The Standard Missile-6 (SM-6) is an endo-atmospheric interceptor, which uses a blast-fragmentation warhead to engage cruise missiles, aircraft, and ballistic missiles in the terminal phase. as its kill vehicle. The U.S. Navy is also upgrading the SM-6 to perform strike missions.
The body of the Standard Missile-6 combines the solid rocket booster and dual thrust rocket motors of the Standard Missile-3 series, the airframe of the Standard Missile-2 series, and the seeker and nosecone of an Advanced Medium-Range Air-to-Air Missile (AMRAAM).1 The dual-mode active and semi-active seeker technology allows the SM-6 to discriminate low flying cruise missile targets even in conditions with significant ground clutter. The SM-6’s built-in targeting radar, combined with the Navy’s updated Naval Integrated Fire Control-Counter Air (NIFC-CA), can receive targeting information from radar sources other than the onboard sensor (such as a SPY-1 radar) of the ship which fired it, allowing over-the-horizon engagements.2 This over-the-horizon capability extends the range of the missile to an estimated 370 km, beyond the range of a SM-2.3
SM-6 Deployment and Upgrades
The first version of the Standard Missile-6 became operational in December 2014 and, in January 2015, the Navy authorized the expansion of its use from five to more than 35 ships by certifying its use on non-Baseline 9 ships.4 In 2015, the Navy tested the first upgrade to the missile known as either the Dual I or Increment I. The SM-6 Dual I can intercept both cruise missiles and ballistic missiles in their terminal phase.5
As of May 2015, Raytheon completed delivery of 180 Standard Missile-6 interceptors. The U.S. Navy plans to eventually purchase 1,800 of the missiles.6 The United States is currently the only nation fielding the missile, but Capt. Michael Ladner, program manager of the surface ship weapons office in the Program Executive Office for Integrated Warfare Systems (PEO IWS 3.0), suggested that six international navies have reached out to discuss purchasing the interceptor.7 In 2015, the Missile Defense Agency Director, VADM James D. Syring, testified in 2015 that an SM-6 Increment 2 would be certified and operational by 2018, though he did not specify what the upgrades will add to the system.8
On January 10, 2017, it was reported that U.S. government cleared the SM-6 for international sale.9
Because of its blast fragmentation warhead and terminal guidance systems based on GPS, multiple commanders in the Navy have also suggested that the SM-6 Dual I could be used to strike land-based targets and even provide an offensive capability against other fleets. 10
In February 2016, Secretary of Defense Ash Carter revealed the U.S. Navy’s intention of further upgrading SM-6 to be able to perform anti-ship strike missions:
“I want to talk to you today about the SM-6, with which we are going to create a brand-new capability.
“Now, you know the SM-6. You launch it from surface ships. It’s a fantastic surface-to-air weapon; highly maneuverable, aerodynamically, and can stop incoming ballistic and cruise missiles that were trying to attack one of our warships. Can do it in the atmosphere, has very low altitude, acquire them, attack them, kill them. It’s one of our most modern and capable munitions.
“I’m announcing today new capability for the SM-6. We’re modifying the SM-6, so that in addition to missile defense, it can also target enemy ships at sea at very long ranges. This is a new anti-ship mode. It makes the SM-6 basically a twofer. Can shoot down airborne threats. And now you can attack and destroy a ship at long range with the very same missile.
“By taking the defensive speed and maneuverability that’s already in our Aegis destroyers’ vertical launch cells, and leveraging them for offensive surface warfare lethality, that makes it a potent new capability for you, surface warfare professionals. It’s also a good deal for the taxpayer, because they’re getting two capabilities in one missile.
“We know this works. We actually tested it secretly last month, and it worked.”11
In that test, which took place in January 2016, the USS Reuben James (DDG-245) reportedly fired an SM-6 at a target ship, sinking it.12 In principle, the SM-6 might evolve further, to acquire a land-attack role. 13