Monday, April 24, 2017

Kongsberg Naval Strike Missile

The Kongsberg Naval Strike Missile (NSM) is being considered for the LCS and, possibly, other US Navy ships.  Let's get to know it a bit better.  It was developed for the Royal Norwegian Navy as an anti-ship missile capable of being launched from Skjold class corvettes and Nansen class frigates as well as coastal defense batteries.  A related variant, the Joint Strike Missile, is being developed as an air launched version intended for use by the F-35.  The missile has been in production since 2007.


The NSM is a sea skimming, completely passive missile with advanced terminal maneuvering and Autonomous Target Recognition (ATR) capability (1).  The missile airframe is somewhat stealthy but not extremely so and incorporates reduced radar cross section and IR signature (5).  The manufacturer claims the missile is resistant to countermeasures.

Naval Strike Missile with Booster 

 Here are some relevant characteristics of the missile:

Length     3.96m / 13′ (2)
Wingspan   27 inches
Weight     407 kg / 900 pound (2)
Range      185+km / 100+nm (2) with a low flight profile;  300+nm with a high flight profile
Speed      high subsonic (4)
Warhead    120 kg / 265 lb titanium blast fragmentation with programmable fuze (2)

Power is provided by a solid propellant rocket booster which is subsequently jettisoned after launch and a Microturbo TRI-40 turbojet engine (2).  The missile uses JP8 or JP10 fuel (4).

“The TRI-40 is a single spool turbojet engine, consisting of a four-stage axial compressor, annular smokeless combustor and a single-stage turbine. It delivers a maximum thrust of 2.5-3.3kN.” (4)

Launchers are clustered packs similar to the US Navy’s Harpoon rack launchers.  They are available in single, 2, 3, 4, or 6 pack arrangements.  The launcher can be angled from 10 – 60 degrees elevation (5).  A 4-pack launcher weighs 8,600 lbs (5).  Individual launch canisters (Launch Missile Module – LMM) are 4.1 m long x 0.85 m wide x 0.90 m high and weight 1951 lbs (5).

4-Pack Launcher

The launcher requires around 4 minutes to power up to full operation and the launch cycle is 2.5 seconds (5).

Guidance is provided by GPS/INS and terrain profile matching (TERPROM). The missile is claimed to use software programming to fly an unpredictable path which enhances survivability (2).  The missile is capable of in-flight retargeting (2).  The missile can also be launched in bearing-only mode (5).

Flight profile control can include no-attack and no-flight zones for safety as well as altitude restrictions (5).

Terminal guidance uses an imaging infrared (IIR) seeker with Automatic Target Recognition (ATR) database and is reportedly capable of targeting specific features of a ship (2).  The manufacturer claims, “Close to zero probability for inadvertently attacking a civilian ship”.

The missile uses high-g terminal “bobbing and weaving” maneuvers to defeat point defense weapons.  Here is a target’s-eye view of a typical terminal flight path (5).

NSM Terminal Flight Profile As Viewed From Target

The lack of a conventional radar seeker makes the missile completely passive which decreases the chance of detection and, thereby, increases the missile’s survivability.

In 2016, Raytheon and Kongsberg announced plans to produce the NSM in Raytheon’s US facilities. (3)

USNI News website suggests the missile will cost slightly less than a Tomahawk Block IV which would put the cost in the $800,000 range. (3)

Kongsberg has reportedly consulted with Lockheed regarding Mk41 VLS integration of the NSM.


The manufacturer believes the combination of passivity, low altitude approach, airframe stealth, and terminal maneuverability obviates the need for supersonic speed.  This approach is at odds with much of the rest of the anti-ship missile world which has emphasized supersonic speed and it remains to be seen whether the manufacturer’s assumption is valid.

The lack of radar guidance capability, while it enhances the stealth of the missile, could also prove to be a detriment.  In a GPS-denied environment, the missile will have only inertial guidance and terrain matching (not really applicable over water) and one has to wonder whether this will provide sufficient accuracy.

