Defense Support Program (DSP) satellites have been monitoring the skies as America’s early-warning system for ballistic missile launches since their first launch in 1970. The current Satellite Early Warning System (SEWS) consists of 5 DSP satellites; 3 provide frontline operational service, with 2 available as backups should problems emerge with the primary satellites.
The program’s lifetime has seen the launch of 23 DSP satellites, and improvements to DSP via 5 upgrade sets have allowed those satellites to exceed their design lifespan. The USAF’s fact sheet lists the satellites’ unit cost at $400 million, though they do not mention what fiscal year baseline that figure is linked to. While the DSP satellites successfully detected Iraqi SCUD launches during Operation Desert Storm, testimony before Congress has noted that there are some classes of missiles the DSP constellation has trouble with. The USAF’s way over-budget SBIRS program was created to address that, but the DSP constellation will be up for a long time. This entry will be updated to cover new developments, contracts, and more.