Three missions, one missile: SM-6 changes the arithmetic; Jane's International Defence Review; March-2017
In January 2017 Raytheon Missile Systems announced the receipt of a USD235 million contract modification from the US Naval Sea Systems Command (NAVSEA) funding existing options for fiscal year 2015/16 (FY 2015/16) production of RIM-174 Standard Missile-6 (SM-6) Block I/IA All-Up Rounds (AURs) and spares. This award constitutes an option as part of the fourth year of full-rate production (FRP-4) for the SM-6 missile, which has already entered service in the extended-range anti-air warfare (AAW) and lower tier ballistic missile defence (BMD) roles. In addition, missiles produced under this FRP-4 buy will embody an anti-surface capability that was first demonstrated in early 2016, making them 'tri-capable'.Having been conceived to push the boundaries of shipborne air defence as part of the Naval Integrated Fire Control - Counter Air (NIFC-CA) construct - SM-6 is claimed by the US Navy (USN) to have broken the record for the longest surface-to-air missile engagement twice during testing in 2016 - this latest incarnation of the Standard Missile line is now being lauded by the service's leadership as a multimission effector in tune with the surface navy's new operating concept of 'Distributed Lethality'.
"We've done the longest surface-to-air intercept ever [employing NIFC-CA]," Rear Admiral Ron Boxall, director, Surface Warfare (N86), told the Surface Navy Association (SNA) annual symposium in Crystal City, Virginia, on 10 January. "That same SM-6 we used in the NIFC-CA mode also has the capability to do Sea-Based Terminal (SBT) defence. We just tested it out at PMRF [Pacific Missile Range Facility] at Kauai [in December 2016] in the first engagement against a very complex medium-range ballistic missile target."We now have one missile that can do more than one thing. And by the way, when we go to the surface domain, SM-6 in the surface mode is a pretty good thing too. So I have one missile that I can use in many different ways. I can save on missile space in all those [vertical launcher cells] I have on cruisers and destroyers out there. That's a good thing for me."
"SM-6 goes long range, very quickly," Captain Mike Ladner, programme manager Surface Ship Weapons, Program Executive Office Integrated Warfare Systems (PEO IWS) in NAVSEA, told Jane's at SNA in January 2017. "What we are now doing is developing software modifications to go multimission. Adding that software-based functionality into existing assets provides us a better use of limited resources."Extended envelope
Also known as the Extended Range Active Missile (ERAM), SM-6 was designed and developed to meet the navy's requirement for an over-the-horizon AAW missile able to engage fixed- and rotary-wing aircraft, unmanned aerial vehicles, and land-attack/anti-ship cruise missiles in flight, both over sea and land. It would do so as part of an integrated fire-control network - what is today NIFC-CA - to extend the AAW battlespace, and take full advantage of proven Standard Missile kinematics.
The SM-6 design philosophy was to marry the airframe and propulsion stack from the existing SM-2 Block IV missile (of which limited production was undertaken for the USN in the 1990s) with guidance and signal processing technology drawn from across the company's product lines. This approach means the SM-6 AUR incorporates much proven Standard Missile hardware, with major non-developmental items (NDIs) including the airframe itself, the Mk 72 Mod 1 rocket booster, the steering control system, the Mk 104 Mod 3 dual-thrust rocket motor, the Mk 125 warhead and the nose radome.
These NDI subsystems are integrated with a new mission computer and a dual-mode (active/semi-active) X-band seeker package that repackages the Phase III seeker associated with the AIM-120C-7 Advanced Medium-Range Air-to-Air Missile (AMRAAM). This new front-end electronics section interfaces to legacy Standard Missile functions - such as the datalink, inertial measurement unit, target-detection device and steering-control system - and re-hosts missile-guidance and control functions.
