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Lacrosse or Onyx is a series of terrestrial radar imaging reconnaissance satellites operated by the United States National Reconnaissance Office (NRO). While not officially confirmed by the NRO or anybody in the U.S. government, for a long time, there was and is widespread evidence to confirm its existence, including one NASA website.〔(NASA - NSSDC - Spacecraft - Details )〕 In July 2008, the NRO itself declassified the existence of their SAR satellite constellation.〔(DoD Buzz | Spy Radar Satellites Declassified )〕〔http://www.nro.gov/NRO_Almanac.pdf〕 According to former Director of Central Intelligence Admiral Stansfield Turner, Lacrosse had its origins in 1978 when a dispute between the Central Intelligence Agency and the U.S. Air Force as to whether a combined optical/radar reconnaissance satellite (the CIA proposal) or a radar-only one (the USAF proposal) should be developed was resolved in favor of the USAF. Lacrosse uses synthetic aperture radar as its prime imaging instrument.〔(Lacrosse / Onyx )〕〔(Ups and Downs of Space Radars )〕 It is able to see through cloud cover and also has some ability to penetrate soil, though there have been more powerful instruments deployed in space for this specific purpose. Early versions are believed to have used the Tracking and Data Relay Satellite System (TDRSS) to relay imagery to a ground station at White Sands, New Mexico. There are some indications that other relay satellites may now be available for use with Lacrosse. The name ''Lacrosse'' is used to refer to all variants, while ''Onyx'' is sometimes used to refer to the three newer units. Unit costs (including launch) in 1990 dollars are estimated to be in the range of US$0.5 to 1.0 billion (inflation adjusted US$}} to }} billion in ).〔(【引用サイトリンク】year=September 1990 )〕 == Future == It had been anticipated that the Lacrosse satellites would be replaced by the radar component of the Future Imagery Architecture (FIA). The severe program problems encountered by FIA in the early 2000s (decade) led to a plan to off-load radar reconnaissance to the Space Based Radar, later simplified to Space Radar, with initial launch anticipated around 2015.〔(The Space Review: Radar love: the tortured history of American space radar programs )〕 This program itself was axed by Congress late 2008.〔 The launch of NROL-41 (USA 215) in September 2010 has all orbital characteristics of a radar remote sensing platform (see FIA) and could be the first of a Lacrosse follow-up program. Its orbit is a retrograde version of the "frozen" Lacrosse orbit,〔(SeeSat-L Sep-10 : Updated elements )〕 the choice for a retrograde orbit itself indicating a SAR role.〔(SeeSat-L Oct-10 : Reason for FIA Radar 1/USA 215 retrograde orb )〕 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「Lacrosse (satellite)」の詳細全文を読む スポンサード リンク
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