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SES-Astra (Société Européenne des Satellites-Astra) is a Luxembourg-based corporation which owns and operates the Astra series of geostationary satellites, which transmit approximately 1100 analogue and digital television and radio channels via 176 transponders to 91 million households across Europe. Formed in 1985 as SES, it was Europe's first private satellite operator.
Its slogan in 1997 was "Astra: The Satellite System". It is currently "Your Satellite Connection to the World".
Orbital Positions
| Satellite | Position | Primary footprint | Manufacturer | Model | Launched | Launch vehicle | Comments |
|---|---|---|---|---|---|---|---|
| 1A | Out of service (December 2004) | GE AstroSpace | GE-4000 | December 11 1988 | Ariane 44LP | In "junk orbit" | |
| 1B | 19.2°E | GE AstroSpace | GE-5000 | March 2 1991 | Ariane 44LP | To be replaced by 1KR | |
| 1C | 19.2°E | Hughes | HS-601 | May 12 1993 | Ariane 42L | To be replaced by 1KR | |
| 1D | 23.5°E | Hughes | HS-601 | November 1 1994 | Described as "troubleshooter" | ||
| 1E | 19.2°E | Hughes | HS-601 | October 19 1995 | Ariane 42L | ||
| 1F | 19.2°E | Hughes | HS-601HP | April 8 1996 | Proton | ||
| 1G | 19.2°E | Hughes | HS-601HP | December 2 1997 | Proton | ||
| 1H | 19.2°E | Hughes | HS-601HP | June 16 1999 | Proton | ||
| 1K | 19.2°E | Scrapped | Alcatel Space | Spacebus 3000B3S | November 26 2002 | Proton | Rocket failure, ditched in Pacific Ocean |
| 1KR | 19.2°E | Under construction | Lockheed Martin | A2100 | Due 2005 | Replacement for 1K | |
| 1L | 19.2°E | Under construction | Lockheed Martin | A2100 | Due 2006 | Backup for 1KR, if successful becomes 1L | |
| 1M | 19.2°E | Under construction | EADS Astrium | Eurostar E3000 | Due 2008 | To replace 2C at 19.2°E | |
| 2A | 28.2°E | Hughes | HS-601HP | August 30 1998 | Proton | ||
| 2B | 28.2°E | Astrium | Eurostar E2000+ | September 14 2000 | Ariane 5 | ||
| 2C | 19.2°E | Hughes | HS-601HP | June 16 2001 | Proton | To be replaced by 1M, will move to 28.2°E | |
| 2D | 28.2°E | Hughes | HS-376 | December 19 2000 | Ariane 5 | ||
| 3A | 23.5°E | Boeing | HS-376 | March 29 2002 | Ariane 44L | ||
Notes
- 19.2°E is the most common orbital position for direct-to-home satellite TV and radio transmission in Germany and Central Europe.
- 1G is also used for home satellite internet (with DVB modems) and the free-to-air TV and radio channels (Astra-Mosaic).
- BSkyB broadcast their Sky Digital direct-to-home television service to the United Kingdom and Republic of Ireland from the 28.2°E satellite constellation. Eutelsat's Eurobird satellite also operates close to this position.
Satellite manufacturer & launch
SES Astra operates satellites designed by Boeing Satellite Systems or BSS (formerly Hughes Space and Communications), Astrium and Alcatel Space.
Astra satellites within a family are not identical, for example of the Astra 2 satellites; 2A and 2C are BSS 601HPs, 2B is an Astrium Eurostar-2000 and 2D is a BSS 376.
The satellites are launched by Arianespace rockets from Kourou, French Guiana or International Launch Services Proton rockets from Baikonur, Kazakhstan. The satellites are launched into an elliptical "temporary transfer orbit" from where they use onboard propulsion to reach their final circular geostationary orbits at 36,000km (22,369 miles). Proton rockets fitted with a fourth stage propulsion unit are capable of launching the satellites several thousand kilometres higher (at the closest point of the elliptical orbit) than Ariane rockets. As a result most satellites launched in this way have to use less fuel to reach their geostationary orbit, increasing their flexibility.
Failures
Astra 1K, the largest commerical communciations satellite ever built, was ordered by SES-Astra in 1997. It was launched by Proton rocket on November 26 2002. The rocket lifted off as planned and reached its "parking orbit" at which point the final stage of the rocket was to initiate a second burn to transfer the satellite to its geostationary orbit. This did not occur and the satellite was released into the parking orbit, making it unuseable. The only way to recover the satellite was the use of an orbiter, however this was rejected. On December 10 SES Astra instructed Alcatel Space (the manufacturer) and the French Space Agency CNES to deorbit the satellite, it broke up on re-entry over the Pacific Ocean.
See also
External links
- SES Astra - Official site
- Home satellite internet.
- Astra transponder footprints (To determine size requirements of a satellite dish - minimum diameter from 50 to 120 cm).