A larger seeker antenna, using all available volume, offers increased sensitivity for longer detection range, improved resolution for superior electronic protection performance, and lower angle noise for improved terminal guidance. Operation in the active mode eliminates the need for a shipborne illuminator, so providing for a high stream raid capability; the additional semi-active mode leverages the AMRAAM high-pulse repetition frequency waveform and rear datalink channel, delivering an increased acquisition range to improve performance against high-speed threats.
Raytheon also predicts significant life-cycle cost benefits accruing from large-scale design reuse (both Standard Missile and AMRAAM), common manufacturing facilities, and in-the-field software reprogramming. The SM-6 also adopts AMRAAM built-in test (BIT) features and in-the-container BIT field recertification is expected to generate substantial through-life cost savings.
As well as introducing an active radar seeker, which offers greater firepower as a result of decreased dependence on illuminators, enhanced fuzing via guidance integrated fuzing, improved sub-clutter visibility and enhanced countermeasures resistance - the SM-6 also delivers the kinematic performance required to defeat current and projected threats that possess low-altitude, high-altitude, high-velocity and manoeuvre characteristics at the maximum range of the missile. These remain classified by the USN, but open sources suggest between 130 and 250 n miles. Moreover, it is not just providing protection for the fleet, but will also extend its coverage over land to contribute to the protection of forward-deployed ground forces.
However, the SM-6 cannot be viewed in isolation. Operating in conjunction with the Aegis weapon system it can be fired on target data organic to the launch ship (using initial and midcourse guidance commands transmitted by SPY-1 radar uplink dwells). As a component of NIFC-CA - and operating with Aegis Baseline 9 - it can also use the Cooperative Engagement Capability (CEC) and remote sensor data of appropriate quality to function as a 'net-enabled' interceptor able to 'engage on remote'.
In NIFC-CA engagements at long range or over-the-horizon, the SM-6 active seeker performs independent endgame intercepts. Alternatively, within the shipboard radar envelope, SM-6 can be supported by the Aegis fire-control system (using shipboard illuminators) to consummate an engagement in semi-active mode.The active mode eliminates the need for a shipborne illuminator, so providing for enhanced high-stream raid capability against numerous threats by means of improved target resolution in range and Doppler, and missile/target pairing logic. However, retention of the legacy semi-active radar homing mode delivers benefits in some specific engagement scenarios.
The SM-6 missile is also to be employed by Aegis Ballistic Missile Defense (BMD) ships in an SBT role, replacing the limited inventory of SM-2 Block IV missiles used in this role. Aegis BMD, which is co-operatively managed by the Missile Defense Agency (MDA) and the USN, is the maritime component of the Ballistic Missile Defense System.In this capacity, the SM-6 missile uses its warhead to defeat ballistic missile threats inside the atmosphere. Missiles enabled for both AAW and SBT missions are now designated SM-6 Dual I.Acquisition and development
The SM-6 acquisition strategy was approved by the Office of the Secretary of Defense Acquisition, Technology, and Logistics in March 2004. Raytheon Missile Systems was awarded a USD440 million System Development and Demonstration (SDD) contract for the SM-6 Block I missile in September 2004 covering design, development, fabrication, assembly, integration, test, and delivery of flight and non-flight assets. This included the build-up of 25 SDD rounds to be expended prior to Initial Operating Capability (IOC).SM-6 had originally been scheduled to achieve IOC in 2012. However, Initial Operational Test and Evaluation (IOT&E) was not without its challenges, with only seven of the 12 intercept attempts achieving success. Flight testing revealed anomalies associated with the uplink/downlink antenna shrouds, the MK 54 safe/arm device, and one still classified deficiency. IOT&E failures experienced during flight testing in July 2011 delayed IOC, and pushed back the start of full production by a year.
The metric set for IOC was defined by the USN as one SM-6 loaded out onto an Aegis Baseline 5.3.8 (or newer) surface combatant. IOC was formally declared in November 2013 with the outload of an undisclosed number of SM-6 AURs on board the DDG-51 Flight IIA guided-missile destroyer USS Kidd (DDG-100) in San Diego, California.
