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Satellite Data System
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<h2 id="orbital-characteristics">Orbital characteristics</h2> <p>SDS satellites have a <a href="/facts/Highly_elliptical_orbit/93YbggYy">highly elliptical orbit</a>, going from about 300 kilometers at <a href="/facts/Apsis/VaL6ow9w">perigee</a> to roughly 39,000 km at <a href="/facts/Apsis/VaL6ow9w">apogee</a> in order to allow communications with <a href="/facts/Geographical_pole/dTShPqll">polar</a> stations that cannot contact <a href="/facts/Geosynchronous/nR2yaeUg">geosynchronous</a> 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 <a href="/facts/Hughes_Aircraft_Company/NURPFI17">Hughes Aircraft Company</a>. </p> <h2 id="mission">Mission</h2> <p>The primary purpose of the SDS satellites is to relay imagery from low-flying <a href="/facts/Reconnaissance_satellite/LkL0IYHH">reconnaissance satellites</a>, notably the <a href="/facts/Corona_(satellite)/oBd9damh">Keyhole</a> optical reconnaissance and <a href="/facts/Lacrosse_(satellite)/lCvLP91E">Lacrosse/Onyx</a> radar reconnaissance satellites to ground stations in the <a href="/facts/United_States/P0sCdLe5">United States</a>.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> </p> <h2 id="sds-1">SDS-1</h2> <p>Each SDS-1 satellite had 12 channels available for <a href="/facts/Ultra_high_frequency/S6XDUaDY">Ultra high frequency</a> (UHF) communication. They were <a href="/facts/Cylinder/0wQPPr3k">cylindrical</a> in shape, roughly 25 ft (7.6 m) long. 980 <a href="/facts/Watt/VK8oqRrm">watts</a> of electrical power were available from <a href="/facts/Photovoltaic_module/5Xefaayl">solar panels</a> and <a href="/facts/Electric_battery/bqEpm4ue">batteries</a>. The SDS-1 had a mass of 630 kg (1,390 lb) and was launched on <a href="/facts/Titan_(rocket_family)/sTTkEDps">Titan-3B</a> rockets. The SDS-1 satellites had similar orbits to the Air Force's <a href="/facts/Jumpseat_(satellite)/hK9347lM">Jumpseat</a> <a href="/facts/Signals_intelligence/Iwzvw6AW">ELINT</a> satellites.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> </p><p>It has been speculated that the early satellites served as data relays for the first <a href="/facts/KH-11_Kennen/yb96hV4E">KH-11 Kennen</a> reconnaissance satellites.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> </p> <h2 id="sds-2">SDS-2</h2> <p>The SDS-2 is significantly more massive at 2,335 kg (5,148 lb), with three separate communication dishes, including one for a <a href="/facts/K_band_(IEEE)/EgQjtNNL">K-band</a> 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 <a href="/facts/Space_Shuttle_program/6Ikdvwsw">Space Shuttle</a> has been used to launch several satellites, possibly on missions <a href="/facts/STS-28/JEPo0T1n">STS-28</a>, <a href="/facts/STS-38/HeUaVAEq">STS-38</a>, and <a href="/facts/STS-53/WLbzo0ED">STS-53</a>. Other launches have used the <a href="/facts/Titan_IV/H0TsgoPC">Titan IV</a> <a href="/facts/Launch_vehicle/g1GCGFJB">launch vehicle</a>. </p> <h2 id="satellites">Satellites</h2> <table><tbody><tr><th>Name</th><th><a href="/facts/International_Designator/AwfuQFUY">COSPAR ID</a><a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a><a href="/facts/Satellite_Catalog_Number/14wHsDDp">SATCAT №</a></th><th>Launch date</th><th>Launch vehicle</th><th>Launch site</th><th><a href="/facts/List_of_NRO_Launches/cr5CUmIT">Launch designation</a></th><th><a href="/facts/Perigee/VaL6ow9w">Perigee</a></th><th><a href="/facts/Apogee/VaL6ow9w">Apogee</a></th><th>Inclination</th><th>Remarks</th></tr><tr><td colspan="10"><h3>First generation</h3></td></tr><tr><td>OPS 7837</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1976-050A">1976-050A</a>08871</td><td>2 June 1976</td><td><a href="/facts/Titan_IIIB/aWEncKhf">Titan III(34)B</a></td><td><a href="/facts/Vandenberg_Air_Force_Base/CHNed3F4">VAFB</a>, <a href="/facts/Vandenberg_Space_Launch_Complex_4/JVoP1fwD">SLC-4W</a></td><td>SDS F-1</td><td>380 km</td><td>39315 km</td><td>63.3 deg</td><td></td></tr><tr><td>OPS 