Why?  Because ESSM has a 10" motor section.  So four-packing produces a container that is at least 20" x 20" (more with spacing, container thickness, etc.).  A Mk41 is only sized to carry 21" diameter weapons. 

A ~7" missile packed 3x3 would be at least 21" x 21".  If that's too big, then make it 6.6" diameter (3x3 = 19.8"x 19.8"), but longer, it doesn't really matter.  One can play with the sizing to fit the cells.  There is plenty of vertical length left for longer missiles.  Even tactical Mk41 cells can handle 16.6 foot long VL-ASROCS. 

Points well taken, Herald.

But who says we need to keep a 40:1 ratio for the whole flight?

Don't the Extended Range versions of Standard SM-2s (and -3 ABMs) drop their booster sections after use?

Would this surface attack round fare any differently?

(Although yeah, a 40:1 does seem extreme.)

 

Would we really need something in a 6-to-7-inch diameter missile to be 20 feet long to get a comparable payload to ranges equal to or exceeding that of the LRLAP?

(we've already established that an AGS turret needs a lot of barrel clearance for turret traversing, but how deep does the proposed reduced-magazine-capacity model sit into a Burke hull with all its fixin's?)

That Israeli LAR-160-derived naval rocket system (6.3-inch diameter) from the Armada pdf you posted up has the potential to get there (even if not currently in a VLS-friendly format), in a variant that wouldn't need to be 20 feet long to get the job done with futher development of rocket motor-to-warhead size ratios, as well as an adequate fin/strake design (Argentina had a same-diameter CAL-160 under development, carrying a 50kg warhead to 30km in a length of just under 11feet at 110kg weight).

 

Any SAM or SSM could see incremental range increases if fitted with expendable launch boosters.

 

I think you're over-exaggerating B.Smitty's idea...

 

 

 

You don't get a long thin 6 inch diameter rocket that burns steadily for 20+ seconds to give you 100n km range without giving up a lot of mass to contain the pressure of the burn as that SRM burns in to out in long thin case. You don't get much payload either that way either.  What do you know about rockets specifically? Telemetry is more my schtick, so I need sa good feel for how ignorant we both are on this subject. 

How much space are you giving up for fins? Separator sleeve walls? etc.etc.etc.

If anything the step rocket makes the inverted pendulum problem WORSE.

And you are using an existing adapatable VLS. That isn't SYLVER, which stupidly lacks the capacity to adapt electrical interfaces and accept collared launch cells much larger than the crap ASTER. So that leaves you the  short, medium, and long versions of the Mark 41 which is so designed to accept a broad family of 21 inch/25+ foot length boosted weapons. 

And as far as payload goes, this missile is competing with LRLAP and ERGM, not POLAR or ATACMS, so the 28kg P44 warhead is perfectly acceptable to me.

28 pounds, not 28kg.
A 28kg warhead ( ~ 61&3/4 pounds) wouldn't have me complaining one bit, though, if we get to keep the 70km range (37.8 nautical still outranges the majority of any other tube artillery).

Herald

1) Who says we're just going to use the stock model?
Compare the differences between a 7-inch diameter, roughly 5 feet long Hellfire, and a 7-inch diameter, roughly 5 feet long NetFires PAM.

Newer electronics, newer propellant, newer rocket motor design, and other improvements (designed around 1980-1990s tech vs today's tech).

The range improvement of a similar-sized PAM is considerable (4-5 fold), warhead weight similar (~ 10kg, + or - a few pounds; not every Hellfire has the 28-pound Metal Augmented Charge).

But the really impressive bit is when we compare the Hellfire's "antiquated" laser seeker to the PAM's multimode seeker.

 

Why then can't we incorporate such technologies into a new generation SSM of 16cm/6.3-inch diameter?

The P44 is almost there now (only about 2/3 of an inch larger in diameter, multimode seeker, etc).

 

2) That effect doesn't stop us from using boosted SM-2s and SM-3s, does it?

Plus, consider also the fact that a number of surface attack cruise missiles (Tomahawks, Harpoons, countless others) do have to use a booster to get off the launcher and up to flight configuration (wings out, turbine fired up), yet we don't hound about the additional weight there.

Read a little on Werner von Braun and grasp his ideas of multistage rockets, as to why it makes no sense to do everything as single-stage systems, because there's no point carrying the extra weight of a spent, empty missile casing once fuel is used up (how long a chunk of that LRLAP, ERGM, and BTERM was the solid propellant flight motor again?).

 

3) On the VLS system: the idea is to, once again, not use the stock Israeli rocket, but one actually built with the intention of interfacing with current and anticipated US VLS equipment (which, moreso than SYLVER, will be used by more nations).

We'd be using off-the-shelf-technology to keep design costs minimal, but no one said we had to stick with current complete off-the-shelf weapons systems. The growth potential for a 16cm diameter munition is there, we just have to figure out the ideal warhead sizes and rocket motor lengths to get the preferred payload : range ratios.

And judging by other system, past, present, and developmental, we won't need 16cm rocket to be 20 feet long to carry a 30 pound payload to 100NM.

 

As to converting current in-service single stage ballistic designs over to navalized fire support systems,

it's already been said of the POLAR that it received a 30% rocket motor length increase to carry a 90kg warhead to 200km.

So for a 9-inch diameter rocket, that still isn't giving us a length of 20 feet (adding 30% to a rocket that's not even 14 feet long- GMLRS- is giving us something in the neighboorhood of 18 feet, still 2 feet shy, and it's definitely no 40:1 ratio).

 

There's another alternative: make it an airbreather.

Either a microturbine flight sustainer like the LAM would've used (although subsonic flight will be the result, with a resulting longer time to target),

or we try to develop some sort of METEOR-esque ducted ramrocket. My guess being, this is going to happen eventually anyway, as mixing propellant with atmospheric oxygen will give us greater range than just a pre-packaged, solid fuel motor, plus a variable/ducted ramrocket gives us greater velocities than any of those microturbines will offer.

 Here though, we're into rising development costs, which will be slightly offset because the whole munition will have a slower acceleration curve, so it won't need to be strengthened to survive high-G gun launches.

And unless it's a SAM model, it needn't be capable of 10+ G maneuvers, either (AFVs, ships, and other surface targets are not the most maneuverable things to try and hit).

 

 

 

Another thing to consider here is that we're comparing AGS to a 61-cell VLS/Mk45 combo. 

Though it would weigh significantly more, I bet the Mk45 could be replaced by another 32 cell VLS. 

If so, the resulting 93 cell VLS could carry 372 POLARS - more than the AGS's 320 LRLAPS in a similar volume/deckspace.  And each POLAR has a much larger warhead and is longer ranged than a LRLAP. 

I would still prefer to keep the Mk45 and develop a smaller missile, but if we are just doing a strict VLS to AGS comparison, I think the VLS will win on volume and deckspace, and deliver larger, longer-ranged, more effective munitions at the same time.

Guys,

just remember that for the purposes of naval gynfire support to troops in contact a larger warhead is not always better.