Do we actually need SD(P)s?

tlb wrote:Here is the quote about the missiles used in Oyster Bay (the next generation after the ones used against Ruzsak) from Mission of Honor, chapter 29:

In the meantime, they'd come up with Cataphract, a variant of their own based on taking the standard missile bodies for the SLN's new-generation anti-ship missiles and adding what amounted to a separate final stage carrying a standard laser head and a counter-missile 's drive system.

So this missile is a standard anti-ship missiles with an added drive from a CM that kicks in last.

Could the CM drive be in the front, outside of the sensor package? That would still put it the correct distance from an end, while giving it maximum separation from the initial drives.

Jonathan_S wrote:But it is described as a separate stage, not just separate drive. That still makes me think that the initial stage, the modified normal anti-ship missile, drops away letting the CM powered separate final stage take the sensors and warhead the rest of the way to the target

I found where this had been discussed in 2016 and had not come to a firm conclusion then, not even from MaxxQ. I wondered if MaxxQ had any more recent ideas and sent him a note. This is the response:

tlb wrote:We are still unclear how a Cataphract is put together. Do you have even a rough sketch?

MaxxQ wrote:Not even a sketch.

Brigade XO wrote:So the initial stage, the modified normal anti-ship missile, drops away letting the CM powered separate final stage take the sensors and warhead the rest of the way to the target.

These are impeller drives so the drive from the second stage will apparently do nothing to the jettisoned 1st stage, (which is theoretically straight behind it) at which point the 2nd stage accelerates away and continues whatever manuvering required to reach their inteneded target.

Something that hasn't come up is what then happens to that now inert 1st stage, "coasting" along at a fair fraction of C with no sensors and no guidance and no power for it's impeller.

Does it have a self-destruct charge? I ask because we are told that apparently all missles are built with self destruct charges to eliminated the weapon if it does not fire it's warhead (well, eject the lazing rods and then use the energy from the exploding warhead being focused through the lazing rods to attempt to hit the target.

Using the shipkiller as a booster/1st stage implys that you would remove at least the warhead and lazing rods from it before affixing the second stage whis the CM with it's warhead.

No self destruct charge in that 1st stage could make life really interesting if the inert 1st stage comes upon something. Fireing these things in the general direction of an inhabited planet or orbital facilities could lead to the spent boosters the size of a pod-launched shipkiller with all the mass that implies hitting things at tremendous speed.
That's an Uncontolled Kenetic Energy Weapon that is going to head in the direction it was last accelerating while being used to try and hit ships underway and while it's guidence was active it was manuvering to hit a moving/evading target along with dealing with that targets ECM.

Sounds like this potential EE hit written all over it. That's just in the time frame of the battle.
If the booster doesn't reach escape velocity for the system, it will likely come back through some time in the future. Right after it's own impeller cuts off, it will vanish from any tactical system that is tracking impellers and be off on a ballistic cruise. Anything downrange isn't going to see it comming. Anthing in the system when the ballistic body comes back through won't even have the potential advantage of knowing there might be debris comming. At that point only God will have any idea of where it is and were it is going after dealing with the various components of the systems gravity sources including the star.
So, does anyone think that perhaps a couple hundred tons of mil-sped metal comming in ballistic at perhaps .2 to .3C is going to be a problem? How about several thousand of them. Shotgun effect perhaps?

It's not just the missiles you have to worry about. Some of the major fleet battles will have millions of tons of warship debris flying about the system at greater than escape velocity. Something like the Operation Beatrice will have created well over a billion tons of potential planet-crushing debris from exploded ships, spent pods, missile fragments, etc. Just because a missile self destructs or a ship's fusion reactors blow doesn't mean all the debris is reduced to ionized dust - and even a chunk of warship armor the size of your head moving at 200 km/s is close to a kiloton of kinetic energy.

