In brief
The satellites used infrared sensors to detect ballistic missile launches, serving a programme that spanned more than half a century.
The US Space Force has retired the last two satellites in its Defense Support Program, RBC-Ukraine reported on October 7, citing Gizmodo. RBC-Ukraine’s report did not specify the retirement date.
Operating in geostationary orbit, DSP satellites used infrared sensors to detect heat from ballistic missile engines. Initially designed to spot Soviet intercontinental ballistic missiles, the system later tracked Iraqi Scud launches during Operation Desert Storm.
The United States launched 23 DSP satellites between 1971 and 2007, according to the report. Successor programmes include the Space Based Infrared System, whose launches began in 2011, and Next-Generation Overhead Persistent Infrared. The report did not specify the deployment status of all Next-Gen OPIR components.