ER GMLRS with Alternative warhead moves closer to fielding

Lockheed Martin has tested the Extended Range Guided Multiple Launch Rocket System (ER GMLRS) rocket with the Alternative Warhead in a series of trials, bringing the round closer to fielding. Western forces are expecting a lot from their rocket artillery as they focus on “fighting in the deep,” where area effects will be essential. 

By Sam Cranny-Evans, published on February 18, 2026. 

Lockheed Martin has completed a series of tests of the ER GMLRS rocket with the Alternative Warhead, according to a February 12 press release. The tests involved launches from the M270A2 Multiple Launch Rocket System (MLRS), the tracked predecessor of the M142 HIMARS. 

The aim was to qualify the Alternative Warhead, which is designed to achieve area effects without cluster munitions. It was attached to an ER GMLRS rocket body, which has a bigger motor, increasing its range to 150 km. The rocket was fired out to a range of 112 km, which is some 42 km further than a standard GMLRS rocket.

The tests mean that this rocket variant has completed its system qualification and can now enter service. Two flight tests were conducted in two weeks, Lockheed said on LinkedIn. “This milestone supports accelerated operational fielding for the US Army and international partners,” the post adds. 

Lockheed completed other tests in December 2025, demonstrating the area effect capability of the Alternative Warhead. Those tests saw the same ER GMLRS and Alternative warhead combination fired from an M142 HIMARS. Soldier-led tests are expected to follow in 2026, the press release states. 

ER GMLRS and the Alternative Warhead programme

The Alternative Warhead programme started life in the early 2000s as the US Army sought to reintroduce area effects. Prior to that, most forces had focused their attention on the unitary warhead. The unitary warhead delivers a single 90 kg high explosive payload to a target. It’s very good, but requires pinpoint accuracy in terms of target data to be effective. And it can only handle one target at a time. 

The Cold War concept of operations that led to the MLRS foresaw extensive use of cluster munitions to destroy Soviet armour. But the unexploded ordnance side of cluster munitions became very unpopular during counter-insurgency campaigns. So, the Alternative Warhead, designated M30A1, carries 160,000 preformed tungsten fragments instead. This is likely sufficient for troops in the open and light vehicles as the image above shows.

The ER GMLRS has its roots in similar requirements, i.e., conventional war. It was expected to enter service in 2023 and service many of the targets normally engaged by ATACMS. For the US Army, the ER GMLRS and Alternative Warhead configuration will serve alongside the PrSM. PrSM will provide much greater reach and the ability to engage ships as well as land targets.

• Lockheed Martin’s missile production in numbers – Calibre Defence 
• US soldiers fire PrSM from all platforms in milestone test – Calibre Defence 

Calibre comment: Fighting deep and the future of warfare

Many countries have concepts and doctrine that place fighting in the deep at the heart of their land warfare concepts. However, achieving effects against targets at long ranges requires potent warheads capable of destroying hard to find targets. An air defence system, for example, might only be targetable for a short window. Area effect munitions allow a volley to be fired and the likelihood of destruction increased. 

• Project ASGARD; the British Army’s path to doubling lethality – Calibre Defence 
• What is Italy’s A2CS programme? – Calibre Defence 

Pairing the Alternative Warhead with the GMLRS-ER round may help realise some of those concepts. Of course, a lot will depend on the willingness of user countries to procure enough missiles, as well as their ability to compete in the ISTAR battle. 

The lead image shows an M142 HIMARS launching an ER GMLRS rocket during tests. Credit: US Army.