7940</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1976-080A">1976-080A</a>09270</td><td>6 August 1976</td><td><a href="/facts/Titan_IIIB/aWEncKhf">Titan III(34)B</a></td><td><a href="/facts/Vandenberg_Air_Force_Base/CHNed3F4">VAFB</a>, <a href="/facts/Vandenberg_Space_Launch_Complex_4/JVoP1fwD">SLC-4W</a></td><td>SDS F-2</td><td>380 km</td><td>39315 km</td><td>63.3 deg</td><td></td></tr><tr><td>OPS 7310</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1978-075A">1978-075A</a>10993</td><td>5 August 1978</td><td><a href="/facts/Titan_IIIB/aWEncKhf">Titan III(34)B</a></td><td><a href="/facts/Vandenberg_Air_Force_Base/CHNed3F4">VAFB</a>, <a href="/facts/Vandenberg_Space_Launch_Complex_4/JVoP1fwD">SLC-4W</a></td><td>SDS F-3</td><td>380 km</td><td>39315 km</td><td>63.3 deg</td><td></td></tr><tr><td>OPS 5805</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1980-100A">1980-100A</a>12093</td><td>13 December 1980</td><td><a href="/facts/Titan_IIIB/aWEncKhf">Titan III(34)B</a></td><td><a href="/facts/Vandenberg_Air_Force_Base/CHNed3F4">VAFB</a>, <a href="/facts/Vandenberg_Space_Launch_Complex_4/JVoP1fwD">SLC-4W</a></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>USA-4</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1984-091A">1984-091A</a>15226</td><td>28 August 1984</td><td><a href="/facts/Titan_IIIB/aWEncKhf">Titan III(34)B</a></td><td><a href="/facts/Vandenberg_Air_Force_Base/CHNed3F4">VAFB</a>, <a href="/facts/Vandenberg_Space_Launch_Complex_4/JVoP1fwD">SLC-4W</a></td><td>SDS F-5A</td><td></td><td></td><td></td><td></td></tr><tr><td>USA-9</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1985-014A">195-014A</a>15546</td><td>8 February 1985</td><td><a href="/facts/Titan_IIIB/aWEncKhf">Titan III(34)B</a></td><td><a href="/facts/Vandenberg_Air_Force_Base/CHNed3F4">VAFB</a>, <a href="/facts/Vandenberg_Space_Launch_Complex_4/JVoP1fwD">SLC-4W</a></td><td>USA-9</td><td></td><td></td><td></td><td></td></tr><tr><td>USA-21</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1987-015A">1987-015A</a>17506</td><td>15 February 1987</td><td><a href="/facts/Titan_IIIB/aWEncKhf">Titan III(34)B</a></td><td><a href="/facts/Vandenberg_Air_Force_Base/CHNed3F4">VAFB</a>, <a href="/facts/Vandenberg_Space_Launch_Complex_4/JVoP1fwD">SLC-4W</a></td><td>SDS F-6</td><td></td><td></td><td></td><td></td></tr><tr><td colspan="10"><h3>Second generation</h3></td></tr><tr><td>USA-40</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1989-061B">1989-061B</a>20167</td><td>2 June 1989</td><td><a href="/facts/Space_Shuttle/7BoyetEv">Space Shuttle</a> <a href="/facts/Space_Shuttle_Columbia/uF51RXWM"><i>Columbia</i></a><a href="/facts/STS-28/JEPo0T1n">STS-28</a>/Orbus-21S</td><td><a href="/facts/Kennedy_Space_Center/zmwszuPr">KSC</a>, <a href="/facts/Kennedy_Space_Center_Launch_Complex_39B/TS56c5d6">LC-39B</a></td><td rowspan="4">N/A</td><td></td><td></td><td></td><td></td></tr><tr><td>USA-67</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1990-097B">1990-097B</a>20963</td><td>15 November 1990</td><td><a href="/facts/Space_Shuttle/7BoyetEv">Space Shuttle</a> <a href="/facts/Space_Shuttle_Atlantis/3NQUThEB"><i>Atlantis</i></a><a href="/facts/STS-38/HeUaVAEq">STS-38</a>/Orbus-21S</td><td><a href="/facts/Kennedy_Space_Center/zmwszuPr">KSC</a>, <a href="/facts/Kennedy_Space_Center_Launch_Complex_39A/pnH83f5s">LC-39A</a></td><td></td><td></td><td></td><td>Geosynchronous satellite, deployed along with <a href="/facts/Prowler_(satellite)/IqLlnYW5">Prowler</a> and initially misidentified as a <a href="/facts/Magnum_(satellite)/fB8w6oH2">Magnum</a> SIGINT spacecraft</td></tr><tr><td>USA-89</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1992-086B">1992-086B</a>22518</td><td>2 December 1992</td><td><a href="/facts/Space_Shuttle/7BoyetEv">Space Shuttle</a> <a href="/facts/Space_Shuttle_Discovery/MmSTr4G0"><i>Discovery</i></a><a href="/facts/STS-53/WLbzo0ED">STS-53</a>/Orbus-21S</td><td><a href="/facts/Kennedy_Space_Center/zmwszuPr">KSC</a>, <a