The Satellite Data System (SDS) is a system of United States militarycommunications satellites. At least three generations have been used: SDS-1 from 1976 to 1987; SDS-2 from 1989 to 1996; SDS-3 from 1998 to the present. It is believed that these satellites were known by the code name Quasar.[1] The first generation was named simply 'SDS', the second generation was named 'Quasar' and the third generation each had their own designations.[2]
The current SDS-3 constellation, consisting of three Molniya orbit type and two geostationary satellites
SDS satellites have a highly elliptical orbit, going from about 300 kilometers at perigee to roughly 39,000 km at apogee in order to allow communications with polar stations that cannot contact geosynchronous satellites. The high apogee meant that the polar regions were visible for long amounts of time, and only two satellites were required in order to achieve constant communications ability. In addition, two geostationary satellites appear to be part of the system. The SDS satellites were constructed by Hughes Aircraft Company.
Releasable Picture of NRO satellite, possible SDS-1
The SDS 3-4 satellite (USA 179, 2004-034A) created a tiny trail perpendicular to the star trails in this 10 second exposure with a Zeiss Sonnar MC 2.8/180mm lens made by amateur satellite observer Marco Langbroek.
Each SDS-1 satellite had 12 channels available for Ultra high frequency (UHF) communication. They were cylindrical in shape, roughly 25 ft (7.6 m) long. 980 watts of electrical power were available from solar panels and batteries. The SDS-1 had a mass of 630 kg (1,390 lb) and was launched on Titan-3B rockets. The SDS-1 satellites had similar orbits to the Air Force's JumpseatELINT satellites.[4]
It has been speculated that the early satellites served as data relays for the first KH-11 Kennen reconnaissance satellites.[5]
SDS-2
The SDS-2 is significantly more massive at 2,335 kg (5,148 lb), with three separate communication dishes, including one for a K-band downlink. Two dishes are 4.5 m (15 ft) in diameter, while the third is 2 m (6 ft 7 in) in diameter. The solar arrays generate 1238 watts of power. It is believed that the Space Shuttle has been used to launch several satellites, possibly on missions STS-28, STS-38, and STS-53. Other launches have used the Titan IVlaunch vehicle.
^Richelson, J.T. (2001). The Wizards of Langley. Inside the CIA's Directorate of Science and Technology. Boulder, Colorado: Westview Press. ISBN9780813340593.
^Day, Dwayne A. (26 February 2018). "Shadow dancing: the Satellite Data System". The Space Review.
^Jonathan's Space Report: List of satellite launches
^"NROL-61 satellite launched Thursday spotted in space by sky-watchers". Spaceflight Now. 30 July 2016.
^Graham, William (15 October 2017). "Atlas V finally launches with NROL-52". NASASpaceFlight.com. Retrieved 15 October 2017.
Vick, Berman, Lindborg, Fellow (March 19, 1997) SDS-1 Military Communications Satellite 28 August 2016 at the Wayback MachineFederation of American Scientists Accessed April 24, 2004
Vick, Berman, Lindborg, Fellow, Pike, Aftergood (March 19, 1997) SDS-2 Military Communications Satellite 20 September 2016 at the Wayback MachineFederation of American Scientists Accessed April 24, 2004
March 24, 2023
satellite, data, system, system, united, states, military, communications, satellites, least, three, generations, have, been, used, from, 1976, 1987, from, 1989, 1996, from, 1998, present, believed, that, these, satellites, were, known, code, name, quasar, fir. The Satellite Data System SDS is a system of United States military communications satellites At least three generations have been used SDS 1 from 1976 to 1987 SDS 2 from 1989 to 1996 SDS 3 from 1998 to the present It is believed that these satellites were known by the code name Quasar 1 The first generation was named simply SDS the second generation was named Quasar and the third generation each had their own designations 2 The current SDS 3 constellation consisting of three Molniya orbit type and two geostationary satellites Contents 1 Orbital characteristics 2 Mission 3 SDS 1 4 SDS 2 5 SDS 3 6 Satellites 6 1 First generation 6 2 Second generation 6 3 Third generation 7 ReferencesOrbital characteristics EditSDS satellites have a highly elliptical orbit going from about 300 kilometers at perigee to roughly 39 000 km at apogee in order to allow communications with polar stations that cannot contact geosynchronous satellites The high apogee meant that the polar regions were visible for long amounts of time and only two satellites were required in order to achieve constant communications ability In addition two geostationary satellites appear to be part of the system The SDS satellites were constructed by Hughes Aircraft Company Mission EditThe primary purpose of the SDS satellites is to relay