The U.S. Army’s new Precision Strike Missile (PrSM) short-range ballistic missile has, for the first time, been successfully employed against a moving target at sea. Taking place during the Valiant Shield 24 Sink Exercise (SINKEX), the engagement also involved high-altitude balloons, equipped with “electromagnetic spectrum sensors and radio networking equipment,” and an ultra-long-endurance aerial drone, which were part of the kill chain. The scenario is very much indicative of the kind of distributed sensor/shooter network the Army has been working on for years now and which is seen as particularly relevant in the Pacific theater.
U.S. Army/Sgt. Perla Alfaro
Two PrSM missiles were fired during the SINKEX, from the Army’s Autonomous Multi-Domain Launcher (AML), in Palau, Micronesia, on June 16. This was, according to the Army, the first time that PrSM and AML had been employed outside of the United States. The units responsible for operating these systems were the Army’s 3rd Multi-Domain Task Force (3MDTF) and 1-181 Artillery Regiment of the Tennessee National Guard.
Valiant Shield 24, which ran from June 7-18, on Guam, the Commonwealth of the Northern Mariana Islands, Palau, and at sea around the Mariana Island Range Complex, was a multinational field training exercise which, according to the U.S. Navy “focused on integrating interoperability in a multi-domain environment.” This included joint forces working together to detect, locate, track, and engage units at sea.
The target vessel for the SINKIEX part of the maneuvers was the decommissioned hulk of the Austin class amphibious transport dock ex-USS Cleveland (LPD-7), located in the North Pacific Ocean, more than 40 nautical miles from the nearest land. As a combined SINKEX, other assets were also involved in attacking the target, including U.S. Marine Corps F/A-18C Hornets, which were noted carrying live examples of the AGM-88 High-speed Anti-Radiation Missiles (HARM) or AGM-88E Advanced Anti-Radiation Guided Missile (AARGM) during the exercise.
Just as notable, however, were the other assets involved in the live-fire exercise and their distributed nature within the kill chain.
Hundreds of miles away from Palau, in Guam, the U.S. island territory in the Western Pacific, soldiers launched Aerostar Industries high-altitude balloons (HABs) from Won Pat International Airport.
“Once launched, the HABs rapidly ascended above 50,000 feet and began operating around the Marianas Islands,” the Army explained in a statement. “Equipped with electromagnetic sensing and mesh communications equipment, the HABs helped inform future maritime domain awareness innovation and experimentation.”
As you can read about here, the Army has a longstanding plan to develop a network of high-altitude balloons that can fly in the stratosphere, from where they will operate as sensor platforms collecting various kinds of intelligence, as communications relays, or even deploy other surveillance systems including swarms of drones. As well as the advantages conveyed by their high-level perch, balloons of this kind are also, in many cases, able to hold position despite prevailing winds, by moderating their altitude. You can also read much more about Aerostar’s high-altitude balloons and their use by the U.S. military in this previous article.
Meanwhile, another contractor, Platform Aerospace, launched its Vanilla ultra-long-endurance unmanned aircraft system (UAS), a small aircraft that’s able to remain aloft for more than eight days. While Vanilla can also be configured for intelligence, surveillance, and reconnaissance (ISR), in these maneuvers it was equipped as a communication relay platform, operating during a 27-hour flight, much of which was conducted during what the Army described as “a violent storm.”
As we have observed in the past, Vanilla reflects growing interest across the U.S. military toward developing long-endurance, lower-cost ISR assets, which have particular relevance when operating over the vast expanses of the Pacific theater.
All these assets were brought together during the exercise by the 3MDTF All-Domain Operations Center (ADOC) on Oahu, in Hawaii, and a battalion command that was set up in Japan.
“Valiant Shield enabled us to integrate with the Combined Joint Force and operate distributed while forward in theater,” explained Col. Michael Rose, the 3MDTF commander. “We were able to build new relationships and continue to deepen existing ties. Valiant Shield and like exercises in the region enable us to test our systems and processes as well as integrate new capabilities alongside our partners and allies, contributing to the continuous transformation of our multi-domain capability and increasing our warfighting readiness.”
As we have reported in the past, PrSM is poised to bring an extremely important new weapon into the hands of the Army, with the service hoping to achieve initial operational capability with the system sometime this year. The Army received its first operational PrSMs late last year.
Currently designed to be ground-launched from M270 Multiple Launch Rocket System (MLRS) and M142 High Mobility Artillery Rocket System (HIMARS) vehicles, PrSM is set to replace the Army’s current Army Tactical Missile System (ATACMS) short-range ballistic missiles. Being smaller than ATACMS, PrSM allows the overall missile payload to be doubled, with two missiles per launch pod.
