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Author Topic: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower  (Read 77156 times)

Offline bobbymike

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #30 on: December 02, 2015, 01:35:48 pm »
What system was the DARPA program Arclight going to use? Cause the range of that system was 2000km IIRK.
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Offline sferrin

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #31 on: December 02, 2015, 01:42:05 pm »
What system was the DARPA program Arclight going to use? Cause the range of that system was 2000km IIRK.

SM-3 Block IIA if I recall correctly.  Plus that was a boost glider. 
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Offline sferrin

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #32 on: December 02, 2015, 03:58:02 pm »
SM-6 has a ridiculously long range that doesn't seem to officially be public (Jane's says 230 nm!).  That compares pretty closely to the book value range for AS-4 (250 nm).  Remember that you would position the AEGIS ship well up-threat of the high-value target if at all possible, and the shooter won't want to launch at absolute maximum range since that would let the target turn away and run the inbounds out of fuel. So the geometry may work out most of the time.  And AS-4 is a pretty stressing threat -- most threat missiles (even Brahmos) are shorter-legged than that.

Just to give a feel for SM-6's possible performance, there was an early SM-3 test wherein they had an inert 3rd stage.  First stage fired, 2nd stage fired, then they separated and let the 3rd stage tumble ballistically.  On the way up it went from 310,000 feet to 350,000 feet in 14 seconds (that's an average vertical velocity component of about 2000 mph),so it would have continued on well past that in altitude.  It appeared in the video to be at about 45 degrees when they separated so the actual velocity would have been much higher.  It was airborne for over 5 minutes.  Don't know how much drag or weight difference there would be between a tumbling SM-3 upper stage and an SM-6.  Yes the SM-6 would weigh more than the SM-3 upper stage but at that point, after 2nd stage motor burnout, it's moot.  Don't know if the timing or the orientation in the video is accurate.  Just taking it at face value.

Start around 9:20:

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Offline marauder2048

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #33 on: December 02, 2015, 05:01:57 pm »
SM-6 has a ridiculously long range that doesn't seem to officially be public (Jane's says 230 nm!).  That compares pretty closely to the book value range for AS-4 (250 nm).  Remember that you would position the AEGIS ship well up-threat of the high-value target if at all possible, and the shooter won't want to launch at absolute maximum range since that would let the target turn away and run the inbounds out of fuel. So the geometry may work out most of the time.  And AS-4 is a pretty stressing threat -- most threat missiles (even Brahmos) are shorter-legged than that.

Just to give a feel for SM-6's possible performance, there was an early SM-3 test wherein they had an inert 3rd stage.  First stage fired, 2nd stage fired, then they separated and let the 3rd stage tumble ballistically.  On the way up it went from 310,000 feet to 350,000 feet in 14 seconds (that's an average vertical velocity component of about 2000 mph),so it would have continued on well past that in altitude.  It appeared in the video to be at about 45 degrees when they separated so the actual velocity would have been much higher.  It was airborne for over 5 minutes.  Don't know how much drag or weight difference there would be between a tumbling SM-3 upper stage and an SM-6.  Yes the SM-6 would weigh more than the SM-3 upper stage but at that point, after 2nd stage motor burnout, it's moot.  Don't know if the timing or the orientation in the video is accurate.  Just taking it at face value.

Start around 9:20:



Wouldn't this analysis tend to overestimate performance since the SM-3's 2nd stage is mostly burning in *much* lower atmospheric pressures than SM-6s?

Offline sferrin

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #34 on: December 02, 2015, 05:05:06 pm »
Wouldn't this analysis tend to overestimate performance since the SM-3's 2nd stage is mostly burning in *much* lower atmospheric pressures than SM-6s?

I think it's quite a stretch to call it an "analysis".   ;D  That said, if the SM-6 is in a lofting trajectory for maximum range, why wouldn't it be in a similar realm? 
« Last Edit: December 02, 2015, 05:16:22 pm by sferrin »
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Offline marauder2048

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #35 on: December 02, 2015, 06:14:21 pm »
Wouldn't this analysis tend to overestimate performance since the SM-3's 2nd stage is mostly burning in *much* lower atmospheric pressures than SM-6s?

