Stealth Missile: Why the AGM-158 XR Will Give U.S. Airpower a Massive Edge

Article Summary and Key Points: Lockheed Martin’s new AGM-158 XR cruise missile is set to revolutionize long-range strike capabilities with a range exceeding 1,000 miles. As an evolution of the JASSM-ER, the XR extends fuel capacity by elongating the fuselage while maintaining stealth, advanced AI-guided targeting, and multi-platform compatibility.

Key Point #1 – This cost-effective upgrade enhances survivability by allowing aircraft to strike from further distances while integrating with existing launch systems like Rapid Dragon.

Key Point #2 – With the ability to overwhelm enemy defenses in mass deployments, the AGM-158 XR will significantly boost U.S. strike power, particularly in contested environments where extended standoff range is critical to mission success.

Lockheed Martin’s AGM-158 XR: The U.S. Military’s Next-Gen Cruise Missile

One of the most strategically valuable new weapons making their way toward service today is Lockheed Martin’s AGM-158 XR, a broadly capable and low-observable cruise missile expected to offer a range in excess of 1,000 miles. 

Lockheed Martin’s AGM-158 family of cruise missiles currently includes the AGM-158 Joint-air-to-surface-standoff missile, the AGB-158B JASSM-ER (extended range), and the AGM-158C Long Range Anti-Ship Missile (LRASM).

These weapons all share identical stealthy external shapes and structures that include deployable wings, but their internal systems and layouts are more specific to their intended use cases and roles. 

The original JASSM is a turbojet-powered weapon with the ability to deliver its 1,000-pound warhead to targets more than 230 miles away. The newer JASSM-ER swaps out that turbojet for a more efficient turbofan engine, which along with a slight redesign of its internal components, allowed for a significant boost in range out to better than 600 miles. 

The LRASM, maintains that 230-mile or so range, while adding more capable onboard guidance and target acquisition capabilities to allow it to hunt enemy warships on the open ocean like a pack of high-explosive wolves.

These weapons are among the most advanced and capable in the U.S. arsenal. This is thanks to their range and stealth, but also advanced guidance capabilities that include jam-resistant GPS-assisted inertial navigation that transitions over to an onboard infrared electrooptical seeker.

This component compares imagery in its field of view to 3D models of intended target systems using advanced onboard artificial intelligence to identify and close with the most vulnerable point in a target to maximize the weapon’s battlefield effect.

Further, when launched in high volumes, these weapons can coordinate with one another and other aircraft via onboard two-way datalinks to distribute targets or shift priorities mid-flight. 

The existing JASSM line of cruise missiles are so broadly capable that the Air Force Research Lab, working on conjunction with Lockheed Martin, established a palletized launch system for these missiles, dubbed Rapid Dragon, that allows cargo aircraft like C-130s and C-17s to rapidly launch dozens of them at once, effectively flooding enemy airspace with AI-enabled stealth cruise missiles from outside the reach of even the most advanced adversary air defense systems. 

However, even the more-than-600 mile range of the JASSM-ER may not always be enough to keep launching aircraft out of harm’s way, especially if attempting to engage a target deep inside contested airspace. And that’s where Lockheed Martin’s believes its new AGM-158 XR can make a significant impact: The new missile will come with a 40% increased range over the other missiles in its family allowing for dramatically expanded operational uses.

JASSM XR. Image Credit: Lockheed Martin.

A U.S. Air Force F-15E Strike Eagle flies with a Joint Air-to-Surface Standoff Missile (JASSM). JASSM-Extended Range has more than two-and-a-half times the range of JASSM for greater standoff distance. Photo credit: U.S. Air Force. (PRNewsfoto/Lockheed Martin)

Development on the AGM-158 XR began, as far as we can tell, in 2018, though Lockheed Martin only officially unveiled the weapon in 2024.

While very few details about this weapon have officially been released, its increase in range appears to be the product of simply elongating the fuselage of the JASSM-ER which provides additional internal volume for fuel storage. This would mean a fairly low cost of production compared to developing an altogether new missile for longer-range engagements, as the existing JASSM production line could simply be expanded to include the longer-fuselage XR while sharing the majority of the other weapon’s onboard systems and components. 

Assuming the weapon is simply longer but maintains the same diameter, it could feasibly be deployed via a long list of aircraft and the Rapid Dragon system as well. At the same time, because launching aircraft won’t have to fly as far to get into range of their targets, they’ll be able to fly more sorties with less risk.

And this seems to be confirmed, at least to some extent, by Lockheed Martin promotional materials that state, “The XR solution provides the warfighter a 1,000lb warhead stealth missile capability with an extreme standoff range in mass quantities, while maintaining compatibility with the same platforms that JASSM and LRASM have today, including the F/A-18 and the soon to be added F-35.”

About the Author: Alex Hollings 

Alex Hollings is the editor of the Sandboxx blog and a former U.S. Marine that writes about defense policy and technology. He lives with his wife and daughter in Georgia.