Editing Satellite Data System (section)

{{Short description|American military satellite communication system}}
{{Use American English|date=January 2019}}
{{Use dmy dates|date=January 2021}}

[[File:SDS3 const.png|thumb|upright=1.3|right|The current SDS-3 constellation, consisting of three [[Molniya orbit]] type and two geostationary satellites]]

The '''Satellite Data System''' ('''SDS''') is a system of United States [[military satellite|military communications satellite]]s.  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''.<ref>[http://planet4589.org/nro/nro.html Jonathan's Space Report: ''NRO Satellite Names'']</ref> The first generation was named simply 'SDS', the second generation was named 'Quasar' and the third generation each had their own designations.<ref>[http://planet4589.org/space/log/satcat.txt Jonathan's Space Report: ''Satellite Catalogue'']</ref>