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tlb
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Joined: Mon Sep 03, 2012 11:34 am
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penny wrote:I thought enemy missiles had to be spread out so their wedges wouldn't interfere with their receivers. Even Manticoran launches. After the advent of Apollo I thought only individual groups of eight missiles and their control missiles were tightly packed; but that the salvo as a whole was spread out to ensure clean communications from the motherhip. At least until the onboard computer took over, in the case of the Apollo launches.
What follows are quotes from the author. Basically the spread that is sufficient to clear the wedges is present from the beginning of the launch. The missiles do not have to keep their rear aspect always pointed at the ship, but can wiggle in a way coordinated with the ship to keep getting information. runsforcelery wrote:First, missile acceleration at launch. Missile acceleration at launch is designed to get them clear of the firing ship's wedge and of one another as rapidly as possible. Missiles are launched on diverging tracks to get separation before they bring their wedges up. They are fired through sidewall "gunports" which open in the sidewall just long enough for the missile to pass through. Those gunports are at least 10KM from the side of the ship and the physical launcher is "connected" to the sidewall by what is, in effect, an extended grav driver which helps push the missiles' velocity upward. They are fired in a single salvo instead of being staggered because it allows the gunports to be opened and closed simultaneously, thus imposing a briefer window of vulnerability in which a Bad Thing Incoming is going to find a hole.
Second, your example seems to posit that missiles must be running exactly parallel to and shoulder-to-shoulder with one another or something else equally silly. A missile salvo comes in on a front, as a cluster, not as a wall in space. The missiles in each ship's individual salvo are fired simultaneously; no one ever said (at least I'm pretty darned sure they didn't) that they light off their drives simultaneously. They don't. They light off in a tight but staggered window so that they are coming in separated along three axes: "height," "width," and "depth." This means they are, in fact, also staggered in time on target, but the interval is so brief that the target is forced to consider them all a single salvo. Laser warheads --- and it was only the laserhead which brought the missile back from the tactical dust heap --- have a standoff range of about 30,000 km. If they were attacking in a 2-dimensional wall (which seems to be what you are positing), that wall would measure 30,000 x 30,000 km, or 900,000,000 sq kilometers. If there were 10,000 missiles in that wall, all coming in at exactly the same time, each of them would have 90,000 sq km of its very own. They are also coming in stacked in depth, however, with the rear missiles in the salvo in effect waiting for the ones in front to be picked off (or fire) before firing their own laser heads, which broadens (or deepens, depending on how one wants to look at it) the "attack basket" significantly. Moreover, quite a few of them are deliberately fired to cover aspects covered by the target's wedge at the moment of launch in case the target rolls ship. That is, some of them are intentionally "wasted" as insurance against the target ship's evasive action.
Third, starship and impeller wedges and fratricide. Missile wedges by Honor's time are a lot more powerful (and bigger) than they were 400-500 years earlier. This gives them better accel, a better compensator effect, longer burn time, and the ability to "shield" one another from counter missiles by (in effect) sweeping a broader volume on their way inbound. (The "rear" missiles of the salvo are at least partially in the protective shadows of the "lead" missiles of the salvo, as described above.)In other words, it makes them somewhat better targets as individuals but also "plows the road" for the rest of the salvo coming along behind them because of the staggered wedge light-off at launch. In the earlier period when missiles used wedge contact to kill enemy ships, they also had to face one another (that is, expose the throats of their wedges) at the moment of firing, and the same thing was true for missile defense. That is, ships were one hell of a lot more vulnerable to "down the throat" shots than they are by Honor's time. One reason missiles fell out of favor and were replaced by energy armaments as the weapons of decision was that fire control and missile defense both got a lot better, as did sidewalls. The defender no longer had to expose his most vulnerable aspects in order to get shots at the incoming, the attacker no longer had to expose his most vulnerable aspect in order to get shots at the defender, and the probability of a missile surviving to get close enough to attack a sidewall plummeted. Hence energy weapons powerful enough to burn through sidewalls became the real shipkillers, at least for capital units, until the introduction of powerful, reliable laser heads.
