbit performance. Some results on the electromagnetic counterpart search for LIGO/Virgo gravitational wave events and the observations of solar modulation and gamma-ray bursts are also included.

Scientific Targets of Tanpopo: Astrobiology Exposure and Micrometeoroid Capture Experiments at the Japanese Experiment Module Exposed Facility of the International Space Station.

The Tanpopo experiment was the first Japanese astrobiology mission on board the Japanese Experiment Module Exposed Facility on the International Space Station (ISS). The experiments were designed to address two important astrobiological topics, panspermia and the chemical evolution process toward the generation of life. These experiments also tested low-density aerogel and monitored the microdebris environment around low Earth orbit. The following six subthemes were identified to address these goals: (1) Capture of microbes in space: Estimation of the upper limit of microbe density in low Earth orbit; (2) Exposure of microbes in space: Estimation of the survival time course of microbes in the space environment; (3) Capture of cosmic dust on the ISS and analysis of organics: Detection of the possible presence of organic compounds in cosmic dust; (4) Alteration of organic compounds in space environments: Evaluation of decomposition time courses of organic compounds in space; (5) Space verification of the Tanpopo hyper-low-density aerogel: Durability and particle-capturing capability of aerogel; (6) Monitoring of the number of space debris: Time-dependent change in space debris environment. Subthemes 1 and 2 address the panspermia hypothesis, whereas 3 and 4 address the chemical evolution. The last two subthemes contribute to space technology development. Some of the results have been published previously or are included in this issue. This article summarizes the current status of the Tanpopo experiments.

The CALorimetric Electron Telescope (CALET) on the International Space Station

The CALorimetric Electron Telescope (CALET) space experiment, developed by Japan in collaboration with Italy and the United States, is a high-energy astroparticle physics mission installed on the International Space Station (ISS). The primary goals of the CALET mission include investigating on the possible presence of nearby sources of high-energy electrons, studying the details of galactic particle propagation and searching for dark matter signatures. During a two-year mission, extendable to five years, CALET can measure the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma-rays to 10 TeV and nuclei with Z = 1 to 40 up to 1,000 TeV. The instrument consists of two layers of segmented plastic scintillators for cosmic-ray charge identification (CHD), a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). CALET has sufficient depth, imaging capabilities and excellent energy resolution to allow for a clear separation between hadrons and electrons and between charged particles and gamma rays. The instrument was launched on August 19, 2015 to the ISS with the H-II Transfer Vehicle 5 (HTV-5) and installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) on August 25. Since the start of operations in mid-October, 2015, a continuous observation has been going on mainly by triggering high energy (>10 GeV) showers without any major interruption. The number of triggered events above 10 GeV is nearly 20 million per month. By using the data obtained during the first two years, we give a summary of CALET observations: (1) Electron + Positron energy spectrum, (2) Proton and Nuclei spectrum, (3) Gamma-ray observation, with results of the performance study on orbit. We also present the results of observations of the electromagnetic counterparts to LIGO-VIRGO gravitational wave events and high-energy counterparts to GRB events measured with the CALET Gamma-ray Burst Monitor (CGBM).

The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

Status and performance of the CALorimetric Electron Telescope (CALET) on the International Space Station

The CALorimetric Electron Telescope (CALET) space experiment, currently under development by Japan in collaboration with Italy and the United States, will measure the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma rays to 10 TeV and nuclei with Z=1 to 40 up to 1,000 TeV during a two-year mission on the International Space Station (ISS), extendable to five years. These measurements are essential to search for dark matter signatures, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy and discover possible astrophysical sources of high-energy electrons nearby the Earth. The instrument consists of two layers of segmented plastic scintillators for the cosmic-ray charge identification (CHD), a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). CALET has sufficient depth, imaging capabilities and excellent energy resolution to allow for a clear separation between hadrons and electrons and between charged particles and gamma rays. The instrument will be launched to the ISS within 2014 Japanese Fiscal Year (by the end of March 2015) and installed on the Japanese Experiment Module-Exposed Facility (JEM-EF). In this paper, we will review the status and main science goals of the mission and describe the instrument configuration and performance.

