View source for Astra 4A

{{Short description|Communications satellite}}
{{Infobox spaceflight
| name                  = Astra 4A
| image                 = 
| image_caption         = 

| mission_type          = 
| operator              = 
| website               = 
| COSPAR_ID             = 
| SATCAT                = 
| mission_duration      = 15 years (planned)<br/>{{time interval|18 November 2007|show=ymd|sep=,}} (elapsed)

| spacecraft_bus        = [[A2100AX]]<ref name="fact"/>
| manufacturer          = [[Lockheed Martin]]
| dry_mass              = 
| launch_mass           = {{convert|4600|kg}}<ref name="fact">''Sirius 4 Factsheet'' SES SIRIUS August 2008</ref>
| power                 = 8,100&nbsp;watts

| launch_date           = {{start-date|18 November 2007}}
| launch_rocket         = [[Proton-M]]/[[Briz-M]] 
| launch_site           = [[Baikonur Cosmodrome|Baikonur]] [[Baikonur Cosmodrome Site 200|200/39]]
| launch_contractor     = [[International Launch Services|ILS]]
| entered_service       = 

| disposal_type         = 
| deactivated           = <!-- {{end-date|[insert date here]}} -->

| orbit_epoch           = 
| orbit_reference       = [[Geocentric orbit|Geocentric]]
| orbit_regime          = [[Geostationary orbit|Geostationary]]
| orbit_periapsis       = 
| orbit_apoapsis        = 
| orbit_inclination     = 
| orbit_period          = 
| orbit_longitude       = 5° East
| orbit_slot            = 
| apsis                 = gee

| trans_band            = 52 [[Ku band|K<sub>u</sub> band]]<br/>2 [[Ka band|K<sub>a</sub> band]]
| trans_frequency       = 
| trans_bandwidth       = {{nowrap|33, 36, 72&nbsp;megahertz (K<sub>u</sub> band)}}<br/>125, 250&nbsp;megahertz (K<sub>a</sub> band) 
| trans_capacity        = 
| trans_coverage        = 
| trans_TWTA            = {{nowrap|49, 116 & 140&nbsp;watts (K<sub>u</sub> band)}}, 118 & 126&nbsp;watts (K<sub>a</sub> band) 
| trans_EIRP            = 50&nbsp;decibel-watts
| trans_HPBW            = 

| programme         = [[SES Astra|Astra constellation]]
| previous_mission  = 
| next_mission      = 
}}

'''Astra 4A''' (originally '''Sirius 4''') is one of the [[Astra (satellites)|Astra]] [[communications satellite]]s owned and operated by [[SES (company)|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 Africa in the 11.70&nbsp;GHz-12.75&nbsp;GHz range of the [[Ku band|K<sub>u</sub> band]] and 18.8&nbsp;GHz-21.75&nbsp;GHz range of the [[Ka band|K<sub>a</sub> band]].

==Overview==
The satellite was launched in November 2007 as Sirius 4 by SES Sirius. At that time, SES owned a 75% shareholding in SES Sirius, which was increased to 90% in 2008 and to 100% in March 2010. In June 2010, the affiliate company was renamed SES Astra (then a subsidiary company of SES) and the Sirius 4 satellite was renamed Astra 4A.<ref>{{cite press release|publisher=SES|date=22 June 2010|url=http://www.ses.com/4233325/news/2010/4489346|title=SES SIRIUS BECOMES SES ASTRA}}</ref>

Astra 4A provides three K<sub>u</sub> band broadcast beams - the Nordic beam to Denmark, Norway, Sweden and Finland, the European beam to Eastern European and Baltic countries including Belarus, Bulgaria, Estonia, Latvia, Lithuania, Romania, Russia and Ukraine, and the African beam to sub-Saharan Africa.

Reception is possible on dishes as small as 60&nbsp;cm from all three beams, with reception from the European beam across Europe and from the African beam across sub-Saharan across Africa with dishes of 90&nbsp;cm-120&nbsp;cm.<ref>{{cite web|url= http://www.ses.com/4628572/astra-4a|title=Astra 4A Footprints|publisher=SES|access-date=26 January 2012}}</ref>

The satellite also carries a dedicated payload of two transponders for K<sub>a</sub> band services, for applications such as interactive and contribution services. Both uplink and downlink within the African footprint are available, and also inter-connectivity between Africa and Europe so broadcasting out of Europe is available without the need for expensive fibre ground links.

Five of these African beam transponders are contracted with ETV and [[Globecast]] having signed one transponder each and three transponders signed by On Digital Media for the South African [[TopTV]] network.<ref>{{cite press release|publisher=SES ASTRA|date=19 April 2010|url=http://www.ses.com/4233325/news/2010/4487850|title=ON DIGITAL MEDIA CONTRACTS THREE TRANSPONDERS ON ASTRA|access-date=26 January 2012}}</ref>

Co-located with Astra 4A at 5°E is the [[SES-5]] satellite. Launched in July 2012, this satellite provides a similar European and African coverage and was originally named Sirius 5, but renamed to Astra 4B in 2010 and then to SES-5 in 2011.
[[File:Astra 4A Ka-Band VSAT Footprint.jpg|thumbnail|Astra 4A Ka-Band VSAT Footprint]]

==Previous use of name==
The Astra 4A designation was originally given in June 2005 to 33 transponders of the NSS-10 craft (itself formerly called AMC-12) owned by another then subsidiary of SES, [[SES New Skies]], and positioned at 37.5° west for broadcast, data, and telecommunications into Africa.<ref>{{cite press release|publisher=SES ASTRA|date=17 February 2006|url=http://www.ses.com/4233325/news/2006/4445997|title=SES Global Africa completes first successful year in African business|access-date=26 January 2012}}</ref>

For the current spacecraft, the Astra 4A designation originally applied only to the FSS Africa beam that provides six 36&nbsp;MHz transponders for sub-Saharan Africa. The remainder of the spacecraft was called Sirius 4 at that time (from November 2007 to June 2010).<ref name="fact"/>

==See also==
*[[Astra (satellite)|SES-5]] co-located satellite
*[[Sirius (satellite)|Sirius 3]] previously co-located satellite
*[[Astra 5°E]] orbital position
*[[SES (company)|SES]] satellite owner
*[[TopTV]] broadcaster

==References==
{{Reflist}}

==External links==
*[https://www.ses.com/our-coverage SES fleet information and map]
*[http://www.ses.com/ Official SES trade/industry site]
*[https://www.ses.com/our-coverage/satellites/330 Astra 4A Ku and Ka footprints at SES.com]
*[http://www.satbeams.com/footprints?beam=6342 Astra 4A Nordic beam footprint on SatBeams]
*[http://www.satbeams.com/footprints?beam=6341 Astra 4A European beam footprint on SatBeams]
*[http://www.satbeams.com/footprints?beam=5679 Astra 4A Africa beam footprint on SatBeams]

{{SES Astra}}
{{Orbital launches in 2007}}

{{DEFAULTSORT:Astra 4A}}
[[Category:Communications satellites in geostationary orbit]]
[[Category:Astra satellites]]
[[Category:2007 in spaceflight]]
[[Category:2007 in Luxembourg]]
[[Category:Satellites of Luxembourg]]
[[Category:Satellites using the A2100 bus]]