Future Point Defense Options

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captinjoehenry wrote:well on the subject of future technology here are a couple of ideas:

Self Guiding PDLC:
if they could make the PDLC self contained like the Phalanx system on current US navy ships they could increase its efficiency as they would not be dependent on the ships primary fire control and detection system

Blindingly good idea, I think, (says me from my spot in the armchair captain's gallery).

Given that an oncoming attack missile has zero stealth and a wedge, I'd wager that a set of fusion driven laser emitters (that don't even need to be reset) could be computer controlled to take out an attack missile's drive at a much greater distance than the 10Km limitation of a CM wedge, even with the given that the attack missile is probably spinning at a maximal rate. (Consider the gunnery exercises where Abigail's team takes out a maneuvering drone in Service of the Sword, for example).

Right/Wrong, maybe?

captinjoehenry wrote:now the FTL CM control is a great idea I think as it would allow longer range intercepts to be possible as the launch ship would be much more capable of guiding the CMs onto their targets as the command loop would be so much shorter and the CM would only need to mount a FTL receiver and not a transmitter which might make it small enough to be practical

I've speculated here about that possibility.

It seems to me that there's a decent chance that it's the transmitter part of the FTL control link that drives up the size of the Apollo control missiles so much.

At close range you probably don't need all that large and sensitive a receiver to read FTL pulses. If so and FTL receive only CM might be possible without adding too much size or cost. And that should give substantially better accuracy out near current max range.

And of course you'll need FTL control channels to talk to the CMs. We've been told that lightspeed CM and SDM/DDM/MDM fire control links are dedicated and even in an emergency you can't use offensive links to control CM (and definitely not the other way round). So I'm not sure even an SD(P) with Keyhole II would be able to talk to the FTL receiver equipped CMs without overhauling the Keyhole into a new varient with CM FTL links. (And for some reason ships don't appear capable of hull mounting FTL fire control links -- and so I guess that limitation would apply even to shorter ranged links for CMs - which likely means that nothing smaller than an SD(P) will be able to utilize even one-way FTL CM links)



Finally if you also want to give a CM even more range you need to either further increase it's acceleration, increase the 75s endurance even further, add a 2nd drive ring, or build a CM drive that can be stepped down to 50% power for increased endurance (but then you need to launch even earlier to pull off an intercept). Most of those are non-trivial and are likely require either lots of R&D or a significantly bigger CM.

SharkHunter wrote:--snipping-

captinjoehenry wrote:well on the subject of future technology here are a couple of ideas:

Self Guiding PDLC:
if they could make the PDLC self contained like the Phalanx system on current US navy ships they could increase its efficiency as they would not be dependent on the ships primary fire control and detection system

Blindingly good idea, I think, (says me from my spot in the armchair captain's gallery).

Your going to track the laser how? Hence, no, you can't use a closed loop tracking system to adjust fire onto the target.

The problem you have is that lasers have a really small spot size and tiny little errors in pointing accuracy means you miss the missile until it gets really, really close.

Duckk wrote:That's basically what the Katana does in fleet combat. Magazines are packed full of CMs and Vipers, and it has 3 SD point defense laser clusters.

I still assume some group at BuShips has crunched the numbers to see how much more effective a pure anti-missile screening LAC might be if it dropped all anti-LAC capabilities.

If you design CM magazines to only hold CMs and not the slightly longer Vipers how many more can you cram in?

How many missiles can you expect to be within your PDLC envelope simultaneously at peak times? If that's greater than 3 then does it make sense to got with more PDLCs even if they have less power (and likely less emitters per cluster). How much lower a percentage of intercept against each missile would that be, and how does that compare to being able to target a 4th, 5th, or 6th missile simultaneously.

Is there anything else the Katana has (endurance possibly) that could be given up to get increased CM magazine sizes?


