SES Astra SA, is a corporate subsidiary of SES, based in Betzdorf, in eastern Luxembourg, that 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 Société Européenne des Satellites-Astra (SES), it was Europe's first private satellite operator. Its slogan is currently "Your Satellite Connection to the World".
The first customer of SES Astra was Sky Television who bought 4 transponders for their service in 1989. UK- and Ireland-aimed channels ceased at 19.2 East in September 2001 with the closure of Sky's analogue service, though their digital service has been the main occupier of Astra's secondary position at 28.2 East since its launch in 1998.
Satellite details
SES Astra operates twelve satellites from three orbital locations, seven at 19.2°E, three at 28.2°E and two at 23.5°E. The company also has two satellites on order to replace early Astra 1 models. Astra's principle of "co-location" (several satellites in the same orbital location) increases flexibility and redundancy.
| 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 |
Out of service (July 2006) |
GE AstroSpace |
GE-5000 |
March 2, 1991 |
Ariane 44LP |
Acquired from GE Americom (Satcom K3). |
| 1C |
4.8°E |
|
Hughes |
HS-601 |
May 12, 1993 |
Ariane 42L |
Inclined orbit for occasional use and professional services. |
| 1E |
19.2°E |
|
Hughes |
HS-601 |
October 19, 1995 |
Ariane 42L |
Capacity reduced following launch of 1KR |
| 1F |
19.2°E |
|
Hughes |
HS-601 |
April 8, 1996 |
Proton |
|
| 1G |
19.2°E |
|
Hughes |
HS-601HP |
December 2, 1997 |
Proton |
Power problems, now max 20 transponders |
| 1H |
19.2°E |
|
Hughes |
HS-601HP |
June 16, 1999 |
Proton |
|
| 1K |
19.2°E |
Failed to reach orbit |
Alcatel Space |
Spacebus 3000B3S |
November 26, 2002 |
Proton |
Rocket failure, ditched in Pacific Ocean. |
| 1KR |
19.2°E |
|
Lockheed Martin |
A2100 |
20 April 2006 |
Atlas V |
Launched after the failure of the Astra 1K. |
| 1L |
19.2°E |
|
Lockheed Martin |
A2100 |
May 4, 2007 |
Ariane 5-ECA |
Replacement for 1E/2C; Ku and Ka bands |
| 1M |
19.2°E |
Under construction |
EADS Astrium |
Eurostar E3000 |
Due 2008 |
|
To replace 1F 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 |
28.2°E |
|
Hughes |
HS-601HP |
June 16, 2001 |
Proton |
Replaced at 19.2°E by 1L; moved to 28.2°E with 2A, 2B and 2D |
| 2D |
28.2°E |
|
Hughes |
HS-376HP |
December 19, 2000 |
Ariane 5 |
|
| 1D |
23.5°E |
|
Hughes |
HS-601 |
November 1, 1994 |
Ariane 42P |
Moved from 19.2°E to 23.5°E to provide HD services and extra capacity in continental Europe |
| 3A |
23.5°E |
|
Boeing |
HS-376HP |
March 29, 2002 |
Ariane 44L |
| 3B |
23.5°E |
Under construction |
EADS Astrium |
Eurostar E3000 |
Due end 2009 |
|
to replace Sirius 2; 52 transponders both in Ku and Ka bands |
| 4A |
37.5°W |
|
Alcatel Space |
Spacebus-4000C3 |
February 3, 2005 |
Proton M |
Leased transponders of AMC-12, marketed as Astra 4A |
| 5A |
31.5°E |
|
Alcatel Space |
Spacebus-3000B2 |
November 12, 1997 |
|
Formerly known as Sirius 2. Moved to 31.5°E and renamed Astra 5A on 29 April 2008 |
Notes
- 19.2°E is the most common orbital position for direct-to-home satellite TV and radio transmission in Germany, Western and Central Europe.
- 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), EADS 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 nearly 36,000 km altitude. 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 commercial communications satellite ever built at the time, 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 unusable. The only way to recover the satellite would have been the use of a Space Shuttle, however this was rejected. On December 10, 2002 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
Coordinates: 49°41′39″N, 06°19′49″E
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