KKM and Plasma Weapons
- Thread starter Ptah
- Start date
Scott Martin wrote:
One approach is to destroy the drive portion of the KKM, if one is possed, then manuever out of the path of the fragments. Another is to vaporize the warhead. Another is deflection.
Nuclear Anti-KKM missiles and plasma weapons
may be the answer for vaporization. Two other options: repulsars and "heavy" sand. The heavy sand idea is to fight fire with fire. A barrage of high density sand/ball bearings is thrown in the path of the warhead. The KKM collides with the sand/ball bearings and expends its energy in this collision, hopefully explosivly given the energy released from the collision.
With respect to seeding missile barrages with "stand-off" warheads, here's a suggestion for the engagement doctrine. Laser anti-missile defense is engage to targets at long range first.
Nuclear anti-KKM missiles (NAKKM) and "heavy sand" are set to target at much closer ranges. It may be this kind of anti-missile missile fire and "heavy sand" fire can not be effectively targeted at long range and thus only comes into its own against contact-to-kill (CTK) munitions such as a KKM.
From a starship combat perspective, this suggests a few things. (1) An extra round of anti-missile fire against KKM because they need to close to contact; and (2) Additional defensive mounts that can counter KKM, e.g., use of a "heavy sand" load in a sandcaster, and use of a NAKKM in a missile turret.
Something to kick this off.
Suggestions on Stopping KKM
One approach is to destroy the drive portion of the KKM, if one is possed, then manuever out of the path of the fragments. Another is to vaporize the warhead. Another is deflection.
Nuclear Anti-KKM missiles and plasma weapons
may be the answer for vaporization. Two other options: repulsars and "heavy" sand. The heavy sand idea is to fight fire with fire. A barrage of high density sand/ball bearings is thrown in the path of the warhead. The KKM collides with the sand/ball bearings and expends its energy in this collision, hopefully explosivly given the energy released from the collision. With respect to seeding missile barrages with "stand-off" warheads, here's a suggestion for the engagement doctrine. Laser anti-missile defense is engage to targets at long range first.
Nuclear anti-KKM missiles (NAKKM) and "heavy sand" are set to target at much closer ranges. It may be this kind of anti-missile missile fire and "heavy sand" fire can not be effectively targeted at long range and thus only comes into its own against contact-to-kill (CTK) munitions such as a KKM.
From a starship combat perspective, this suggests a few things. (1) An extra round of anti-missile fire against KKM because they need to close to contact; and (2) Additional defensive mounts that can counter KKM, e.g., use of a "heavy sand" load in a sandcaster, and use of a NAKKM in a missile turret.
Something to kick this off.
Scott Martin
SOC-13
Hello
This would be a discussion on KKM's
Warning that much of this post is me "Thinking out loud". The summary of it is that I will probably use Sigg's suggestion to treat KKM damage as "Tamped explosive" although realistically if your ship takes a hit, it's dead.
This still doesn't get into the "hard" part of how to model KKM's in traveller (specifically in Brilliant lances) for things like resolving whether they hit or not, point defence or anti-KKM KKM's and so forth.
Use of KKM's (even if you don't let the players have them) will significantly slant your Traveller universe: fixed defenses get a lot harder to cost-justify, and small military ships again rule the heavens. Vessels in the multi-Kton range will probably be limited to merchant shipping. Nukes suddenly stop being a big scary deal...
Most of this post examines the effects of a 10g submunition at a velocity of 12 "Brilliant Lances" hexes/turn closing velocity (conveniently 200 km/second: not even close to relativistic speeds) ballpark penetration using a variety of TNE and FF&S methods suggest that your ship has a hole in it unless it has 10 meters of steel armour, or a "mere" 1.5 meters of bonded superdense.
