Missile warning

What it is

Missile warning is the detection, tracking, and characterization of ballistic and hypersonic missile launches in time for political and military leaders to respond. The US system has two mutually reinforcing layers: space-based infrared sensors that detect the heat signature of a rocket motor within seconds of launch, and ground-based phased-array radars that track objects above the radar horizon. The US Space Force operates both layers, feeding raw data to NORAD, the US-Canada bi-national command, and to US Strategic Command, which issue attack assessments within minutes. For an ICBM fired at the continental United States, the warning window is 25 to 30 minutes; for a submarine-launched or shorter-range missile, it can fall below ten.

History

The United States built its first systematic missile warning architecture during the Cold War. The Ballistic Missile Early Warning System (BMEWS) became operational between 1960 and 1964 at three Arctic stations: Clear Space Force Station in central Alaska, Pituffik Space Base in Greenland, and RAF Fylingdales in the United Kingdom. The geometry gave US commanders 10 to 25 minutes of warning before a Soviet ICBM reached American soil. A complementary space layer, the Defense Support Program (DSP), began operating from geosynchronous orbit in 1970, detecting launches by their infrared signature rather than radar cross-section. DSP operated for nearly four decades.

Congress approved the DSP replacement, the Space-Based Infrared System (SBIRS), in 1996 with an estimated cost of $4.4 billion for five satellites. Chronic software problems and requirements growth pushed that figure to $18.3 billion for six satellites by 2012, one of the largest development cost overruns in US satellite history. SBIRS reached initial operating capacity in 2013, and the sixth GEO satellite launched in 2022, completing the constellation.

Current state

As of mid-2026, six SBIRS satellites in geosynchronous orbit and two SBIRS-hosted sensors in high elliptical orbit (HEO) remain the backbone of US space-based warning. The successor program, Next Generation Overhead Persistent Infrared (Next-Gen OPIR), is in production. Lockheed Martin holds the GEO prime contract and delivered the first satellite in September 2025; launch is scheduled no earlier than mid-2026. Northrop Grumman is developing two polar Next-Gen OPIR satellites targeting 2028 launch. In April 2026 the US Space Force awarded Lockheed a $68.6 million contract modification to continue Next-Gen OPIR work.

A parallel hypersonic-focused sensor layer, the Hypersonic and Ballistic Tracking Space Sensor (HBTSS), placed two prototypes in orbit in February 2024. L3Harris, the HBTSS prime contractor, declared readiness for full-rate production in April 2025, and a March 2025 Missile Defense Agency test confirmed that HBTSS data could detect, track, and feed a simulated intercept of a maneuvering hypersonic target. FY26 US reconciliation legislation added $7.2 billion for space-based sensors to sustain and expand the warning architecture.

On the ground, three Upgraded Early Warning Radars (UEWR) operate at Beale Air Force Base in California, RAF Fylingdales in the UK, and Pituffik Space Base in Greenland. Beale was the first to complete its upgrade, in 2005. All three now pass tracking data directly to the Ground-based Midcourse Defense (GMD) interceptor network.

Relationships

The US Space Force missile-warning portfolio draws on over $40 billion in FY26 funding once reconciliation is counted. The space sensor layer fronts the broader Golden Dome missile defense architecture, feeding tracks to interceptors via the proliferated LEO sensor constellation. Threat analysts cite North Korea's ballistic test tempo and China's DF-17 hypersonic glide vehicle as the programs that most strain the legacy SBIRS design, built before maneuvering warheads became a primary concern. The counterspace threat is driving survivability requirements into Next-Gen OPIR that SBIRS never needed.

What to watch

• The first Next-Gen OPIR GEO satellite launch, expected in 2026, will be the first new US space-based warning satellite in four years and the test of Lockheed's survivability improvements.
• An L3Harris full-rate HBTSS production contract and quantity decision, which will determine the density and tracking quality of the hypersonic-capable sensor layer feeding Golden Dome.
• Whether FY27 US appropriations sustain the $7.2 billion reconciliation-level investment in space sensors, or whether Congress treats it as a one-time surge.
• The Space Force polar Next-Gen OPIR schedule, now targeting 2028 under Northrop Grumman, which closes the final coverage gap in the space-based warning grid.