Galactic Sapper wrote:It's not just the missiles you have to worry about. Some of the major fleet battles will have millions of tons of warship debris flying about the system at greater than escape velocity. Something like the Operation Beatrice will have created well over a billion tons of potential planet-crushing debris from exploded ships, spent pods, missile fragments, etc. Just because a missile self destructs or a ship's fusion reactors blow doesn't mean all the debris is reduced to ionized dust - and even a chunk of warship armor the size of your head moving at 200 km/s is close to a kiloton of kinetic energy.

I suggested that if were the MA I'd be sending out ships to collect debris from BoM. Most particularly missile pods or missiles that were duds or just missed. David assured us that every honorverse missile has a 100% effective self-destruction system that only goes off when it's supposed to.

Whatever.

kzt wrote:

Galactic Sapper wrote:It's not just the missiles you have to worry about. Some of the major fleet battles will have millions of tons of warship debris flying about the system at greater than escape velocity. Something like the Operation Beatrice will have created well over a billion tons of potential planet-crushing debris from exploded ships, spent pods, missile fragments, etc. Just because a missile self destructs or a ship's fusion reactors blow doesn't mean all the debris is reduced to ionized dust - and even a chunk of warship armor the size of your head moving at 200 km/s is close to a kiloton of kinetic energy.

I suggested that if were the MA I'd be sending out ships to collect debris from BoM. Most particularly missile pods or missiles that were duds or just missed. David assured us that every honorverse missile has a 100% effective self-destruction system that only goes off when it's supposed to.

Whatever.

Which is why I stressed it's not just the missiles that are a problem. A 300 ton chunk of armor from an exploded Havenite SD isn't going to have a self destruct but can still make a hell of a crater when it smacks a planet at 200 kps.

Relative speed is far more of a factor than mass alone. There would be thousands of potential Yawata-level debris strikes possible from a major space battle if the geometry happened to line up wrong.

Maybe we're just supposed to assume the geometry never lines up such that debris would be aimed at a planet, and no amount of nuking or drive failures could ever generate enough side vector to change that. Seems pretty naive to me, but whatever.

But do LACs, even dedicated ones, have enough computing power to control hundreds of shipkiller missiles in a salvo and accurately target the enemy ships? They obviously can't be within 1 million km of the enemy, otherwise the enemy will simply blast them with energy mounts (or even counter missiles). A LAC that lights up active sensors will be targeted by the enemy at any distance, especially if it's helping the shipkillers. It may be too late for the first salvo, but any enemy survivors will have a lock on the LACs

If you're staying 'near' your own fleet, then there's a real question whether just using that volume to put fire control processing power on the ship, rather than putting it in an LAC, which sits in a bay, essentially giving you far less volume available for the volume invested.

Where an LAC - or drone, or whatever - near your own fleet is useful is as a relay. Firing missiles is a pain in the neck because a wall of gravetic wedges can't be easily seen through and it's hard to talk to the salvo(s) in front of the last one launched, or clearly observe the target, as a result. The analogy of 'gunsmoke' was used in one book (I forget which but I'm sure someone will tell me).

One big part of ghost rider was the 'off axis' fire control relay, and friendly LACs might be useful in the role for a broadside-heavy fleet.

That's probably less of an issue when you're using pod-based launchers; if relatively few (if any) of your missiles are coming from your broadside, then your broadside is 'clear' and can see and communicate with the missiles pretty easily.



Where a 'fire control LAC' might be useful is in forward fire control. Sending an LAC in close to the enemy fleet is....pretty suicidal (as you noted, going within energy range is guaranteed death), but if you don't have the equivalent of an Apollo control missile and FTL comms, then the only way to have meaningful accuracy with MDMs (or cataphracts) is to have someone closer to the other end of the missile flight with a fire control computer and a datalink.

Getting up there isn't actually that hard, provided you're not being over-optimistic. Getting to, say, standard missile range sounds doable. SLN stealth tech has been repeatedly mentioned as the one thing that isn't too far behind manticoran-level tech.

