U.S. Navy's Hugely Versatile SM-6 Missile Keeps Scoring Hits

Latest test aimed at improving the weapon's capabilities against ballistic missiles in light of emerging threats.

MDA

The U.S. Missile Defense Agency and the U.S. Navy have successfully intercepted a surrogate medium-range ballistic missile (MRBM) with a pair of Standard Missile-6 (SM-6) surface-to-air missiles during a test off the coast of Hawaii. This is the second time the SM-6 has knocked down an MRBM-type weapon and the third time it has hit a ballistic missile of any kind. It also comes as concerns about ballistic missile programs in North Korea and elsewhere around the world are growing.

As part of the continued development of the complete Aegis Ballistic Missile Defense (BMD) system, U.S. military personnel launched the mock MRBM from the Pacific Missile Range Facility on Kauai, Hawaii early on Aug. 30, 2017. The Navy’s Arleigh Burke-class destroyer USS John Paul Jones subsequently tracked the missile using its on board AN/SPY-1 radar and then fired two SM-6s at it during the experiment, also known as Flight Test Standard Missile-27 Event 2 (FTM-27 E2).

MDA

Ballistic missile target being fired from Kauai for FTM-27 E2.

"We are working closely with the fleet to develop this important new capability, and this was a key milestone in giving our Aegis BMD ships an enhanced capability to defeat ballistic missiles in their terminal phase," MDA Director U.S. Air Force Lieutenant General Sam Greaves said in a statement. "We will continue developing ballistic missile defense technologies to stay ahead of the threat as it evolves."

In August 2015, an SM-6 intercepted a short-range ballistic missile target. Then, in December 2016, one of the missiles successfully destroyed a surrogate MRBM for the first time. 

The U.S. Navy has had SM-6, also known as the RIM-174A Extended Range Active Missile (ERAM), in service since 2013, but primarily as a traditional air defense weapon targeting air-breathing threats such as aircraft and cruise missiles. Since then, the weapon’s manufacturer Raytheon has been working with MDA to expand its ability to intercept both MBRM and shorter-range ballistic missiles in their terminal phases of flight, as they fall onto their targets. SM-6 fits into any standard Mk 41 Vertical Launch System (VLS) cell and also now features a secondary surface- and land-attack capability.

The overall concept is for the SM-6 to complement the Standard Missile-3 (SM-3), which is a dedicated ballistic missile interceptor. Also known as the RIM-161A, SM-3 has the ability to engage intermediate range ballistic missiles (IRBM), as well as hit shorter-ranged ballistic missiles in the middle of their flight, owing to its own higher altitude performance. This is called mid-course intercept capability. 

MDA

"Earlier this year, our customer requested an enhanced capability to deal with a sophisticated medium-range ballistic missile threat," Mike Campisi, Raytheon's SM-6 senior program director, said in a separate statement about the August 30 test. "We did all this – the analysis, coding and testing – in seven months; a process that normally takes one to two years."

MDA stressed it had planned the test long in advance and that it was not in response to any particular world events. Still, it is difficult, especially given Raytheon’s statement, not to see it in light of North Korea’s increasingly advanced ballistic missile development programs.

KCNA

North Korea launches a Hwasong-12 IRBM on Aug. 29, 2017.

On Aug. 28, 2017, the reclusive dictatorship sent a Hwasong-12 IRBM flying straight over Japan's Hokkaido Island, prompting warnings in that country about a potential incoming attack, before the missile plunged into the Pacific Ocean. This was the latest and perhaps most provocative test of the year, which has also seen multiple successful launches of North Korea's first real ICBM design, known as the Hwasong-14, which can likely reach significant portions of the continental United States.

Unless a SM-6 equipped U.S. Navy surface combatant was patrolling in an enemy missile's target areas, their SM-6 missiles would likely not be of much use and the SM-6 has not been tested against IRBMs or ICBMs, such as the Hwasong-12 and -14 respectively. Still, it is an important part of the U.S. military’s plans for a layered missile defense shield, able to take down the kind of shorter-range weapons that North Korea fired off earlier in August 2017 in protest to annual U.S.-South Korean military exercises.

BMD

With enhanced terminal intercept capability, Aegis BMD ships can also be deployed near suspected targets areas, like say off the coast off Okinawa, where the U.S. has large air bases. With a combination of SM-3 and SM-6 onboard, a single vessel could provide both mid-course and terminal ballistic missile defense capabilities once on station. 

Given North Korea’s increasing belligerence, Japan had already been exploring the possibility adding Aegis Ashore missile defense sites to supplement its Aegis-equipped ships, most of which have ballistic missile capability, too. In May 2017, the War Zone’s own Tyler Rogoway provided an in depth look at why this made particularly good sense, especially when employing both SM-3 and SM-6 missiles.

Notably, Japan is already working together with the United States on the development of the SM-3 interceptor, contributing to the design and production of components. The addition of the SM-6, which the U.S. government has approved its sale to allies, to the Japanese military’s arsenal would only make its ships and any shore-based facilities more versatile. In the case of Aegis ashore, it would also make the installations more survivable against high-volume saturation attacks.