The manufacturer puts great stock in the Advanced Target Recognition (ATR) capability but the statement, “Close to zero probability for inadvertently attacking a civilian ship”, recognizes that autonomous targeting capability is less than perfect.  To be fair, this is a weakness inherent in any autonomous weapon and represents a possible (likely?) significant limitation in the weapon’s usage analogous to the restrictions imposed on Phoenix BVR (Beyond Visual Range) missiles and any other BVR weapon.  The US historically has declined to take advantage of BVR weapons due to the possibility of inadvertent civilian damage or friendly fire.  Thus, autonomy, while theoretically useful, is not as useful on a practical basis.

Range is decent, at 100 nm for the manufacturer’s suggested low flight profile but not outstanding compared to many of its competitors.  On the other hand, the range is compatible with likely sensing range, especially for use on smaller ships which will have limited sensor range and limited access to high value, long sensor range, theater surveillance assets.  Thus, the NSM seems suited to the LCS but less so for a Burke which could benefit from a longer ranged missile.

A NSM was test fired from the deck of the USS Coronado, LCS-4, in Sep 2014.  However, the test was nothing more than an NSM “parked” on the deck of the LCS.  It was not integrated into the ship’s combat system, sensors, or fire control.  The test could have equally been performed from a dock or parking lot as far as what it demonstrated about the shipboard usefulness or suitability of the missile.  It was simply a public relations stunt.

Kongsberg’s proposal for the LCS shows dual 6-pack launcher arrangements for the LCS-1 variant and three 6-pack launchers for the LCS-2 (5).

Proposed NSM Launcher Arrangements

In summary, the NSM seems like a potentially useful anti-ship missile for smaller combatants although the entire passive/subsonic/non-stealthy approach is questionable until proven in realistic testing.  If the Navy is willing to subject the missile to realistic testing and the manufacturer’s assumptions prove out, the missile could provide a welcome boost to the LCS’ firepower.


(1)Kongsberg website, retrieved 21-Apr-2017,

(2)Defense Industry Daily website, retrieved 21-Apr-2017,

(3)USNI News website, “Raytheon, Kongsberg Ink Deal to Build Naval Strike Missile in U.S.”, Sam LaGrone, 13-Jul-2016,

(4) website,

(5)Kongsberg, “Kongsberg Naval And Joint Missiles Update”, Precision Strike Annual Review, PSAR-14, 13-Mar-2014


  1. I wonder if the Navy would do the 'dual missile' role or try to do what they did with Harpoon and keep every ship having one missile. I imagine one missile would make logistics easier, and that's not something to sneeze at.

    the Super/Subsonic thing seems to be a point of disagreement between some Western navies and Russia/China/Taiwan. I can see logic in both arguments.

    If I had the choice I'd prefer both in my quiver; but it seems that the Navy is very sold on subsonic missiles.

    1. I think the speed issue is more related to the required missile size. Supersonic missiles tend to be much larger, more expensive, and, thus, you get fewer of them. Of course, if they're more effective then fewer is not an issue. I thought that when the Navy went to the Mk57 peripheral launch cells on the Zumwalt, that they might go with a supersonic missile but that hasn't been the case (which makes one question why the Mk57 VLS, but, I digress).

      The jury is still out on which route is better. Possibly, this is a case where either route will work and it's just a matter of preference. Only combat will tell.

    2. Having a greater volume of missiles is valuable in that the larger salvos are more likely to exhaust the enemy's defensive magazines.

    3. "Having a greater volume of missiles is valuable in that the larger salvos are more likely to exhaust the enemy's defensive magazines."

      Proponents of supersonic missiles would say that fewer missiles are needed because more will get through and each one that does will be many times more effective. Again, only combat or some very realistic testing will settle the issue!

    4. CNO, actual speeds for supersonic missiles on a low profile aren't significantly higher than high sub-sonic missiles, pushing into high mach at sea level takes enormous amounts of energy and none of the SS AShM can do it. So most SS missiles are really only SS on high top attack patterns.

      Second, SS missile tend to have horrendous IR signatures, which is simply a by product at moving at such speeds, making them easier to detect.

