SM-6 missile launch

WASHINGTON: Instead of picking a single missile to be its thousand-mile Mid-Range Capability, the Army has chosen to mix two very different Navy weapons together in its prototype MRC unit: the new, supersonic, high-altitude SM-6 and the venerable, subsonic, low-flying Tomahawk.

“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,” says a Rapid Capabilities & Critical Technologies Office (RCCTO) statement released this afternoon. “The Army will leverage Navy contract vehicles for missile procurement in support of the Army integration OT [Other Transaction Authority] agreement.”

Lockheed Martin won the OTA contract, worth up to $339.4 million with all options, to integrate the two missiles – both built by Raytheon – into the Army fire control systems, vehicles, and support equipment required for a fully functioning artillery battery. Lockheed builds the current wheeled HIMARS and tracked MLRS launchers, which can handle a wide variety of current and future Army weapons, but neither the service nor the company would say whether they could fire either SM-6 or Tomahawk, citing security concerns.

They are set to enter service in 2023.

I asked the Army if it would modify either weapon to better its needs: The answer is no. “The Army will not modify the Navy missiles,” an official said in an email to Breaking Defense. That means the Army’s going to buy exactly what the Navy is getting.

However, the announcement’s mention of “variants” gives the Army leeway to buy the latest and most upgraded models. That’s important for both weapons.

Navy photo

Testing the Maritime Strike Tomahawk, a variant of the venerable TLAM

A Mix of Missile Options

The subsonic Tomahawk cruise missile is the long-serving mainstay of long-range strike. It was first fielded in the Reagan era and has been much upgraded since, with more than 2,000 fired in combat since 1991. There used to be a whole family of different versions, but nuclear-tipped, land-based, air-launched, and anti-ship variants were retired after the Cold War. That left the Navy’s conventional-warhead Tomahawk Land Attack Missile (TLAM), which can only be fired from ships and submarines, and only at stationary targets ashore.

Tomahawk Block IV cruise missile

But in recent years, anxiety over the growing Chinese fleet led the Pentagon to build a new anti-ship model, the Maritime Strike Tomahawk (MSM). The Army and Marine Corps are both intensely interested in turning Pacific islands into forward outposts bristling with ship-killer missiles, so they’re likely to buy the Maritime Strike model.

The supersonic SM-6 is the latest and sexiest version of the Navy’s Standard Missile family, whose primary role is defensive, built to shoot incoming enemy aircraft and missiles out of the sky. But the new SM-6 is also capable of striking surface targets on land and sea.

The SM-6 selection surprised me at first, because its reported ranges are well short of the 1,000 miles the Army wants for the Mid-Range Capability. While the real range is classified, estimates range up to 290 miles (250 nautical miles).

However, the Navy is now developing an extended-range model of the SM-6, the Block 1B. (It’ll use the rocket booster from another Standard Missile variant, the ICBM-killing SM-3, which is known to have a range greater than 1,000 miles). What’s more, while the current SM-6 maxes out at Mach 3.5, the SM-6 Block 1B will reportedly reach hypersonic speeds, i.e. above Mach 5. While the Navy plans for Block 1B to complete development only in 2024, it wouldn’t be a stretch to have a handful of missiles available early for the Army’s MRC roll-out in late 2023.

Navy photo

The USS John Paul Jones test-fires an SM-6 missile from a Vertical Launch System (VLS)

Why mix both SM-6 and Tomahawk in the same unit? Part of the answer is probably cost. Tomahawk is relatively affordable at about $1.4 million each, or perhaps $2.5 million for the anti-ship variant. The current model of SM-6 is nearly $5 million, and the hypersonic, extended-range SM-6 1B will no doubt cost more. That allows the Army to buy more Tomahawks than SM-6s and reserve the faster, more expensive missiles for harder or higher-priority targets.

The other benefit is tactical. The Tomahawks come in relatively low and slow, trying to get under radar, while the SM-6s fly high and fast. A missile defense that stops one may not stop the other, complicating the enemy’s countermeasures.

Both missiles are available in the near term, a crucial consideration given the Army’s urgency to field the Mid-Range Capability by the end of 2023. In the longer run, however, the Army may well develop a new weapon for the MRC role, perhaps derived from DARPA’s hypersonic OpFires experiment.

Why should the Army be launching long-range missiles at all?

That’s not something it’s done since the Pershing was retired, and some critics consider it redundant to the existing Navy and Air Force arsenals. But the Army is eager to prove its relevance to future wars against high-tech adversaries, especially in the vast Pacific, and it argues that truck-launched missiles are cheaper to deploy and easier to hide than weapons mounted on ships and planes.

The Army’s official press release and its full responses to my questions follow.

Army Awards Mid-Range Capability (MRC) Other Transaction (OT) Agreement_Final by BreakingDefense on Scribd

“The Army and joint service partners have conducted extensive mission thread analysis to solidify the kill chain and communications systems required to support MRC operations. Details are not publicly releasable due to OPSEC considerations,” Army officials wrote me in an email.

“The Tomahawk and SM-6 were chosen in order to accelerate a mature capability to address near-peer threats. They provide the required mix of capability to engage desired targets at mid-range distances. Working closely with the Navy, the Army will be able to integrate these missiles for the MRC prototype battery to meet the FY23 fielding date.

“The Army will not modify the Navy missiles. While working on materiel solutions, the Army is also consistently doing analysis to determine the best mix of weapons systems, how the enemy is going to fight against new capabilities, and how to address capability gaps.

“The MRC prototype battery is planned to include a mix of both SM-6 and Tomahawk missiles to provide the desired capability in FY23.”