|Mission type||Earth observation|
|Operator||ISAS · University of Tokyo|
|Mission duration||Final: 26 years, 2 months, 1 day|
|Launch mass||294 kg (648 lb)|
|Start of mission|
|Launch date||21 February 1989, 23:30UTC|
|Rocket||M-3SII, mission M-3SII-1|
|Launch site||Uchinoura Space Center, Japan|
|End of mission|
|Deactivated||23 April 2015|
|Perigee altitude||300 km (190 mi)|
|Apogee altitude||8,000 km (5,000 mi)|
|Epoch||20 February 1989, 19:00 UTC|
Akebono (known as EXOS-D before launch) is a satellite to study aurora and Earth's magnetosphere environment. It was developed by Institute of Space and Astronautical Science and launched by M-3SII rocket on February 22, 1989.
After 26 years of successful observation, operation was terminated on April 23, 2015, due to the degradation of solar cells and the decay of orbit.