The Army Has Officially Selected The Navy's SM-6 Missile To Be Used In A Strike Role

A ground-launched SM-6 could become one of the Army's most versatile weapons.

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Just as The War Zone had predicted and reported on as recently as two months ago, the U.S. Army has now officially chosen to adopt the Navy's SM-6 (RIM-174) surface-to-air missile to satisfy its ground-based Mid-Range Capability (MRC) as part of its larger Long-Range Precision Fires initiative. As such, the weapon's secondary ballistic missile-like surface-to-surface strike capabilities will become a primary capability set for the Army units equipped with it in the future. This will initially be a prototype effort to combine the missile with a fully integrated ground-based fire control and launching system, but barring any unforeseen major setbacks, which are unlikely for a relatively mature off-the-shelf system like SM-6, it will facilitate the fielding of the missile in an operational capacity in 2023. 

The Navy's BGM-109 Tomahawk cruise missile was also selected by the Army to become its staple ground-launched cruise missile in the post-Intermediate-Range Nuclear Forces treaty (INF) era. This was all but a given as testing has already begun for introducing this capability, which the Marines are also looking to field in some fashion, and it is similar to the Army's BGM-109G Gryphon ground-launched derivative of the Tomahawk that was fielded during the twilight of the Cold War. It's also worth noting that the latest Tactical Tomahawk is far more capable than its predecessors. It can be retargeted mid-flight, it can avoid hostile air defenses, home in on its target using an imaging infrared sensor, and is fully capable of anti-ship operations. Unlike the BGM-109G, this is a conventionally armed weapon as it sits today, though. 

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Gryphon missile launch from its purpose-built mobile launcher. 

An official announcement from Redstone Arsenal offers some justification for the award:

REDSTONE ARSENAL, Ala. (November 6, 2020)– The U.S. Army awarded a prototype Other Transaction (OT) agreement to advance its development and delivery of a ground-launched, mid-range fires capability that will enable the United States to deter, and if necessary, defeat near-peer competitors. 

The Mid-Range Capability (MRC), part of the Army’s number one modernization priority of Long-Range Precision Fires, will be designed to hit targets in the range between the Precision Strike Missile and the Long Range Hypersonic Weapon. The MRC prototype, consisting of launchers, missiles, and a battery operations center (BOC), will be fielded to an operational battery in Fiscal Year 2023. 

The MRC addresses a need identified in the Army’s Fiscal Year 2020 Strategic Fires Study in coordination with Combatant Commanders in key theaters. The Army Rapid Capabilities and Critical Technologies Office (RCCTO) will develop and deliver the prototype MRC. “Adapting existing systems as much as possible will allow us to move faster than traditional acquisition methods to get this capability into the hands of Soldiers in support of the National Defense Strategy,” said LTG L. Neil Thurgood, Director of Hypersonics, Directed Energy, Space and Rapid Acquisition, who leads the RCCTO. “Soldier feedback and touchpoints will be embedded throughout the prototyping effort in order to make this system operationally effective the day it is delivered.”

On November 6, 2020, the Army awarded the prototype OT agreement on a sole source basis to Lockheed Martin in the amount of $339.3 million, inclusive of options. Under this agreement, Lockheed Martin will design, build, integrate, test, evaluate, document, deliver, and support the MRC prototype battery capability. In order to accelerate fielding to meet the FY23 timeline, the MRC prototype will utilize and modify existing hardware and software from the Army and joint service partners, and integrate additional technologies to achieve new operational effects. 

Following a broad review of joint service technologies potentially applicable to MRC, the Army has selected variants of the Navy SM-6 and Tomahawk missiles to be part of the initial prototype. The Army will leverage Navy contract vehicles for missile procurement in support of the Army integration OT agreement. The MRC will complement other critical systems in the Army’s long range fires portfolio, providing a combined operational and strategic capability that can attack specific threat vulnerabilities in order to penetrate, disintegrate and exploit targets in deep maneuver areas critical to the joint fight. 

The capability also allows the Army and joint services to synchronize and leverage modernization efforts and investments across mid-range missile programs in support of multi-domain operations. The MRC supports one of the Army’s chief roles in multi-domain operations: to use strategic fires to penetrate and disintegrate enemy layered defense systems, creating windows of opportunity for exploitation by the joint force

As to the question of what configuration of the SM-6 will the Army adopt, we have an answer to that thanks to Breaking Defense. The wider form-factor borrowed from the SM-3 Block IIA ballistic missile interceptor, a cousin of the SM-6, will be available in the future. This new SM-6 variant is already under development and will extend the range of the missile, which is already measured in hundreds of miles, and increase its kinetic performance significantly. You can read all about this new SM-6 variant in this past War Zone article. But as it stands now, the MRC capability will initially be fielded with the existing SM-6 the Navy is currently buying with an eye on upgrading to the more capable variant once it is fully developed. 

We don't know what type of launcher configuration would be used for a ground-based SM-6, although it could share the one being developed for the ground-launched Tomahawk, as both were originally designed to fit into the Navy's Mk 41 Vertical Launch System cells.

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Ground-launched Tomahawk test using a trailer-mounted Mark 41 VLS. 

Another huge outstanding question we have is will the Army's ground-launched SM-6 also leverage its surface-to-air missile capability, which is effective against air-breathing threats like aircraft and cruise missiles, as well as ballistic missiles in their terminal stage of flight. One can imagine just how beneficial this secondary capability could be if it was distributed throughout a theater of war. The Army is introducing a highly integrated air defense architecture that is perfectly suited for enabling such a dual-role system. It could also serve as an offensive command and control system for engaging ground targets with the SM-6, as well. You can read all about the Integrated Battle Command System in this in-depth interview of ours here. So, we may be looking at an enormously flexible capability set the Army is adding that will work far beyond the surface and ground strike roles. 

The bottom line here is that the Army is racing to get a ground-launched cruise missile (Tomahawk) and a quasi-ballistic missile (SM-6), the latter of which approaches or exceeds hypersonic velocities during its terminal stage of the flight, into service and the Navy just happens to have what it needs. Adapting these proven missile designs and integrating them into the Army's larger command and control networks and overall strategy not only speeds their entry to service, but it also stands to save massive sums of money. 

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SM-6

There is one other major benefit to these choices. Both programs, SM-6 and Tomahawk, will have another huge customer now. Not only will much larger combined purchases of these weapons lower their unit cost, but it could also significantly accelerate research and development of additional improvements and upgrades for these systems via the sharing of those costs as well. 

So, there you have it. The Tomahawk will find itself in a U.S. Army ground-based launcher once again and the SM-6 could become one of the most versatile weapons in the service's entire arsenal. 

Contact the author: Tyler@thedrive.com