I think it's quite a stretch to call it an "analysis".   ;D  That said, if the SM-6 is in a lofting trajectory for maximum range, why wouldn't it be in a similar realm?

Like a min-energy ballistic trajectory? I wouldn't think that that trajectory would put the missile at good attitude for the terminal seeker.

Offline sferrin

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #36 on: December 02, 2015, 06:39:03 pm »
Wouldn't this analysis tend to overestimate performance since the SM-3's 2nd stage is mostly burning in *much* lower atmospheric pressures than SM-6s?

I think it's quite a stretch to call it an "analysis".   ;D  That said, if the SM-6 is in a lofting trajectory for maximum range, why wouldn't it be in a similar realm?

Like a min-energy ballistic trajectory? I wouldn't think that that trajectory would put the missile at good attitude for the terminal seeker.

By the time it was coming down it would be.  Midcourse guidance updates until it's headed down and then the active seeker starts up at the end.
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Offline marauder2048

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #37 on: December 02, 2015, 07:16:15 pm »
Wouldn't this analysis tend to overestimate performance since the SM-3's 2nd stage is mostly burning in *much* lower atmospheric pressures than SM-6s?

I think it's quite a stretch to call it an "analysis".   ;D  That said, if the SM-6 is in a lofting trajectory for maximum range, why wouldn't it be in a similar realm?

Like a min-energy ballistic trajectory? I wouldn't think that that trajectory would put the missile at good attitude for the terminal seeker.

By the time it was coming down it would be.  Midcourse guidance updates until it's headed down and then the active seeker starts up at the end.

Ah. I was thinking the longer midcourse component would put it out of range of most of the uplinking platforms requiring the active seeker to start illuminating earlier.

Offline Moose

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #38 on: December 02, 2015, 09:54:35 pm »
Wouldn't this analysis tend to overestimate performance since the SM-3's 2nd stage is mostly burning in *much* lower atmospheric pressures than SM-6s?

I think it's quite a stretch to call it an "analysis".   ;D  That said, if the SM-6 is in a lofting trajectory for maximum range, why wouldn't it be in a similar realm?

Like a min-energy ballistic trajectory? I wouldn't think that that trajectory would put the missile at good attitude for the terminal seeker.

By the time it was coming down it would be.  Midcourse guidance updates until it's headed down and then the active seeker starts up at the end.

Ah. I was thinking the longer midcourse component would put it out of range of most of the uplinking platforms requiring the active seeker to start illuminating earlier.
Would not be out of range of an E-2D positioned between the fleet and the incoming threat.

Offline marauder2048

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #39 on: December 02, 2015, 10:47:56 pm »
Wouldn't this analysis tend to overestimate performance since the SM-3's 2nd stage is mostly burning in *much* lower atmospheric pressures than SM-6s?

I think it's quite a stretch to call it an "analysis".   ;D  That said, if the SM-6 is in a lofting trajectory for maximum range, why wouldn't it be in a similar realm?

Like a min-energy ballistic trajectory? I wouldn't think that that trajectory would put the missile at good attitude for the terminal seeker.

By the time it was coming down it would be.  Midcourse guidance updates until it's headed down and then the active seeker starts up at the end.

Ah. I was thinking the longer midcourse component would put it out of range of most of the uplinking platforms requiring the active seeker to start illuminating earlier.
Would not be out of range of an E-2D positioned between the fleet and the incoming threat.

Probably got lost in the chatter but I was referring to the CSBA analysis in which the surface fleet did not have access (for whatever reason) to carrier AWACs/ISR assets.

Offline sferrin

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #40 on: December 03, 2015, 02:58:34 am »
Probably got lost in the chatter but I was referring to the CSBA analysis in which the surface fleet did not have access (for whatever reason) to carrier AWACs/ISR assets.