In January 2015 it was disclosed that the USN had approved the deployment of SM-6 on additional Aegis ships following certification of the Aegis Combat System Baselines 5.3 and 3.A.0 series to operate with the missile. SM-6 has subsequently been integrated and authorised for use with Aegis Baseline 9A (February 2015) and Baseline 9C.1 (November 2015).Follow-on Operational Test and Evaluation (FOT&E) events were conducted from FY 2014 to FY 2016. Seven SM-6 Block 1 test missions were flown in FY 2014 - four supporting Aegis Baseline 9, three supporting NIFC-CA From-the-Sea (FTS) Increment I - all of which were successful. Six of these were conducted at the Point Mugu Sea Range, California; one was flown overland (against a low flying subsonic target) at White Sands Missile Range (WSMR), New Mexico. One of the three NIFC-CA flight tests, performed in January 2014, was the longest-range engagement by SM-6 to date.
A further seven SM-6 Block I tests were flown during FY 2015. Of the planned launches, two of three successfully supported FOT&E with Aegis Baseline 9 (both engaging targets employing jamming); one test resulted in a missile failure-to-launch owing to a misfire; and one, performed at WSMR in support of NIFC-CA FTS Increment 1, successfully engaged a full-scale fighter target.
The other three FY 2015 tests saw SM-6 Dual I missiles successfully support the MDA's SBT testing and air warfare retention capability. Conducted from the destroyer USS John Paul Jones (DDG 53), these were part of a series of four flight test events, designated Multi-Mission Warfare (MMW) Events 1-4, conducted at the PMRF to demonstrate the Aegis Baseline 9.C1 (BMD 5.0 Capability Upgrade) using SM-6 Dual I and SM-2 Block IV missiles.
During MMW Event 1, flown on 28 July 2015, an SM-6 Dual I missile intercepted a short-range ballistic missile (SRBM) target launched from PMRF in a northwesterly trajectory. This was the first SM-6 Dual I live fire event.
MMW Event 3 (flown on 31 July) and MMW Event 4 (performed on 1 August) were both conducted to demonstrate air warfare capability retention. In the former, the SM-6 Dual I missile successfully engaged a supersonic AQM-37C high-diver target, while an SM-6 Dual I missile successfully engaged a BQM-74E subsonic low-altitude target as part of MMW Event 4.
MMW Event 2, flown on 29 July, was a repeat of Event 1 but used a legacy SM-2 Block IV missile. MMW Events 1 and 2 were the 30th and 31st successful BMD intercepts in 37 flight test attempts for the Aegis BMD programme since flight testing began in 2002.A further six SM-6 Block I tests were flown in FY 2016. Of these, four successfully supported FOT&E with Aegis Baseline 9 and one successfully supported the NIFC-CA Tactical Demonstration.According to the office of the Director, Operational Test and Evaluation (DOT&E) 2016 annual report, the four FOT&E tests, flown from John Paul Jones at PMRF, pushed the envelope against a series of very different, and very complex, threat presentations. Flight Test D1A successfully engaged a maximum down-range target, Flight Test D1B successfully engaged a maximum cross-range target, Flight Test D1D successfully pitted two SM-6s against two subsonic targets (an Aegis Weapon Control System integration problem appeared that did not affect the mission), and Flight Test D1Ga successfully engaged a target that was using electronic attack against the SM-6. The last mission was a repeat of the March 2015 SM-6 Block I missile that failed owing to a misfire.
The tests, supported by CEC, demonstrated both maximum down-range and a maximum cross-range intercepts in over-the-horizon, engage-on-remote missions. USS Gridley (DDG 101) was on station to perform as the Aegis assist ship for the engage-on-remote endgame; Flight Test D1A broke the record for the longest engagement range.However, the record did not last long. In September 2016, at the Pacific Missile Test Center, California, the USN conducted an at-sea flight demonstration of the NIFC-CA FTS Increment I. The SM-6 missile, fired from the cruiser USS Princeton (CG 59), destroyed an over-the-horizon target; this is recorded as being the longest range surface-to-air intercept of its kind in naval history, although as with previous record claims, neither the USN nor Raytheon will divulge details of the exact range.
