Jikiken

Launch data: Designation 11027 / 78087A Launch date 16 Sep 1978 - 14:00 JST Launch site Kagoshima Space Center Launch vehicle Mu-3H (#3) Mission Scientific: Earth′s magnetophere study Highly elliptical Earth orbit on: Perigee / Apogee  220 x 30100 km Eccentricity   Inclination  31 deg Period  524 min

Spacecraft data: Prime contractor   Platform   Operator   Mass at launch  92 kg Dry Mass   kg Basic shape   Dimension (m)  dia= 0.75m height= 0.6m Equipment  4 booms Solar array   Stabilization   Propulsion   DC power

Credit: JAXA

Scientific Instruments:

• Particle energy monitor
• Electron beam radiation experiment instrument
• Data processing unit (DPU)

Decay:

Mission details:

• Objectives: 1. Research on the region from the plasmasphere to the deep magnetosphere (region from 60,000 to 70,000 km from the earth)
  2. Participation in the International Magnetospheric Study (IMS) conducted from 1976 to 1979.
• Operation: From September 23, the antennas started to extend but full extension was prevented by problems such as the rise in temperature of the control circuit. Antenna deployment was stopped when the two pairs of antennas reached the same length.
• Results: One month after launch, all the instruments became operable and full scientific observations started. The satellite retrieved data on the mechanism of auroral kilometer radio wave and the formation of plasma pose. JIKIKEN was used to develop a picture of wave-particle interaction in the magnetosphere. Communications and data exchange were also carried out with foreign scientific satellites such as GEOS. In addition, the satellite succeeded in receiving low-frequency signals transmitted from the Antarctic, thus contributing to research on the interaction between plasma and wave in the magnetosphere.
• Japan′s Jikiken (EXOS-B) magnetospheric research satellite, which operated in elliptical orbit from 1978 to 1985, reentered on Apr 22, 2018. The small satellite, with a mass of 92 kg, deployed long wire antennae to measure the electric field in the magnetosphere. The antennae were designed to span 206 metres, although in the end they were only deployed to 103m span.