The big problem is that LACs without Grayson-style compensators and fission plants can't use heavy energy weapons to threaten capital ships, and won't have the acceleration to act as 'dogfighters' against enemy LACs, but if they were prepared to hang off at 'standard' missile range, it's possible that on silent running and using stuff like whisker lasers you could provide last-minute fire control that would seriously improve the terminal accuracy of a cataphract.

Obviously if they get spotted, they're dead, and relying on them being there is therefore a bad idea, but it feels like the most useful thing you can do with an LAC.

The question is if you can provide enough sensor detail from passive sensors to meaningfully 'help', what range you can stay covert at, and what bandwidth you can provide a datalink to missiles at without advertising your position to the enemy.




Obviously, the other big use for LACs is countermissile platforms.

They're cheap, expendable, and put a lot of CM tubes into a region of space that don't have to worry about interfering with broadside salvos. Given that SLN designs are supposed to be catastrophically light on missile defences, converting a single ship in the formation to be a carrier with CM-armed LACs is probably a lot easier than refitting every SD with additional CM tubes, or giving up shipkiller tubes to throw CM canisters.

(Yes, I know they're still going to lose against modern designs)

I guess that most space battles end up with lots of pieces of ships heading out-system (even if they go through the system to do it) and once into intersteller space arn't going to be much concern for anybody for a long time. How long would it take anything from the destruction of the SLN fleet at Sol by Harrington to reach the Alpha Centauri system (at 4.37 light-years distance) even if it was on the right ballistic trajectory to begin with?

At Hypatica in UH, the people doing S&R put beacons and reflectors in the debris field for the RMN ships that was heading out-system. That was mentioned just before the life pod with the Admiral Kotouch was found. What was not mentioned was what was going on in the eventual start os search for pods plus damaged/wrecked SLN ships and the debries field for those that had been blown apart. Debris field sounds so contained but particularly if the ship or object in question was either coasting-not in an orbit- or was under acceleration you are going to get an expanding "cloud" of bits and chunks plus gas etc- also heading generaly in the last direction the ship was heading. Things blown off, at say 90º from the base course of the ship will have that latteral movement as well as at least some of the energy it had heading in the same direction as the rest of the ship.
How far away is it practical to send ships out to recover wreckage vs. recovery of bodies?

We have seen a number of battles where both Haven and Manticore have lost ships and where there was little discussion about tracking down either primarily life pods or any substantial pieces of runied ships. There was the piece about Abigale with a S&R/Boarding party chasing down a SLN SD after the Battle of Manticore. But once the ship had been cleared of it's crew- living and dead- was that one recovered or just left heading wherever on a ballistic trajectory?

How long after a battle does it become impractical to both search for wreckage and then recover anything? Sure, the Alignment could send ships to a system where RHN and RMN each lost dozens of ships but even if there was nobody with sensors at either the RHN or RMN state of sensitivity still there to notice even a conventional ship operated by the Alighment, where are they going to start looking for the debris and how are they going to get even an idea of where any given ship was heading when it was damaged and even abandoned (without scuttling charges) or sections were observed intact and moving somewhere.
If you show up two or three months after a battle and have sensor readings showing where (and how fast) ships were moving when the impellers signatures vanished, how long will it take to calculate where that debries is now (relative to the system's present location) and get to where you can get a sensor return of bits of ship with no funtioning power source?
Salvage can be great. Finding where that salvage is if it was last seen- with no energy readings-moving fast "that way" from System X four months ago will be a non-trivial challange.

Brigade XO wrote:I guess that most space battles end up with lots of pieces of ships heading out-system (even if they go through the system to do it) and once into intersteller space arn't going to be much concern for anybody for a long time. How long would it take anything from the destruction of the SLN fleet at Sol by Harrington to reach the Alpha Centauri system (at 4.37 light-years distance) even if it was on the right ballistic trajectory to begin with?

A trick question? The debris at Sol wasn't going anywhere far; everything was (carefully) destroyed in orbit. ~.2c would reach Centauri in around 25 years, though.

Frankly, any debris piece moving at a decent fraction of C has long passed galactic escape velocity. It will essentially straight-line out of the system(and only curve out of the galaxy with a close flyby of a very large mass).

