JCSAT-1

JCSAT-1

Mission type	Communications
Operator	JSAT Corporation
COSPAR ID	1989-020A [1]
SATCAT no.	19874
Mission duration	8 years (planned)
Spacecraft properties
Spacecraft	JCSAT-1
Spacecraft type	JCSAT
Bus	HS-393
Manufacturer	Hughes
Launch mass	2,280 kg (5,030 lb)
BOL mass	1,364 kg (3,007 lb)
Dimensions	3.7 m × 10 m × 2.3 m (12.1 ft × 32.8 ft × 7.5 ft) with solar panels and antennas deployed.
Power	2.350 kW
Start of mission
Launch date	6 March 1989, 23:29:00 UTC [2]
Rocket	Ariane 44LP
Launch site	Centre Spatial Guyanais, ELA-2
Contractor	Arianespace
End of mission
Disposal	Graveyard orbit
Deactivated	1998 [3]
Orbital parameters
Reference system	Geocentric orbit [4]
Regime	Geostationary orbit
Longitude	150° East
Transponders
Band	32 Ku-band × 27 MHz [5]
Bandwidth	864 MHz
Coverage area	Japan
TWTA power	20 watts
JSAT constellation JCSAT-2  →

JCSAT-1 was a geostationary communications satellite designed and manufactured by Hughes (now Boeing) on the HS-393 satellite bus. It was originally ordered by Japan Communications Satellite Company (JCSAT), which later merged into the JSAT Corporation. It had a Ku-band payload and operated on the 150° East longitude until it was replaced by JCSAT-1B. ^[5]

Satellite description

The spacecraft was designed and manufactured by Hughes on the HS-393 satellite bus. It had a launch mass of 2,280 kg (5,030 lb), a mass of 1,364 kg (3,007 lb) after reaching geostationary orbit and an 8-year design life. When stowed for launch, its dimensions were 3.4 m (11 ft) long and 3.7 m (12 ft) in diameter. ^[6] With its solar panels fully extended it spanned 10 m (33 ft). ^[5] Its power system generated approximately 2350 watts of power thanks to two cylindrical solar panels. ^[5] It also had a two 38 Ah NiH₂ batteries. ^[5] It would serve as the main satellite on the 150° East longitude position of the JSAT fleet. ^[5]

Its propulsion system was composed of two R-4D-12 liquid apogee engine (LAE) with a thrust of 490 N (110 lb_f). It also used two axial and four radial 22 N (4.9 lb_f) bipropellant thrusters for station keeping and attitude control. ^[6] It included enough propellant for orbit circularization and 8 years of operation. ^[5] Its payload is composed of a 2.4 m (7 ft 10 in) antenna fed by thirty-two 27 MHz Ku-band transponders for a total bandwidth of 864 MHz. ^[5] The Ku-band transponders had a Traveling-wave tube#Traveling-wave-tube amplifier (TWTA) output power of 20 watts. ^[5]

History

With the opening of the Japanese satellite communications market to private investment, Japan Communications Satellite Company (JCSAT) was founded in 1985. ^{[7] [8]} In June of the same year, JCSAT awarded an order to Hughes Space and Communications for two identical satellites, JCSAT-1 and JCSAT-2, based on the spin-stabilized HS-393 satellite bus. ^[5] JCSAT-1 would become the first commercial Japanese communications satellite. It was successfully launched aboard an Ariane-44LP on 6 March 1989 at 23:29:00 UTC. ^[5] Originally expected to be retired in 1997, it was finally sent to a graveyard orbit on 1998. ^[3]

References

1. "Display: JCSAT 1 1989-020A". NASA. 10 February 2021. Retrieved 20 March 2021. This article incorporates text from this source, which is in the public domain.
2. "Trajectory: JCSAT 1 1989-020A". NASA. 10 February 2021. Retrieved 20 March 2021. This article incorporates text from this source, which is in the public domain.
3. Yanagisawa, Toshifumi (9 March 2016). "Lightcurve observations of LEO objects in JAXA" (PDF). JAXA. Archived from the original (PDF) on 26 August 2016. Retrieved 16 August 2016.
4. "JCSAT 1". N2YO.com. Retrieved 16 August 2016.
5. Krebs, Gunter (21 April 2016). "JCSat 1, 2". Gunter's Space Page. Retrieved 20 July 2016.
6. "JCSAT 1, 2". Boeing. Archived from the original on 7 February 2010. Retrieved 16 August 2016.
7. "History". SKY Perfect JSAT. Archived from the original on 13 November 2018. Retrieved 28 July 2016.
8. "JCSAT". Global Security. Retrieved 4 August 2016.

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