Highlights of the NASA Particle Astrophysics Program

The NASA Particle Astrophysics Program covers Origin of the Elements, Nearest Sources of Cosmic Rays, How Cosmic Particle Accelerators Work, The Nature of Dark Matter, and Neutrino Astrophysics. Progress in each of these topics has come from sophisticated instrumentation flown on long duration balloon (LDB) flights around Antarctica over the past two decades. New opportunities including Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging for the next major step. Stable altitudes and long durations enabled by SPB flights ensure ultra-long duration balloon (ULDB) missions that can open doors to new science opportunities. The Alpha Magnetic Spectrometer (AMS) has been operating on the ISS since May 2011. The CALorimetric Electron Telescope (CALET) and Cosmic Ray Energetics And Mass (CREAM) experiments are being developed for launch to the Japanese Experiment Module Exposed Facility (JEM-EF) in 2014. And, the Extreme Universe Space Observatory (EUSO) is planned for launch to the ISS JEM-EF after 2017. Collectively, these four complementary ISS missions covering a large portion of the cosmic ray energy spectrum serve as a cosmic ray observatory.

Atmospheric Remote Sensing on the International Space Station

The Remote Atmospheric and Ionospheric Detection System (RAIDS) is a new NASA experiment studying the Earth's thermosphere and ionosphere from a vantage point on the International Space Station (ISS). The RAIDS mission focuses on the coupling and transition from the coldest part of the atmosphere, the mesopause near 85 kilometers, up to the hottest regions of the thermosphere, above 300 kilometers in altitude. Built jointly by the Naval Research Laboratory (NRL) and The Aerospace Corporation, RAIDS also is serving as a pathfinder experiment for atmospheric remote sensing aboard the ISS. RAIDS and a companion experiment, NRL's Hyperspectral Imager for the Coastal Ocean (HICO), make up the HICO‐RAIDS Experiment Payload (HREP), the first U.S. payload on the Japanese Experiment Module—Exposed Facility (JEM‐EF). The experience developing and operating RAIDS for this mission provides useful insights for utilizing the ISS as a platform for atmospheric science.

Calorimetric electron telescope mission: Search for dark matter and nearby sources

We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module—Exposed Facility, JEM-EF, of the International Space Station, ISS. Major scientific objective is a search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in 1 GeV–20 TeV and the gamma-rays in 20 MeV-several TeV. CALET has, moreover, a capability to measure cosmic ray H, He and heavy ions up to 1000 TeV. It will also have a function to monitor the solar activity and the gamma-ray bursts. The phase A study has started on a schedule of the launch in early 2014 by the H-II Transfer Vehicle, HTV, for a 5-year observation.

Calorimetric Electron Telescope (CALET) to observe cosmic-ray electrons and gamma-rays on the International Space Station

We have proposed to make observations of high energy cosmic rays with CALET (CALorimetric Electron Telescope) on the International Space Station. Our main objective is to observe electrons up to 20TeV to investigate origin and propagation of electrons in the Galaxy. Acceleration in nearby supernovae can lead to contributions to the electron spectrum in energies up to tens of TeV. Balloon experiments have observed an excess at sub TeV energies, which could, according to some models, be associated with dark matter particles. CALET will be able to confirm the anomaly with high energy resolution and high statistics. Gamma-rays from 20MeV to 10TeV and nuclei up to 1000TeV can be also observed by CALET. We have finished the conceptual design for CALET. The selection process for the next phase is scheduled for mid-2009. If approved, CALET will be launched in 2013 and will be placed at the Japanese Experiment Module-Exposed Facility (JEM-EF) at the International Space Station (ISS).

Overview of the Natural Space Environment and ESA, JAXA, and NASA Materials Flight Experiments

AbstractSpace environmental effects on materials are very severe and complex because of the synergistic interaction of orbital environments such as high-energy radiation particles, atomic oxygen, micrometeoroids, orbital debris, and ultraviolet irradiation interacting synergistically, along with thermal exposure. In addition, surface degradation associated with contamination can negatively impact optics performance. Materials flight experiments are critical to understanding the engineering performance of materials exposed to specific space environments. Likewise, the spacecraft designer must have an understanding of the specific environment in which a spacecraft will operate, enabling appropriate selection of materials to maximize engineering performance, increase mission lifetimes, and reduce risk. This article will present a methodology for assessing the engineering performance of materials baselined for a specific spacecraft or mission. In addition, an overview of the space environment, from low Earth orbit to interplanetary space, will be provided along with an overview on the effects of the space environment on materials performance. The majority of this article is devoted to materials flight experiments from the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and from the National Aeronautics and Space Administration (NASA). Some of the experiments reviewed include ESA's Materials Exposure and Degradation Experiment on the International Space Station (ISS), JAXA's Micro-Particles Capturer and Space Environment Exposure Device experiments on the ISS Service Module and on the ISS Japanese Experiment Module Exposed Facility, and NASA's Long Duration Exposure Facility satellite and the Materials International Space Station Experiment series flown on the exterior of ISS.

