Sirius was a constellation of

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a Transponder (satellite communications), transponder; it creates a communication channel between a source transmitter and a Rad ...

s operated at 5.0° East in

geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular orbit, circular geosynchronous or ...

(GEO) by NSAB (later SES Sirius, and now a non-autonomous part of SES, owner and operator of the

Astra satellites Astra (Latin for "stars") may refer to: People * Astra (name) Places * Astra, Chubut, a village in Argentina * Astra (Isauria), a town of ancient Isauria, now in Turkey * Astra, one suggested name for a hypothetical fifth planet (hypothetical), ...

). They carried

digital Digital usually refers to something using discrete digits, often binary digits. Businesses *Digital bank, a form of financial institution *Digital Equipment Corporation (DEC) or Digital, a computer company *Digital Research (DR or DRI), a software ...

satellite television Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.ITU Radio Regulations, Section IV. Radio Stations and Systems ...

to the countries of

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

Baltic states The Baltic states or the Baltic countries is a geopolitical term encompassing Estonia, Latvia, and Lithuania. All three countries are members of NATO, the European Union, the Eurozone, and the OECD. The three sovereign states on the eastern co ...

Eastern Europe Eastern Europe is a subregion of the Europe, European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural and socio-economic connotations. Its eastern boundary is marked by the Ural Mountain ...

and

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, including the Viasat

pay TV Pay television, also known as subscription television, premium television or, when referring to an individual service, a premium channel, refers to subscription-based television services, usually provided by multichannel television providers, b ...

system, along with several pay TV packages for Eastern Europe, the TopTV package for Africa, a number of Ukrainian channels and the national Latvian and Lithuanian channel service

free-to-air Free-to-air (FTA) services are television (TV) and radio services broadcast in unencrypted form, allowing any person with the appropriate receiving equipment to receive the signal and view or listen to the content without requiring a subscri ...

Satellites

Sirius 4

A fourth satellite, Sirius 4, was ordered in 2005 and launched at 22:39:47 UTC on 17 November 2007. It carries 52 active Ku-band

transponder In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight trans ...

s and two active Ka-band transponders. Sirius 4 was built by

Lockheed Martin Space Systems Lockheed Martin Space is one of the four major business divisions of Lockheed Martin. It has its headquarters in Littleton, Colorado, with additional sites in Valley Forge, Pennsylvania; Sunnyvale, California; Santa Cruz, California; Huntsville ...

based upon the A2100AX design. Among the services carried are Viasat and Viasat Ukraine which has used the Sirius satellites for their digital platform since its launch. Sirius 4 was renamed to Astra 4A in June 2010, when the SES took full ownership and control of SES Sirius.

Sirius 5

Sirius 5 was the original name of the

SES-5 SES-5 (also known as Astra 4B and Sirius 5) is a commercial geostationary communication satellite operated by SES It was launched on 9 July 2012. The launch was arranged by International Launch Services (ILS). History In October 2008, SE ...

satellite. SES-5 that was launched in July 2012 and is now co-located with Astra 4A (Sirius 4) at 5.0° East. This satellite provides a similar European and African coverage as Astra 4A. When ordered by the SES Sirius AB of

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

in October 2008, the name of the satellite was Sirius 5. SES Sirius was acquired by SES in 2010 and the company was named

SES Astra SES Astra SA was a corporate subsidiary of SES, based in Betzdorf, in eastern Luxembourg, that maintained and operated the Astra series of geostationary communication satellites between 2001 and 2011. Formed in 1985 as Société Européenne ...

(a subsidiary of SES). This led to the satellite being renamed to Astra 4B in 2010. The name was changed to SES-5 in 2011.

Retired satellites

Sirius 1

Sirius 1 (later Sirius W) was purchased from

British Sky Broadcasting Sky UK Limited (formerly British Sky Broadcasting Limited (BSkyB)), trading as Sky, is a British broadcaster and telecommunications company that provides television, broadband internet, fixed line and mobile telephone services to consumers a ...

after Sky Television's merger with

British Satellite Broadcasting British Satellite Broadcasting plc (BSB) was a television company, based in London, that provided satellite television, direct broadcast satellite television services to the United Kingdom. It started broadcasting on 25 March 1990. The company ...

(BSB) (the merger was conducted on Sky's terms and BSB's satellites were sold in favour of Sky's leased Astra satellite operations). The satellite had previously operated as Marcopolo 1. It operated at 5.0° East from 1994 until 2000, when it was moved to 13.0° West. It operated here before being moved to a

graveyard orbit A graveyard orbit, also called a junk orbit or disposal orbit, is an Orbit (physics), orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellit ...

in 2003.

Sirius 2

Sirius 2 was manufactured by

Aérospatiale Aérospatiale () was a major French state-owned aerospace manufacturer, aerospace and arms industry, defence corporation. It was founded in 1970 as () through the merger of three established state-owned companies: Sud Aviation, Nord Aviation ...

and launched from Kourou on 12 November 1997 to replace the Tele-X satellite. It is of the model Spacebus 3000B2 and has 32 K_u-band transponders with beams targeting both the Nordic region and all of Europe. It was moved to 31.5° East () and renamed Astra 5A on 29 April 2008. The Astra 5A satellite mission ended on 16 January 2009 due to an abnormal condition with the spacecraft.

Sirius 3

Sirius 3 was stationed at 51.2° East at the end if its lifetime () in an inclined orbit. Sirius 3 was leased to SES immediately after its launch on 5 October 1998 for a period of 12 months (after which it was moved to its original destination of 5.0° East) to provide capacity at 28.2° East and to back up Astra 2A, pending the launch of Astra 2B on 14 September 2000. Satellite was retired in 2015 and moved to a

Sirius Satellite Radio

The Sirius satellites are not the satellites used for the American

Sirius Satellite Radio Sirius Satellite Radio was a satellite radio ( SDARS) service that operated in the United States and Canada. Sirius launched in 2002, and primarily competed with XM Satellite Radio, until the two services merged in 2008 to form Sirius XM. Li ...

service, whose satellites are named Radiosat 1-4 due to being launched after the Sirius fleet of satellites.

References

External links

Sirius 1 info from Swedish Space Corporation

Sirius 2 info from Swedish Space Corporation

Sirius 3 info from Swedish Space Corporation
* {{satbeams footprint, 5642, Sirius
SES
- Official SES site
SES fleet information
SES (company) Communications satellite constellations de:SES Sirius