| 词条 | AMC-21 |
| 释义 |
| name = AMC-21 | image = | image_caption = | mission_type = Communication | operator = {{nowrap|SES Americom (2008-2009)}} SES World Skies (2009—2011) SES S.A. (2011—) | website = | COSPAR_ID = 2008-038B | SATCAT = | mission_duration = 16 years | spacecraft_bus = STAR-2[1] | manufacturer = Thales Alenia Space Orbital | dry_mass = | launch_mass = {{convert|2500|kg|lb}}[1] | power = | launch_date = {{start-date|14 August 2008, 20:44|timezone=yes}} UTC | launch_rocket = Ariane 5ECA | launch_site = Kourou ELA-3 | launch_contractor = Arianespace | entered_service = | disposal_type = | deactivated = | orbit_epoch = | orbit_reference = Geocentric | orbit_regime = Geostationary | orbit_periapsis = | orbit_apoapsis = | orbit_inclination = | orbit_period = 24 hours | orbit_longitude = 125° West[2] | apsis = gee | trans_band = | trans_frequency = | trans_capacity = | trans_coverage = | trans_TWTA = | trans_EIRP = | trans_HPBW = }} AMC-21, or Americom-21, is a communications satellite operated by SES S.A., formerly SES World Skies and SES Americom. It was launched in August 2008 and is expected to remain in service for approximately 15 years. It is currently located at 125° West longitude. Spacecraft and mission designAMC-21 is based on a STAR-2 platform that provides 4.4 kilowatts of power for the communications payload. The platform will support a 15-year on-orbit mission life.[3] It carries 24 J band (IEEE {{Ku band}}) transponders, which will be used to broadcast television signals to Canada the Caribbean, Mexico, and the United States.[2] Manufacture and launchThales Alenia Space was the prime contractor for AMC-21, and provided the satellite's communications payload. The STAR-2 bus was subcontracted to Orbital Sciences Corporation, as were integration and testing of the satellite.[3] As prime contractor, Thales Alenia Space delivered the completed satellite to SES Americom. AMC-21 was launched, along with the Superbird 7 satellite, by an Ariane 5ECA rocket on 14 August 2008.[4] The satellite separated from the carrier rocket in a geosynchronous transfer orbit. An onboard IHI-500N engine then raised it to an operational geosynchronous orbit and placed it at a longitude of 125° West of the Greenwich Meridian.[1] After successful completion of in-orbit testing, SES Americom took operational control of AMC-21 in September 2008.[5] In September 2009, SES Americom merged with SES New Skies to form SES World Skies, to which all of its operational satellites, including AMC-21, were transferred. External links
References1. ^1 2 {{cite web|url=http://space.skyrocket.de/doc_sdat/amc-21.htm |publisher=Gunter's Space Page |title= AMC-21}} {{SES World Skies}}{{Orbital launches in 2008}}{{Use American English|date=January 2014}}2. ^1 {{cite web|url=http://www.ses.com/4628068/amc-21|publisher=SES|title= AMC-21}} 3. ^1 {{cite web |url=http://www.orbital.com/SatellitesSpace/Communications/AMC21/index.shtml |title=AMC-21 |publisher=Orbital Sciences Corporation}} 4. ^{{cite press|title=Another successful Arianespace launch: Superbird-7 and AMC-21 in orbit |publisher=Arianespace |date=August 14, 2008 |url=http://www.arianespace.com/news-press-release/2008/08-14-08-Superbird7-AMC-21-launch.asp |deadurl=yes |archiveurl=https://web.archive.org/web/20100918032347/http://arianespace.com/news-press-release/2008/08-14-08-Superbird7-AMC-21-launch.asp |archivedate=September 18, 2010 }} 5. ^{{cite press|url=http://www.orbital.com/NewsInfo/release.asp?prid=674 |title=Orbital Reports Third Quarter 2008 Financial Results |date=16 October 2008 |publisher=Orbital}} 4 : Communications satellites in geostationary orbit|Spacecraft launched in 2008|SES satellites|Satellites using the GEOStar bus |
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