imagery from low flying reconnaissance satellites notably the Keyhole optical reconnaissance and Lacrosse Onyx radar reconnaissance satellites to ground stations in the United States 3 SDS 1 Edit Releasable Picture of NRO satellite possible SDS 1 The SDS 3 4 satellite USA 179 2004 034A created a tiny trail perpendicular to the star trails in this 10 second exposure with a Zeiss Sonnar MC 2 8 180mm lens made by amateur satellite observer Marco Langbroek Each SDS 1 satellite had 12 channels available for Ultra high frequency UHF communication They were cylindrical in shape roughly 25 ft 7 6 m long 980 watts of electrical power were available from solar panels and batteries The SDS 1 had a mass of 630 kg 1 390 lb and was launched on Titan 3B rockets The SDS 1 satellites had similar orbits to the Air Force s Jumpseat ELINT satellites 4 It has been speculated that the early satellites served as data relays for the first KH 11 Kennen reconnaissance satellites 5 SDS 2 EditThe SDS 2 is significantly more massive at 2 335 kg 5 148 lb with three separate communication dishes including one for a K band downlink Two dishes are 4 5 m 15 ft in diameter while the third is 2 m 6 ft 7 in in diameter The solar arrays generate 1238 watts of power It is believed that the Space Shuttle has been used to launch several satellites possibly on missions STS 28 STS 38 and STS 53 Other launches have used the Titan IV launch vehicle SDS 3 EditSatellites EditName COSPAR ID 6 SATCAT Launch date Launch vehicle Launch site Launch designation Perigee Apogee Inclination RemarksFirst generation EditOPS 7837 1976 050A08871 2 June 1976 Titan III 34 B VAFB SLC 4W N AOPS 7940 1976 080A09270 6 August 1976 Titan III 34 B VAFB SLC 4WOPS 7310 1978 075A10993 5 August 1978 Titan III 34 B VAFB SLC 4WOPS 5805 1980 100A12093 13 December 1980 Titan III 34 B VAFB SLC 4WUSA 4 1984 091A15226 28 August 1984 Titan III 34 B VAFB SLC 4WUSA 9 195 014A15546 8 February 1985 Titan III 34 B VAFB SLC 4WUSA 21 1987 015A17506 15 February 1987 Titan III 34 B VAFB SLC 4WSecond generation EditUSA 40 1989 061B20167 2 June 1989 Space Shuttle ColumbiaSTS 28 Orbus 21S KSC LC 39B N AUSA 67 1990 097B20963 15 November 1990 Space Shuttle AtlantisSTS 38 Orbus 21S KSC LC 39A Geosynchronous satellite deployed along with Prowler and initially misidentified as a Magnum SIGINT spacecraftUSA 89 1992 086B22518 2 December 1992 Space Shuttle Discovery STS 53 Orbus 21S KSC LC 39AUSA 125 1996 038A23945 3 July 1996 Titan IV 405 A CCAFS LC 40Third generation EditUSA 137 1998 005A25148 29 January 1998 Atlas IIA CCAFS SLC 36A NROL 5 Capricorn Molniya orbitUSA 155 2000 080A26635 6 December 2000 Atlas IIAS CCAFS SLC 36A NROL 10 Great Bear geosynchronous satellite at 10 WestUSA 162 2001 046A26948 11 October 2001 Atlas IIAS CCAFS SLC 36B NROL 12 Aquilla geosynchronous satellite at 144 WestUSA 179 2004 034A28384 31 August 2004 Atlas IIAS CCAFS SLC 36A NROL 1 Nemesis Molniya orbit final Atlas II launchUSA 198 2007 060A32378 10 December 2007 Atlas V 401 CCAFS SLC 41 NROL 24 Scorpius Molniya orbitUSA 227 2011 011A37377 11 March 2011 Delta IV M 4 2 CCAFS SLC 37B NROL 27 Gryphon geosynchronous satellite at 10 West replaced USA 155USA 236 2012 033A38466 20 June 2012 Atlas V 401 CCAFS SLC 41 NROL 38 Drake geosynchronous satellite at 144 West replacement for USA 162USA 252 2014 027A39751 22 May 2014 Atlas V 401 CCAFS SLC 41 NROL 33 Geosynchronous satelliteUSA 269 2016 047A 41724 28 July 2016 Atlas V 421 CCAFS SLC 41 NROL 61 Spike Geosynchronous orbit might be a new generation 7 USA 279 2017 066A 42973 15 October 2017 Atlas V 421 CCAFS SLC 41 NROL 52 Likely Geosynchronous orbit 8 References Edit Spaceflight portal Jonathan s Space Report NRO Satellite Names Jonathan s Space Report Satellite Catalogue Richelson J T 2001 The Wizards of Langley Inside the CIA s Directorate of Science and Technology Boulder Colorado Westview Press ISBN 9780813340593 National Reconnaissance Office NRO Brochure circa 1997 permanent dead link Day Dwayne A 26 February 2018 Shadow dancing the Satellite Data System The Space Review Jonathan s Space Report List of satellite launches NROL 61 satellite launched Thursday spotted in space by sky watchers Spaceflight Now 30 July 2016 Graham William 15 October 2017 Atlas V finally launches with NROL 52 NASASpaceFlight com Retrieved 15 October 2017 Vick Berman Lindborg Fellow March 19 1997 SDS 1 Military Communications Satellite Archived 28 August 2016 at the Wayback Machine Federation of American Scientists Accessed April 24 2004 Vick Berman Lindborg Fellow Pike Aftergood March 19 1997 SDS 2 Military Communications Satellite Archived 20 September 2016 at the Wayback Machine Federation of American Scientists Accessed April 24 2004 Retrieved from https en wikipedia org w index php title Satellite Data System amp oldid 1142237452, wikipedia, wiki, book, books, library,
