SatellitesThere are 16 operational Astra satellites, the majority in five orbital locations - Astra 19.2°E, Astra 28.2°E, Astra 23.5°E, Astra 5°E, Astra 31.5°E. Astra's principle of "co-location" (several satellites are maintained close to each other, all within a cube with a size of 150 km) increases flexibility and redundancy.
Manufacture and launchAstra satellites have been designed by Boeing Satellite Development Center, Boeing Satellite Systems (formerly Hughes Aircraft Company, Hughes Space and Communications), Airbus Defence and Space (formerly Astrium), Alcatel-Lucent, Alcatel Space, and Lockheed Martin. The Astra satellites within a family are not identical, for example of the Astra 2 satellites; Astra 2A and Astra 2C are BSS Boeing 601, 601HPs, Astra 2B is an Eurostar (satellite bus), Astrium Eurostar E2000+ and Astra 2D is a HS-376, BSS 376. The satellites have been launched by Arianespace Ariane (rocket), rockets from Kourou, French Guiana, International Launch Services Proton (rocket family), Proton rockets from Baikonur Cosmodrome, Baikonur, Kazakhstan, and ILS Atlas V, Atlas rockets from Cape Canaveral Air Force Station, Cape Canaveral, Florida, United States. 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 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 (rocket family), Ariane rockets. As a result, most satellites launched in this way have to use less fuel to reach their geostationary orbit, increasing their lifetime.
Sirius and Astra 4AThe Sirius (satellite), Sirius series of satellites (not connected with the North American Sirius Satellite Radio service) was started in 1993 with the purchase of the British Satellite Broadcasting, BSB Sirius (satellite), Marcopolo 1 satellite (renamed Sirius 1) by SES Sirius, Nordic Satellite AB (NSAB) for Satellite television, direct to home broadcasts to the Nordic and Baltic regions from the 5° East Earth's orbit, orbital position. Subsequent satellites launched to this location include Astra 5A, Sirius 2 (1997), Sirius (satellite), Sirius 3 (1998) and Sirius (satellite), Sirius 4 (2007) and the position's coverage has been expanded to include Eastern Europe and . In 2000, SES (then SES Astra) bought the 50% shareholding in NSAB owned by Teracom and TDC A/S, Tele Danmark and in 2003 increased that holding to 75%, renaming the company SES Sirius AB. In 2008, Astra acquired further shares to take its shareholding in SES Sirius to 90% and in March 2010 took full control of the company. In June 2010, the affiliate company was renamed SES Astra and the Sirius (satellite), Sirius 4 satellite renamed Astra 4A. The Astra 4A designation was originally given in 2005 to part of the List of SES satellites, NSS-10 craft (33 transponders) owned by another subsidiary of SES, SES New Skies, and positioned at 37.5° West for broadcast, data, and telecommunications into Africa, and in 2007 to part of the Sirius (satellite), Sirius 4 satellite (six transponders of the FSS Africa beam) owned and operated by SES Sirius. From June 2010, the Astra 4A designation has applied to the entire satellite previously known as Sirius 4.
FailuresAstra 1K, the largest commercial communications satellite ever built at the time, was ordered by SES in 1997. It was launched by Proton rocket on 26 November 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 10 December 2002, SES instructed Thales Alenia Space, Alcatel Space (the manufacturer) and the French Space Agency CNES to deorbit the satellite, it broke up on Atmospheric entry, re-entry over the Pacific Ocean. On 16 January 2009, Astra 5A at Astra 31.5°E, 31.5° East "experienced a technical anomaly leading to the end of the spacecraft's mission" some four years ahead of the spacecraft's expected end of life. Traffic carried by the satellite (especially channels for German cable service, Kabel Deutschland) was transferred to Astra 23.5°E. In March 2009, SES (then SES Astra) announced that in April, the Astra 2C satellite was to be moved from the Astra 28.2°E, 28.2° East position to 31.5° East to temporarily take over Astra 5A's mission until Astra 3B is launched to Astra 23.5°E, 23.5° East, when another craft currently there can be released to 31.5° East. The move of Astra 2C was started in May 2009 and completed on 11 May 2009 with the first transponders coming into use at the new position in the subsequent two weeks.
Broadcasting statisticsAt the end of 2018, Astra satellite broadcasts were received in 167 million households in Europe. In all, 39.3% of all European TV households receive Satellite television, DTH satellite TV, 23.3% receive cable TV, 13.9% receive Internet Protocol television, IPTV, and 23.4% receive terrestrial broadcasts. With provision via DTH, cable and IPTV, 65% of European TV homes receive TV from Astra satellites. From Astra satellites, 110 million European homes receive HD channels and 29 million European homes receive Ultra HD channels.
See also* Astra Digital Radio * ''High Above (book), High Above'' (book) * HD+ * List of broadcast satellites * SES Americom * SES Broadband * MX1 Ltd, MX1 * SES New Skies * SES S.A. (operator) * SES Sirius * EchoStar Mobile