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Subject: Redundancy US missile programs?
dwightlooi    8/11/2004 2:07:12 AM
It seems to me that the US is in the habit of having two or three programs that strive for similar goals and which can be merged into one system. 1) PAC-3 and SM-3. These two could have been one system. Or at least, the SM-3 could have used the PAC-3 airframe. It'll certainly fit into the Mk41 cell envelope. And it is arguably better than relying on the 40 year old TARTAR airframe. 2) THAAD can actually be a land and naval system the 37cm by 6 m THAAD airframe fits neatly into the Mk41 envelope too. And there is no reason why some variation of the missile cannot be put to sea. 3) The ESSM should have been a navalized AMRAAM from the beginning. I am not saying that there aren't technical issues with adapting one system to another use, but whatever it is it'll be more economical than have two separate developments with similar objectives.
 
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Herald12345       2/24/2008 12:19:18 AM

I just skimmed this thread from the dead. The basic idiocy contained herein brasses me off. (Not you stinger.)

Yep-especially about ASTER, STANDARD, and ESSM.

Two missiles underestimated as to modernity and EFFECTIVENESS, and a PoJ even remotely compared in quality to them.

The ESSM has as much to compare NOW to the original dog, SPARROW, as the latest STANDARD II to the original TARTAR.

Evolution is not obsolescence.

Herald
 
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dwightlooi       2/26/2008 11:20:55 AM

What has a longer range the AIM-120 or the ESSM?


There is really no comparison between the two, the ESSM has almost 2.5 times the kinematic performance of the AIM-120. When fired from a zero-zero condition, an AMRAAM is 20~25km SAM. The ESSM goes to over 50km. When fired from a zero-zero condition, the AMRAAM typically goes about Mach 2.5. The ESSM reaches in excess of Mach 4. The ESSM is essentially the forward one-third of the sea sparrow grafted to a 10" rocket motor, controls shifted from the wings to the tails.

The advantages of the ESSM over missiles like the Aster 15 is that it is a single stage weapon (which allows for a shorter minimum range) and it is designed specifically for packaging density (a single Mk41 VLS cell holds 4 ESSMs). The weapons has demonstrated lethality against seaskimming AShM targets including maneuvering supersonic targets.

The ESSM is a semi-active homing missile. The decision to stay with SA homing is based on many reasons. The first being that in a horizon range weapon, there is no illuminator horizon issues. The second being it places target discrimination on the ship instead of leaving it up to the much more limited electronics you can pack in a missile. The third being that a powerful illuminator or multifunction radar on a ship is much more resistant to ECM than an tiny active seeker running on batteries. Finally, there is of course the direct compatibility with legacy sea sparrow control hardware already in service. The only disadvantage is the need for illuminator time from the launching vessel. The problem is really a non-issue on bigger, better equipped ships like the AEGIS destroyers with 3D radars. The ESSM is guided via inertial autopilot and datalink updates for most of its flight, and with three illuminators and each missile needing illumination only for the last 6 to 8 seconds of the engagement means that about 22 to 30 ESSM shots per minute -- which is more than is tactically likely. It is also a non-issue with X-band AESA equipped vessels like the German frigates using this weapon which can perform interrupted continuous wave illumination for the a practically unlimited number of ESSMs while time sharing or beam splitting for other radar tasks. However, in older, lesser ships with only one mechanical tracker/illuminator and a 2D air search radar the SA homing model limits the vessels to about 2 shots per minute because the lack of 3D positional updates means that the ESSM has to be fired in semi-active all the way mode with one dish per missile dedication until impact.
 
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doggtag    difference between a RIM- and an AIM-   2/26/2008 12:55:06 PM




What has a longer range the AIM-120 or the ESSM?




There is really no comparison between the two, the ESSM has almost 2.5 times the kinematic performance of the AIM-120. When fired from a zero-zero condition, an AMRAAM is 20~25km SAM. The ESSM goes to over 50km. When fired from a zero-zero condition, the AMRAAM typically goes about Mach 2.5. The ESSM reaches in excess of Mach 4. The ESSM is essentially the forward one-third of the sea sparrow grafted to a 10" rocket motor, controls shifted from the wings to the tails.

Good points.
But, take into effect that,
from its onset,
AMRAAM (AIM-120) was intended as an air-to-air weapon.
In that envelope, its range is in excess of any surface-launched ESSM (RIM-162).
 