Finally, you clearly do not understand what is involved in missile evasive movement and dispersal. I've already mentioned the fact that missile dispersal appears to include at least two dimensions you weren't allowing for (i.e., depth and time). As for maneuver, of course they can dodge and weave without "running into" one another. I never said they could stop, nor did I ever mean to imply that they could suddenly negate their base vectors. They can generate Delta V only relative to that base vector, but that's quite enough to make them difficult targets for counter missiles which are coming at them at equally insane velocities and with self-targeting sensors which are nowhere near as capable as those of the ship which launched the CM. And missiles are well aware of where other members of their same salvo are located --- at least while they're in range of their launching ships' telemetry links --- while each missile is equally capable of altering heading at the same acceleration as every other missile in the salvo. That is, they are not suddenly going to slam on the brakes and get rear-ended by one of their fellows. One reason accuracy goes down once the links are cut is that the missiles are no longer talking to each other (courtesy of wedge interference). Their ability to maneuver as a salvo is reduced, and as they go into terminal attack mode, they are also (in the absence of telemetry links; another reason Apollo is so important) limited to whatever evasive maneuvers were programmed into them as of their last contact with their links. This limits the effectiveness of their evasion and also leads to a higher degree of fratricide as they lose track of where the other members of their own salvo are relative to themselves. I've always visualized the missiles as individual nodes in a dispersed targeting constellation but with the difficulty that their own propulsion system cuts holes in their data net. In this respect, the launching ship acts as a clearing house which distributes information from all the attack missiles' sensors (which allows a much richer "map" of the target) while simultaneously updating them as to the positions of other members of the same salvo which may not be able to communicate directly with them. The light-speed limitations build up to a point at which the updates to the birds come in too late to do much good or become worse than what the shipkillers' onboard systems can do based on their last stored updates and what their own sensors can "see" as they close. That's the point at which the launching ship cuts the link and hands off to each missile's autonomous control, at least pre Apollo.
LAC not so usefil after all?runsforcelery wrote:When I began putting together the tech bible essay for the books, before I wrote word one of On Basilisk Station, I created the initial "weapons platform" and laid out the general directions in which weapons technology would evolve in the course of the books. At that time, I knew that eventually a multidrive missile would evolve and that (eventually) faster than light telemetry links would be added to the package. The initial — that is, the "starting point" — missile technology for the combatants always visualized the missiles as communicating with the launching ship not simply so that the launching ship could provide detailed targeting corrections, however. I'm genuinely not sure who was doing what in this regard in terrestrial weaponry back in 1990 when I started thinking about this, but it had occurred to me from the beginning that simply because of the ranges involved the sensors available to the launching platform, however good they might be, would be at a significant disadvantage both in terms of communications lag and sheer distance to the target. Because of that, I never thought about the telemetry link as providing "one-way" sensor information from the firing ship to the missile. Rather, the missiles were always visualized both attack weapons and as remote, expendable sensor platforms which provided the launching ship with additional (and in many ways "better") sensor data on the target and the general tactical environment despite the fact that their own sensors were far inferior to those mounted aboard the ship which launched them.
Remember that I've always described the missiles as "myopic." That means (a) their sensor arrays have less sensitivity and their onboard computer support has less capability to "massage" the data than the sensors/computers back aboard the all of warship which fired them and (b) because of the relatively smaller size of the missile wedge (smaller as in comparison to a starship's wedge) and the placement of the missile inside the wedge it has a more limited view of the target. It's not quite like looking through a soda straw, but there are definite bounds to the missile's field of view and those bounds are much more constricted than the ones available to a warship. Because of this, missiles' onboard targeting capacity has always been much less capable than that available to it through its telemetry links, and the fact that the ship at the other end of that link is receiving sensor data from every other missile in the salvo further enhances the capability of each individual unit of the salvo. You could certainly fire an Honorverse SDM or early-generation MDM at a target without a telemetry link and without any additional input from other missiles involved in the same attack, and you would still have a chance of scoring a hit. It would, however, be a far lower chance, and you would begin getting into levels of comparative capability in which the antimissile defense systems would have a progressively greater margin of superiority. In other words, you would basically be throwing the missile away if you fired it against an alert opponent because the base chance of hit would be low and the defense's chance of an interception would be high.
Apollo simply takes what the earlier missiles with light-speed telemetry were doing, transforms it into a faster-than-light communications loop through the control missile, and because of the increase in the size and the base expense of the FTL platform includes greatly enhanced on board AI. This last point is perhaps a bit more subtle than some of the others, but essentially the control missile forms a node capable of doing for the attack missiles from its pod what the mothership did for "old style" Honorverse missiles. It receives, combines, collates, and utilizes the sensor intake from all the missiles in its own, personal, tiny "salvo." Since it was going to be the primary collection node for the missiles and its pod anyway, and since building it with the absolute minimum capability Manticoran needed was already going to make it pretty darn pricey, it made a lot of sense to BuWeaps to go ahead and make it even pricier in order to maximize its utility and capabilities.