Simulated performance of the calorimetric electron telescope (CALET) experiment

CALET is a detector planned to be on-board the Japanese Experiment Module Exposed Facility (JEM-EF) of the International Space Station. The CALET mission aims at revealing unsolved problems in high energy phenomena of the Universe by carrying out a precise measurement of the high energy electrons in 1 GeV–20 TeV, the gamma-rays in 20 MeV to a few TeV and the nuclei in a few 10 GeV–1000 TeV. The main detector is composed of imaging calorimeter (IMC), total absorption calorimeter (TASC), silicon pixel array (SIA) and anti-coincidence detector (ACD) to detect various kinds of particles in very wide energy range. The total absorber thickness is 31 radiation lengths for electromagnetic particles and 1.4 interaction mean free paths for protons. Monte Carlo simulation study has been carried out for optimization of the detector performance in observing each kind of particles. We obtained following performance about the observation of very high energy (>100 GeV) electrons, which is a main target of the CALET experiment: (1) Effective geometrical factor is about 7000 cm 2 sr. (2) Energy resolution is better than a few %. (3) Angular resolution is better than 0.1°. (4) Proton rejection power is ∼10 5 with the electron detection efficiency better than 95%. We also present the simulated performance of the CALET experiment in observing other particles.

The JEM-EUSO mission

JEM-EUSO is a space science mission to explore the extreme energies and physics of the Universe. Its instrument will watch the darkside of the earth and will detect UV photons emitted from the extensive air shower caused by an ultra-high energy cosmic ray (UHECR above 1018 eV), or an extremely high energy cosmic ray (EHECR) particle (e.g. above about 1020 eV). Such a high-rigidity particle as the latter arrives almost in a straight line from its origin through the magnetic fields of our Milky Way Galaxy and is expected to allow us to trace the source location by its arrival direction. This can open the door to new astronomy with charged particles. In its 5 years of operation including the tilted mode, Extreme Universe Space Observatory an Japanese Experiment Module (JEM-EUSO) will detect at least 1000 events with E>7×1019 eV with the Greisen–Zatsepin–Ku'zmin (GZK) suppression spectrum. It can determine the energy spectrum and source locations of GZK to super-GZK regions with a statistical accuracy of several percent. JEM-EUSO is planned to be deployed by H2 transfer vehicle (HTV) and will be attached to the Japanese Experiment Module/ Exposure Facility (JEM/EF) of International Space Station. JAXA has selected JEM-EUSO as one of the mission candidates of the second phase utilization of JEM/EF for launch in the early-to-mid 2010s.

The JEM-EUSO Mission

The Extreme Universe Space Observatory (EUSO) on Japanese Experiment Module (JEM) is a science mission on the International Space Station (ISS) led by the Japan Aerospace eXploration Agency (JAXA) to investigate the nature and origin of Extreme Energy Cosmic Rays (EECR) beyond energy E 0 > 7 × 10 19 eV . The main objective of the mission is to perform charged-particle astronomy in this energy region by collecting a large sample of events (∼1000 events above E 0 ) in 3-5 years of operation, measure their energy, arrival direction and composition with sufficient accuracy ( Δ E 30 % , Δ ang 2 ° , hadron/photon/neutrino separation Δ X max 120 g / cm 2 ). With the above statistics, dozen of events per source are expected, which are enough to infer their energy spectrum. JEM-EUSO is a wide-angle telescope (field of view ±30°, integrated aperture > 4 × 10 5 km 2 ⋅ sr ⋅ yr ) and consists of high-transmittance Fresnel lenses with a 2.5 m diameter, an advanced photo-sensitive detector at the focal surface and a suitable electronics. An infrared camera and a LIDAR system will be also used to monitor the earth's atmosphere. JEM-EUSO has been selected by JAXA as one of the mission candidates of the second phase utilization of JEM / Exposed Facility (JEM/EF) with launch expected in early 2010s and it is right now undertaking the Phase-A (concept study and technical feasibility). The scientific motivations of the mission, its objectives and expected performance are here summarized together with its links with other space-based projects such as Super-EUSO.

The CALET mission for detection of cosmic ray sources and dark matter

We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. Major scientific objectives are to search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in 1 GeV - 10 TeV and the γ rays in 20 MeV - several TeV. CALET has a unique capability to observe electrons and γ rays over 1 TeV since the hadron rejection power is more than 105 and the energy resolution better than a few % over 100 GeV. The detector consists of an imaging calorimeter by SciFi and W, and a total absorption calorimeter by BGO. CALET has also a capability to measure protons and nuclei up to 1000 TeV, and will have a function to monitor solar activity and γ ray bursts with additional instruments. The phase A study has started on a schedule of launch in 2013 by H-II Transfer Vehicle (HTV) for 5 years observation.