Depending on the mass and velocity, it is possible contact with interstellar gas medium will ablate such pieces to harmlessness long before another star system is encountered.

locarno24 wrote:If you're staying 'near' your own fleet, then there's a real question whether just using that volume to put fire control processing power on the ship, rather than putting it in an LAC, which sits in a bay, essentially giving you far less volume available for the volume invested.

Where an LAC - or drone, or whatever - near your own fleet is useful is as a relay. Firing missiles is a pain in the neck because a wall of gravetic wedges can't be easily seen through and it's hard to talk to

Fire control "LAC's" are called.... Keyholes, RD's

locarno24 wrote:If you're staying 'near' your own fleet, then there's a real question whether just using that volume to put fire control processing power on the ship, rather than putting it in an LAC, which sits in a bay, essentially giving you far less volume available for the volume invested.

Where an LAC - or drone, or whatever - near your own fleet is useful is as a relay. Firing missiles is a pain in the neck because a wall of gravetic wedges can't be easily seen through and it's hard to talk to

Relax wrote:Fire control "LAC's" are called.... Keyholes, RD's

If we agree that a LAC is manned, then it is qualitatively different than either a Keyhole or a RD. Even if a Keyhole were to cost more than a LAC; we would still make more effort to avoid losing the LAC, because we value people more than machines.

Galactic Sapper wrote:

kzt wrote:I suggested that if were the MA I'd be sending out ships to collect debris from BoM. Most particularly missile pods or missiles that were duds or just missed. David assured us that every honorverse missile has a 100% effective self-destruction system that only goes off when it's supposed to.

Whatever.

Not practical. As BrigadeXO wrote above, there are two insurmountable problems with this:

First, arriving in the system without being noticed. Especially after Oyster Bay, all systems are going to be on alert for unexplained hyperspace translations and investigate. Translating 9 light-months out from Manticore may be sufficient to be out of range of the detectors, but it would mean a year in real-space to reach the probable location of the debris.

Second, it's locating the debris itself. One thing explosions aren't is tidy. You may know with good accuracy the original base velocity vector of the ship when it blew up and ceased accelerating, but you simply can't know the velocity imparted on each of those pieces by the explosion. Of course, the more massive the piece is, the smaller the delta-v, but let's say it's 5 m/s random. After 1 month, the piece has moved up to 13,000 km in any direction. After a year, that's 157.7 million km. That means the search would be trying to find something with roughly the same temperature as the interplanetary or interstellar medium in a volume of a cubic AU or 4 million billion cubic km.

That's probably worse than trying to find a needle in a haystack when you don't know which planet the barn with the haystacks is.

Galactic Sapper wrote:Which is why I stressed it's not just the missiles that are a problem. A 300 ton chunk of armor from an exploded Havenite SD isn't going to have a self destruct but can still make a hell of a crater when it smacks a planet at 200 kps.

Relative speed is far more of a factor than mass alone. There would be thousands of potential Yawata-level debris strikes possible from a major space battle if the geometry happened to line up wrong.

Maybe we're just supposed to assume the geometry never lines up such that debris would be aimed at a planet, and no amount of nuking or drive failures could ever generate enough side vector to change that. Seems pretty naive to me, but whatever.

We don't have to. Since those pieces are not accelerating, the only possible deviations from a perfect ballistic trajectory are collisions between the pieces themselves, transferring momentum from one to another. So you can easily calculate the trajectory of debris pieces that intersect the orbit of your planet. First, you recover any pieces big enough to be worth feeding your orbital smelters. Then you send a tug with an overpowered wedge to clean everything else up.

Unlike the case of recovering intel one year after the battle, you do this soon after it, a few days at most, like the Hypatians did. The cloud of debris is still fairly concentrated at that point (relatively speaking, it's still over a billion cubic km). You can also ignore anything that has achieved escape velocity out of the ecliptic plane, so you don't need with a spherical volume, but instead a flattened cylinder (like a CD or DVD).