That being the case I'd think you'd be limited by the horizon then.  Unless a satellite is feeding the surface ship ELINT information on the enemy aircraft/missile there wouldn't be anything to acquire targeting data for the mid-course updates.
« Last Edit: December 03, 2015, 03:30:05 am by sferrin »
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Offline TomS

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #41 on: December 03, 2015, 05:38:33 am »
Assuming we're looking at high-altitude targets, SPY-1 has LOS and the range to see that far, easily.  But it may take software changes to suit the seeker to a look-down terminal engagement at such long range. OTOH, AMRAAM was already designed to do look-down/shoot-down engagements, and SM-6 was being touted for long-range cruise missile defense, which means it already has the ability to look down into clutter.

They may also be talking about possible software changes that would let SM-6 use GPS to engage targets ashore, such as coastal-defense cruise missile batteries, high-value SAM sites, etc.  Basically Land-attack Standard Missile (SM-4) on steroids.


Offline sferrin

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #42 on: December 03, 2015, 05:45:46 am »
Assuming we're looking at high-altitude targets, SPY-1 has LOS and the range to see that far, easily.  But it may take software changes to suit the seeker to a look-down terminal engagement at such long range. OTOH, AMRAAM was already designed to do look-down/shoot-down engagements, and SM-6 was being touted for long-range cruise missile defense, which means it already has the ability to look down into clutter.

They may also be talking about possible software changes that would let SM-6 use GPS to engage targets ashore, such as coastal-defense cruise missile batteries, high-value SAM sites, etc.  Basically Land-attack Standard Missile (SM-4) on steroids.

What size is SM-6s warhead?  IIRC SM-4s was so small (~125lbs or so) they figured the bang for the buck wasn't there.  Pretty sure SM-6s isn't any larger.
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Offline bobbymike

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #43 on: December 03, 2015, 06:57:02 am »
Assuming we're looking at high-altitude targets, SPY-1 has LOS and the range to see that far, easily.  But it may take software changes to suit the seeker to a look-down terminal engagement at such long range. OTOH, AMRAAM was already designed to do look-down/shoot-down engagements, and SM-6 was being touted for long-range cruise missile defense, which means it already has the ability to look down into clutter.

They may also be talking about possible software changes that would let SM-6 use GPS to engage targets ashore, such as coastal-defense cruise missile batteries, high-value SAM sites, etc.  Basically Land-attack Standard Missile (SM-4) on steroids.


I have posted to other threads - the Air Force, in a couple of cases, strongly hinting the US can precision target using space assets if not now, very, very soon (as in the assets are in space ready for use).

IIRC the last article was about Red Flag when a USAF general said, cryptically, we have classified assets, space assets we cannot use in this exercise for identification and targeting.
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Offline TomS

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Re: Navy Seeks Rail Guns, Lasers, Cruise Missiles To Improve Pacific Firepower
« Reply #44 on: December 03, 2015, 07:12:13 am »
SM-6 has the the same warhead as LASM but it's gotten a bit smarter -- the version of the Mk 125 used in SM-6 is a focused blast-frag warhead that can concentrate its fragmentation toward the target.  Nopt sure if that matters much ina  lad-taack mode, though.  A 125-pound warhead isn't huge but it's nothing to sneeze at either, and it would be more than sufficient to kill soft targets like missile launchers and radars.  The excuse given that LASM couldn't engage mobile or hard targets is sort of true, but  there is a large target set of non-mobile, non-hardened targets of significant concern.  I think the Navy wanted NTACMS and thought getting LASM would stop that effort.  In the end it got neither.

LASM as a dedicated missile might not have made sense (I think it did, at least as an interim capability).  Having land-attack mode as a  switch you can throw on the whole inventory of SM-6 missiles instead is interesting.  It's cheap and doesn't tie up VLS cells for single-role land-attack missiles.  Plus, using the SM-6 airframe should add a lot of range compared to SM-4.