Lockheed Martin has introduced the AGM-158 FLEX, a modular cruise missile concept built around the airframe of the AGM-158 Joint Air-to-Surface Standoff Missile (JASSM) — one of the U.S. Air Force's primary air-to-ground weapons. Announced in mid-September 2026, the concept is designed to expand what the JASSM family can do without starting from scratch, leveraging an existing production base that also supports the Long-Range Anti-Ship Missile (LRASM).
A Modular Architecture for a Familiar Weapon
The defining feature of the FLEX concept is its interchangeable nose section. By making the forward portion of the missile swappable, Lockheed envisions a single core airframe that can accept different warhead types, payloads, and sensor packages depending on the mission★. This approach sidesteps the cost and time of developing entirely new platforms for each new capability requirement — a significant consideration given how long modern weapon programs take to field.
Beyond payload flexibility, the FLEX concept also proposes multiple launch configurations. That means the same airframe could potentially be deployed from a wider variety of platforms, expanding the number of aircraft or launch systems that could carry it. Lockheed has indicated the design is intended to enable longer-range variants as well, suggesting the company sees the concept as a growth path rather than a static upgrade.
Why Modularity Matters in Contested Environments
The broader logic behind modular weapon design reflects a shift in how defense planners think about platform longevity. Rather than retiring a missile system when a specific threat changes or a new sensor becomes available, a modular architecture allows the core airframe to remain relevant through component-level updates. For a widely fielded weapon like JASSM, that kind of flexibility can extend the investment already made in production lines, logistics chains, and aircrew training.
By sharing production infrastructure with LRASM, the company can potentially keep unit costs lower even as the number of variants grows★.
Lockheed's announcement is a concept reveal rather than a confirmed program of record★, so timelines for development or procurement remain unclear. Still, the unveiling signals where the company sees the JASSM family heading — toward a more adaptable, multi-role platform suited for a range of contested-environment scenarios rather than a fixed-configuration legacy weapon.
★ AI inference: One or more analytical conclusions in this article were drawn by the AI from cited facts and are not directly stated in the cited sources.