Take a look here for a good background in KKM's:
http://www.projectrho.com/rocket/rocket3x.html#kinetic
I am using the "neat" conversion of 4.5MJ = 1kg of TNT = 1 demolition point
According to FF&S the formula for penetration for KEAP rounds is Ek (in MJ) x4 (x a multiplier for round type: I'll just assume a steel ball)
This gives a 1 kg KKM projectile (submunition) at 1 "Brilliant Lances" hex/turn (relative) velocity an energy in excess of 275 MJ. In TNE terms that's penetration rating of 1,111, or the ability to penetrate more than 5 meters of hard steel. For comparison, the belt armour of a WW2 battleship is around 1/2 meter, so this would punch through 4-5 battleships side to side. 1 hex/turn relative velocity is *small* most KKM's I have designed using FF&S run in the area of 10-12 hexes/turn relative at impact, which gives ball bearings (at 10 grams each) 400 MJ of kinetic energy each, AKA a penetration value of 1600 AKA 8 meters of steel armour or 40 meters of re-enforced concrete.
For comparison this would be a FF&S PAW with a discharge energy of over 100 gigajoules (suggesting that one or both of these sequences have issues) so I'm considering Sigg Odara's proposal of calling KKM hits "tamped explosives" of the appropriate energy, although this gives the ball bearing a concussion / DP value of "only" 2108 pts (doubled because it is considered tamped: base is 1054 and "leaning on or against" would be a "mere" 527 points. DP values from TNE page 303) The untamped value is in the same range as the KEAP "submunition" round damage value. Of course that's before modifying it for materials, since a depleted uranium round triples this penetration which puts it well above the value for a "tamped" explosion, and realistically most of this energy is going *in*
This does give results similar to what I would expect from the Real World(tm) since using this type of weapon makes armour pointless, and will probably shift your universe towards the "Small ship" model, since *any* ship that is hit by one of these is probably at least a mission kill. The ball bearing example has slightly less energy than 90 TONS of TNT, so a 2.5 kg projectile at 12 hexes/turn is roughly equavalent to a Hiroshima bomb *as a penetrating direct hit*
I figure I'll call that a day, since I have a pile of other stuff to do in the Real World(tm) as well.
hmmm... sand grains / tiny gravel (0.1 g each) would only penetrate 1 meter of steel at this velocity, and I bet you could get a LOT of dispersion... still overkill for anti-KKM KKM's, so fine dust (1 mg per grain, penetration of 10 cm of steel per hit) is probably the submunition of choice for anti-KKM KKM's: I'll have to model a 100 kg warhead with a 10 KG bursting charge and 90 KG of dust for dispersion (90 million particles in spherical distribution should sweep a lot of KKMs from use)
Scott Martin
This would be a discussion on KKM's
Warning that much of this post is me "Thinking out loud". The summary of it is that I will probably use Sigg's suggestion to treat KKM damage as "Tamped explosive" although realistically if your ship takes a hit, it's dead.
This still doesn't get into the "hard" part of how to model KKM's in traveller (specifically in Brilliant lances) for things like resolving whether they hit or not, point defence or anti-KKM KKM's and so forth.
Use of KKM's (even if you don't let the players have them) will significantly slant your Traveller universe: fixed defenses get a lot harder to cost-justify, and small military ships again rule the heavens. Vessels in the multi-Kton range will probably be limited to merchant shipping. Nukes suddenly stop being a big scary deal...
Most of this post examines the effects of a 10g submunition at a velocity of 12 "Brilliant Lances" hexes/turn closing velocity (conveniently 200 km/second: not even close to relativistic speeds) ballpark penetration using a variety of TNE and FF&S methods suggest that your ship has a hole in it unless it has 10 meters of steel armour, or a "mere" 1.5 meters of bonded superdense.
Take a look here for a good background in KKM's:
http://www.projectrho.com/rocket/rocket3x.html#kinetic
I am using the "neat" conversion of 4.5MJ = 1kg of TNT = 1 demolition point
According to FF&S the formula for penetration for KEAP rounds is Ek (in MJ) x4 (x a multiplier for round type: I'll just assume a steel ball)
This gives a 1 kg KKM projectile (submunition) at 1 "Brilliant Lances" hex/turn (relative) velocity an energy in excess of 275 MJ. In TNE terms that's penetration rating of 1,111, or the ability to penetrate more than 5 meters of hard steel. For comparison, the belt armour of a WW2 battleship is around 1/2 meter, so this would punch through 4-5 battleships side to side. 1 hex/turn relative velocity is *small* most KKM's I have designed using FF&S run in the area of 10-12 hexes/turn relative at impact, which gives ball bearings (at 10 grams each) 400 MJ of kinetic energy each, AKA a penetration value of 1600 AKA 8 meters of steel armour or 40 meters of re-enforced concrete.