JEM EUSO mission on the International Space Station

The Extreme-Universe Space Observatory (EUSO) on Japanese Experiment Module (JEM) is a mission on ISS [1], led by Japan Aerospace Exploration Agency (JAXA) to investigate the nature and origin of extremely-high-energy cosmic rays (EHECRs). This is the sole window on the extreme-energy universe. JAXA has selected JEM-EUSO for study as one of two international mission candidates for installation on the JEM Exposure Facility by 2013. JEM-EUSO (hereafter, EUSO) is designated to pioneer measurements of EHECR-induced extensive air showers (EAS) from space. As the detector, it uses the whole earth, observing from the International Space Station (ISS) where a remote sensor is located. The signal is fluorescent and Cherenkov light from the Extensive Air Showers (EAS).

The CALET experiment on ISS

We are preparing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. The scientific objective is to reveal unresolved problems in high-energy phenomena of the Universe by carrying out a precise measurement of the electrons in 1 GeV ∼ 10 TeV and the γ − rays in 20 MeV ∼ several TeV. The CALET has a unique capability to measure the electrons and γ -rays over 1 TeV since the hadron rejection power might be as much as ∼ 10 6 and the energy resolution of electromagnetic particles better than a few % over 100 GeV. Therefore, it is promising to detect the change of energy spectra related to the acceleration, source and propagation of cosmic-rays and the γ -ray line signature expected from dark matter annihilation. We will discuss not only the science but the techniques, the observation and the current status of project. The CALET is expected to be launched around 2012 by the Japanese H-II Transfer Vehicle, HTV, and to be on orbit for three years.

CALET for High Energy Electron and Gamma-Ray Measurements on ISS

The CALorimetric Electron Telescope, CALET, mission is proposed for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. The mission goal is to reveal the high-energy phenomena in the universe by carrying out a precise mesurement of the electrons in the range 1 GeV-10 TeV and the gamma-rays in the range 20 MeVto several TeV. The detector will be composed of an imaging calorimeter of scintillating fibers (IMC) and a total absorption calorimeter of BGO (TASC). The total absorber thickness is 36 r.l for electromagnetic particles and 1.8 m.f.p for protons. The total pay-load weight is nearly 2.5 t and the effective geometrical factor for the electrons ∼1.0 m 2 sr. The CALET has a unique capability to measure the electrons and gamma-rays above 1 TeV since the hadron rejection power can be 10 6 and the energy resolution for electromagnetic particles is better than a few % above 100 GeV. Therefore, it is promising to detect any change of the energy spectra and a line signature in the energy distribution, as expected from the dark matter.

The CALET, CALorimetric Electron Telescope, on ISS/JEM

The CALorimetric Electron Telescope, CALET, mission is proposed for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. The mission goal is to reveal the high-energy phenomena in the universe by carrying out a precise mesurement of the electrons in 1 GeV – 10 TeV and the gamma-rays in 20 MeV – several TeV. The instrument will be composed of an imaging calorimeter of scintillating fibers and a total absorption calorimeter of BGO. The total thickness of absorber is 36 r.l for electro-magnetic particles and 1.8 m.f.p for protons. Total weight of the payload is nearly 2,500 kg, and the effective geometrical factor for the electrons might be ∼ 1.0 m2sr. The CALET has a unique capability to measure the electrons and gamma-rays over 1 TeV since the hadron rejection power can be 106 and the energy resolution of electro-magnetic particles is better than a few % over 100 GeV. Therefore, it is promissing to detect the change of energy spectra and the line feature of energy distribution expected from the dark matter. We are expecting to launch the CALET around 2010 by the Japanese H-II Transfer Vehicle, HTV, and to carry out the observation more than three years.

Thermodynamic performance predictions for the low temperature micro-gravity physics facility

The Low Temperature Micro-gravity Physics Facility (LTMPF) designed by Ball Aerospace & Technologies Corp. contains a 180-l superfluid helium dewar for conducting fundamental physics experiments. The dewar and ancillary experiment electronics will be located on the Japanese experiment module-exposed facility (JEM-EF), a module of the International Space Station. The helium is expected to deplete over approximately 5 months, after which the facility will be returned for new experiments, refurbished, refilled and relaunched on a projected 22-month cycle time. Because of the JEM-EF envelope constraints, the dewar has a unique ob-round cross section. The strut-mounted helium tank has provisions to accommodate two separate experiments, one at each end of the tank. Until the cryostat is constructed and tested, assessments of cryostat performance must be accomplished with analytic models. This paper documents the predicted thermal/thermodynamic performance of the cryostat from final launch top-off operations, through post-launch transients, to steady-state on-orbit performance.