On Aug. 30, 2017, Reuters reports that three unnamed sources had confirmed the Japanese military was pushing ahead with plans to have Aegis Ashore batteries operational by 2023. In addition, Japan had reportedly asked the U.S. government for the ability to purchase Raytheon’s advanced AN/SPY-6 Air and Missile Defense Radar (AMDR) to go along with them.

Already in development for the U.S. Navy, the radar is eminently scalable system, being made up of a number of self-contained emitters, each inside its own two square foot container. The standard AMDR has 37 of these so-called “radar modular assemblies,” but the design means Raytheon could reconfigure same gallium-nitride-based technology to fit almost any platform. These electronically scanned units can perform individual functions or operate linked together to focus their combined energy on a single task.

Concerns about how sending the Terminal High Altitude Air Defense (THAAD) ballistic missile system to South Korea might impact relations with the Chinese government had been a major consideration ahead of that deployment. There is the possibility that similar issues could have an impact on sales of Aegis Ashore and SPY-6 radar to Japan. But with the Trump Administration’s increasing sanctions on Chinese nationals and businesses over North Korea weapons programs, as well as President Donald Trump himself often criticizing China over North Korea situation, this may not be the issue it once was, though. And considering that North Korea is now sending ballistic missiles over Japan's population centers, the arguments against a need for Aegis Ashore would be dubious at best. 

But beyond North Korea, the SM-6 represents an increasingly important capability for the U.S. Navy, and its allies, broadly, as ballistic missile threats proliferate around the world. Most seriously, China has been expanding its own arsenal of these long range weapons, including the DF-21D anti-ship MRBM and the DF-26 anti-ship IRBM. Both types are specifically designed for engaging large maritime targets, such as aircraft carriers, over great distances.

MDA

There have even been reports that the People’s Liberation Army is interested in developing an air-launch capability for the DF-21D, as well. Equipped with SM-6s, Aegis BMD capable surface combatants escorting Navy carrier battle groups would be able to offer an important additional defense against these weapons and any other similar future anti-ship ballistic missile designs. With SM-3s and SM-6s, the ships could also stand watch against threats inbound to other strategic American facilities throughout the Pacific, including Guam.

In all of these cases, ships with the missiles could make use of the U.S. Navy's increasingly networked sensor architecture to extend their target detection and engagement ranges. In a not too distant future, this integrated network, now dubbed Navy Integrated Fire Control-Counter Air (NFC-CA), could include information coming in from other ships in a carrier battle group or other naval surface task forces, E-2 Hawkeye radar aircraft, P-8 maritime patrol aircraft, F/A-18E/F Super Hornets, F-35 Joint Strike Fighters, drones, as well as assets from other services in the air and on land. 

Imaginechina via AP Images

Road-mobile DF-21D anti-ship ballistic missiles.

Under this concept, a Super Hornet operating outside the radar range of a U.S. Navy cruiser can use its own sensors to detect and engage an aerial target, but instead of firing its own missile, a SM-6 from said cruiser flies out and kills the target. This is accomplished all via data link architecture, and the SM-6 is uniquely capable of supporting such a concept.

On top of that, the SM-6 could give the Arleigh Burkes the Navy has tasked in part with missile defense more flexibility to operate in more tightly constrained areas elsewhere, including the Baltic and Black Seas in Europe, which Russia would be able to quickly saturate with aircraft and shore-based defenses in any potential conflict. Especially in the Black Sea, where an international treaty limits the total number of warships the U.S. Navy can operate there at any one time, the versatility of the SM-6 would be especially significant, offering American commanders anti-aircraft, anti-surface, and limited ballistic missile defense all in one weapon.

USN

The Arleigh Burke-class destroyer USS Carney departs the Black Sea in July 2017.

For allies, the missiles could similarly improve the capabilities of existing ships, especially smaller surface combatants with limited  Mark 41 Vertical Launch System space for weapons to begin with. Though they might not have the necessary sensors to take advantage of its ballistic missile defense features, the SM-6 would still be a dual purpose anti-aircraft and surface- or land-attack weapon. And as with the notional Aegis Ashore systems in Japan, the facility in Romania and the up-coming site in Poland could gain the ability to take on an expanded scope of targets, and better protect themselves, with a combination of SM-3s and SM-6s. 

This latest SM-6 test increases overall confidence in the Aegis BMD concept and underscores the missile's growing flexibility and value. It will be interesting to see how the missile continues to evolve. But already, just half a decade into its operational life, its multi-pronged abilities are downright impressive and they are only going to get better.

Maybe a next generation SM-6 will take advantage of the SM-3 Block IIA's thickerrocket "stack," increasing its range against air, surface, and land targets, and its ability to swat down incoming ballistic missiles. 

The bottom line is that the SM-6 looks like it is primed to be the Navy's multi-role networked missile of choice for the foreseeable future. 

Contact the author: jtrevithickpr@gmail.com