For comparison this would be a FF&S PAW with a discharge energy of over 100 gigajoules (suggesting that one or both of these sequences have issues) so I'm considering Sigg Odara's proposal of calling KKM hits "tamped explosives" of the appropriate energy, although this gives the ball bearing a concussion / DP value of "only" 2108 pts (doubled because it is considered tamped: base is 1054 and "leaning on or against" would be a "mere" 527 points. DP values from TNE page 303) The untamped value is in the same range as the KEAP "submunition" round damage value. Of course that's before modifying it for materials, since a depleted uranium round triples this penetration which puts it well above the value for a "tamped" explosion, and realistically most of this energy is going *in*
This does give results similar to what I would expect from the Real World(tm) since using this type of weapon makes armour pointless, and will probably shift your universe towards the "Small ship" model, since *any* ship that is hit by one of these is probably at least a mission kill. The ball bearing example has slightly less energy than 90 TONS of TNT, so a 2.5 kg projectile at 12 hexes/turn is roughly equavalent to a Hiroshima bomb *as a penetrating direct hit*
I figure I'll call that a day, since I have a pile of other stuff to do in the Real World(tm) as well.
hmmm... sand grains / tiny gravel (0.1 g each) would only penetrate 1 meter of steel at this velocity, and I bet you could get a LOT of dispersion... still overkill for anti-KKM KKM's, so fine dust (1 mg per grain, penetration of 10 cm of steel per hit) is probably the submunition of choice for anti-KKM KKM's: I'll have to model a 100 kg warhead with a 10 KG bursting charge and 90 KG of dust for dispersion (90 million particles in spherical distribution should sweep a lot of KKMs from use)
Scott Martin
GURPS Traveller has, somewhat by accident, demonstrated the effects of KKMs on Traveller. Which is that, basically, ships are impervious to KKM barrages up to a certain number of missiles, and beyond that number of missiles the ship is probably destroyed in one attack. It doesn't make for very interesting combat.
mike wightman
SOC-14 10K
In the CT Missiles special supplement sand could incapacitate missiles.
Roll 12+ for each 25mm of sand the missile has to pass through.
In Striker and MT the sandcaster is a giant shotgun.
Roll 12+ for each 25mm of sand the missile has to pass through.
In Striker and MT the sandcaster is a giant shotgun.
TheEngineer
SOC-14 1K
Hi !
Maybe we should consider, that the creation of a KKM needs a multiple of the energy, we want to deploy at the target. Well, thats typical for "transfer" weapon systems = transport of energy from source to target.
If we want 500 GJ of projectil energy, we usually have to put 500+ GJ inside first.
At least, its all about the level of energy. Variants occur in the way to transfer it. And, with respect, a KKM is just a relativ slow way to do that
We had regular discussions on starship KKMs, which take their advantage from the Traveller bug/feature, that maneuver drives ignore energy conservation laws....
So, if we would stay on a "hard SF line", where is the advantage here compared to other weapon systems, which effect is much more instant (lasers or PAWs - somehow a KKM variant) ?
Regards,
Mert
Maybe we should consider, that the creation of a KKM needs a multiple of the energy, we want to deploy at the target. Well, thats typical for "transfer" weapon systems = transport of energy from source to target.
If we want 500 GJ of projectil energy, we usually have to put 500+ GJ inside first.
At least, its all about the level of energy. Variants occur in the way to transfer it. And, with respect, a KKM is just a relativ slow way to do that
We had regular discussions on starship KKMs, which take their advantage from the Traveller bug/feature, that maneuver drives ignore energy conservation laws....
So, if we would stay on a "hard SF line", where is the advantage here compared to other weapon systems, which effect is much more instant (lasers or PAWs - somehow a KKM variant) ?
Regards,
Mert
TheEngineer
Accordingly, although the raw numbers on the energy look impressive with the assumption that the KKM is going to hit at high velocity, in practice having a long enough straight run at the target to achieve such velocities is probably going to be impossible unless the target can't manuever.
