Summary
BSAT-1b was a geostationary communications satellite designed and manufactured by Hughes (now Boeing) on the HS-376 platform. It was originally ordered and operated by the Broadcasting Satellite System Corporation (B-SAT). It was used as backup of BSAT-1a to broadcast television channels for NHK and WOWOW over Japan. It had a pure Ku band payload and operated on the 110°E longitude until it was replaced, along its twin BSAT-1a, by BSAT-3a.[2][4][6][7]
| Mission type | Communication |
|---|---|
| Operator | JSAT Corporation |
| COSPAR ID | 1998-024B[1] |
| SATCAT no. | 25312 |
| Mission duration | 13 years |
| Spacecraft properties | |
| Spacecraft | BSAT-1b |
| Bus | HS-376 |
| Manufacturer | Hughes |
| Launch mass | 1,236 kg (2,725 lb) |
| BOL mass | 723 kg (1,594 lb) |
| Dimensions | 3.15 m × 2.17 m (10.3 ft × 7.1 ft) (stowed for launch)[2] |
| Power | 1.2 kW |
| Start of mission | |
| Launch date | 22:53, April 28, 1998 (UTC)[3] |
| Rocket | Ariane 44P V-108 |
| Launch site | Kourou ELA-2 |
| Contractor | Arianespace |
| Entered service | August 1, 1998 |
| End of mission | |
| Disposal | placed in a graveyard orbit |
| Deactivated | August 2011[4] |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Graveyard orbit |
| Semi-major axis | 42,373 km |
| Perigee altitude | 35,987.0 km |
| Apogee altitude | 36,018.1 km |
| Inclination | 14.5° |
| Period | 1,446.8 minutes |
| Epoch | 00:00:00 2016-09-08[5] |
| Transponders | |
| Band | Ku band: 4 (plus 4 spares)[2] |
| Coverage area | Japan |
| TWTA power | 106 Watts |
Satellite description edit
The spacecraft was designed and manufactured by Hughes on the HS-376 satellite bus. This spin-stabilized platform had two main sections. One, the spinning section, was kept rotating at 50 rpm to maintain attitude, and a despun section that was used by the payload to maintain radio coverage. The spinning section included the Star-30BP Apogee kick motor, most of the attitude control, the power subsystem and the command and telemetry subsystems. The despun section contained the communications payload, including the antennas and transponders.[2][8]
It had a launch mass of 1,236 kg (2,725 lb), a mass of 723 kg (1,594 lb) after reaching geostationary orbit and a 10-year design life. When stowed for launch, its dimensions were 3.15 m (10.3 ft) long and 2.17 m (7 ft 1 in) in diameter. With its solar panels fully extended it spanned 7.97 m (26.1 ft).[2] Its power system generated approximately 1,200 Watts of power thanks to two cylindrical solar panels.[8] It also had a NiH2 batteries for surviving solar eclipses.[2] It would serve along BSAT-1a on the 110°E longitude position for the B-SAT.[8]
Its payload was composed of a four active plus four spares Ku band transponders fed by a TWTA with an output power of 106 Watts. Its footprint covered Japan and its surrounding island.[2]
History edit
Broadcasting Satellite System Corporation (B-SAT) was founded in 1993 to broadcast by satellite the analog signals of NHK and WOWOW, including analog high definition Hi-Vision channels.[6] In June 1994, it orders two HS-376 satellite from Hughes (now Boeing), BSAT-1a and BSAT-1b.[2]
During 1997 B-SAT completed its Kawaguchi and Kimitsu satellite control centers, launched and commissioned BSAT-1a.[4] At 22:53 UTC, April 28, 1998, the Ariane-44P flight V-108 successfully launched BSAT-1b, along Nilesat 101, from Kourou ELA-2 launch pad.[3][8]
On August 1, 1998, BSAT-1b entered into commercial service. In December 2000, due to launch delays of BSAT-2a, BSAT-1b started digital broadcasting services for B-SAT.[4]
During May 2005, B-SAT ordered BSAT-3a, the replacement satellite for BSAT-1a and BSAT-1b. It was successfully launched in August 2007, and accepted into the fleet the next month. During November, 2007 BSAT-3a took over the broadcasting of analog and digital signals from BSAT-1a and BSAT-1b. In August 2011, BSAT-1b was placed in a graveyard orbit and decommissioned.[4][9]
References edit
- ^ "BSAT 1B". NASA Space Science Data Coordinated Archive. 27 April 2016. Retrieved 2016-08-04.
- ^ a b c d e f g h "BSAT-1". Boeing Satellite Development Center. Archived from the original on 2010-02-07. Retrieved 2016-09-08.
- ^ a b "BSAT 1B". NASA Space Science Data Coordinated Archive. 27 April 2016. Retrieved 2016-08-04.
- ^ a b c d e "Milestones". Broadcasting Satellite System Corporation. Archived from the original on 2016-09-08. Retrieved 2016-09-09.
- ^ "BSAT 1B". n2yo.com. Retrieved 2016-09-08.
- ^ a b "Broadcasting Satellite System Corporation (B-SAT)". Global Security. Retrieved 2016-09-08.
- ^ "Space Japan Milestone – Broadcasting Satellite System Corporation (B-SAT)" (PDF). Space Japan Review (English Version) (36). AIAA JFSC. September 2004. Archived from the original (PDF) on 2016-09-09. Retrieved 2016-09-09.
- ^ a b c d Krebs, Gunter Dirk (2016-09-08). "BSat 1a, 1b". Gunter's Space Page. Retrieved 2016-07-20.
- ^ Hattori, Yoshihito (January 2008). "Report – Trends in Satellite Broadcasting" (PDF). Space Japan Review (English Version) (53). AIAA JFSC. Archived from the original (PDF) on 2016-09-09. Retrieved 2016-09-09.
