Some questions about the future developments in the US Navy’s, SAM and ABM missile developments.
Question one; with the introduction of the SM-6 along with the quad packed Evolved Sea Sparrow Missile then make the SM-2 obsolete?
Question two; will a scaled down version of the SM-3, or something like it, be developed to fit into Tactical length MK-41 VLS launchers?
Question three, will the Theater Area Defense Missile be adapted for ship board use.
To address question number one fully, let us cover some of the operational consideration used in employing the SM-2 as it currently now stands. This question has two serious considerations that must be addressed which are of tactical concern. The first is what are the various maximum and minimum ranges of the various missile variants under review and second, what are the tradeoffs of their different terminal guidance characteristics?
To review, all guided missiles launched from a stationary position have to travel a minimum distances before they become in effect true guided weapons, and for safety reasons to arm the warhead. For weapons that are aerodynamic controlled, and all current SAM’s are at least to some extent aerodynamic controlled, even if they are equipped with booster vector thrust control and axillary maneuvering jets. The reason is not only does the missile need to overcome the pull of gravity in a controlled and stable manner but it must also gain enough air speed for their fins and flunks (the air foils to be more exact), begin to have an effect in controlling missile flight and stability. True you could do this entirely with thrust producing devices like many of you have probably seen on the videos of exo-atmospheric kill vehicles tests designed for use where aerodynamic control is not even an option but this is not a practical choice here. In vertical launched systems, this is even truer than it was for the older, point and shoot, rail launched missile systems of the past. The SM-2 and SM-2 XR minimum ranges are classified thus making any analyses very hard.
Obliviously the shorter the minimum range of a weapon the better it is, especially against fast moving targets that pop up low on the horizon where you have very little time to react. Larger minimum engagement ranges cuts the available time to react or to evaluate a kill and to then fire again. But what about other targets like a helicopter or fast speed boats, which could get within your minimum range and then stands off at five hundred yards and blow the hell out of you with rockets and guns. It might not sink your ship but it would put your ship out of the fight.
For this reason the SM-2 comes in two versions the normal and extended range. The normal version is not only smaller and cheaper to make, it also has a much shorter minimum range. The extended version does not even begin controlled flight until after the booster stage has been jettisoned. Since these missiles use, an up and over flight profile so as to then seek the intercept with an energy efficient downward going angle to the target, they do not necessary take the quickest path to the target. But everything in the world is tradeoff.
The Evolved Sea Sparrow Missile has a shorter minimum range than the normal SM-2 which is good but does it have a sufficient maximum effective range or the speed to adequately overlap with the minimum range of the SM-6’s envelope? If it does and if it is it in every other way just as effective for close in targets then you get as a bonus, of four missiles per cell instead of one, and they are probably cheaper per missile as well when used against air targets or maybe even speed boats.
But what about the final stage of ballistic missile defense engagement which has very different energy kinetics especially for cross range targets. Where the target is not your ship but a ship that you must guard within the task group?
The SM-6 seems to be able to do everything that the SM-2 ER can do and much more except possibly for the SM-2 Block IIIB extended range semi-active homering with passive IR guidance variant. Not much information is publicly available on this model except that they haven’t made very many and that they cost allot of money. There was once some speculation that Passive IR was the best tracking mode for the interception of plunging ballistic missiles because of the supersonic speeds they travel they radiate very bright IR signatures. I do not know if that is true or not but sounds that it could be possible. If so would abandoning the SM-2 lose this capacity? Or is that capacity even very valuable? Are we stuck with having to support three missile types for the same engagement ranges and target profiles soaking up more cells or can we cut it to two types?
Another question, with the AGEIS system being extended too much smaller sized vessels than was true in the past would it not be a waste if these upcoming platforms will not have any ABM capacity at all. Especially now that they can be supported in engagements by other detecting and tracking assets (be they airborne, ground, sea, or even space) that will be coming on line at about the same time they are built? If they are used to fire their rounds by remote launch protocols their less powerful radars might be less critical to their sucesses. The missile used would undoubtedly be less capable than the current SM-3 but against short to medium range ballistic missile intercepts still a very useful weapon when used in the areas of costal defense. The THAAD is a smaller lighter missile than the SM-3 Block IA and it has the desired abilities but it is almost as long as the SM-3. As I understand it, it is the length of the round is the problem for these smaller ships.
This is an area of much change in the tactics and strategy in naval warfare and it is not clear to me which way we are going. What do you think?
