Editing Satellite Data System (section)

== SDS-1 ==
[[File:NRO comm satellite.PNG|thumb|upright=1.3|right|Releasable Picture of NRO satellite, possible SDS-1]]
[[File:USA179 SDS 3 4.jpg|thumb|upright=1.3|right|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 [[Cylinder|cylindrical]] in shape, roughly {{cvt|25|ft|m}} long. 980 [[watt]]s of electrical power were available from [[Photovoltaic module|solar panel]]s and [[Electric battery|batteries]]. The SDS-1 had a mass of {{cvt|630|kg}} and was launched on [[Titan (rocket family)|Titan-3B]] rockets. The SDS-1 satellites had similar orbits to the Air Force's [[Jumpseat (satellite)|Jumpseat]] [[Signals intelligence|ELINT]] satellites.<ref>[http://www.zianet.com/jpage/black/NRO%20Brochure.pdf National Reconnaissance Office: "NRO Brochure circa 1997"]{{dead link|date=December 2017|bot=InternetArchiveBot|fix-attempted=yes}}</ref>

It has been speculated that the early satellites served as data relays for the first [[KH-11 Kennen]] reconnaissance satellites.<ref name=TheSpaceReview20180267>{{cite web|first=Dwayne A.|last=Day|date=26 February 2018|url=http://www.thespacereview.com/article/3440/1|title=Shadow dancing: the Satellite Data System|publisher=The Space Review}}</ref>