Then once they had all those tradeoffs then decide if there's enough benefit over the more flexible Katana to justify building a pure anti-missile design that won't be able to dogfight against other LACs. (And it may well be that they've done the design tradeoff studies and decided that the benefits aren't worth the costs)



Going with an even somewhat physically larger LAC would probably require different CLACs (or major refits to existing ones), so that's likely out. (although I guess it's not impossible for the new assault CLACs to be built with oversized bays; capable of handling the current designs plus a larger screening design. But that hurts flexibility, and I doubt it'll happen.

SharkHunter wrote:Given that an oncoming attack missile has zero stealth and a wedge, I'd wager that a set of fusion driven laser emitters (that don't even need to be reset) could be computer controlled to take out an attack missile's drive at a much greater distance than the 10Km limitation of a CM wedge, even with the given that the attack missile is probably spinning at a maximal rate. (Consider the gunnery exercises where Abigail's team takes out a maneuvering drone in Service of the Sword, for example).

Right/Wrong, maybe?

Two points:

1: A separate fusion reactor would probably mean additional cofferdams/armor for each PDLC similar to the cofferdam requirements for Mk16/23 launchers. Fusion Reactors are dangerous if something goes wrong; it's much safer to supply power for PDLCs from the main/weapons buss from the ship's main reactors.

2: PDLC clusters are much bigger than many ideas assume; they're too large to mount on drones or missiles, for example. LAC PDLCs have fewer emitters to make them small enough to mount on LACs.

kzt wrote:
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Your going to track the laser how? Hence, no, you can't use a closed loop tracking system to adjust fire onto the target.

The problem you have is that lasers have a really small spot size and tiny little errors in pointing accuracy means you miss the missile until it gets really, really close.

What I am talking about is to build in a radar / LIDAR / Grav sensor into the PDLC mount so that they do not need to use the ships main LIDAR / radar array so they are in effect independent of the ships primary system so that those resources can be used for other purposes. Look at the Phalanx weapon system which has a radar built into the weapons mount so it does not need to use the ships radar system.

Jonathan_S wrote:Then once they had all those tradeoffs then decide if there's enough benefit over the more flexible Katana to justify building a pure anti-missile design that won't be able to dogfight against other LACs. (And it may well be that they've done the design tradeoff studies and decided that the benefits aren't worth the costs)

IIRC, the Ferret is a better starting point for a pure anti-missile design than either the Shrike or Katana. It already has more CM and PDLC than either attack-LAC and has an enhanced ECM suite as an additional anti-missile asset.

Replacing its shipkiller launchers with CM launchers would double or triple a Ferret's counter-missile launch capacity.

Weird Harold wrote:IIRC, the Ferret is a better starting point for a pure anti-missile design than either the Shrike or Katana. It already has more CM and PDLC than either attack-LAC and has an enhanced ECM suite as an additional anti-missile asset.

... except that the most effective method an enemy has of taking out missile defense LACs is with attack LACs, and you need a way of fighting that off.

drothgery wrote:... except that the most effective method an enemy has of taking out missile defense LACs is with attack LACs, and you need a way of fighting that off.

Huh? How do they get close? Are you assuming that you are going to sit there for an hour as they close? And if they try, you do what the RHN does, which is you use MDMs to kill them at range. Their survivability depends on them not being directly targeted.

captinjoehenry wrote:What I am talking about is to build in a radar / LIDAR / Grav sensor into the PDLC mount so that they do not need to use the ships main LIDAR / radar array so they are in effect independent of the ships primary system so that those resources can be used for other purposes. Look at the Phalanx weapon system which has a radar built into the weapons mount so it does not need to use the ships radar system.

They have that. What Phalanx does is use its radar to do a closed loop of seeing the outgoing rounds and adjusting where the gun is aiming to get the rounds to intersect the incoming missile.

As lasers are invisible you can't do that.

This ignores the minor detail that the phalanx system apparently works better in theory than practice against typical anti-ship missiles.