A project to arm the U.K.'s Joint Strike Fighter force with a new, indigenous, small-diameter, precision-guided munition is advancing and could also form the basis for a surface-launched weapon for naval vessels and land operations.

The Selective Precision Effects At Range (Spear) program aims to provide a range of new, cost-effective accurate weapons for the U.K.'s Lightning IIs and Typhoons. Raytheon's Paveway IV, fitted with a series of upgrades, fits the bill as Spear Capability 1, while the Capability 2 will entail adding an improved version of the MBDA Dual-Mode Brimstone (DMB) missile, which has been used to dramatic effect in Afghanistan and Libya.

But Spear Capability 3 is perhaps the most challenging. The 80-kg (175-lb.) network-enabled weapon is being developed to strike mobile and static targets in a range of environments, from the open battlefield to urban areas, with low collateral damage. MBDA is proving the technologies for the weapon and will begin a series of trials next year that will lead to the first drops of a Spear 3 weapon from a Eurofighter Typhoon as early as 2015.

“The customer wanted the ability to strike static or moving targets in all weathers and achieve a range of military effects across a broad spectrum,” says Paul Wester, sector head of Spear Capability 3.

The weapon is envisioned for use on the F-35: Four will be carried on a launcher in each of the JSF's two weapon bays. Aircrews can plot the weapon's intended flight path with mission-planning software before it is launched and update it using the weapon's data link once it is in flight. Spear 3's seeker builds on development of the DMB missile, which features an MBDA enhanced imaging seeker with millimeter-wave radar and a semi-active laser that can be used independently and collaboratively.

The weapon is stowed upside down in the launcher, and upon release, turns upright, deploys its wings and starts the Hamilton Sundstrand TJ-150 turbojet. Two small intakes on each side of the rear airframe provide airflow to the engine.

“Having an engine improves the chances of getting the weapon to the target,” says Wester. He cites other small weapons in Spear 3's class that do not have engines and could potentially lose energy while turning, or lose range because of headwinds. While the Defense Ministry's Spear 3 range requirement is classified, engineers are confident of a range of at least 100 km (62 mi.).

The program has not been without issues, however. When development work began in 2010, the U.K. had settled on the F-35C conventional carrier-borne variant with a larger weapons bay. But the 2012 decision to revert back to the F-35B set the Spear 3 program back nine months. Engineers had to reduce the length of the weapon by 20 cm (8 in.) so it would fit the F-35B's smaller bay. “Repackaging the weapon into a smaller airframe has been one of the most challenging aspects of the program,” Wester says.

The cost per weapon will be between those of the Brimstone and Storm Shadow but closer to that of Brimstone, MBDA officials say.

But the weapon's now-smaller size has opened another opportunity. MBDA has used the airframe of the Advanced Short-Range Air-to-Air Missile (Asraam)—developed with the U.K. Defense Ministry during the 1990s—as the basis for a new weapon, the Common Anti-Air Modular Missile (CAMM), chosen by the U.K. to equip its Type 23 frigates and, eventually, the new Type 26 Global Combat Ship as part of the Sea Ceptor system. It has also been selected by New Zealand to upgrade the Anzac frigate.

MBDA engineers believe the CAMM modularity model also can be applied to Spear 3. Wester says that with minor changes to the weapon's software and the addition of a booster rocket, Spear 3 could be turned into a Common Anti-Surface Modular Missile (CAsMM) that could provide ships with a precision land-attack and anti-small-ship capability. With a booster, a surface-launched Spear 3 could hit a target at least 70 km away, he notes.

MBDA is working with Lockheed Martin on a project to enable MBDA-built weapons to be fired from Lockheed's Mk. 41 Vertical Launching System (VLS). A trial conducted in the U.K. in September proved that the CAMM could be soft-ejected from the Mk. 41 VLS and quad-packed into the launcher. CAsMM's similar dimensions mean that four of them could be fitted into each launcher.

MBDA has high hopes for the export potential of its Spear program weapons, and it aims to widen the scope of platforms to which they may be fitted. A Typhoon could carry up to 16 of the weapons externally. Several unnamed countries have an observer status on the program.