Sirius was a constellation of

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth ...

s operated at 5.0° East in geostationary orbit (GEO) by NSAB (later SES Sirius, and now a non-autonomous part of

SES S.A. SES S.A. is a Luxembourgish-French satellite telecommunications network provider supplying video and data connectivity worldwide to broadcasters, content and internet service providers, mobile and fixed network operators, governments and insti ...

, owner and operator of the

Astra satellites Astra 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 that became the asteroid belt En ...

). They carried digital

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. The signals are received via an outdoor parabolic antenna comm ...

to the countries of

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...

, Baltic states,

Eastern Europe Eastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russia, whic ...

and

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

, 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 StarSat (formerly TopTV until 31 October 2013) is a South African direct broadcast satellite Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth di ...

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 subscripti ...

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 The Ku band () is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz). The symbol is short for "K-under" (originally german: Kurz-unten), because it is the lower part of the ori ...

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 The Ka band (pronounced as either "kay-ay band" or "ka band") is a portion of the microwave part of the electromagnetic spectrum defined as frequencies in the range 26.5–40 gigahertz (GHz), i.e. wavelengths from slightly over one centime ...

transponders. Sirius 4 was built by Lockheed Martin Space Systems based upon the

A2100AX The A2100 is a model of communications satellite spacecraft made by Lockheed Martin Space Systems. It is used as the foundation for telecommunications payloads in geosynchronous orbit, as well as GOES-R weather satellites and GPS Block IIIA satel ...

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 Astra 4A is one of the Astra communications satellites owned and operated by SES at the Astra 5°E orbital slot providing digital television and radio broadcasts, data, and interactive services to Nordic countries, eastern Europe and sub-Saharan ...

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 S.A. It was launched on 9 July 2012. The launch was arranged by International Launch Services (ILS). History In October 2008, S ...

satellite. SES-5 that was launched in July 2012 and is now co-located with

(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 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 de ...

(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 is a British broadcaster and telecommunications company that provides television and broadband Internet services, fixed line and mobile telephone services to consumers and businesses in the United Kingdom. It is a subsidiary of ...

after Sky Television's merger with

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

(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 that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellites are moved into ...

in 2003.

Sirius 2

Sirius 2 was manufactured by Aérospatiale and launched from

Kourou Kourou () is a commune in French Guiana, an overseas region and department of France in South America. Kourou is famous for being the location of the Guiana Space Centre, the main spaceport of France and the European Space Agency (ESA). It i ...

on 12 November 1997 to replace the

Tele-X Tele-X was the first communications satellite serving the Nordic countries. It was launched with an Ariane 2 launch vehicle from Kourou, French Guiana, on 2 April 1989. On 16 January 1998, its fuel was exhausted and it was moved into graveyar ...

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 Astra 5A was one of the Astra communications satellites owned and operated by SES at the Astra 31.5°E. Launched in 1997 to the 5° East position by NSAB (Nordiska Satelit AB) (later SES Sirius, and now a non-autonomous part of SES) as Sir ...

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 Astra 2A is one of the Astra communications satellites owned by Société Européenne des Satellites. Launched in 1998 into the 28.2° East orbital position, half its expected end-of-life capacity of 28 transponders were pre-booked by BSkyB, w ...

, 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) and online radio service operating in North America, owned by Sirius XM Holdings. Headquartered in New York City, with smaller studios in Los Angeles and Memphis, Sirius was officially lau ...

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 S.A. Communications satellite constellations de:SES Sirius