      Third, radar really doesn't provide any better targeting than IIR at the ranges required. And radar provides no help in targeting ships when you can't see them, the only case where GPS/INS matters. That's largely the reason that newer AShM are switching over to IIR, it provides better terminal targeting than radar and is passive.

  2. The LCS-2 may finally find its niche as a missile corvette, hugging the littorals to attenuate its radar signature (somewhat) while launching sneak missile attacks from an opponents "rear" , almost like a skirmisher/picket ship, while proper blue water naval units manoeuvre engage from a more favourable azimuth. Land attack support for marine raids and the like is another possibility.

    1. That's an appealing scenario and concept but it fails to account for the extremely limited endurance of the LCS and the designed in need to put into port every two weeks for maintenance. In this 'skulking around the littorals' concept, where would the LCS be operating from? Presumably, we're talking about littorals fairly deep inside enemy waters. The LCS just doesn't have the legs to get there, skulk around for an extended period of time, and then return.

      So many possible uses for the LCS founder on the shoals of lack of endurance and shore side maintenance.

    2. Sounds like a great idea but not only endurance but how long can a LCS "skulk" around before being spotted? Once spotted, LCS is more than likely toast.

      It would need to be smaller to be really LO so have a very low probability of detection or maybe bigger with more capability to able to fight it out and survive being spotted....

    3. NICO, yes, this is almost the PT boat scenario of WWII. The PT boats were successful, to they extent they were, due to expendability (low cost), numbers, and extremely forward basing, none of which apply to the LCS.

    4. On the issue of LCS range, is it possible to load 1-2 cargo containers filled with fuel into their storage space and hook up a hose to their internal fuel tank? So you have 4-12 missiles per LCS, then you secretly load extra fuel, and the LCS moves a few hundred nm further than where the enemy thinks it's proper range should allow it to be.


    5. What is the current top speed of LCS? Are we down to sub 40kts?

    6. As best I can tell, it's around 35-38 kts, depending on load (weight), sea state, etc.

    7. "is it possible to load 1-2 cargo containers filled with fuel into their storage space and hook up a hose to their internal fuel tank?"

      Possible? Yes. Would anyone want to do it? Not likely. Fuel tanks on ships are generally deep in the ship for protection, have dedicated fire suppression systems, have pressure venting, may have seawater compensation, etc. Simply sitting a big tank of fuel high up in the open with no special protections is tantamount to carrying a fuel-air bomb around. Good luck getting crew to serve on an LCS with that!

    8. "As best I can tell, it's around 35-38 kts, depending on load (weight), sea state, etc."

      Which highlights how deeply compromised this is. We have a ship that has the same speed profile as some WWII Destroyers, but that sacrificed a *ton* to get there that is operationally relevant: Range; maintainability, etc.

      Maybe the odd class is different; I've read it has better range.

      I have been a proponent in the past of trying to keep the LCS line going; maybe as a peacetime type 3rd rate cruiser to do anti-piracy things; all because its a line that is running and maybe we could make them more cheaply.

      But the design is a hard one to love.

      Even with more firepower, it has so many limitations that I wonder if the logistics strain/vulnerabilities will be counter productive.

      If this were something that could be put on an island with a minimal footprint like a PT 'base' then it becomes more interesting.

      As it has to have larger bases where contractors can come in and do work, and limited range/endurance... I don't know.

      It would be very interesting to see how they work this out in war games.

    9. Even if we opted to construct forward operating bases for LCS maintenance, what would we do for the contractor technicians that are required for the advanced (and a lot of basic) maintenance? Civilian contractors, by law, are not allowed in forward combat zones and the Navy has not even pretended to try to train sufficiently advanced technicians.

      Do a little research some time and check out how many contractors sail on deployments with aircraft carriers. We're going to be in a world of hurt when war comes and they all stay home. Aircraft (I'm looking at you, F-35) are going to be grounded because we lack the highly trained factory techs who do the advanced maintenance. This is one of the dirty little secrets of our modern military. We are vulnerably dependent on contractors, as I recently posted.

