For over 50 years the Pentagon has had early warning satellites in orbit aimed at spotting launches of ballistic missiles, especially the big intercontinental kind that can fly around the globe in less than 30 minutes and bring about nuclear Armageddon. Recently, these satellites have made news for their “secondary capabilities,” spotting the downing of Metrojet Flight 9268 and Malaysian Airlines Flight 17. These are the shadowy satellites that are capable of such amazing feats, and an idea of how they work.


In 1960, at the height of the Cold War and at the dawn of the space age, the first Missile Defense Alarm System (MiDAS) satellite was launched into low earth orbit. Six years later there was a constellation of nine of these satellites roaming the heavens, each scanning the Soviet Union for large infrared plumes, the tell-tale sign of a ballistic missile or rocket launch.

These fairly crude, low-earth orbit satellites, along with the radar-based Ballistic Missile Early Warning System, would be the basis for a Cold War ballistic missile surveillance system that would become ever more complex and capable as the years went by. If ballistic missile launches were detected and deemed a threat, the decision to retaliate would mean the National Command Authority making the call to do so within half an hour, an act that could bring an the end of humanity’s reign on Earth, permanently.

The first really reliable and full coverage space-based ballistic missile early warning capability came with the launch of the first Defense Support Program (DSP) satellite in 1970. These new satellites were much more capable than their MiDAS predecessors.


Early DSP satellite design was relatively straight forward, with the satellites’ spinning around their center axis while in geosynchronous orbit. This allows their telescopic infrared sensor to continuously sweep an area of the planet in a relatively brief amount of time, around six times in one minute. If something were detected, the information would immediately be data-linked to controllers on the ground at the 460th Space Wing located at Buckley AFB in in Colorado.

A total of 23 of these satellites have been launched over the program’s life, with constant upgrades made along the way. A DSP satellite was launched by the Space Shuttle on STS-44 in 1991, and the last one was launched by a Delta IV Heavy in 2007. Most famously, the Defense Support Program constellation of satellites were used to detect launches of SCUD missiles during Operation Desert Storm.

Although many DSP satellites are still in service today, the next generation of infrared ballistic missile early warning satellites has arrived and is called Space-Based Infrared System, or SBIRS (pronounced “sibbers”)for short. This vastly upgraded capability is based around two types of satellite payloads, the main geostationary orbit type has two-sensors instead of one, a scanner and a step-starer.

This dual sensor design gives SBIRS the ability to scan a wide area of the earth’s surface and stare at, or quickly flip between others areas in great detail, at the same time. This way, one sensor can view the globe persistently for launch detection, while the other can be tasked to more closely watch certain regions or even possibly to track missiles not just during launch, but after their rocket motors burn out and they are coasting in space or the extremes of the upper atmosphere. In doing so, the system can help differentiate the reentry vehicles/warheads from decoys or debris. This data can then be incorporated into the National Missile Defense sensor information “ecosystem”for tracking and targeting.

The other highly elliptical orbit type of SBIRS payload is launched as part of a vehicle carrying multiple systems and uses a single infrared detection device that can be steered like a telescope. The two systems in separate orbits work together to give expanded coverage and detection capabilities.



SBIRS can also be used to collect intelligence on enemy and friendly ballistic missile and rocket test launches. From this data, capabilities can be closely evaluated. North Korea, Russia, China and Iran are of particular interest. SBIRS or a DSA satellite also detect the shooting down of MH17 and the explosion aboard Metrojet 9268. Wildfires and volcano eruptions are also said to be able to be detected with these satellites.

Because SBIRS high-fidelity sensors, which are said to be at least three times as sensitive as older systems, it is rumored that these satellites can detect and possibly track many other things than just ballistic missile launches. These speculations include surface-to-air and air-to-air missiles, artillery fire, and even aircraft in flight. It is also unclear if SBIRS high-fidelity infrared scanning capabilities are linked into the USAF’s real-time intelligence air combat capability. For instance, are air-to-air missile, or surface-to-air missile launches, or even the detection of enemy aircraft and their locations made by SBIRS relayed to battlefield command and control assets and passed on to combat aircraft flying in harms way in real time? Obviously such a capability would be highly useful.

Currently there are six SBIRS satellites in orbit. Two are payloads aboard classified satellites which are in high-elliptical orbit (HEO) around the poles and four dedicated SBIRS two-sensor satellites are in geosynchronous orbit. The SBIRS constellation will continue to grow, with the 7th and 8th units already on the procurement horizon. Each satellite is stated to last at least 12 years, but their life-cycle can be extended if fuel is conserved.

This animation shows this amazing constellation of new satellites, and their DSP cousins, in action.

Even with their high cost, with an estimated price tag on average of about $1.1 billion dollars per satellite, and much more when research and development is factored in, the capability SIBRS provides has become more of necessity in recent years.


Russia has surged back onto the geopolitical scene in a not so calm manner, and is rapidly remodeling its intercontinental ballistic missile inventory. Iran has become a more powerful player in the middle east, a country that has ever more capable ballistic missiles. North Korea not only has an array of ballistic missiles but they also possess nuclear weapons capability. It is only a matter of time until they can miniaturize and harden a nuclear warhead so that it can be deployed aboard one of their ballistic missiles. China is rapidly expanding its ballistic missile capabilities, including adding conventional warheads that can target warships from thousands of miles away. Finally, not-state actors are always looking to acquire ballistic missile capability, and there has been increasing use of short-range ballistic missiles by groups such as Houthi rebels in Yemen and ISIS in Syria has been seen toting SCUDs in the past.

Because the U.S. does not have a way of defending itself against a large-scale nuclear ballistic missile attack, SBIRS and DSP are critical assets as they underscore the feasibility of America’s nuclear deterrent. Because we can see an enemy missile launch as it occurs, we have more time to respond to an incoming attack. This makes our nuclear deterrent credible.


Without these satellites we would depend on radar alone, which has a limited view due to the curvature of the earth and can itself be preemptively attacked. Because a portion of Russia and China’s nuclear arsenal is deployed on submarines that are hard to track and detect, enemy missiles could arrive over the U.S. in just a few minutes from the time they are launched. As such, every second is critical not just to respond operationally, but to make potential enemies believe the U.S. can do so in a very short period of time. In other words, beyond offering useful tactical intelligence, these satellites make our modern nuclear deterrent much more credible and in doing so, much more effective.

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