The missile has a range of at least 310 miles, although this could potentially be increased to well over 400 miles in the future.
The baseline version of the PrSMs missile, also known as Increment 1, is capable of hitting static targets only using a GPS-assisted inertial navigation system (INS) guidance package. Such targets might include air defense systems, ballistic missile launchers, command and control centers, troop assembly/staging areas, and other objectives with fixed coordinates.
However, the Army is already working on an Increment 2 version — also known as the Land-Based Anti-Ship Missile (LBASM) — with an additional seeker system primarily for use against ships, even ones on the move. The service hopes to be able to start fielding PrSM Increment 2 as soon as 2026. While the Army didn’t state which version of the missile was used in the Valiant Shield 24 SINKEX, the reference to a moving target indicates it was either representative of Increment 2 or an earlier iteration of the same capabilities.
That would also make sense given the Army revealing in January this year that initial flight testing of the seeker for PrSM Increment 2 was completed in 2023, as we reported at the time.
With its ability to strike moving warships, Increment 2 PrSM addresses an arguably significant gap in the U.S. military’s armory, especially with anti-ship ballistic missiles (ASBMs) being a major topic of discussion in the context of a potential future conflict between the United States and China in the Pacific. This year, ASBMs have also been employed in combat for the first time, as part of the Houthi campaign against shipping in and around the Red Sea. Overall, ASBMs are establishing themselves as a critical weapon against ships, which are generally less well-defended against attacks of this kind.
At the same time, there has been no footage released so far of the SINKEX so it’s not immediately how the target vessel was moving, although it’s possible it was under tow. A SINKEX targeting a moving vessel is rare for the U.S. Navy, although China recently released footage of a Type 074 amphibious landing ship being destroyed by a torpedo in one of its own sinking exercises, as you can read about here.
As well as PrSM Increment 2, the Army is busy exploring other new weapons that will allow it to strike enemy warships at extended ranges. Chief among these are land-based launchers that will be able to fire multi-purpose SM-6 and Tomahawk cruise missiles, both of which can have a long-range anti-ship function.
In addition, the Army is looking at the possibility of further expanding the mission scope and range of PrSM. The planned PrSM Increment 4 missile is expected to incorporate an air-breathing propulsion system and have a maximum range of 620 miles. Meanwhile, PrSM Increment 3 is expected to carry unspecified “enhanced” payloads, which could include swarms of loitering munitions, also known as kamikaze drones.
Another interesting aspect of the SINKEX was the use of the AML, an uncrewed launch vehicle derived from the HIMARS. Capable of a certain degree of autonomous operation, AML was developed with the Pacific theater very much in mind. Concepts of operation call for the remote launcher to be airlifted onto islands via austere airstrips. Once there, it can launch PrSM missiles — as well as precision-guided 227mm artillery rockets and ATACMS — against a wide variety of targets.
AML is designed to navigate using a combination of cameras, LIDAR sensors, and GPS. In its initial form, AML has a ‘drive-by-wire’ capability that can autonomously follow a series of waypoints or operate in a ‘follow-the-leader’ mode tethered to another vehicle, such as a crewed HIMARS launcher. It can receive targeting information and launch commands remotely or directly, the latter through a control panel on the side of the vehicle.
As we have discussed in the past, an uncrewed launcher of this kind offers multiple benefits. On the one hand, larger numbers of launchers can be deployed without having tp significantly increase the number of personnel. Operating autonomously, it is quicker and easier to move AMLs to a new location or distribute them across a broader area, increasing their operational flexibility, while also reducing their vulnerability to counterattacks.
On the one hand, a live-fire test of the PrSM against a naval surface target in the Pacific was a milestone in itself and one that points to the growing emphasis on maritime strike capabilities in the context of a potential future high-end conflict against China.
Just as importantly, the exercise also stressed the Army’s emerging capabilities in terms of long-range sensors and communications, to ensure a seamless engagement across a significant distance, including gathering and distributing the required targeting data. Distributed assets — including command and control — are seen as a critical aspect of warfare in the Pacific theater and were also integral to the Valiant Shield SINKEX.
Significantly, the exercise also comes at a time in which the Army increasingly finds itself having to justify its role in a future campaign in the Pacific, of the kind that would be expected to be fought against China.
With that in mind, the importance of the Valiant Shield 24 SINKEX shouldn’t be understated. As well as proving the ability of the Army’s new short-range ballistic missile to target ships, the exercise also provided a powerful reminder of the relevance of the U.S. Army in the Pacific theater, including its ability to adapt to new and non-traditional missions.
Contact the author: thomas@thewarzone.com