US Space Force retires final Defense Support Program missile-warning satellites

The US Space Force has officially ended its 55-year Defense Support Program after the last two DSP satellites raised their orbits in early September and were moved to graveyard orbits. The constellation detected missile launches since 1970.

• The final two DSP satellites raised their orbits by a few hundred kilometers in early September
• Early DSP satellites carried about 2,000 infrared detectors; later ones more than 6,000
• DSP satellites launched from 1970 to 2007, including DSP-16 aboard shuttle Atlantis in 1991
• DSP is succeeded by SBIRS and the upcoming NGI OPIR satellites, the first launching on Vulcan within a year