One other SM-6 flight test, supporting the Aegis 'Agile Prism' demonstration, was flown in 2016 ('Agile Prism' refers to a complex but publicly undisclosed threat type). This was the only black mark for the year: conducted at PMRF in March, the SM-6 Block I missile failed to successfully engage either of the two low-altitude threat targets.
According to the DOT&E, the USN successfully demonstrated the SM-6 maximum range key performance parameter, and the maximum cross-range and launch availability key system attributes during FY 2016 FOT&E events. In the latter case, the navy stored seven missiles aboard an operational ship for at least eight months (prior to firing during FOT&E) with no launch availability problems noted.
"We completed the SM-6 Block 1 FOT&E flight tests back in January of last year ," said Capt Ladner. "We finished the last four flight tests, all successful.
"That anchors our modelling and simulation for the Baseline 9 Aegis combat system with SM-6, and now we're going to [do] a lot of runs for the record to fill out the rest of the battlespace performance predictions, and understand what that capability is."In addition, FOT&E flight test events will be completed to validate the software fix for the classified deficiency uncovered during IOT&E flight tests OT-5 and OT-15. "We're testing that this year," confirmed Capt Ladner. "So we feel pretty good about what the fix is, we've modelled it, predicted it, and now we're going to flight test it. That should retire the issue [and that] software fix will populate through the inventory that's been delivered."
Achievement of FOC had been planned for March 2016, but this milestone was re-baselined to December 2017 due to the navy's inability to complete outstanding Operational Test and Evaluation events due to target moratoriums and FY 2015 and FY 2016 funding shortfalls. However, this revision in FOC does not affect the capability level, or the number of missiles being delivered into the fleet inventory."The programme is on track to achieve [FOC] by December 2017," Capt Lander confirmed. "We're very happy with the progress of the programme,"Terminal defence
For the navy, the ability to expand missile functionality without the need to re-design and recertify hardware is a game changer. "If I can make software-only modifications to those missiles I now have the ability to pace the threat without having to go back in and change hardware and complete a development effort," said Capt Ladner. "It's like a Windows 10 upgrade … the software is updated and now I get a new capability rolled out. What I [need to] do is to be nimble in how I make those software upgrades."
SBT Increment 1 is the first example of a software upgrade that is endowing additional capability, introducing functionality to enable the SM-6 Dual I missile to defeat short-range ballistic missile threats inside the atmosphere in their terminal phase. The SM-6 Dual I was entered in the MDA's Operational Capability Baseline in December 2015 and delivered to the fleet.Having completed a first SM-6 Dual 1 flight test in July 2015 - intercepting and destroying a short-range ballistic missile target in its final seconds of flight - the MDA and the USN conducted a second test, designated Flight Test Standard Missile-27 (FTM-27), off the coast of Hawaii in December 2016. On this occasion the destroyer John Paul Jones , configured to Aegis Baseline 9.C1, fired a salvo of two SM-6 Dual I missiles against a medium-range ballistic missile (MRBM) target fired from PMRF.
Lockheed Martin's Targets and Countermeasures team designed, built and launched the MRBM target vehicle. Although it has been widely reported that the target was flying a trajectory typical of a Chinese DF-21 anti-ship ballistic missile, the MDA has made no comment as to the specific threat type being replicated by the MRBM target.Surface mode
In February 2015 then Secretary of Defense Ash Carter confirmed that the USN was developing a modification to SM-6 enabling an over-the-horizon anti-shipping strike role. A demonstration at PMRF on 18 January 2016 proved this capability when an SM-6 missile successfully engaged and hit the hull of the frigate ex-USS Reuben James (FFG 57).
