The US Navy has contracted Lockheed Martin to integrate the PAC-3 MSE missiles into its Aegis system. The upgrade could provide an additional layer of defence against ballistic missiles.

By Sam Cranny-Evans, editor of Calibre Defence, published on April 22, 2026.

Lockheed Martin (NYSE: LMT) has won a US Navy contract to integrate the PAC-3 MSE air defence missile into the Aegis air defence system. According to an April 21 press release, Lockheed has already invested its own funds to integrate the missile into the Mk 41 Vertical Launch System.

This is work that Lockheed has been conducting for some years, but the US Navy contract will now take the project further and into service. Further integration hurdles include modifying the missile so that it can communicate with the Aegis command and guidance frequencies, according to Naval News.

Land-based tests are expected to follow in 2027, followed by initial fielding in 2028. The US Navy has already requested 405 PAC-3 MSE interceptors in its 2027 budget request. Pending further changes to make them fit for Aegis integration, they will join Lockheed’s expanding PAC-3 production line. The service ordered 12 interceptors in 2026 to support integration activities.

Combined, the budget request and contract with Lockheed suggests that fielding will be significantly advanced in the next year. Although the project has been underway for some time, it is likely that Operation Epic Fury has added impetus.

US forces in the Middle East are estimated to have launched between 1,380 and 2,050 air defence missiles during Operation Epic Fury. According to analysis released by CSIS on April 21, this includes SM-3, SM-2, and PAC-3. Replacing some of these missiles, especially the SM-3, could take years, not months, despite recent framework contracts to increase production.

What does PAC-3 add to an Arleigh Burke?

Arleigh Burke-class destroyers (DDG) are the backbone of the US Navy’s surface fleet. They bring with them the Aegis combat system, which supports both defensive and offensive missions. The arsenal of these ships includes a range of defensive missiles summarised in the table below. The PAC-3 MSE will add terminal-phase ballistic missile defence, as well as an anti-cruise missile capability. It will join the SM-3 from Raytheon, which serves a slightly different purpose.

Missile Name	Estimated range	Target Intercept Capabilities
RIM-161 (SM-3)	900 – 2,500 km	Short-to-intermediate-range ballistic missiles (Exo-atmospheric/in space).
RIM-174 (SM-6)	240 – 370 km	Fixed-wing aircraft, cruise missiles, and terminal-phase ballistic/hypersonic threats.
RIM-66 (SM-2)	74 – 170 km	Anti-ship missiles and aircraft (the fleet’s primary “workhorse”).
PAC-3 MSE (New 2026)	~35 – 100 km	Advanced tactical ballistic missiles, cruise missiles, and “hit-to-kill” intercepts.
RIM-162 (ESSM)	50+ km	High-speed, highly manoeuvrable anti-ship cruise missiles.
RIM-116 (RAM)	10 km	Subsonic and supersonic anti-ship missiles (typically on SeaRAM mounts).

The costs of these missiles is often compared and used as a blunt tool for analysis of air defence. The SM-3 comes out quite unfavourably, with a unit cost of around $10 million. Hopefully the table above reflects why that cost is so high, however. As a system, it must reach space in a matter of minutes and engage a target moving at hypersonic speeds. This is the peak of complexity when it comes to in-service missile threats and technology. While it is effective, and has achieved several successes during Operation Epic Fury, the addition of PAC-3 should expand the options available to a naval commander. They may be able to save SM-3s for more complex threats, for example, and rely on the PAC-3, which also has hundreds of successful intercepts under its belt.

Calibre comment:  Defence in depth needs magazine depth

Speakers at the 2026 RUSI Integrated Air and Missile Defence conference repeatedly emphasised the need for magazine depth. Several of them, having studied different conflicts, came to the same solution: That magazine depth should come from high performance interceptors, as well as low performance interceptors. The difference, they observed is that some systems need to be nearly perfect, with a high degree of complexity and assurance. The complexity of the interceptor needs to scale linearly with the complexity of the intended threat. So, a manoeuvring ballistic missile needs a very complex and capable interceptor, a slow one-way attack drone far less so.

In both cases, the magazine depth needs to match the expected threat. Too few missiles and an attacker can succeed with mass. This reflects the fact that air defence is about endurance and withstanding or minimising the damage from attacks as much as possible. Adding the PAC-3 MSE to Arleigh Burke destroyers would both increase options for ballistic missile defence but also increase magazine depth for naval engagements.

If you would like to read more on PAC-3, naval air defence, and missile production, check out the links below.

• Defence in brief: CENTCOM repels Houthi attack
• RTX to double missile production under DoW frameworks
• Lockheed receives first contract on path to tripling PAC-3 MSE production
• US advances defence against hypersonic missiles

The lead image shows an Arleigh Burke destroyer with a PAC-3 launch digitally added. Credit: Lockheed Martin.