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A collection of posts by David Weber containing background information for his stories, collected and generously made available Joe Buckley.

Fire control uplink flexibility

So the points under question are:

(1) Are the fire control computers and telemetry links for offensive missiles and counter-missiles interchangeable.

(2) If the links are interchangeable, would the need to deal with a sudden, massive salvo force a fire control officer to choose between continuing to control missiles already headed downrange and switching to the control of additional counter-missiles?

(3) If the control links to offensive missiles were suddenly cut in favor of controlling counter-missiles, would it be possible for the firing ship to reassert control of the offensive missiles after dealing with the need to control counter-missiles?

(4) Would it make sense to hold the fire of your tractored pods until after the enemy has committed to several, possibly very large (especially if he fired off all of his own tractored pods) salvos? This comes in two subvarients: (a) if fire control and counter-missiles control links are interchangeable, would the sudden much larger salvo of your fire screw up his defensive fire control or compel him to choose between continuing to control his offensive missiles and counter-missiles, and (b) would holding fire with your pods until the range had fallen give you a better chance of hitting with the very large salvo which would result from firing them when you finally do.

Please bear in mind that the proposed firing tactic presupposes that if you have pod-layers of your own, they will be launching their own offensive salvos as quickly as they can roll pods. The idea here is primarily to screw up the other side's defensive capabilities (assuming that the control links are interchangeable) and/or to maximize the accuracy of the heavy salvo you intend to lay down when you finally flush your own towed pods.

 

Richard --

From the painstakingly neutral tone of your entire e-mail (which, as you see, I'm quoting only in part above), I strongly suspect that you are a party to one side or the other of this particular debate. In answer to your questions, however:

(1) I don't believe that I have ever suggested, anywhere, that offensive and defensive control links are interchangeable. I have no idea where the idea came from, and I hope it wasn't yours, because you ought to know better if anyone does, given our gaming experiences. Offensive control links are maximized to control offensive missiles at extreme ranges. They are large, complex, and expensive in terms of both mass and volume. Counter-missile control links are maximized to control the maximum number of relatively short-range missiles with a maximum powered flight endurance of no more than a minute. They are for short ranged use only, they are relatively small, less sophisticated, and available in much larger numbers because they cost less both financially and in terms of mass and volume. Moreover, for very good reasons, defensive and offensive fire control are completely separate control systems. The designers have very carefully segregated them from one another specifically to avoid overload conditions on one overloading the other. The same fire control computers which feed through the control links to the counter-missiles also drive the point defense clusters. They are fed by completely separate active sensor nets which are dedicated to defensive use and configured specifically to take over from the long-range tracking sensors once the incoming missiles enter their engagement ranges (think of them as the illuminating radars from wet-navy warships, not so much in terms of what they do, but in terms of their dedication within the specifically defensive regimen). It would not make sense, operationally or from a design viewpoint, to rely upon a single sensor suite -- however large and capable -- or to combine the offensive and defensive functions into a single system. While it might seem to make sense to do something like this in an ideal world, in a pragmatic world where "real life" (you should pardon the phrase, when we're talking about a literary universe) constraints have to be taken into consideration, you do not run both your offensive and defensive fire control through a single, non-redundant system. And you do build to give yourself the best mix of capabilities at the operational range of the weapons systems -- whether offensive or defense -- being controlled. By building shorter, dedicated fire control sensors and control links into their warships, Honorverse naval architects are able to provide a far "deeper" defensive basket into their ships than they could manage if their control links were, in fact, interchangeable. Basically, you can control about four counter-missiles for the "control link cost" of a single offensive missile. So, if all of your control links were interchangeable, you'd have about 25% of the maximum counter-missile capability available. Obviously, the number would be somewhat larger than that, since you'd get back the tonnage and volume currently dedicated solely to counter-missile control, but the numbers would still work out yielding significantly lower defensive capabilities. And another point to be considered is that defensive fire control is more important to the survival of the warship than offensive fire control. Traditionally, designers have deliberately provided far greater redundancy in defensive fire control links than in offensive links. The smaller size, cost, and mass of the arrays in question helped to permit that sort of redundancy and survival of capability through dispersal.

(2) Since they aren't interchangeable, this question clearly has no applicability.