I don't know the length of TNE or T4 combat turns but if they are anywhere near the scale of CT, there is no way a moving target is going to sit still for a full turn such that a KKM can put together a straight run and gain velocity equal to one full turn of acceleration. In practice the, the KKM is probably only going to be able to accelerate in a straight line towards a target for a very small fraction of a turn (on the order of seconds). The result is that in practice, the KKM is going to actually impact at a far lower velocity if it is to home in on the target.
In comparison, an "explosive" warhead does not care how fast it hits, KE is a nice plus but the damage is from the "explosive." In addition, contact is not required, the missile can be flying by at a fair clip and all it needs to do is explode when in proximity.
My take home view of KKM at this moment, in theory they look frightening, and they are if you can't change course, but in practice their impact velocity is far, far less than given by theory. How much less depends on design rules for missiles, i.e., how much acceleration they have, do they have a limited range/fuel, etc.
hmmm....with vector based movement some of this should be alleviated? That is, since the KKM needs to contact the target, if it is screaming in at 50/hex turn then all the target needs to do is "slip sideways" a small amount and there is no way the KKM can turn in time.
Accordingly, although the raw numbers on the energy look impressive with the assumption that the KKM is going to hit at high velocity, in practice having a long enough straight run at the target to achieve such velocities is probably going to be impossible unless the target can't manuever.
I don't know the length of TNE or T4 combat turns but if they are anywhere near the scale of CT, there is no way a moving target is going to sit still for a full turn such that a KKM can put together a straight run and gain velocity equal to one full turn of acceleration. In practice the, the KKM is probably only going to be able to accelerate in a straight line towards a target for a very small fraction of a turn (on the order of seconds). The result is that in practice, the KKM is going to actually impact at a far lower velocity if it is to home in on the target.
In comparison, an "explosive" warhead does not care how fast it hits, KE is a nice plus but the damage is from the "explosive." In addition, contact is not required, the missile can be flying by at a fair clip and all it needs to do is explode when in proximity.
My take home view of KKM at this moment, in theory they look frightening, and they are if you can't change course, but in practice their impact velocity is far, far less than given by theory. How much less depends on design rules for missiles, i.e., how much acceleration they have, do they have a limited range/fuel, etc.
Scott Martin
SOC-13
Ptah:
TNE turns are 30 minutes long, TNE deals with light speed delay by firing salvos that cover the area where a target could maneuver to in the time between last known position and the energy beam getting there
Scott Martin
TNE turns are 30 minutes long, TNE deals with light speed delay by firing salvos that cover the area where a target could maneuver to in the time between last known position and the energy beam getting there
Scott Martin
Scott Martin
SOC-13
Mert:
From an "energy transfer" point of view, the primary difference between a KKM and another weapons system is that the energy transfer to target happens over the course of a long time period (up to hours or days, depending on the design) and the KKM doesn't have to saturate the area to generate a hit (assuming integral sensors) because it knows *exactly* where the target is (no light speed delay for a contact hit)
-increase in KKM energy because it's not spread into multiple packets to saturate the area where the target could be by the time the beam gets there
-Increase to KKM energy because it can be generated over a longer time period
-Increase in KKM energy because Traveller drives produce more energy than is put into them
-Decrease in KKM energy because most KKM's will probably be set to blow into submunitions to reduce the probability of intercept
I think that the most significant of these is the drive variance, but I can explain it (and it ties in with other folks "complaining" about the relative inefficiency of fusion drives) - more detail when I'm not dashing off a quick post at work
Scott Martin
From an "energy transfer" point of view, the primary difference between a KKM and another weapons system is that the energy transfer to target happens over the course of a long time period (up to hours or days, depending on the design) and the KKM doesn't have to saturate the area to generate a hit (assuming integral sensors) because it knows *exactly* where the target is (no light speed delay for a contact hit)
-increase in KKM energy because it's not spread into multiple packets to saturate the area where the target could be by the time the beam gets there
-Increase to KKM energy because it can be generated over a longer time period
-Increase in KKM energy because Traveller drives produce more energy than is put into them
-Decrease in KKM energy because most KKM's will probably be set to blow into submunitions to reduce the probability of intercept
I think that the most significant of these is the drive variance, but I can explain it (and it ties in with other folks "complaining" about the relative inefficiency of fusion drives) - more detail when I'm not dashing off a quick post at work
Scott Martin
TheEngineer
SOC-14 1K
Hi Scott !