The primary purpose of the anti-surface warfare (ASuW) flight test, conducted from John Paul Jones , was to validate that the legacy anti-surface capability of the Aegis Weapon System Mk 7 and the SM-2 missile had been successfully carried forward into the latest Aegis Baseline 9 with the SM-6 missile. Few details of the SM-6 surface mode test were disclosed, beyond the fact that the missile modifications were limited to software changes only, and that another DDG-51 destroyer was on station as the 'assist ship' for the engagement. No details of the engagement range or flight profile were revealed.
However, what is known is that this new over-the-horizon offensive anti-surface capability for Aegis Baseline 9 ships is network-enabled by a remote sensor in much the same way as NIFC-CA. Moreover, the potential employment of SM-6 in an anti-shipping role is very much aligned to the US surface force's new operational concept of 'Distributed Lethality'.Incremental growth
The SM-6 programme was conceived as an evolutionary, low-risk capabilities-based acquisition programme that could use spiral development to incrementally add capability to the baseline Block I missile to pace emerging threats. Block 1A constitutes that first spiral and introduces a series of hardware and software improvements.
A first land-based launch (Guidance Test Vehicle-1 [GTV-1]) of a pre-production SM-6 Block IA missile was performed in August 2014 at WSMR, with the missile successfully engaging a high-altitude subsonic target over land. A second successful mission (GTV-2) was flown in FY 2015."Block IA is a pre-planned improvement to Block 1 to continue to pace advanced threats," said Capt Ladner. "So we're implementing an ECP [Engineering Change Proposal] to the guidance section that introduces hardware changes, including a GPS receiver and modified software."
He continued, "The introduction of GPS helps us with co-ordinate frame alignment because of the speeds and the distances we're going, and the threats were going up against."GPS could enable some other missions in due course. We'll go look at these."
According to Capt Ladner, one more land-based SM-6 Block IA test is planned before at-sea testing commences. "We've flown two land-based test flights, and we'll fly a third land-based test later this year. We have confidence that the design is right, and the third will prove that we have the manufacture process right. Then we're ready to go to sea."
Raytheon is now transitioning the SM-6 line to Block IA standard, according to Thad Smith, Raytheon Missile Systems' SM-6 business lead. "Our first LRIP [for Block IA] was in our FY 2015 contract," he told Jane's . "We've procured many of those parts [and] we expect that the first all-up-round is going to be delivered this year. Our planned full-rate production starts in 2018."
The SM-6 Block IA missile embodying SBT capability will be known as Dual II.Production lineThe USN initially set an SM-6 inventory goal of 1,200 missiles. In March 2013, a resources and review board gave approval to increase the procurement offtake to 1,800 AURs, with Raytheon holding out the prospect that this could increase still further
Final assembly of the SM-6 AUR takes place at Raytheon's production facility at Redstone Arsenal in Huntsville, Alabama, alongside assembly of the SM-3 exo-atmospheric interceptor. Opened in November 2012, the 70,000 sq ft (6,503 sq m) facility has subsequently been expanded to incorporate a new test cell.
Following four annual low-rate initial production buys, the SM-6 programme transitioned to full series production in FY 2013: first FRP deliveries commenced in April 2015.Raytheon has to date delivered more than 330 SM-6 AURs from the Huntsville line. The company is currently producing FY 2014 missiles, with FY 2015 production cutting in later this year.
"The intention is that …once we get the Engineering Change Proposal approved the SM-6 missiles that we produce will have all three mission capabilities," Smith explained. "We can inject the software into whatever version of the AUR. It doesn't have to be boutique.
"You have a code plug that attaches [to] the missile in the cell that is able to identify which missile, and which software load. The Aegis baseline 9 weapon system can then select which mission it will perform [according to] the target type."