(3) Again, since they aren't interchangeable, this really doesn't have much bearing on the questions you're asking. On the other hand, it's probably worth answering anyway. Yes, if for some reason the control link to a missile is interrupted, and if there is a clear transmission path between the firing ship or one of its consorts and the missile's receivers, it is possible to regain control of the missile even at extreme range. Indeed, one of the techniques which have been forced upon designers and tacticians by the emergence of such missile-heavy combat has been the need to expand control links through the use of time-sharing systems. Salvos are currently fired with flight profiles intended to separate them as widely as possible from other salvos directed at the same target(s) in order to help avoid the "Gunsmoke" issues of fire control, and the control arrays on more modern ships are designed to move back and forth between missiles in different salvos so that several of them can be jockeyed simultaneously. There are some drawbacks to the system -- for example, some missiles are going to get "lost," no matter how good the new control systems are, and the need to move constantly back and forth between several salvos at once means that you lose at least a tiny degree of accuracy on all of them -- but it permits the pod-layers to handle the far larger, far denser salvos which are now the norm.

(4) Frankly, I can conceive of very few, if any, circumstances under which would make sense to reserve your towed pods if you intend to fire them in a single, massive salvo. There's at least one perfectly valid reason for reserving launch which I can see, which I'll mention below, but let's deal with the "delayed single-salvo launch" scenario first. Obviously, since the control links aren't interchangeable, this is a nonstarter from the beginning in terms of having any effect whatsoever on the other side's defensive or offensive fire control. It also makes absolutely no sense from the perspective of "closing the range," since the range is going to drop so slowly, compared to the maximum engagement ranges now available. You said something in the part of your e-mail which I didn't quote about the differences in the acceleration capabilities of Manticoran and Havenite MDMs and flight times, and it is true that the flight times for Manty missiles will be slightly shorter. In terms of effect of this is going to have on the accuracy or on the degree of difficulty they're going to create for missile-defense officers, however, the difference is completely negligible. Whatever the flight time of the salvos involved, the interval between salvos is going to be effectively identical for both sides, and the minor difference final velocity isn't going to do anything to make the faster missiles harder targets than they would have been anyway.

As far as holding fire while the range closes is concerned, I think this is also pretty much a nonstarter. Even pods tractored inside the mother ship's wedge and are going to be vulnerable to destruction by laser heads which manage to punch through the mother ship's sidewalls but might not have sufficient destructive effect to get through the armor of a waller. And, obviously, pods outside their mother ship's wedge are going to be highly vulnerable to the famous "proximity kills." In either case, you're going to lose pods -- much more rapidly if they're outside the wedge, of course -- while you're trying to "close the range." This is effectively equivalent to the erosion of launchers, and will have a potentially serious negative effect on the weight of fire you ultimately lay down when you finally flush the survivors. Given the relatively low rate at which the range is going to change, you'll almost certainly lose much more in terms of destroyed pods than you could possibly hope to gain in terms of improved accuracy, since the accuracy improvement will be effectively nonexistent. This is why any sane commander is going to fire his towed pods (at the very least, any towed pods outside an impeller wedge) before the other side's first waves of warheads arrive. He may hold his fire until the very last moment before the said warheads arrive, but even that it is a somewhat questionable decision under most circumstances. The entire operational doctrine of pod-based missile combat is, as the Royal Navy put it prior to World War I, to hit as early and as often as possible. Wallers are very, very tough. They basically have to be battered to death, and you need to begin the battering process as early as possible and conduct it at as rapidly as possible. This is what pods do, and allowing your opponent to get off any salvos without beginning the attrition of his launch capability as quickly as you possibly can is a false strategy. Holding fire if you are still in a position to refine your fire control solutions right up to the last instant before the enemy's first salvos arrive probably would make sense; holding fire after the enemy's salvos begin to arrive would not. (But see below.)

Now, there is one circumstance under which I might very well reserve fire on towed pods, especially those towed inside the wedge of the firing ship. If you have non-pod-layers which find themselves in a position in which long-range combat sustainability becomes a factor, then it would make sense for them to spend their pods in a larger number of smaller salvos. For example, if you're trying to keep the enemy guessing as to whether they're up against pod-layers or pre-pod designs, you might fire them in six-pod salvos. Or if you're up against, say, pod-laying battlecruisers, or a Hexapuma-style MDM-armed cruiser, if might make a lot of sense in a maneuvering battle to fire individually smaller salvos while using your wedge and sidewalls to protect your own towed pods as much as possible. Under the circumstances of one wall fighting another wall, however, I don't see very much logic in holding the fire of your towed pods at all.

Take care, David