One of the consequences of this (which most definitely did occur to the more wild and woolly thinkers and BuWeaps) is that an Apollo pod is a much more effective "fire and forget" weapon system than any earlier generation of missiles. That may sound a little odd, since the entire function of the control missile, especially in Apollo's initial visualization/iteration, is to allow the firing ship to remain in the link longer and to greater ranges, but it actually makes sense and helps to explain the decision to invest as much in the control missile as Manticore has. Because the control missile's onboard computers and AI are already sorting, using, and updating sensor data from all of the other missiles in the pod, and because it is preprocessing that information, that data, before it transmits it to the firing ship, it struck BuWeaps as only logical to give that control missile more autonomy as a fire control node, as well as a data node, in case for some reason the FTL link was lost. (For example, because the launching ship were to be destroyed before the missile reached its target and no one else was available to pick up the control links.) But what this also means is that the control missile can be loaded with a hierarchy of targeting options and launched to ranges at which FTL communication with the launching ship has not only reacquired a transmission delay but also to ranges at which FTL communication is flatly impossible. At that point, the control missile has full responsibility for targeting and coordinating the attacks of all of its missiles. Further, if multiple Apollo pods are launched at the same distant target, with a ballistic phase programmed into the attack, the control missiles of different pods are capable of cross communicating with one another, compiling all the sensor data available from all the attack missiles of all the pods in the salvo using directional communications lasers which will be effectively undetectable by their targets because their targets won't have anything in the transmission path. And what that means is that an Apollo salvo fired to beyond effective FTL control range will still have a significantly higher hit probability than an old-style single-drive missile at, say, 2 light-minutes range.
Put another way, these things were going to be big enough and cost enough anyway that it was no longer practical to trade off "good enough" capabilities against greater numbers of available rounds. In that sense, it might be fair to say that Apollo is the equivalent of late twentieth century "smart weapons"in that each of them is very expensive compared to earlier missiles but the price/effectiveness trade-off still comes down firmly on the side of the more expensive weapon, and my original concept for the weapons family had more to do with precision guided munitions and remotely provided targeting data (most of this was in pre-UAV days or when the entire concept was just getting started) than it did with particular families of rocketry or specific real world tactical doctrines.
As I said in the above paragraph, Apollo is more expensive than an MDM, and an MDM is more expensive than a single-drive missile, but that's not to suggest that weapons costs have rocketed out of control for the RMN. Because of the sheer volume of production, and because the production process had been refined, and then re-refined, and then re-refined yet again over the duration of the First Havenite War, the absolute cost of Apollo missiles, while far higher than those of the single-drive missiles of the early war years, is nowhere near as much higher than some people may have assumed. In a galaxy in which the basic manufacturing capacity and plant which had been producing them has been blown apart by Operation Oyster Bay, the cost of producing them somewhere else is going to be very, very high until Manticore and/or that "somewhere else" have rebuilt the facilities and reinstituted that multiply refined production process. Aside from the control missile itself, however, Apollo missiles are not appreciably more expensive than last pre-Apollo-generation Manticoran MDMs.
Apollo, inspired by KIROV and SS-N-19 antiship missile?Following quote from this same page:runsforcelery wrote:Annachie wrote:Given that that missile description you gave makes it sound like that missiles, or at least the older style missiles, don't have the capacity to sight through their own wedges like an all up ship can, does that mean they have/had to trail out an antena to improve the communication back to the patent ship?
