COMETS

Japan

International Sat. n°:

Japanese satellite n°: 87

COMmunications and Broadcasting Engineering Test Satellite, also called KAKEHASHI (means bridge)

Launch data:

Designation	25175 / 98011A
Launch date	21 Feb 1998 - 07:55 UT
Launch site	Tanegashima
Launch vehicle	H-2-5F (#6)
Mission	Communications
Earth orbit on:
Perigee / Apogee	247 / 1883 km
Inclination	30.05°
Period	min
Location	n/a (121°E initially planned)

Was to demonstrate inter-orbit links and Ka-band transmissions and mobile K-band transmissions (onboard relay).
Planned synchronous orbit. Early shutdown of the second stage left the satellite in low orbit (44 seconds out of the 192 seconds planned). The apogee motor should be used to higher the orbit and enable a few experiments on a 500/17700 km orbit)

In Jan 1999 communications and broadcasting experiments ended. The satellite was damaged by going through the Van Allen belt. It will now be used for signal attenuation measurements and radiation influence.

Specifications:

Prime contractor
Platform	derived from ETS 6
Mass at launch	3960 kg
Mass in orbit	2000 kg
Dimension	2 x 3 x 3 m
Solar array	15 m span
Stabilization	3-axis
DC power	EOL: 5300 W
Design lifetime	3 years

Is equipped with ETS 6's apogee motor. Has 4 Xenon thrusters

Suffered an electrical overcharge before launch.

Ka-band

Main transponders	5
Backup transponders	1
Power	200 W
Bandwidth
Coverage	Japan only
EIRP max
Polarization

+ S-band capacity

+ 1 transponder with uplink at 44 GHz, downlink at 476 GHz
Downlink: 22.696 GHz 20.165 GHz

Ref.: #15, #102 - update: 12.09.10

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