A secret payload launched in 1970

In November nineteen seventy, a Titan IIIC rocket launched from Cape Canaveral Air Force Station carrying a top secret payload for the US military. The payload was a Defense Support Program satellite.

Watching for nuclear missile launches

The Defense Support Program satellites were sensitive infrared telescopes launched into geosynchronous orbit. Each carried about two thousand infrared detectors and could detect the launch of a nuclear warhead at the country.

Essential for Cold War deterrence

The Defense Support Program became one of the primary elements of American military space power during the Cold War. Initially built to identify Soviet ICBMs, they were essential for nuclear deterrence and later detected Iraqi Scud missile launches.

Fifty five years of continuous operation

For more than fifty five years, at least a handful of Defense Support Program satellites flew as silent sentinels. The final two surviving satellites, presumably DSP twenty and DSP twenty two, participated in an on orbit maneuvering exercise in early September.

Program officially retired last month

The two final satellites raised their orbits by a few hundred kilometres in early September, a move associated with disposing of them into graveyard orbits. The US Space Force confirmed this marked the Defense Support Program's official retirement.

“The DSP constellation was foundational to the defense of our nation.”

Newer systems take over the mission

The Space Based Infrared System began launching in two thousand eleven with better sensors that detect dimmer events and provide longer warning time. The military is developing Next Generation Overhead Persistent Infrared satellites, with the first potentially launching within twelve months on a Vulcan rocket.