If I'm understanding what you're saying, that's correct. In fact, it's correct even for the latest models of missiles. For that matter, it's mostly correct for warships, as well. A warship can "see" through the bands of its impeller wedge, that only very, very poorly, and it requires extraordinarily capable sensor hardware and computational ability. That's the reason Rafe Cardones' ability to target Thunder of God's incoming missiles through Fearless' belly bands was so inferior to what he could have obtained had he dared to expose the cruiser's broadside (i.e., sidewalls) directly to incoming fire. Missiles have never been able to "see" through their wedges. Partly that's because it would be insanely expensive to even try to build the minimum sensor/computer package sufficient to accomplish that into something the size of a missile which is going to be expended when it's fired, whether or not it strikes its target. It might — might — be physically possible to build that sort of capability into something the size of a Mark 23, but it would come at the expense of so many other capabilities (there's only so much space you can shoehorn things into) that it would disastrously compromise the missile's effectiveness as a weapon. It makes far, far more sense to build those capabilities (or something which gives you the same effect as those capabilities) into a drone platform which is even bigger than the missile, restricted to much lower accelerations, but also has much greater endurance and drive flexibility. Missiles don't "trail an antenna." Instead, they periodically "clear the wedge" by reorienting so that the open stern aspect of their wedge is presented to the controlling ship. The ship's computers know when each missile will carry out that maneuver, and it has a data packet waiting when the wedge is cleared, just as it is waiting to receive from that missile at that moment. This is one reason why missile salvos have to be "choreographed" as carefully as they are. It's also one of the vulnerabilities that missile defense looks for. If you can find a pattern for the order in which the missiles in a salvo "clear their wedges," you can adjust (to some extent, at least) your defensive fire. Also, if you keep an eye on the incoming missiles, map their vectors carefully, and know the bearing to the ship(s) firing/controlling the missiles, your computers can keep track of the last time at which they could have been updated. This forms one component in missile defense's threat ranking for incoming fire. If you know that Missile A has been updated within 20 seconds of the time in which it will enter its standoff attack range but that Missile B's "youngest" update can't be any fresher than 60 seconds of the time in which it will enter attack range, then Missile A is clearly the greater threat and stopping it should be assigned a higher priority. All of this is going on continually, on both sides, which is one reason that the FTL capability of Apollo is so decisive. I suppose I should also point out that as an impeller wedge's acceleration rate increases its geometry alters. I'm pretty sure I've already said this, but one of the things that happens as acceleration rate goes up is that the throat of the wedge narrows and that the kilt grows proportionately "deeper." Now, missile acceleration rates are purely insane compared to those of any man's platform, and what this means is that missile wedges are flatter compared to ships' wedges. In addition, the missile is proportionately further to the rear of the wedge. This has two implications. Implication #1 is that it squeezes down the "windshield frame" through which the missile sensors — which can only see what is in front of the missile, not through the roof or floor — can collect information. Implication #2 is that as the kilt deepens (which is another way to say "opens"), the missile's communications array has a wider" aperture through which it can transmit and receive. This, by the way, is also part of the reason that counter missiles require (and are [i]designed to require) better shipboard control than shipkillers do. Their view of what's in front of them is even more restricted than a shipkiller's view, and their ability to receive shipboard control is much greater because (a) they have a larger keyhole through which they can communicate and (b) they are usually fired on a much "straighter" vector. That is, they are being directed against an incoming threat rather than following a programmed-in evasion pattern to get through someone's defenses, which means that their after aspects are going to spend a lot more time pointed directly at the ships controlling them. Counter missiles are usually "steered" right up to the moment at which their onboard sensors lock on to their designated target. That's because their narrow field of view makes it so much harder for them to see the entire spectrum of incoming missile threats compared to what the control ship's onboard systems, looking through an entire galaxy of arrays — remote platforms, shipboard sensors, input from the shipkillers' sensors, input from all of the counter missiles currently deployed, etc. — that it would be stupid to rely on their own rudimentary capabilities. Note here that "rudimentary" is being used in the sense of "limited by unavoidable technical constraints" rather than in the sense of "boy, this is crude technology." Navies don't waste a lot of money building in capabilities the CMs couldn't use anyway, so even their theoretical capabilities are significantly lower than for a shipkiller, but the primary reason for not wasting the money is that bit about "couldn't use anyway." The fact that the Viper has more "shipkiller DNA" built into it — that it is, in effect, a hybrid weapon — explains why Vipers are so much more expensive than standard CMs. I think some people underestimate the sophistication and "density" of the data management of a squadron or a fleet engagement. Consider an SD(P) battle squadron with Keyhole-Two. There may be literally thousands of MDMs, coupled with scores or hundreds of stealthed recon platforms, backed up by the sensor take of every LAC and starship in the engagement. Much of that data — at any given moment — will be unavailable to any given SD(P) in the battle squadron, but it will probably be available to some SD(P) in that battle squadron or (in a fleet engagement) in another battle squadron. This is significant because, the Keyhole platforms, being outside the starship wedges, will be able to maintain continual cross-platform communications, which means that in theory any SD(P) in any battle squadron will have very close to full real-time access to the vast majority of the sensor information coming back from all of those attack, reconnaissance, and — remember the CMs — defensive platforms. The more missiles there are in flight, the greater the depth and "richness" of the data stream available to the firing ships. All of this flows together to build the "battlefield awareness" which guides the fleet/squadron tactical officers in managing offensive and defensive fire, and the speed with which it can be received and with which tactical decisions based upon that awareness can be transmitted to attack and defensive platforms has huge implications for the squadron or fleet's effectiveness in action. And that, my children, is yet another reason that Apollo is such a devastating offensive advantage.
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