    10. Which was a great post. Excluding all other issues, this could make our entire model of war a paper tiger unless we somehow draft these contractors. How many sorties would it take for our weapons systems to start falling offline?
      If we are contractor dependent with the F-18; which was supposed to be built to be easy to maintain, the F-35 could be a disaster.

      To sum up, so far as I can tell we have:

      A) Anti Air systems we don't know will work against modern ASCM threats.

      B) Questionable long term usability of aircraft/radar systems without civilian contractors

      C) No good current ASCM

      D) Atrophied ASW skills

      E) Aging airwings of questionable size

      F) No current over-arching strategy against which we can measure new designs

      G) Questionable maintenance of what we have.

      Have I missed anything? This doesn't even touch things like the F-35/Zumwalt.

  3. "The jury is still out on which route is better. Possibly, this is a case where either route will work and it's just a matter of preference. Only combat will tell."

    If only we had anti air war ships that we were thinking of retire that we could use to test and determine such things....

  4. This comment has been removed by the author.

    1. The point being the addition of the BAE PRF added to the IR head should improve the PK.

      See below

    2. This doesn't impact the NSM, at the moment.

  5. Norway and Australia reached agreement Sep. 2015 for a BAE passive RF seeking capability to be integrated into the JSM by Kongsberg, the airlaunched version of the NSM being developed for the F-35, the R&D of the PRF will be financed by the Australian Govt. , integration costs to be shared.

    In an offset for Norwegian Feb. 2017 buy of four TKMS Type 212NG submarines Norway and Germany are to co-develop an evolved version of Kongsberg's NSM.

    The advantage for the Navy is the NSM re. the longer ranged LRASM is its less than half the weight, a must for the weight challenged Freedom and Independencs LCS classes if they are to install a meaningfull number of missiles per ship for the OTH SUW module/package.

    1. The JSM is a different version than the naval NSM unless you've read that the RF seeker will be added to the NSM?

  6. It appears that some of those concept integrations will occupy the Weapon Zones and thus cost the ship the GMM and SSMM modules, eroding the swarm/self defense capability.

    1. Good observation. I hadn't picked up on that. Of course, it's just a proposal, at the moment, and the NSM may not be selected or, if it is, it/they may be located in other spots. The launchers can be simply bolted to the deck anywhere. Still, good observation!

    2. Current proposal mockup of LCS-2 frigate design can be see at ~3:30 on

      Basically, the notched the flight deck at the back to create an additional weapons space and plan on putting 2 sets of launchers back there with another 2 sets in front behind the existing space for VL. In addition they added 2x8 MK41 VLS on top and a fire controller radar for the Mk110. So all told 16 VLS, 16-20 AShM, 2x25mm Mk38 RWS, SeaRAM, and Mk110, which is a fair bit of firepower at least. Who knows how much all of that will end up costing.

    3. Given the "success" of the anti swarm tests thus far I'm not all that bothered.

      That said, I'd like to avoid just bolting stuff on things till we have an idea, any idea, it will work.

      Right now it seems that the Navy is throwing things at the wall and seeing what sticks.

  7. There are a few limitations to the NSM, but also some niche design constraints which drove aspects of the development.

    For example, fighting in the fjords and around islands (rather than the blue water Harpoon). Radar terminal seekers wouldn't do much good in such an environment - you'd be just as likely to hit an island or a fishing boat as the planned target.

    What will be interesting to see is if they add a mid course datalink update option, to narrow that terminal search basket down. If it can be done for the JSOW then it should be possible to add such connectivity (and reduce dependence on GPS).

    The real sobering thing here is that Norway developed a Penguin SSM replacement that is broadly suitable as a Harpoon ASM/SSM replacement. They did it on a relatively shoestring budget, and have a weapon that is fit for purpose.

    Meanwhile the RN is about to lose it SSM capability when its Harpoons life-expire in 2018. And the USN hasn't even been fitting Harpoons to its main class of surface combatants. Nor does it have a replacement (beyond the LRASM, which will solve all the ills, apparently; but it is also managed by LM, IIRC). As such, expect LRASM to be behind schedule and over budget, purchased in numbers too small to fully replace the Harpoon in USN service.