href="/facts/Kennedy_Space_Center_Launch_Complex_39A/pnH83f5s">LC-39A</a></td><td></td><td></td><td></td><td></td></tr><tr><td>USA-125</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1996-038A">1996-038A</a>23945</td><td>3 July 1996</td><td><a href="/facts/Titan_IV/H0TsgoPC">Titan IV(405)A</a></td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Space_Launch_Complex_40/z6Ql3cuD">LC-40</a></td><td></td><td></td><td></td><td></td></tr><tr><td colspan="10"><h3>Third generation</h3></td></tr><tr><td>USA-137</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1998-005A">1998-005A</a>25148</td><td>29 January 1998</td><td><a href="/facts/Atlas_II/JBCEQcuF">Atlas IIA</a></td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Launch_Complex_36/IXGlSACg">SLC-36A</a></td><td>NROL-5</td><td></td><td></td><td></td><td><i>Capricorn</i>, <a href="/facts/Molniya_orbit/uGEqtoSw">Molniya orbit</a></td></tr><tr><td>USA-155</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2000-080A">2000-080A</a>26635</td><td>6 December 2000</td><td><a href="/facts/Atlas_II/JBCEQcuF">Atlas IIAS</a></td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Launch_Complex_36/IXGlSACg">SLC-36A</a></td><td>NROL-10</td><td></td><td></td><td></td><td><i>Great Bear</i>, geosynchronous satellite at 10° West</td></tr><tr><td>USA-162</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2001-046A">2001-046A</a>26948</td><td>11 October 2001</td><td><a href="/facts/Atlas_II/JBCEQcuF">Atlas IIAS</a></td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Launch_Complex_36/IXGlSACg">SLC-36B</a></td><td>NROL-12</td><td></td><td></td><td></td><td><i>Aquila</i>, geosynchronous satellite at 144° West</td></tr><tr><td>USA-179</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2004-034A">2004-034A</a>28384</td><td>31 August 2004</td><td><a href="/facts/Atlas_II/JBCEQcuF">Atlas IIAS</a></td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Launch_Complex_36/IXGlSACg">SLC-36A</a></td><td>NROL-1</td><td></td><td></td><td></td><td><i>Nemesis</i>, <a href="/facts/Molniya_orbit/uGEqtoSw">Molniya orbit</a>, final Atlas II launch</td></tr><tr><td><a href="/facts/USA-198/0tVeUd3w">USA-198</a></td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2007-060A">2007-060A</a>32378</td><td>10 December 2007</td><td><a href="/facts/Atlas_V/5SNgegyt">Atlas V</a> 401</td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Space_Launch_Complex_41/QBUVHdSb">SLC-41</a></td><td>NROL-24</td><td></td><td></td><td></td><td><i>Scorpius</i>, <a href="/facts/Molniya_orbit/uGEqtoSw">Molniya orbit</a></td></tr><tr><td><a href="/facts/USA-227/kw4qm0DL">USA-227</a></td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2011-011A">2011-011A</a>37377</td><td>11 March 2011</td><td><a href="/facts/Delta_IV/QWun0yHh">Delta IV-M+(4,2)</a></td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Space_Launch_Complex_37/bGEN3MjW">SLC-37B</a></td><td>NROL-27</td><td></td><td></td><td></td><td><i>Gryphon</i>, geosynchronous satellite at 10° West, replaced USA-155</td></tr><tr><td>USA-236</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2012-033A">2012-033A</a>38466</td><td>20 June 2012</td><td><a href="/facts/Atlas_V/5SNgegyt">Atlas V</a> 401</td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Air_Force_Station_Space_Launch_Complex_41/QBUVHdSb">SLC-41</a></td><td>NROL-38</td><td></td><td></td><td></td><td><i>Drake</i>, geosynchronous satellite at 144° West, replacement for USA-162</td></tr><tr><td>USA-252</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2014-027A">2014-027A</a>39751</td><td>22 May 2014</td><td><a href="/facts/Atlas_V/5SNgegyt">Atlas V</a> 401</td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Space_Launch_Complex_41/QBUVHdSb">SLC-41</a></td><td>NROL-33</td><td></td><td></td><td></td><td>Geosynchronous satellite</td></tr><tr><td>USA-269</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2016-047A">2016-047A</a>41724</td><td>28 July 2016</td><td><a href="/facts/Atlas_V/5SNgegyt">Atlas V</a> 421</td><td><a href="/facts/Cape_Canaveral_Air_Force_Station/dwJ9MCPH">CCAFS</a> <a