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Arase is scientific satellite objected on research on ionosphere of Earth. It was built on SPRINT satellite bus; it weighs 350 kg and is powered by four deployable solar arrays. It will operate on 300 km x 30000 km orbit with inclination of 31°. Its mission is mainly devoted measuring charge of electrons remaining inside Van Allen belt and how space storms affect on them. It will use number of devices: extremely high-energy electron experiments (XEP-e), high-energy electron experiments (HEP-e), medium-energy particle experiments - electron analyzer (MEP-e), low-energy particle experiments - electron analyzer (LEP-e), medium-energy particle experiments - ion mass analyzer (MEP-i), low-energy particle experiments - ion mass analyzer (LEP-i), magnetic field experiment (MGF), plasma Wave Experiment (PWE) and software-type wave particle interaction analyzer (S-WPIA)

Arase will repeatedly fly through the Van Allen belts high above Earth, helping scientists sort out how chaotic geomagnetic storms form and evolve and potentially endanger astronauts, spacecraft and infrastructure vital to life on the ground.

Key questions scientists hope the Arase mission will answer include how the particles in the radiation belts are accelerated to such extreme velocities, and what are the fundamental drivers that determine the intensity of geomagnetic storms. Answers to those questions could help forecasters predict the likelihood, danger and locations of geomagnetic storms ahead of time.

Alternate Names

  • 41896
  • ERG
  • Exploration of Energization and Radiation in Geospace
  • Sprint-B

Facts in Brief

Launch Date: 2016-12-20
Launch Vehicle: Epsilon
Launch Site: Uchinoura Space Center, Japan

Funding Agency

  • Japan Aerospace Exploration Agency (Japan)


  • Space Physics

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office

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