What is the AGM-158 JASSM-ER? Lockheed Martin’s Stealthy Long-Range Air-to-Surface Missile, Explained
The AGM-158 JASSM (Joint Air-to-Surface Standoff Missile) is the U.S. Air Force and Navy’s stealthy, long-range, autonomous air-launched cruise missile, designed by Lockheed Martin Missiles and Fire Control. The current production variant is the AGM-158B-2 JASSM-ER (Extended Range), a 900 km weapon, and the next-generation AGM-158C-3 LRASM (Long-Range Anti-Ship Missile) brings JASSM-class stealth and autonomy into the anti-ship domain. With more than 3,000 rounds produced across all variants and deployment on B-1B, B-2A, B-52H, F-15E, F-16C/D, F-35A, F/A-18E/F and now Ukrainian F-16s, JASSM is the most-deployed Western stealth strike missile.
Key facts at a glance
| Attribute | Value |
|---|---|
| Type | Stealthy air-launched cruise missile |
| Manufacturer | Lockheed Martin Missiles & Fire Control |
| In service | 2009 (JASSM); 2014 (JASSM-ER); 2018 (LRASM) |
| Length | 4.27 m |
| Diameter | 635 mm (stealthy lifting-body shape) |
| Launch weight | 1,020 kg (JASSM); 1,100 kg (JASSM-ER) |
| Warhead | 450 kg WDU-42/B penetrator/blast-fragmentation |
| Range (JASSM) | 370 km |
| Range (JASSM-ER) | 900+ km |
| Range (JASSM-XR, planned) | 1,900 km |
| Speed | Mach 0.8 |
| Guidance | INS + GPS + imaging IR seeker terminal (LRASM adds passive RF homing) |
| Engine | Williams F107 turbofan (single) |
| Operators | U.S., Australia, Finland, Poland, Netherlands, Japan (planned), Ukraine |
| Unit cost (JASSM-ER, FY2024) | ~ USD 1.5 million per round |
The variant family
| Variant | Year | Key feature |
|---|---|---|
| AGM-158A JASSM | 2009 | 370 km baseline range |
| AGM-158B JASSM-ER | 2014 | Larger fuel tank, more efficient engine; 900 km range |
| AGM-158B-2 JASSM-ER | 2021 | Improved seeker, anti-jam GPS |
| AGM-158C LRASM | 2018 | Anti-ship; passive RF + imaging IR seekers; 370 km range |
| AGM-158C-3 LRASM | 2024 | Range extended past 600 km |
| AGM-158D JASSM-XR (planned) | 2026+ | 1,900 km range; extended fuselage |
Design philosophy: low-observable stand-off
JASSM is shaped specifically to defeat S-300, S-400 and equivalent integrated air defenses. The lifting-body fuselage, ventral inlet, blended trailing edge and absorbent material coatings give the missile a frontal radar cross-section reported in defense literature as comparable to a small bird. Cruise altitude varies — high subsonic in safe airspace, sub-100 m terrain-following inside contested zones. Mid-course updates can be received from a launching aircraft via the secure datalink; the terminal phase is fully autonomous, with an imaging-infrared seeker matching the impact point to stored target imagery.
Combat record
- 2018 — Syria. 19 JASSM-ERs were fired by B-1B Lancers against the Barzah and Him Shinshar chemical-weapons facilities in the joint U.S.-UK-French strike of 14 April. This was the first combat use of JASSM-ER.
- 2023 — Red Sea. USAF F-15E Strike Eagles used JASSM-ER against Houthi-controlled targets in Yemen, including ballistic-missile production sites.
- 2024–2025 — Ukraine. Ukrainian Air Force F-16s and modified Su-24Ms began launching JASSM and JASSM-ER rounds against high-value Russian targets in occupied Crimea, including Belbek airfield, Saky airbase, and Russian command centers near Sevastopol. JASSM strikes on Russian S-400 batteries in autumn 2024 contributed to the collapse of effective Russian air-defense coverage over western Crimea.
Operators
| Country | Variant | Notes |
|---|---|---|
| United States | JASSM, JASSM-ER, LRASM | Primary operator |
| Australia | JASSM-ER, LRASM | F/A-18F and EA-18G integration |
| Finland | JASSM-ER | F/A-18C/D Hornets (transitioning to F-35A) |
| Poland | JASSM-ER | F-16C/D Block 52+; 70 rounds purchased |
| Netherlands | JASSM-ER | F-35A integration |
| Japan | JASSM-ER (purchase 2023) | F-15J and F-35A integration |
| Ukraine | JASSM, JASSM-ER | Delivery from 2024 |
JASSM vs. its peers
| JASSM-ER | Storm Shadow / SCALP | Kh-101 | Tomahawk Block V | |
|---|---|---|---|---|
| Range | 900 km | 560 km | 2,500 km | 1,600 km |
| Launch platform | Aircraft | Aircraft | Aircraft | Ship, submarine, truck |
| Stealth shaping | Extensive | Yes | Partial | No |
| Anti-ship variant | Yes (LRASM) | No | No | Yes (MST) |
| Combat record | Syria, Yemen, Ukraine | Iraq, Libya, Ukraine | Ukraine (Russian use) | Iraq, Libya, Syria, Iran |
The JASSM-XR future
Lockheed Martin is working on the JASSM-XR (Extended Range, Extended Range), which will roughly double the JASSM-ER’s range to nearly 1,900 km by adding a fuel-tank stretch. JASSM-XR is intended to give 4th-generation fighters (F-15E, F-16, F/A-18) deep-strike reach competitive with the new generation of fifth-generation aircraft. First test flights are planned for 2026 with operational fielding in 2028. LRASM C-3 — already in low-rate production — adds equivalent range to the anti-ship variant.
Production today
Lockheed Martin’s Troy, Alabama plant is increasing JASSM family production from 550 rounds in 2022 to roughly 1,100 rounds per year by 2027, driven by Pacific theater requirements and Ukraine demand. The Pacific Deterrence Initiative funding has been heavily weighted toward JASSM-ER and LRASM acquisition as the primary anti-China strike weapons of the U.S. Air Force.
Why JASSM matters
JASSM proved that a 1,000 kg stealth cruise missile could be carried in numbers by 4th-generation fighters and used to strike strategically significant targets from beyond the engagement envelope of modern integrated air defenses. The platform’s success in Syria, Yemen and Ukraine has validated nearly three decades of Lockheed Martin investment, and the JASSM-XR / LRASM-ER combination will keep this family at the center of U.S. and allied stand-off strike planning through the 2030s.
