| 词条 | Astra 1A | |||||||||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
| name = Astra 1A | image = | image_caption = | mission_type = Communication | operator = SES S.A. SES Astra | website = | COSPAR_ID = | SATCAT = 19688 | mission_duration = 12 years (planned) 16 years (achieved) | spacecraft_bus = AS-4000 | manufacturer = RCA Astro Electronics (acquired by General Electric as GE AstroSpace as part of acquisition of RCA, later sold to Martin Marietta which in turn merged with Lockheed to form Lockheed Martin Space Systems) | dry_mass = | launch_mass = {{convert|1780|kg}} | power = 1,675 watts | launch_date = {{start-date|December 11, 1988}} | launch_rocket = Ariane 4 V27 | launch_site = Kourou ELA-2 | launch_contractor = Arianespace | entered_service = | disposal_type = Decommissioned | deactivated = {{end-date|December 2004}} | auto = all | orbit_epoch = January 23, 2015, 14:51:52 UTC[1] | orbit_reference = Geocentric | orbit_regime = Geosynchronous-belt graveyard orbit | orbit_periapsis = {{convert|36286|km|mi}}[1] | orbit_apoapsis = {{convert|36401|km|mi}}[1] | orbit_inclination = 11.77 degrees[1] | orbit_period = 1464.33 minutes[1] | orbit_longitude = 19.2° East (1989–2001) 19.4° East (2001) 5.2° East (2001–2004) | orbit_slot = Astra 1 (1989-2001) | apsis = gee | trans_band = 16 Ku band | trans_frequency = | trans_bandwidth = 26 megahertz | trans_capacity = | trans_coverage = | trans_TWTA = 45 watts | trans_EIRP = 50 decibel-watts | trans_HPBW = }} Astra 1A was the first satellite launched and operated by SES (Société Européenne des Satellites), launched in December 1988. During its early days, it was often referred to as the Astra Satellite, as SES only operated one satellite originally.{{citation needed lead|date=July 2012}} The satellite provided television coverage to Western Europe from 1989 through 2004 and was revolutionary as one of the first medium-powered satellites, allowing reception with smaller dishes than before.{{citation needed lead|date=July 2012}} Astra 1A was retired and became derelict in December 2004. ChannelsAmong the channels carried in the early years after launch were the entire four channel Sky Television (later British Sky Broadcasting, after the merger with rival British Satellite Broadcasting on the Marcopolo satellite), the services consisted of Sky One/Sky Channel, Sky News, Sky Movies and Eurosport, the Scandinavian TV3 and TV1000, the German Pro7, Sat.1, RTL plus, 3sat and Teleclub, the Dutch RTL4 as well as FilmNet, Screensport, MTV Europe, The Children's Channel and Lifestyle.[2] Astra 1A began television broadcasts on February 5, 1989. Until 1998 all of SES' satellites were co-located with 1A at 19.2° east, leading that position to be known mostly as Astra 1 (later, Astra 19.2°E), although Astra 2C also used to operate there, before it moved to 28.2° east in autumn 2007.{{citation needed|date=July 2012}} HistoryThe satellite came into its position on January 7, 1989. FilmNet became the first channel on the satellite when it launched on transponder 11 on February 1. Other channels such as Sky Channel, Eurosport, Sky News and Sky Movies from Sky Television, as well as the Scandinavian TV3 and MTV Europe all launched in February. The Children's Channel/Lifestyle and Screensport followed in March. The Scandinavian pay channel TV1000 launched in August 1989. Sky Television had originally planned to launch The Disney Channel and Sky Arts on the Astra satellite in 1989,[3] but these plans failed to materialize. The transponders intended for these channels, were used for Eurosport and the Dutch RTL Veronique (which would later become RTL4), respectively. The first German language programmes, RTL plus, Sat.1 and Pro 7 all launched on December 8. With the launch of 3sat in March 1990 and Teleclub in June all transponders were occupied. Lifestyle was replaced by VOX in January 1993. Soon thereafter, Screensport merged with Eurosport and its transponder was replaced by RTL2. RTL 4 moved to Astra 1D in 1995 and was replaced by Super RTL. Teleclub was replaced by Kabel 1 during the same year. TV3 and