KODAMA (DRTS), a data relay test satellite launched by the H-II A launch vehicle from the Tanegashima Space Center (TNSC), serves as a data relay station.
A data relay test satellite is a kind of communications satellite in a geostationary orbit that relays data among Low Earth Orbit (300-1,000 km altitude) spacecraft (such as satellites) and ground stations. This relay can dramatically extend the area where real-time communication between Low Earth Orbit spacecraft and ground stations are possible.
When a direct communication link is used, contact time between a Low Earth Orbit spacecraft and a ground station is limited to approximately 10 minutes per visible pass. When KODAMA relays data between an LEO spacecraft and a ground station, real-time communications are possible in 60% of the flight path of the spacecraft. This enables Japan, a relatively small country, to greatly extend contact time between its spacecraft and a small number of ground stations.
Furthermore, transmission from KODAMA has reached a data rate exceeding 240 Mbps - a communications speed that would enable the simultaneous transmission of data contained in 11 BS Digital High Vision channels. KODAMA is scheduled to relay data to and from the Advance Land Observing Satellite "Daichi" and the Japanese Experiment Module "KIBO" on the International Space Station (ISS), and will be used to broadcast the activities of astronauts.
|International Designation Code||2002-042B|
|Launch Date||17:20, September 10, 2002 (JST)|
|Launch Vehicle||H-IIA Launch Vehicle No.3|
|Location||Tanegashima Space Center|
|Shape||structure : 2.2 m x 2.4 m x 2.2 m
|Weight||Approx. 1500kg (at the beginning of mission life)|
|Orbiter||Geostationary orbit(GEO) (Longitude 90 degree East)|
|Period||Approx. 24 hours|
|Attitude Control||Three-axis stabilization (Controlled bias momentum)|