Not then that there equates an even fair comparison: naturally, a smaller-diameter missile like the 7" AMRAAM (or even Aster) could even come close to compraing the range achievable in the 10" main-body-diameter ESSM.
(Perhaps somewhere should propose an air-launched ESSM, just to see actually how far range-wise it could compare to an AMRAAM...? Then we'd have a fair comparison.)
Mind you though: an air-launched ESSM might be the perfect start point for a non-air-breathing long range AAM that, effectively, fills the role left vacant by Phoenix (AIM-54) in the USN (not that they deem that role specifically needs filled by something more capable than an AMRAAM,..yet. But both the range and warhead potential are there).
 
Then again though: Sparrow was originally an air-to-air missile, even if considerably mediocre in performance,
but became a very formidable weapon when developed into the surface-launched Sea Sparrow.
(...or maybe it was just superior marketing by the US upon NATO, seeing as we don't have any Sea Flash (Sky Flash was UK's Sparrow replacement), even though Italy has successfully adopted their Aspide (their Sparrow replacement) into a surface-launched SAM weapon, and developed it further into the Sea Killer anti-ship/surface attack variants, with some featuring a 50+kg warhead in an enlarged forward section, IIRC)).
 
Naturally, anything with a diameter larger than 7" (and length longer than 12&1/2 feet) is going to have the potential to always be able to outrange (and carry a larger payload than) anything that does use a 7" diameter.
So don't expect any AMRAAM variants to ever surpass ESSM, as any electronics wonders and rocket motor tech packed into AMRAAM could just as readily be engineered to fit into the larger ESSM and allow it to keep a considerable margin in capability above its smaller brethren (both of 'em are Raytheon stablemates).
Same as how any given Standard (current in-service rounds) are always going to be capability-superior to ESSMs.
 
Depending on how well the Norwegians continue to develop, and market, their NASAMS system that uses surface-launched AMRAAMs, they may or may not be able to upset the Sea Sparrow's predominance (Aster is still an inch less in diameter than Sea Sparrow's 8").
 
In some smaller vessels, ESSM isn't going to be one-for-one exchangeable for Sea Sparrow: in VLS cells, it can be.
But for anyone still using those eight-round trainable launchers, the ESSM is too big (weight and volume).
But a newer-technology surface-launched AMRAAM (in NASAMS or even modified SLAMRAAM guise) may prove more of an asset worth purchasing than it would be to hang on to older-generation Sea Sparrows whose electronics haven't been upgraded comparably.
There's little reason that any surfaced-launched AMRAAM can't occupy the same cubic space aboard any Sea Sparrow launcher.
But is the reduced warhead of an AMRAAM (20-25kg?)  when compared to the Sea Sparrow's (30-40kg?) worth the gain in using updated electronics that may improve engagement abilities?
 

 
 
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benellim4       2/26/2008 5:44:59 PM
In some smaller vessels, ESSM isn't going to be one-for-one exchangeable for Sea Sparrow: in VLS cells, it can be.
But for anyone still using those eight-round trainable launchers, the ESSM is too big (weight and volume).
 
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Herald12345    Until somebody redesigns it like they are doing with the Block III SM-6   2/26/2008 5:50:25 PM
the ESSM killbody is still an 8"  diameter tube on a 10" booster.

Herald.
 
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benellim4       2/26/2008 6:54:25 PM
I'm bored, so I thought I'd address these four year old questions.

1) PAC-3 and SM-3. These two could have been one system. Or at least, the SM-3 could have used the PAC-3 airframe. It'll certainly fit into the Mk41 cell envelope. And it is arguably better than relying on the 40 year old TARTAR airframe. 
As someone else mentioned, the PAC-3 is what the USN wanted in the SM-2 Block IV and is trying to get in the Block IV SBT and SM-6. The advantage to the Block IV/SM-6 is that it leverages the very good SM-2 airframe. The SM-2 is under-rated in this thread. It is a very very good missile that is often overlooked because it doesn't get the press Patriot does. But few Navy weapon systems do except Tomahawk.

By the way, the SM-4 was the Land Attack Standard Missile (LASM). The best I can tell the SM-5 was a design that never came to fruition.

2) THAAD can actually be a land and naval system the 37cm by 6 m THAAD airframe fits neatly into the Mk41 envelope too. And there is no reason why some variation of the missile cannot be put to sea. 
The THAAD is more akin to the SM-3. However, the SM-3 was making successful intercepts long before THAAD. THAAD didn't make a successful intercept until 2006.  SM-3 had six successful intercepts by then. Not putting all your eggs in one basket is the lesson here.

3) The ESSM should have been a navalized AMRAAM from the beginning. 
Personally, I'd love for ESSM to have its own active homer or IR guidance, but that was not the design requirements. Remember ESSM was an upgrade to the NATO SeaSparrow system. It had to be reverse compatible with the older SeaSparrow missile. Not only that, like most successful programs, it took things a little bit at at time. A new seeker and new airframe would have increased the project's risk. Spiral development is the way to go. Perhaps in a future development it will become director-less.