TV1000 left Astra in 1996 and their transponders were taken over by BSkyB who used them for Fox Kids/Sky Two and Granada Plus/Granada Men & Motors. Filmnet also left in 1996, to be replaced by Bloomberg Germany in 1997. BSkyB ended their analogue service in 2001, which meant that its services closed down. By the end of 2001, the satellite was moved from 19.2 degrees east to serve few years at 5.2 degrees east. On 19.2 degrees east, the satellite was replaced by Astra 1F. Many channels, including RTL II, RTL, Eurosport, VOX, Sat.1, Kabel Eins, Super RTL and ProSieben were still broadcasting in analogue on the same frequencies in 2009.[4] In December 2004 Astra 1A was moved into a "Graveyard orbit" after some time at 5.2°E providing data services. Technical issuesAs with all RCA Astro-manufactured satellites, the RCA AS-4000 Ku-band satellite design was used for the spacecraft bus, propulsion, thermal protection and solar array, the thermal protection made to protect Astra 1A's 16 transponder payload onboard. While never confirmed by SES, Astra 1A is believed to have experienced a number of technical problems throughout its lifetime, including overheating and power system anomalies.[5] After the launch of Astra 1C in 1993, two transponders (4 and 15) were moved from 1A to 1C.[5][6] Transponder 1 was also moved to Astra 1F after its launch, leaving 13 operational transponders on 1A in the late 1990s.[6] Between February and April 1999, transponder 10 was also moved to 1F.[7] In mid-1999, the satellite experienced a loss of power which reduced its usable payload to 6 transponders.[5][8] Transponders 3, 7, 8, 11, 12 and 16 remained on 1A while the others were transferred to 1F; 1C continued to carry 4 and 15 as before.[8] Documentation provided by SES since this event stated the usable payload as 5/6 transponders.[9] Transponders
References1. ^1 2 3 4 {{cite web|url=http://www.n2yo.com/satellite/?s=19688|title=ASTRA 1A Satellite details 1988-109B NORAD 19688|publisher=N2YO|date=January 23, 2015|accessdate=January 25, 2015}} 2. ^{{cite newsgroup|url=https://groups.google.com/group/eunet.followup/browse_thread/thread/744da2f168e2c99d/d6c1a3afb2226cd6|title=Astra satellite channels|date=September 9, 1990}} 3. ^Leaflet from Astra sent out to German reatilers in May 1989 {{webarchive |url=https://web.archive.org/web/20090319062856/http://www.broadbandtvnews.com/wp-content/gallery/astra/AstraLeaflet.jpg |date=March 19, 2009 }} 4. ^{{cite web|url=http://www.lyngsat.com/astra1f.html|title=Lyngsat Astra 1F|accessdate=February 8, 2009| archiveurl= https://web.archive.org/web/20090204013450/http://lyngsat.com/astra1f.html| archivedate=February 4, 2009 | deadurl= no}} 5. ^1 2 {{cite web|url=http://www.tbs-satellite.com/tse/online/sat_astra_1a.html|title=TSE - Astra 1A|accessdate=December 6, 2014}} 6. ^1 {{cite web|url=http://www.lyngsat.com/astra1a.shtml|title=LyngSat Astra 1A|accessdate=December 6, 2014| archiveurl= https://web.archive.org/web/19990209030514/http://www.lyngsat.com/astra1a.shtml| archivedate=February 9, 1999| deadurl=yes}} (channels marked AH1, AV2, AH2 or AV1 were on 1A) 7. ^{{cite web|url=http://www.lyngsat.com/astra1a.shtml|title=LyngSat Astra 1A|accessdate=December 6, 2014| archiveurl= https://web.archive.org/web/19990428105010/http://www.lyngsat.com/astra1a.shtml| archivedate=April 28, 1999| deadurl=yes}} (transponder 10 moved to 1F) 8. ^1 {{cite web|url=http://www.lyngsat.com/astra1a.shtml|title=LyngSat Astra 1F|accessdate=6 December 2014| archiveurl= https://web.archive.org/web/19991013132308/http://lyngsat.com/astra1f.shtml| archivedate=October 13, 1999| deadurl=yes}} (all but 6 transponders moved to 1C and 1F) 9. ^{{cite web|url=https://es.ses-astra.com/18579787/1A-footprint-fact-sheet.pdf|title=SES fact sheet on Astra 1A at 5.2° east (February 2003)|accessdate=June 12, 2014}} External links{{Portal|Spaceflight}}
6 : Astra satellites|Derelict satellites orbiting Earth|1988 in Luxembourg|Satellites of Luxembourg|First artificial satellite of a country|Spacecraft launched in 1988 |
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