Optical investigations of ionosphere. EXOS-C (OHZORA). Optical study of the stratosphere and middle atmosphere. Study of the specific phenomena of the ionospheric plasma over the southern Atlantic geomagnetic anomaly zone which was discovered by the third scientific satellite "TAIYO". Launch vehicle Mu-3S-4, launching organization ISAS (Institute of Space and Astronautical Science).

Typical orbit: 352 x 8507 km, 61.5 deg inclinaton.

• 1978 February 4 - SS-05 Kyokko - Launch Site: Kagoshima. Launch Complex: M. Launch Vehicle: Mu. Mass: 103 kg (227 lb). Perigee: 639 km (397 mi). Apogee: 3,952 km (2,455 mi). Inclination: 65.40 deg. Period: 134.00 min.
  Auroral studies. Active life - two years. Function: 1) Observation of wide angle global auroral pictures using UV television camera. 2) Spectrophotometry of ultraviolet air glow. 3) Observation of the energy spectrum of photoelectrons and auroral electrons. 4) Mass spect rometry of the ionized atmospheric species in the thermosphere. 5) Measurements of density and temperature of ambient electrons in the thermosphere. 6) Observation of electromagnetic and plasma waves and the emission associated with auroral phenomena.

• 1978 September 16 - SS-06 Jikiken - Launch Site: Kagoshima. Launch Complex: M. Launch Vehicle: Mu. Mass: 100 kg (220 lb). Perigee: 251 km (155 mi). Apogee: 21,192 km (13,168 mi). Inclination: 31.30 deg. Period: 370.90 min.
  Launching organization: Institute of Space and Aeronautical Science, University of Tokyo. Stimulated plasma wave experiment, natural plasma wave measurement, plasma parameter measurement by VLF Doppler technique, electric field probe and plasma density me asurement, energetic particle analysis, and controlled electron beam emission experiment. Characteristics: weight 90.5 kg, configuration - polyhedron with 38 faces, height 0.6m , diameter 0.75m, attitude control spin stabilization, life two years.

• 1984 February 14 - SS-09 Onzora - Launch Site: Kagoshima. Launch Complex: M. Launch Vehicle: Mu. Mass: 180 kg (390 lb). Perigee: 247 km (153 mi). Apogee: 331 km (205 mi). Inclination: 74.60 deg. Period: 90.30 min.
  Optical investigations of ionosphere. EXOS-C (OHZORA). Optical study of the stratosphere and middle atmosphere. Study of the specific phenomena of the ionospheric plasma over the southern Atlantic geomagnetic anomaly zone which was discovered by the third scientific satellite 'TAIYO'. Launch vehicle Mu-3S-4, launching organization ISAS (Institute of Space and Astronautical Science). Launch time 0800 GMT.

• 1989 February 21 - Akebono - Launch Site: Kagoshima. Launch Complex: M. Launch Vehicle: Mu. Mass: 295 kg (650 lb). Perigee: 272 km (169 mi). Apogee: 8,554 km (5,315 mi). Inclination: 75.10 deg. Period: 185.90 min.
  Studied aurora borealis, auroral australis. EXOS-D (Akebono). Observation in high precision of behaviour and acceleration mechanism of aurora particles in Earth magnetosphere. Launching organization ISAS. Launch time 2330 GMT.