I am not saying that there aren't technical issues with adapting one system to another use, but whatever it is it'll be more economical than have two separate developments with similar objectives.
Economical? I don't think so. There needs to be some sort of competition to keep the contractors honest. Single sourcing these things only leads to soaring costs.
 
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dwightlooi       2/26/2008 10:53:37 PM

As someone else mentioned, the PAC-3 is what the USN wanted in the SM-2 Block IV and is trying to get in the Block IV SBT and SM-6. The advantage to the Block IV/SM-6 is that it leverages the very good SM-2 airframe. The SM-2 is under-rated in this thread. It is a very very good missile that is often overlooked because it doesn't get the press Patriot does. But few Navy weapon systems do except Tomahawk.


The SM-2 Block IV is a two stage missile with a 370km range. Kinematically, it far exceeds the PAC-3. The PAC-3 is more ESSM class in terms of kinematics -- a little worse actually since it is carry more ahead of the motor.

The SM-2 Block IV however was never really a practical ABM platform. The reason is that it is an aerodynamically steered weapon. Once you get past about 24 km or so in altitude, the aerodynamic controls are useless. Even at 18~24km they become very sluggish. This is why the PAC-3 has lateral divert control thrusters. The SM-3's LEAP is 100% thruster steered. The Block IV didn't have a similar system which limits its engagement altitude and terminal accuracy. Like the PAC-2 the Block IV was a very good SAM with some marginal lower tier ABM capability.
 
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doggtag       2/27/2008 7:57:23 AM


Feh! We can't always get everything right.
The data I pulled from is a rather older Raytheon product sheet, (same as those pdf's you can find on a contractor's site,
but considerably different from the current pdf on Raytheon's site:
copyrighted 2006-2007), acquired at a defense expo ages ago, when ESSM was still in its infancy.
It clearly states: "The RIM-162 series will be compatible with the Mk41 VLS system. RIM-162A is for use with the Aegis combat system, while RIM-162B is intended for vessels lacking the Aegis combat suite."
 
There's no mention of compatability with the Mk29, but at over a hundred pounds heavier than a RIM-7 Sea Sparrow, the additional weight from 8 ESSMs would create mass balancing issues (and possibly strain servo motors) with an unmodified Mk29.
 
(sorry, there's no copyright date on the data sheet, but it was picked up with scores of others from various exhibitions from 1998-2003...)
 
However, over at Designation-Systems.Net,
,their entry for the ESSM does state generally the same info f
 
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benellim4       2/27/2008 10:57:05 AM




As someone else mentioned, the PAC-3 is what the USN wanted in the SM-2 Block IV and is trying to get in the Block IV SBT and SM-6. The advantage to the Block IV/SM-6 is that it leverages the very good SM-2 airframe. The SM-2 is under-rated in this thread. It is a very very good missile that is often overlooked because it doesn't get the press Patriot does. But few Navy weapon systems do except Tomahawk.




The SM-2 Block IV is a two stage missile with a 370km range. Kinematically, it far exceeds the PAC-3. The PAC-3 is more ESSM class in terms of kinematics -- a little worse actually since it is carry more ahead of the motor.

The SM-2 Block IV however was never really a practical ABM platform. The reason is that it is an aerodynamically steered weapon. Once you get past about 24 km or so in altitude, the aerodynamic controls are useless. Even at 18~24km they become very sluggish. This is why the PAC-3 has lateral divert control thrusters. The SM-3's LEAP is 100% thruster steered. The Block IV didn't have a similar system which limits its engagement altitude and terminal accuracy. Like the PAC-2 the Block IV was a very good SAM with some marginal lower tier ABM capability.
You're getting too technical on me. My point about the PAC-3 is what the Navy wanted the Block IV to be is a mission requirement statement not a technical one. A hit to kill lower tier terminal BMD defense. 

Regarding kinematics, the Block IV airframe must be good enough. It is the basis for the Block IV SBT and the SM-6.
 
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benellim4       2/27/2008 11:05:28 AM
Raytheon will make what customers want. So far they want the ESSM. They don't want a navalized AMRAAM. No sense in it. Putting an AMRAAM seeker on the ESSM, maybe. Let's see how SM-6 works out.

As for launcher mods, the Raytheon literature says nothing about it:
ht tp://www.raytheon.com/products/stellent/groups/public/documents/content/cms01_055809.pdf

The MK29, like most mechanical systems from that era was overbuilt, probably for upgrades like ESSM.
 
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