Countering the Spider – Real World Inspirations

The E wrote:In my mind, detecting Spider-drive ships as they translate is good, but not critical. Detecting them before they enter weapons range is, and that's a completely different (but more easily solvable) problem.

A thought:

We know that with the Ghost Class spider drive ships -- and presumable other spider drive ships with similar stealth features -- there is always one aspect that can't be stealthed because of the need to radiate waste heat and that side has to be kept turned away from possible enemy detection.

If a percentage of a System Sensor net's sensors are turned inward to look for anomalous heat sources, it won't be possible to keep the waste heat emissions turned away from possible detection. I fact, the waste heat should be visible to at least two sensors, which would enable triangulation of the anomalous source's position to guide interceptors.

Weird Harold wrote:

The E wrote:In my mind, detecting Spider-drive ships as they translate is good, but not critical. Detecting them before they enter weapons range is, and that's a completely different (but more easily solvable) problem.

A thought:

We know that with the Ghost Class spider drive ships -- and presumable other spider drive ships with similar stealth features -- there is always one aspect that can't be stealthed because of the need to radiate waste heat and that side has to be kept turned away from possible enemy detection.

If a percentage of a System Sensor net's sensors are turned inward to look for anomalous heat sources, it won't be possible to keep the waste heat emissions turned away from possible detection. I fact, the waste heat should be visible to at least two sensors, which would enable triangulation of the anomalous source's position to guide interceptors.

It depends on how narrow a beam that waste heat is projected in. If it is projected as a laser (like the one David Brin described in Sundiver), then the probability of being in the beam approaches zero. Especially if the sensors are at known positions which the stealth ship can avoid aiming at.

In any case, since the system sensor net is well inside the hyper limit, detecting them at that point is too late. You need a different sensor net.

SWM wrote:It depends on how narrow a beam that waste heat is projected in. If it is projected as a laser (like the one David Brin described in Sundiver), then the probability of being in the beam approaches zero.

Assuming that that particular piece of tech actually is a thing that works in the Honorverse (IIRC, it isn't actually clear whether it would work IRL).

Anyway, the point is that no vessel can be stealthy in all aspects at all times; it's the old "fool all sensors some of the time, or some sensors all of the time" problem.

The E wrote:

SWM wrote:It depends on how narrow a beam that waste heat is projected in. If it is projected as a laser (like the one David Brin described in Sundiver), then the probability of being in the beam approaches zero.

Assuming that that particular piece of tech actually is a thing that works in the Honorverse (IIRC, it isn't actually clear whether it would work IRL).

Anyway, the point is that no vessel can be stealthy in all aspects at all times; it's the old "fool all sensors some of the time, or some sensors all of the time" problem.

That is correct. David Brin's refrigeration laser is a curious unproven concept. And it is true that there will be some angle at which you can detect the heat exhaust of the stealth ship. That has been the detection method most commonly suggested in the past on this forum. As I said, it depends on how narrow a beam they project it in. David has said that it is a very narrow beam. You will not get two ships in the beam at the same time. But if you have enough scattered detectors, you can detect the ship.

Let's suppose that the heat is projected in a beam 2 degrees wide. Let us also suppose that you want to be able to detect a stealth ship before it gets more than 1 light-minute inside the hyper-limit. You have an array of detectors arranged at the hyper limit, aimed inward. That means your detectors will have to be placed no more than 2 light-seconds apart to prevent the beam from being able to miss your detectors. If the hyper limit is 22 light-minutes radius, that means you need 350,000 detectors [edit]correction, that should be 20,000,000 detectors[/edit] scattered around the hyper limit. And the stealth ship could avoid those detectors by aiming the beam inward after it crossed the hyper limit, so you will also need other detectors inside the hyper limit looking outward.

So, as I said, how useful this method is depends on how narrow the beam is.

There are quite a few ideas which come to mind.

First of all, Spider drive ships have slow acceleration, which means that they can be chased down by everything smaller than medium-size merchant ships with civilian-grade particle screens and compensators. There will be no shortage of ships capable of being used for hunting. Putting military-grade lidar and radar would help, but I believe the best search would be provided by drones actively pinging volumes of space with their onboard sensors.

Another method, which is more like a brute-force approach, would be using BFNs to "clear" volumes of space or use the sheer power of the explosion as a search device. After all, either the smart paint of a spider ship manages to "swallow" the radiation and energy, in which case there will be a suspicious "black hole" in the blast wave sphere, or the paint will not manage, which would mean damage to the surface. I wonder whether that could strip bare the stealth paint? If it does, then the stealth ship won't be stealthy anymore, meaning it could be targeted with regular MDMs. A remodelled triple ripple would probably be quite good for the purpose.

