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AGM-158 JASSM

Lockheed Martin · Air-to-Surface · USA · Modern (1992–2009)

The AGM-158 JASSM (Joint Air-to-Surface Standoff Missile) is an American long-range stealth cruise missile — Lockheed Martin's principal precision-strike weapon for US Air Force + US Navy + allied forces. Lockheed Martin developed the JASSM in 1995-2003 to provide standoff strike from outside enemy air-defence engagement zones; service entry 2003. About 3,000+ JASSMs have been delivered across all variants. The missile is used by US Air Force + US Navy + Royal Australian Air Force + Finland + Poland + Netherlands + Japan + South Korea + others.

The AGM-158B JASSM-ER (extended-range variant) uses 1 × Williams F107 turbofan. Maximum speed Mach 0.8 (subsonic). Length 4.27 m, weight 1,022 kg. Range: 1,000 km (JASSM) / 1,000 km (JASSM-ER) / 1,900 km (JASSM-XR, in development). Warhead: 450 kg WDU-42/B penetrator (anti-hardened-target). Guidance: GPS / INS midcourse + imaging IR terminal seeker + autonomous target recognition. The low radar cross-section airframe + low-altitude flight profile minimise detection. Launch platforms: B-1B Lancer, B-2 Spirit, B-52H Stratofortress, F-15E Strike Eagle, F-16C, F/A-18E/F Super Hornet, F-35 Lightning II.

JASSM combat use began in 2018 — US Air Force B-1Bs fired 19 JASSM-ERs in the April 2018 Syria strike against chemical-weapons facilities (the first JASSM combat use). Ukraine has fired air-launched JASSMs at Russian targets from 2024 onwards (after F-16 deliveries). Australia + Finland + Poland are major operators. The JASSM family is being progressively expanded with the AGM-158C LRASM (Long-Range Anti-Ship Missile) maritime-strike variant + the planned AGM-158D JASSM-XR with 1,900 km range. Production continues at Lockheed Martin Troy, with annual deliveries exceeding 500 missiles in 2026.

For Kids — a shorter, friendlier version

The AGM-158 JASSM (Joint Air-to-Surface Standoff Missile) is an American stealth cruise missile. Lockheed Martin developed it from 1995 to 2003. The JASSM entered service in 2003. More than 3,000 have been delivered. The missile is used by America, Australia, Finland, Poland, Japan, South Korea, and others.

The JASSM is 14 feet long and weighs 2,253 pounds, smaller than a school bus. One Williams F107 turbofan engine powers it. Top speed is about 600 mph, faster than most race cars, just below the speed of sound. The standard JASSM flies 230 miles, the JASSM-ER reaches 575 miles, and the new JASSM-XR will go 1,200 miles.

The JASSM is stealthy: its faceted body and low-altitude flight make it hard for enemy radars to see. A heavy penetrator explosive can break through hardened bunkers. The missile uses GPS, inertial navigation, and an infrared camera to find its target exactly.

The JASSM is launched from many American aircraft: the B-1B Lancer, B-2 Spirit, B-52H Stratofortress, F-15E Strike Eagle, F-16, F/A-18, and F-35. The first combat use was in April 2018, when B-1Bs fired 19 JASSM-ERs at Syrian chemical-weapons sites. Ukraine has fired air-launched JASSMs at Russian targets from 2024 onwards.

Fun Facts

The AGM-158 JASSM is an American stealth cruise missile.
The JASSM is 14 feet long, smaller than a school bus.
Top speed is about 600 mph, faster than most race cars.
More than 3,000 JASSMs have been delivered since 2003.
The new JASSM-XR will fly 1,200 miles to its target.
The first combat use was 19 JASSM-ERs against Syria in April 2018.
Ukraine has fired JASSMs at Russian targets since 2024.

Kids’ Questions

What is standoff strike?

Standoff means firing from far away, outside enemy air-defense range. The JASSM can be launched 230 miles or more from its target, so the firing plane stays safe. The JASSM then flies the rest of the way on its own using GPS and an infrared camera. This is much safer than flying right over the target.

How does it find the target?

The JASSM uses three systems together. GPS satellites tell it where it is. Inertial navigation (gyros and computers) gives backup if GPS is jammed. Near the target, an infrared camera in the nose looks for the right object based on stored pictures. The missile then steers itself to the exact spot.

Why so stealthy?

The JASSM has a faceted body with angled flat surfaces that bounce radar waves away. It also flies low and slow (just below the speed of sound) to avoid being spotted. The combination of stealth shape, low altitude, and small size makes the JASSM very hard for enemy radars to find before it hits.

Variants

AGM-158A JASSM (2003): Original 370 km range.
AGM-158B JASSM-ER (2014): Extended-range 1,000 km. Most-numerous variant.
AGM-158C LRASM (2018): Anti-ship variant with imaging seeker.
AGM-158D JASSM-XR (2027): 1,900 km range. In development.

Notable Operators

US Air Force + Navy (2003-present): Principal operator. B-1B, B-2, B-52H, F-15E, F-16, F-35 carriage.
8+ export operators: Australia, Finland, Poland, Netherlands, Japan, South Korea, Ukraine, others.

Frequently Asked Questions

How does the JASSM differ from the Tomahawk?

The AGM-158 JASSM is air-launched only (from bombers + fighter jets); the BGM-109 Tomahawk is sea-launched + ground-launched only. JASSM has a smaller airframe (4.27 m vs Tomahawk's 6.25 m) + lighter warhead (450 kg vs Tomahawk's 450 kg conventional). JASSM uses imaging IR terminal seeker + autonomous target recognition for hard targets; Tomahawk uses GPS / INS + (some variants) DSMAC (Digital Scene-Matching Area Correlator) for fixed targets. Both have ~1,000 km range; the planned JASSM-XR will exceed Tomahawk. The two missiles are complementary — JASSM for stealth aircraft-launched standoff strike, Tomahawk for Navy + Marines mass surface-launch.

Sources

Wikipedia — AGM-158 JASSM