href="/facts/Cape_Canaveral_Air_Force_Station_Space_Launch_Complex_41/QBUVHdSb">SLC-41</a></td><td>NROL-61</td><td></td><td></td><td></td><td><i>Spike</i>, <a href="/facts/Geosynchronous_orbit/nR2yaeUg">Geosynchronous orbit</a>, might be a new generation <a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a></td></tr><tr><td>USA-279</td><td><a href="https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2017-066A">2017-066A</a>42973</td><td>15 October 2017</td><td><a href="/facts/Atlas_V/5SNgegyt">Atlas V</a> 421</td><td><a href="/facts/Cape_Canaveral_Space_Force_Station/dwJ9MCPH">CCAFS</a>, <a href="/facts/Cape_Canaveral_Space_Launch_Complex_41/QBUVHdSb">SLC-41</a></td><td><a href="/facts/List_of_NRO_launches/cr5CUmIT">NROL-52</a></td><td></td><td></td><td></td><td>Likely <a href="/facts/Geosynchronous_orbit/nR2yaeUg">Geosynchronous orbit</a><a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a></td></tr></tbody></table> <ul> <li>Spaceflight portal</li></ul> <ul><li>Vick, Berman, Lindborg, Fellow (March 19, 1997) <a href="https://fas.org/spp/military/program/com/sds_1.htm">SDS-1 Military Communications Satellite</a> <a href="https://web.archive.org/web/20160828024008/http://fas.org/spp/military/program/com/sds_1.htm">Archived</a> 28 August 2016 at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a> <i>Federation of American Scientists</i> Accessed April 24, 2004</li> <li>Vick, Berman, Lindborg, Fellow, Pike, Aftergood (March 19, 1997) <a href="https://fas.org/spp/military/program/com/sds_2.htm">SDS-2 Military Communications Satellite</a> <a href="https://web.archive.org/web/20160920050553/https://fas.org/spp/military/program/com/sds_2.htm">Archived</a> 20 September 2016 at the <a href="/facts/Wayback_Machine/nmQ3a6JC">Wayback Machine</a> <i>Federation of American Scientists</i> Accessed April 24, 2004</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Jonathan's Space Report: NRO Satellite Names <a href="http://planet4589.org/nro/nro.html" target="_blank">http://planet4589.org/nro/nro.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Jonathan's Space Report: Satellite Catalogue <a href="http://planet4589.org/space/log/satcat.txt" target="_blank">http://planet4589.org/space/log/satcat.txt</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Richelson, J.T. (2001). The Wizards of Langley. Inside the CIA's Directorate of Science and Technology. Boulder, Colorado: Westview Press. ISBN 9780813340593. <a href="9780813340593" target="_blank">9780813340593</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>National Reconnaissance Office: "NRO Brochure circa 1997"[permanent dead link] <a href="http://www.zianet.com/jpage/black/NRO%20Brochure.pdf" target="_blank">http://www.zianet.com/jpage/black/NRO%20Brochure.pdf</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Day, Dwayne A. (26 February 2018). "Shadow dancing: the Satellite Data System". The Space Review. <a href="http://www.thespacereview.com/article/3440/1" target="_blank">http://www.thespacereview.com/article/3440/1</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Jonathan's Space Report: List of satellite launches <a href="http://planet4589.org/space/log/" target="_blank">http://planet4589.org/space/log/</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>"NROL-61 satellite launched Thursday spotted in space by sky-watchers". Spaceflight Now. 30 July 2016. <a href="https://spaceflightnow.com/2016/07/30/nrol-61-satellite-launched-thursday-spotted-in-space-by-sky-watchers/" target="_blank">https://spaceflightnow.com/2016/07/30/nrol-61-satellite-launched-thursday-spotted-in-space-by-sky-watchers/</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Graham, William (15 October 2017). "Atlas V finally launches with NROL-52". NASASpaceFlight.com. Retrieved 15 October 2017. <a href="https://www.nasaspaceflight.com/2017/10/ula-atlas-v-nrol-52-launch-cape-canaveral/" target="_blank">https://www.nasaspaceflight.com/2017/10/ula-atlas-v-nrol-52-launch-cape-canaveral/</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> </ol>