Second, spider drive ships are fragile. Since they don't have inertia compensators, the lives of their crews depend on the continued function of their gravplates, which means that practically every hit could disable various sections of gravplates, with gruesome results for those occupying the compartments(provided they have managed to survive in the first place).

Spider Drive ships require three sets of projectors to stay balanced in N-space. What happens if say one side is damaged? Directionless travel? Kaboom? I will have to use a gruesome example, inspired by the name of the class of the ships used in Oyster bay. Cutting the fins off sharks makes them unable to swim, which in quite a few cases means death by suffocation, or in any case means the shark will die from being unable to escape from predators, or feed.

As a matter of fact we don't really know how the MAN intends to use their spider drive ships. If they are supposed to be terror raid weapons, they would have to come to their targets. If they are to be used as WW2 subs, then they would have to concentrate on choke points, which can be patrolled by hunter groups.

I'm not sure about that, it seems to me that in grav waves those ships will be useful because their heavy armor and spider drive "legs" will give them marked superiority, and they could use their torpedoes. However, it seems their acceleration will still be much lower than that of even the biggest merchant, so...

Still, I have always wondered about something. Why do those ships have to be found by special equipment? I mean, a 9 megaton ship has the same mass as a block of granite 150 meters on a side. Nobody is going to notice that there is a 150 meter asteroid equivalent that travels at ten percent of light speed through the system? Would it just go unnoticed?

torongill wrote:There are quite a few ideas which come to mind.

First of all, Spider drive ships have slow acceleration, which means that they can be chased down by everything smaller than medium-size merchant ships with civilian-grade particle screens and compensators. There will be no shortage of ships capable of being used for hunting. Putting military-grade lidar and radar would help, but I believe the best search would be provided by drones actively pinging volumes of space with their onboard sensors.

It seems likely that the smart paint will reduce the effectiveness of active search beams drastically. Unless you are lucky enough to be extremely close to the target, you won't detect it this way.

Another method, which is more like a brute-force approach, would be using BFNs to "clear" volumes of space or use the sheer power of the explosion as a search device. After all, either the smart paint of a spider ship manages to "swallow" the radiation and energy, in which case there will be a suspicious "black hole" in the blast wave sphere, or the paint will not manage, which would mean damage to the surface. I wonder whether that could strip bare the stealth paint? If it does, then the stealth ship won't be stealthy anymore, meaning it could be targeted with regular MDMs. A remodelled triple ripple would probably be quite good for the purpose.

You don't explain what you mean by BFN. I will assume that you mean Big Nukes.

Your first scenario depends on seeing the target ship against the glow produced by the explosion. Unfortunately, the volume which will be glowing enough to use as background illumination is rather small, compared to deep space. Suppose you manage to make a volume 10,000 km in radius glow (a rather remarkable achievement!). Suppose the target ship ship is a mere 1 light-second away from the explosion. In order for an observer to see the target ship against the background of the explosion, the observer would have to be within a mere 2 degrees of the direct line from the explosion to the target ship. If the target ship is more than 1 light-second away from the explosion, the angle gets even smaller.

The second scenario basically means that the target ship has to be within the volume of the explosion itself. If you don't already know where the target ship is, the probability of hitting it is nearly nonexistent. If you can hit it with a nuke, then you've already localized it.

Still, I have always wondered about something. Why do those ships have to be found by special equipment? I mean, a 9 megaton ship has the same mass as a block of granite 150 meters on a side. Nobody is going to notice that there is a 150 meter asteroid equivalent that travels at ten percent of light speed through the system? Would it just go unnoticed?

Yes, it would go unnoticed, unless you happened to see it. It's just not massive enough to be detectable by gravity unless you are already very close to it.

torongill wrote:I'm not sure about that, it seems to me that in grav waves those ships will be useful because their heavy armor and spider drive "legs" will give them marked superiority, and they could use their torpedoes. However, it seems their acceleration will still be much lower than that of even the biggest merchant, so...

My understanding is that in grav waves acceleration is via the sails, and they allow very high acceleration. Since you need a sail to survive in a grav wave it would appear logical that spiders have sails. If they have yet another means to operate inside grav waves then I have no idea that would imply.

kzt wrote:

torongill wrote:I'm not sure about that, it seems to me that in grav waves those ships will be useful because their heavy armor and spider drive "legs" will give them marked superiority, and they could use their torpedoes. However, it seems their acceleration will still be much lower than that of even the biggest merchant, so...

My understanding is that in grav waves acceleration is via the sails, and they allow very high acceleration. Since you need a sail to survive in a grav wave it would appear logical that spiders have sails. If they have yet another means to operate inside grav waves then I have no idea that would imply.

