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The A2100 is a communications satellite spacecraft model made by Lockheed Martin Space Systems in the 1990s-2010s for telecommunications in geosynchronous orbit. The Lockheed Martin A2100 geosynchronous spacecraft series is designed for a variety of telecommunications needs including Ka band broadband and broadcast services, fixed satellite services in C-band and Ku band payload configurations, high-power direct broadcast services using the Ku band frequency spectrum, and mobile satellite services using UHF, L-band and S-band payloads.〔("Lockheed Martin: A2100" )〕 The A2100 satellite system was developed by a Skunk Works team at the Astro Space East Windsor, New Jersey facility. A group of Space Architects, including Brian Stewart, John Close, Pete Wise, Jim Wilson (GE R&D Lab), and Keith Davies delivered a flexible common bus with fewer components, lower spacecraft weight, and reduced customer delivery time.〔("A2100 History" )〕 The first satellite, AMC-1, was launched September 8, 1996, and has achieved 15-year on-orbit service life. Since 1996 there have been over 45 of the A2100 based satellites launched, with over 400 years of total on-orbit service.〔("Lockheed Martin-Built A2100 Satellites: Over 400 Cumulative Years In Orbit And Counting" )〕 Recent A2100 spacecraft include JCSAT-13 and VINASAT-2, which were launched May, 2012 on an Ariane 5 rocket. 〔("Ariane 5 ECA launches JCSAT-13 and VINASAT-2 into orbit" )〕 In 2002 Lockheed Martin Commercial Space Systems was given a Frost and Sullivan Satellite Reliability Award for excellence in the production of flexible and reliable communications satellites used in geosynchronous Earth orbit.〔("Frost & Sullivan Award )〕 A2100 customers includes communications companies around the world, including Astra, Telesat, JSAT Corporation and others. ==Propulsion system== The attitude control system includes reaction wheels, with momentum desaturation and main motor maneuver attitude control propulsion provided by small monopropellant hydrazine motors. This hydrazine supply is contained in a central propellant tank of 0.90 m diameter and up to 2.00 m length depending on the customer's requirements.〔("ATK SSI P/N 80395-1 Datasheet" )〕 This tank's maximum length was later increased to 2.55 m.〔("ATK SSI P/N 80443-1 )〕 The liquid apogee engine uses hydrazine fuel from the central tank along with nitrogen tetroxide oxidizer from two flanking tanks of 0.54 m diameter and up to 1.65 m long.〔("ATK SSI P/N 80405-1 Datasheet" )〕 Orbit maintenance is performed by the small hydrazine motors and ion thrusters.〔("Lockheed Martin-Built A2100 Satellites: Over 400 Cumulative Years In Orbit And Counting" )〕 The maximum propellant supply (with the largest tanks at 95% fill factor) are 1368 kg of hydrazine fuel and 627 kg of nitrogen tetroxide oxidizer. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lockheed Martin A2100」の詳細全文を読む スポンサード リンク
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