Satellite Data System (SDS) spacecraft are communication relay satellites for transmitting real-time data from US reconnaissance satellites (e.g. KH-11, Onyx, Topaz) in polar areas. They are also used for communications to USAF aircraft on polar routes and connect the various ground stations of the Air Force Satellite Control Network (AFSCN). The spacecraft relay the downlinked data to a ground station at Fort Belvoir, Virginia.
These satellites are the third generation of the system, the SDS-3. Some of them (#15, #16) are in highly elliptical Molniya orbits, but the other (#13, #14, #17, #18, #19) have a geostationary position. Unlike the Trumpet Follow On SIGINT satellites, the SDS-3 satellites are not placed directly into the Molniya orbit, but use a lower apogee transfer orbit. The replensihment of the Molniya-orbit constellation appears to have ended with the 2007 launch.
The code-name QUASAR has been confirmed by leaked budgets in 2013 to be associated with these satellites.
Note: The numbering is not sure, as it is not confirmed, how many first generation Quasar were launched.
Note: The NROL designations refer to the launch, not to the payload.
|Type / Application:||Comsat / Relay, early warning|
|Orbit:||Molniya Orbit (#12, #15, #16), GEO (#13, #14, #17, #18, #19)|
|Quasar 13 (SDS-3 1, USA 155, NROL 10)||2000-080A||06.12.2000||CC SLC-36A||Atlas-2AS|
|Quasar 14 (SDS-3 2, USA 162, NROL 12)||2001-046A||11.10.2001||CC SLC-36B||Atlas-2AS|
|Quasar 15 (SDS-3 3, USA 179, NROL 1)||2004-034A||31.08.2004||CC SLC-36A||Atlas-2AS|
|Quasar 16 (SDS-3 4, USA 198, NROL 24)||2007-060A||10.12.2007||CC SLC-41||Atlas-5(401)|
|Quasar 17 (SDS-3 5, USA 227, NROL 27)||2011-011A||11.03.2011||CC SLC-37B||Delta-4M+(4,2)|
|Quasar 18 (SDS-3 6, USA 236, NROL 38)||2012-033A||20.06.2012||CC SLC-41||Atlas-5(401)|
|Quasar 19 (SDS-3 7, USA 252, NROL 33)||2014-027A||22.05.2014||CC SLC-41||Atlas-5(401)|