Yes, the acceleration in a grav wave is via the sails. The question is whether the spider ships have an inertial compensator. If they don't, then their acceleration is limited to the amount their grav plates can counter--i.e. the same as their acceleration under spider drive.

However, since spider drives apparently can generate Warshawski sails, it seems likely that the Alignment would also have installed inertial compensators to allow them to take full advantage of grav wave acceleration.

SWM wrote:It seems likely that the smart paint will reduce the effectiveness of active search beams drastically. Unless you are lucky enough to be extremely close to the target, you won't detect it this way.

one thing is active search beams, and I suppose another is a full power burst mode from short range that could get you a hull-plate number. It's a given that it will reveal the position of the drones, but drones are expendable, and even if one of them is destroyed, it would provide a general vector for the search. And yes, it would be clearing small volumes of space at any given moment, but use enough of them in a pattern, and that volume would be big.

You don't explain what you mean by BFN. I will assume that you mean Big Effin' Nukes.

Your first scenario depends on seeing the target ship against the glow produced by the explosion. Unfortunately, the volume which will be glowing enough to use as background illumination is rather small, compared to deep space. Suppose you manage to make a volume 10,000 km in radius glow (a rather remarkable achievement!). Suppose the target ship ship is a mere 1 light-second away from the explosion. In order for an observer to see the target ship against the background of the explosion, the observer would have to be within a mere 2 degrees of the direct line from the explosion to the target ship. If the target ship is more than 1 light-second away from the explosion, the angle gets even smaller.

The second scenario basically means that the target ship has to be within the volume of the explosion itself. If you don't already know where the target ship is, the probability of hitting it is nearly nonexistent. If you can hit it with a nuke, then you've already localized it.

Not illumination in the visible spectrum, more about the radiation from the nuke. The reach of that one would be greater, and of course there will be more than one set of eyes looking at the blast, and from different angles. It's not obligatory to use one nuke, multiple can be used to create a wide front of radiation. The triple ripple, using LAC-sized missiles, is supposed to have blinding radiation effect against shielded targets from 40 thousand km. If the effect is not to blind sensors, but to force the stealth paint to react to that radiation, the stand-off range would be quite a bit higher The point is to force the stealth systems to react and observe the effect from multiple angles. It would probably take a Hemphill-Foraker-Simoes brain trust to figure it out, but it would be like using active radiation sonar.

P.S. Spider Drive ships don't have inertial compensators, that's why they need grav plates and are of a "building" design, with the "top" being the stem and the "bottom" being the stern.

torongill wrote:P.S. Spider Drive ships don't have inertial compensators, that's why they need grav plates and are of a "building" design, with the "top" being the stem and the "bottom" being the stern.

Nitpick, spider drives don't provide a grav "sump" to allow a compensator to work. But nothing appears to prevent a designer from installing one anyway. There would be no point if the only drive is the spider; but if there is a sail then you get the compensator under sails but have to fall back on grav plate when under spider.

SWM wrote:That is correct. David Brin's refrigeration laser is a curious unproven concept. And it is true that there will be some angle at which you can detect the heat exhaust of the stealth ship. That has been the detection method most commonly suggested in the past on this forum. As I said, it depends on how narrow a beam they project it in. David has said that it is a very narrow beam. You will not get two ships in the beam at the same time. But if you have enough scattered detectors, you can detect the ship.

Let's suppose that the heat is projected in a beam 2 degrees wide. Let us also suppose that you want to be able to detect a stealth ship before it gets more than 1 light-minute inside the hyper-limit. You have an array of detectors arranged at the hyper limit, aimed inward. That means your detectors will have to be placed no more than 2 light-seconds apart to prevent the beam from being able to miss your detectors. If the hyper limit is 22 light-minutes radius, that means you need 350,000 detectors [edit]correction, that should be 20,000,000 detectors[/edit] scattered around the hyper limit. And the stealth ship could avoid those detectors by aiming the beam inward after it crossed the hyper limit, so you will also need other detectors inside the hyper limit looking outward.

So, as I said, how useful this method is depends on how narrow the beam is.

I've got what's probably a stupid question. Assuming a very narrow, and therefore very locally hot, beam:
1) how often would it hit random denser bits of space (gas, micro-asteroids,ect)?
2) how visible would that kind of small junk be when hit by a very hit narrow beam which should quickly raise the junk's temperature?

I'm wondering if you could use a smaller number of IR sensors looking for secondary effects of the very hot narrow beam, instead of the beam itself.

(Like I said this is probably a stupid question given how unfathomely vast space is)