Space Force Retires Aging Warning Satellites

November 2026

The U.S. Space Force retired its final two satellites in a missile-warning constellation that operated for more than five decades as the service prepares to field its next-generation infrastructure amid quickening competition over space dominance.

Illustration of a Defense Support Program satellite on station. The U.S. Space Force recently retired its final two satellites in a DSP missile warning constellation as it moves to deploy new systems. (Photo courtesy of Northrop Grumman)

Ahead of decommissioning, the satellites participated in a U.S. Space Command exercise in early September before being moved into a graveyard orbit, the Space Force’s Combat Forces Command announced Oct. 1.

First launched into orbit in 1970, Defense Support Program (DSP) satellites used infrared sensors to detect missile launches and provide early warning of potential nuclear attacks during the Cold War. The constellation later supported detection of theater missile launches during the 1991 Gulf War and helped protect U.S. forces in subsequent conflicts.

“These last two satellites were the culminating end to over a half century of space-based early warning. The DSP constellation ensured deterrence during the Cold War and protected our deployed war-fighters from the Gulf War until their retirement last month,” said U.S. Space Force Col. Brandon Davenport, the Mission Delta 4 commander.

The military has since deployed the space-based infrared system constellation, which has provided improved missile-warning capabilities through more advanced infrared sensors since 2011. There are currently four of these sensors aboard satellites in highly elliptical orbit and six satellites in geosynchronous orbit. The Space Force is now developing Next-Generation Overhead Persistent Infrared satellites to replace the space-based infrared system and improve detection of smaller missile threats.

In August 2025, contractor Lockheed Martin announced that the first geosynchronous next-gen satellite had completed environmental testing, including thermal vacuum and acoustic tests. Recent anticipated launch dates for the satellites have passed, and new anticipated launch dates have been set for as late as 2029. In the fiscal year 2027 defense budget, the Space Force has proposed terminating the polar satellites in favor of lower-orbital satellites, leaving the future of missile-warning architecture uncertain.—JOCELYN BRIDGES