Astra 1B
Astra 1B was the second of the Astra communications satellites launched and operated by SES (Société Européenne des Satellites). SES bought the satellite from failed DBS company Crimson Satellite Associates while still under construction by GE AstroSpace (as Satcom K3).[2] It was launched to add extra capacity to the satellite television services from 19.2° east, serving Germany, the UK and Republic of Ireland (SES later acquired GE Americom, which was to operate Satcom K3, resulting in the latter being renamed SES Americom as a result of SES' acquisition from General Electric, which acquired former parent RCA Corporation in 1986).
| Operator | SES S.A. SES Astra |
|---|---|
| COSPAR ID | 1991-015A |
| SATCAT no. | 21139 |
| Mission duration | 10 years |
| Spacecraft properties | |
| Bus | GE-5000 (formerly known as AS-5000) |
| Manufacturer | GE AstroSpace (formerly RCA AstroSpace, Electronics division) |
| Launch mass | 1,562 kilograms (3,444 lb) |
| Power | 2,136 watts |
| Start of mission | |
| Launch date | March 2, 1991 UTC |
| Rocket | Ariane 4 V42 |
| Launch site | Kourou ELA-2 |
| Contractor | Arianespace |
| End of mission | |
| Disposal | Decommissioned |
| Deactivated | 14 July 2006 |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Geosynchronous-belt graveyard orbit |
| Longitude | 19.2°E |
| Slot | Astra 1 |
| Perigee altitude | 36,253.7 kilometres (22,527.0 mi)[1] |
| Apogee altitude | 36,335.2 kilometres (22,577.6 mi)[1] |
| Inclination | 8.6 degrees[1] |
| Period | 1461.77 minutes[1] |
| Epoch | 2 March 2015, 07:38:46 UTC[1] |
| Transponders | |
| Band | 22 Ku-band (16 main, 6 backup) |
| Bandwidth | 26 MHz |
| TWTA power | 60 watts |
| EIRP | 52.5 decibel-watts |
On June 4, 1991 Astra 1B suffered an attitude control failure, causing minor drift in north/south direction, meaning that it became difficult to obtain a steady lock on the satellite. This was most notable on analogue transmissions where the picture would move from clear to carrying sparklies and back again. The failure was likely caused by recent solar winds which impacted the electronics on both the primary and the backup momentum wheels. In September 1991 SES dealt with the failure by permanently deactivating the automatic control mode for the attitude subsystem.[3]
Along with Astra 1C, Astra 1B was to be replaced in 2002 with Astra 1K, which failed to launch successfully, and as a result it continued to serve a longer life than expected, only falling from use when digital television on Astra 2A removed the majority of UK and Ireland targeted channels from 19.2° east.
From 2005, SES claimed that the satellite was in use for VSAT services, however no transponders were powered, and the satellite drifted to around 19.5° east. One transponder was reactivated in October 2005, but was carrying only colour bars.
On June 16, 2006 SES confirmed that Astra 1B would be decommissioned and de-orbited within weeks after Astra 1KR, the satellite which would replace Astra 1B and 1C, reached the operational orbital position of 19.2° east.[4] It was officially end-of-lifed on July 14, 2006; close to four years after it had ceased carrying signals, ending SES's claims that the craft was operational.
Transponders
Astra 1B transponders were used in the following ways during the operational life of the satellite:
| Transponder | Frequency | Channels carried |
|---|---|---|
| 17 | 11,464 H | Premiere (1991–2003), Sonnenklar.TV (2003-2009) |
| 18 | 11,479 V | The Movie Channel (1991–1997), Sky Movies Screen 2 (1997–1998), Sky Premier (1998–2001) |
| 19 | 11,494 H | ARD 1 Plus (1991–1993), Das Erste (1993-2012) |
| 20 | 11,509 V | Sky Sports (1991–2001) |
| 21 | 11,523 H | Tele 5 (1991–1992), DSF (1993-2010), Sport 1 (2010-2012) |
| 22 | 11,538 V | Eurosport (1991–1992), MTV Europe (1992–1993), VH1 UK (1993–2001), GOD (2001-2002) |
| 23 | 11,553 H | Astra Video (1991), FilmNet (1991–1992), UK Gold (1992–2001), What's In Store (1993-1997), HSN (1997), Screenshop (1997-2000), Astra Vision (2001-2002), Tele 5 (2002-2012) |
| 24 | 11,568 V | JSTV (1991-1996), The Children's Channel (1991-1994), CMT Europe (1994–1996), Sky Barker (1996–1997), Sky Soap (1997–1999), The History Channel UK (1997–2001), Sci-fi Channel UK (1997–2001), GOD (1997-2001), Adult Channel (1997-2000), Bloomberg UK (2001-2002), SFB1 (2001-2002) |
| 25 | 11,582 H | Nord 3 (1991–2001), NDR Fernsehen (2001-2012) |
| 26 | 11,597 V | Astra Info (1991), Comedy Channel (1991-1992), TV Asia (1991-1994) The Adult Channel (1991-1993), Sky Movies Gold (1992-1997), Disney Channel UK (1995–2001), Sky Box Office 1 (1997-1999) |
| 27 | 11,612 H | TV3 Denmark (1991–1996), Nickelodeon Nordic/Sci-Fi Channel Nordic/Nova Shop (1996), VH1 Germany/Nickelodeon Germany (1996-1998), MTV Germany (1999-2010), VIVA (2011) |
| 28 | 11,627 V | CNN International (1992-2010) |
| 29 | 11,641 H | TV3 Denmark (1991), Astra Info (1992), n-tv (1992-2012) |
| 30 | 11,656 V | Astra Info (1991-1992), Cinemanía (1992-1997), ORB Fernsehen (1997-2003), RBB Brandenburg (2003-2012) |
| 31 | 11,671 H | TV3 Norway (1991–1996) Sky Sports 3 (1996–2001), TV Shop (1996-2000), Playboy TV (1996-1999), Midnight Blue (1999-2001), Nick Junior (1999-2000), TV Puls (2002-2003) |
| 32 | 11,686 V | Documanía (1992–1996), Sportsmanía (1996-1997), Astra Vision (1997), BR alpha (1998-2002) |
See also
References
- "ASTRA 1B Satellite details 1991-015A NORAD 21139". N2YO. 2 March 2016. Retrieved 2 March 2016.
- Astra 1B JPL Mission and Spacecraft Library. Accessed June 27, 2017
- "Engineers snatch back control of 'wobbly' satellite". New Scientist. 21 September 1991. Retrieved 10 June 2020.
- "ASTRA 1KR OPERATIONAL AT ORBITAL POSITION 19.2° EAST" (Press release). SES ASTRA. June 16, 2006.