DOD has previously attempted to replace the Defense Support Program with :
The Defense Support Program is a strategic surveillance and early warning satellite system with an infrared capability to detect long - range ballistic missile launches , and has been operational for over 30 years .
DOD has previously attempted to replace the surveillance     with :
The Defense Support Program is a strategic surveillance and early warning satellite system with an infrared capability to detect long - range ballistic missile launches , and has been operational for over 30 years .