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Astra 1K was a communications satellite manufactured by Alcatel Space for SES. When it was launched on November 25, 2002 it was the largest civilian communications satellite ever launched, with a mass of .〔 (【引用サイトリンク】 Proton 8K82K / 11S861-01 )〕 Intended to replace the Astra 1B satellite and provide backup for 1A, 1C and 1D at the Astra 19.2°E orbital position, the Blok DM3 upper stage of the Proton launch vehicle failed to function properly, leaving the satellite in an unusable parking orbit. Although some attempts were made to "rescue" the satellite, it was intentionally de-orbited on December 10, 2002.〔(ASTRA 1K - Satellite Information ), accessed 2013-09-27〕 The satellite featured frequency re-use for some of its transponders, using dual patterns coverage, one covering eastern Europe, the other covering Spain. This design was meant to cover specific markets only, in order to expand the capacity of the fleet, as frequency re-use enables more channels to be transmitted simultaneously at the same frequency, with the drawback that channels broadcast on the Spain beam wouldn't be receivable by any means (no matter how large the receiving dish would be) in the east beam and vice versa. This would have left for example the Netherlands and parts of neighbouring countries without reception of either of the beams, as the beams overlap over those countries, efficiently jamming each other. Astra 1K also featured multiple Ka Band capabilities, originally intended to provide an upload path for satellite internet services. SES later developed such a 2-way commercial satellite internet service with ASTRA2Connect, using Ku band for upload and download paths. A replacement craft, Astra 1KR was successfully launched in 2006. ==See also== *SES *Astra *Astra 19.2°E *Astra 1A *Astra 1B *Astra 1C *Astra 1KR 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「Astra 1K」の詳細全文を読む スポンサード リンク
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