Arase, formerly known as Exploration of energization and Radiation in Geospace (ERG), is a scientific satellite to study the Van Allen belts. It was developed by the Institute of Space and Astronautical Science of JAXA. While there was a scientist working on a similar project with the surname Arase, the satellite's name has nothing to do with him but instead named after a river beside the launch point.

It was launched aboard Epsilon launch vehicle at 11:00:00, 20 December 2016 UTC into apogee height 32250 km, perigee 214 km orbit. Subsequent perigee-up operation moved its orbit to apogee 32110 km, perigee 460 km of 565 minutes period.[2]

Spacecraft

The Arase spacecraft is the second satellite based on SPRINT bus, after Hisaki (SPRINT-A). Arase weighs about 350 kg, measures about 1.5 m × 1.5 m × 2.7 m at launch.[3] Once in orbit, it will extend four solar panels, two 5 m masts, and four 15 m wire antennas.[3] The spacecraft is spin-stabilized at 7.5 rpm (8 seconds).[3]

Planned mission duration was for one year of scientific observation, [3] but the mission remains active over 5 years later.

Launch

Arase's launch on the enhanced Epsilon's maiden flight was originally scheduled for 2015, but was postponed to the 2016 financial year due to satellite development delays.[4]

Instruments

Arase carries following instruments:[3]

  • XEP-e (Extremely high-energy electron sensor)[5]
  • HEP-e (High-energy particle sensor – electron)
  • MEP-e (Medium-energy particle sensor – electron)
  • LEP-e (Low-energy particle sensor – electron)
  • MEP-i (Medium-energy particle – ion)
  • LEP-i (Low-energy particle – ion)
  • MGF (Magnetic Field Experiment)
  • PWE (Plasma Wave Experiment)
  • S-WPIA (Software Wave-Particle Interaction Analyzer)

MGF is located at the end of 5 m extended mast.[3]

PWE consists of a search coil (PWE-MSC) located at the end of another 5 m extended mast, four 15 m wire antennae (PWE-WPT), and associated electronics unit (PWE-E).[3]

S-WPIA will analyse the data obtained by other instruments.[3]

See also

References

  1. ^ "Arase (ERG) Geospace Probe - JAXA". JAXA. Retrieved 2018-03-14.
  2. ^ ジオスペース探査衛星「あらせ」（ERG）の軌道変更運用（近地点高度上昇）の完了について (in Japanese). JAXA. 13 January 2017. Retrieved 18 January 2017.
  3. ^ a b c d e f g h プレスキット/2016年11月18日（木） (PDF) (in Japanese). November 18, 2016. Archived from the original (PDF) on December 26, 2016. Retrieved November 27, 2016.
  4. ^ Shogo Matsuda (16 January 2015). "Japan's Epsilon rocket shoved aside?". Nikkei Asian Review. Retrieved 6 February 2015.
  5. ^ "Exploration of energization and Radiation in Geospace (ERG)". JAXA. 2012. Archived from the original on 2013-10-30. Retrieved 2013-09-08.

External links