"While SM-6 is not a cheap missile, you get a lot of capability for the price," said Capt Ladner. "Raytheon has an affordability programme in train, and we're exploring with them and the MDA as to how we continue to drive costs down. Can we contract better? Can we do a multi-year procurement?"
Work is also continuing to examine how and when SM-6 could be further adapted for other missions. "We're looking at where SM-6 can perform in an adjacent mission space to either add new capability to the missile, or drive into another different domain," Smith said. "Can you use SM-6 for a mission for land, to go against something else? Would that work, how would you communicate with the missile, what kind of weapon system would you need ashore to do that?"
He added, "We have a joint roadmap that we work together with the US Navy and the Applied Physics Laboratory [APL] at Johns Hopkins University on what is the threat of tomorrow, and beyond. We're also looking on addressing obsolescence, and what new technologies have we developed APL, NRL [Naval Research Laboratory] or any other agency developed that might be able to go into SM-6."Export release
After several years of policy in the making, the US Department of Defense in late 2016 approved the release of SM-6 to a number of international customers. "We've been pursuing international release policy on SM-6 for quite some time, and we've been briefing countries," Capt Ladner told Jane's . "I'm fully expecting letters to start coming in [requesting price and availability] from several countries who are very interested in either the long range-AAW capability or the sea-based terminal/dual-mission capability for SM-6."
While the full approved list has not been disclosed, Smith has pinpointed Australia, Japan, and the Republic of Korea as the three most immediate prospects based on their existing investments in the Aegis combat system. "These three navies all have Aegis [surface combatant] programmes, which could align to the baseline appropriate to SM-6," he said. "The Australians have already called out SM-6 as a capability they desire for the future."
Australia's 2009 defence white paper, 'Defending Australia in the Asia-Pacific Century', explicitly identified SM-6 as the means to deliver an enhanced AAW capability for the Royal Australian Navy's three new Hobart-class Air Warfare Destroyers. This aspiration has been formalised under Project SEA 1360 Phase 1 Maritime Extended Range Air Defence, and features as part of the 2012 Defence Capability Guide.
Smith commented, "The current Defence White Paper  identified an extended-range active missile [and] previous iterations of the white paper had actually called out SM-6.
"In that current white paper, it also calls out a combat systems upgrade to align those Air Warfare Destroyers with a current Aegis baseline that's in the US Navy. To employ SM-6 on those Aegis ships they need to get a baseline upgrade. They are currently Baseline 8, they would need to go to Baseline 9, and that would bring the capability of SM-6."
Japan and the Republic of Korea are also investing in the latest Aegis baseline. "Japan's [two] new construction [27DD] destroyers are at Aegis Baseline 9," said Smith. "A Letter of Offer and Acceptance [LOA] has already been signed for those ships.
"Their two existing [Atago-class] ships could also be upgraded to Aegis Baseline 9. So there could be the option to deliver four ships that would be SM-6 capable.
"As for the Republic of Korea, its three new-construction [KDX-III Batch 2] ships will be Aegis Baseline 9 also. That LOA has already been executed by the US government. With that Baseline 9 you also bring in the option to fire SM-6."Smith does not foreclose SM-6 sales outside of the Aegis community, but points out that this would require some modification to the missile communications. "For SM-6 to go into a non-Aegis weapon system, using a different uplink [frequency] requires some sort of development to add a new [communications] band.
"Now the Evolved SeaSparrow Missile [ESSM] Block 2 will have dual-band transceiver capability with an S- and X- band plate. That is funded through the consortium.
"ESSM Block 2 is a 10-inch plate. SM-6 is a 13-inch missile, so we've funded our own internal efforts to look at that capability of having a dual-band capability, not only in SM-6 but also in the SM-3 and SM-2 missiles."
This graphic depicts the USN's first live fire demonstration to test the integration of the F-35 with existing NIFC-CA architecture. During the September 2016 test at White Sands Missile Range, New Mexico, an F-35B acted as an elevated sensor to detect an over-the-horizon threat. (US Navy)