    Seeing what the Norwegians did, and what they spent to achieve it, this begs the question - why couldn't the US do something similar? Just something to give credible SSM capabilities to its major combatants while the uber-next-gen-weapons are developed.

    The Harpoon Block III was an option. VLS-capable. An old-ish weapon, but some SSM option is likely better than nothing.

    Instead, all we have is a laundry list of cancelled programs, and legacy missiles that are life-expired.

    NSM might be the affordable 90% solution we need.


  8. Navy ASCM's big picture?

    The Navy is scrambling to counter what it sees as a rising threat to American naval dominance by the Chinese and Russians and assessed the existing Harpoon missile did not have the range or survivability to defeat new enemy ships. To address the urgent operational need for the development of an air-launched, long-range, anti-surface warfare missile the Navy have taken over funding of the DARPA LRASM with the $1.5 billion March 2016 Offensive Anti-Surface Warfare Increment 1, OASuW Increment 1, contract. DARPA had picked the Lockheed Martin’s USAF AGM-158B JASSM-ER as host for the all important passive BAE Systems seeker head. USAF plans IOC on Air Force B-1 bombers in 2018 and Navy F/A-18E/F in 2019.

    The Navy OASuW Increment 1 program with LRASM is for only 110 operational missiles to meet the urgent operational needs for aircraft only, the big prize is OASuW Increment 2 which will be used by aircraft, surface warships and possibly submarines.

    Now that the Pentagon has acknowledged as high priority anti-surface warfare missiles with proposed budgets you have Raytheon became US agent for the Kongsberg NSM for the LCS competition and OASuW Increment 2 as replacement for the Harpoon plus new Tomahawk for longer range in surface ships and submarines, possible the JSM for the F-35A and C, will not fit in the shorter F-35B weapons bay.

    Boeing the incumbent with the old Harpoon has the new update the II+ with its net enabled capability/data link is in flight testing with F-18E/F and  is due for integration with the P-8A, with its active radar-homing seeker and an extended-range variant that uses a lighter warhead and improved turbojet engine to approximately double the Harpoon’s range from 67nm to 134nm. Boeing is offering the Navy the Harpoon Block II+ ER for the Navy’s OTH anti-ship missile in competition with NSM and LRASM for the LCS. The Harpoon's perceived disadvantage is that it uses an active seeker whereas both NSM and LRASM are passive.

    Raytheon has also partially funded a new seeker for the Tomahawk and has undergone trials  The seeker, coupled with mid-course in-flight target updates, to autonomously detect, track and intercept a moving target on either land or sea, understand includes two-way data link, terrain navigation, digital scene-matching cameras, inertial navigation system, infrared guidance, RF targeting and GPS system and new active radar. Navy’s 2017 budget request included $439 million to further develop and integrate the software and hardware seeker for IOC FY2022.

    So the LM LRASM will face stiff competition from Raytheon Tomahawk and may be the JSM or Harpoon II+ER if Navy decides the pursue the lower cost option of just updating ~ 3500 Tomahawk active seekers trumps the LRASM advantages of a sophisticated passive seeker and lower RCS.

  9. I think that at this point, the LCS is a sunk cost. It's best to stop the program and start from scratch all over again on a better ship.

    Maybe this would work for the existing hulls, but I would not advise building anymore. Frankly, I wouldn't be sure it works until DOT&E (provided that's not compromised) says it does.

  10. One other thought about the LCS. If this is just a makework project, then any whistleblowers that come out will probably be retaliated against.

    Just see this:

    I wonder if there is anything else going on behind closed doors.

    1. WOW! Don't need much imagination to wonder how much sh%t has been swept under the rug over the years.

    2. The problem is in such an environment, would be whistleblowers must live in constant fear of reprisals.

  11. The USN needs a range of ASCMs to deal with several different threats from CV size down to FACs.

    *If* NSM works, and *if* it can be purchased for reasonable cost, then we should buy it in quantity and deploy it on DDGs as well.

    The USN will still need a much larger ASCM, but something like NSM is needed now, and in quantity. Make mine a 12-pack.