| 词条 | Astra 3B |
| 释义 |
| name = Astra 3B | image = | image_caption = | mission_type = | operator = | website = | COSPAR_ID = | SATCAT = 36581 | mission_duration = 15 years | spacecraft_bus = | manufacturer = Astrium (now Airbus Defence and Space) | dry_mass = | launch_mass = {{convert|5472|kg}} | power = 10 kW | launch_date = {{start-date|May 21, 2010}} | launch_rocket = Ariane 5ECA V194 | launch_site = Kourou ELA-3 | launch_contractor = Arianespace | entered_service = | disposal_type = | deactivated = | auto = all | orbit_epoch = January 23, 2015, 04:48:48 UTC[1] | orbit_reference = Geocentric | orbit_regime = Geostationary | orbit_periapsis = {{convert|35785|km|mi}}[1] | orbit_apoapsis = {{convert|35798|km|mi}}[1] | orbit_inclination = 0.07 degrees[1] | orbit_period = 1436.07 minutes[1] | orbit_longitude = 23.5° East | orbit_slot = Astra 23.5°E | apsis = gee | trans_band = 52 Ku band 4 Ka band | trans_frequency = | trans_bandwidth = 33/36 megahertz | trans_capacity = | trans_coverage = | trans_TWTA = 140 watts | trans_EIRP = 52 decibel-watts | trans_HPBW = }} Astra 3B is one of the Astra communications satellites owned and operated by SES, launched in 2010 to the Astra 23.5°E orbital slot providing digital television and radio for direct-to-home (DTH), and two-way satellite broadband services across Europe and the Middle East. Astra 3B was used by SES to broadcast its first demonstration 8K television signal in May 2018.[2] HistoryThe satellite provides three broadcast beams, of horizontal and vertical polarisation that cover three areas of the Earth’s surface. The Pan-European Wide beam provides DTH reception on 60 cm dishes across Europe from Spain to the Black Sea and from Greece to Scandinavia. The European spot beam (for central and eastern Europe) and the Middle East spot beam (the Arabian Peninsula, Iran and Iraq) provide for contribution and distribution services, and data and IP trunking services between the two regions with Ka band uplink and downlink used in Europe and Ku band in the Middle East.[3] Astra 3B was finally launched in May 2010[4] after nearly two months delay caused by technical problems to the main stage pressurization system of the Ariane 5 rocket, including two on-the-launch-pad postponements on March 24, 2010 and April 9.[5] Astra 3B became commercially operational in June 2010 to initially provide DTH broadcast services mainly to the Benelux region and Eastern Europe as well as the two-way broadband service, ASTRA2Connect across Europe and the Middle East. In January 2011 Astra announced that Bulgarian DTH operator Satellite BG would launch a package of more than 60 standard definition channels and 12 high definition channels, including sports, film, factual and children’s TV, and all major Bulgarian public and commercial services on February 1, using three transponders on Astra 3B to reach TV homes across Bulgaria.[6] The deployment of Astra 3B helped to optimize the spectrum use at 23.5° east and enabled SES to release the Astra 1E and Astra 1G satellites previously at Astra 23.5°E for use at other orbital positions.[7] See also{{Portal|Spaceflight}}
References1. ^1 2 3 4 {{cite web|url=http://www.n2yo.com/satellite/?s=36581|title=ASTRA 3B Satellite details 2010-021A NORAD 36581|publisher=N2YO|date=January 23, 2015|accessdate=January 25, 2015}} 2. ^{{cite press release |url= https://www.ses.com/press-release/ses-showcases-its-first-broadcast-8k-television |title =SES Showcases its First Broadcast of 8K Television |publisher=SES |date=May 23, 2018|access-date=June 26, 2018}} 3. ^SES Astra ASTRA 3B Middle East spot beam. (February, 2009). Company factsheet 4. ^{{cite press release |publisher=SES ASTRA|date=May 22, 2010|url=http://www.ses.com/4233325/news/2010/4488421|title=ASTRA 3B SATELLITE SUCCESSFULLY LAUNCHED|accessdate = January 26, 2012}} 5. ^{{cite press release |publisher=Arianespace|date=April 14, 2010|url=http://www.arianespace.com/news-mission-update/2010/688.asp|title=Quality is focus of Arianespace following Ariane 5’s launch postponement |accessdate = January 26, 2012}} 6. ^{{cite press release |publisher=SES ASTRA |date=January 17, 2011|url=http://www.ses-astra.com/business/uk/news-events/news-latest/index.php?pressRelease=/pressReleases/pressReleaseList/11-01-17/index.php|title=SES ASTRA EXPANDS IN CENTRAL AND EASTERN EUROPE AND ENTERS THE BULGARIAN MARKET}} 7. ^{{cite press release |publisher=SES ASTRA|date=June 16, 2010|url=http://www.ses.com/4233325/news/2010/4488898|title=ASTRA 3B SATELLITE NOW OPERATIONAL |accessdate = January 26, 2012}} External links
7 : Astra satellites|Spacecraft launched in 2010|2010 in Luxembourg|Satellites of Luxembourg|Communications satellites in geostationary orbit|Ariane commercial payloads|Satellites using the Eurostar bus |
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