Missile AGM-158B JASSM-ER

Development of the missile system began in 1995 following the cancellation of the AGM-137 program. The requirement specified a low-observable standoff weapon capable of high-precision strikes. Following a design competition initiated in 1996, a development contract was awarded in 1998. The extended-range variant received its designation in 2002 and entered operational service in 2014.

The missile is an air-launched cruise missile utilizing a stealthy airframe to minimize radar detection. It is powered by a turbofan engine and features a wing structure that deploys after launch. Guidance is facilitated through an inertial navigation system and Global Positioning System updates, with newer variants utilizing M-code receivers. Terminal homing and target recognition are achieved via an imaging infrared seeker. A weapon data link allows for status transmission and post-launch retargeting. The primary armament is a WDU-42/B penetrator warhead utilizing an FMU-156/B or FMU-162/B detonation mechanism. The airframe design permits high-altitude flight profiles. Specialized variants include a version carrying a high-power microwave payload for non-kinetic electronic warfare and an anti-ship derivative. The system is compatible with heavy bombers and multirole fighters and can also be deployed via palletized modules from cargo aircraft.

The system is operated by the United States Air Force and is exported to several countries, including Australia, Finland, and Poland. Procurement has been approved for additional operators, including Italy, Japan, and the Netherlands. The missile was first used in combat in April 2018 during strikes against the Barzah Research Center in Syria. It was subsequently employed in 2019 to destroy a compound during the Barisha raid and was used during military operations in Yemen in 2025. In the Syrian engagement, 19 missiles were launched from B-1 Lancer platforms to neutralize target facilities.