Your target of choice is a static one (because You know exactly, where it is...) ?
Guess its about the scenario to attack a grounded base or something else, which could not run away ?
And You plan this attack to be a longer process ?
So we do not talk about space combat here, if I understood it right..
Well, the Traveller drive and energy thing is the glitch I dislike the most and I am still not sure if it is a design bug or a feature.
But I am quite interested in Your explanation
.
Without this "feature" the accelaration process for a KKM is quite a problem...
Kepp on working.
Best regards,
Mert
Your target of choice is a static one (because You know exactly, where it is...) ?
Guess its about the scenario to attack a grounded base or something else, which could not run away ?
And You plan this attack to be a longer process ?
So we do not talk about space combat here, if I understood it right..
Well, the Traveller drive and energy thing is the glitch I dislike the most and I am still not sure if it is a design bug or a feature.
But I am quite interested in Your explanation
Without this "feature" the accelaration process for a KKM is quite a problem...
Kepp on working.
Best regards,
Mert
Scott Martin
SOC-13
Hello again
Yes, we are discussing the ability of KKM's to hit maneuvering targets.
At the kinds of velocities we are talking about, there is *no appreciable difference* in delivered energy whether the KKM "payload" is the most advanced chemical explosive you can name or a bottle of coke. At around 10 Km/second the kinetic energy (pound for pound) delivered is similar to that of current nuclear weapons (remember that you have to include the delivery package, electronics and trigger elements in the "weight" of a nuke) Having an explosive warhead means that your missile is a lot less "safe" to deal with in terms of loading, servicing etc, while an "inert" warheaded KKM could be subject to a lot more abuse without fear of it blowing holes in valuable equipment. This is doubly true if it's powerplant and drive are not live until it is launched. (Remember that unlike current missiles the only "volatile" is lHyd, and this can be loaded when the missile is in the launcher!) I'm in favor of missiles that my inept crew can drop without endangering the ship!
Ptah:
your "sidestep" idea only works at high relative velocities *if you are using a hex map* because hex maps require a quantized amount of "turn" energy for each 60 degree turn: a hex map can't handle less than 60 degree (or for some systems 30 degree) turn.
If my missile has generated a closing velocity of 50 km/second, and has a thrust capability of 12 gravities (120 m/sec/sec) and the "target" vessel has a "mere" 6 gravities of maneuverability, no matter what your ship does, it cannot generate a miss (make me miss it) because the *best* it can do is generate a vector at 90 degrees to the intercept vector, and I can match that until you have more thrust than I do. Let me know if you aren't following this, but in practice it means that a KKM will hit its target unless:
1) the missile has less fuel than your ship (Fuel reserve drops so low that you can "dodge" with more total Velocity change (Delta-V) than the missile can generate
2) your ship has more thrust than my missile (dodge at the ships convenience)
3) The ship does something to stop the missile (you shoot my missile down)
Think of the threat volume of my missile as a cone with the point away from your ship, and the avoidance area that your ship can maneuver into is a ball (sphere). If the sphere is completely within the cone, you can't avoid the missile, and I can prove mathematically that this is *always* the case unless you have more thrust than I do, as long as my start vector is pointing at the target. (since I fired the missile *at* you in the first place, for the vast majority of cases my start vector either intersects your ship, or isn't divergent enough to really matter)
More esoteric things to kill my missile (decoys etc) need to assume that I'm *really* stupid (Oh look, my targeting parameters are set in such a stupid way that I'll chase that decoy that looks a bit like my target, despite a drive putting out 4 orders of magnitude less energy!)
TheEngineer:
You're pointing out one of the issues I have with TNE "operator directed" missiles: without a sensor package, the missile "firing" is at a delay based on how far the controlling ship is from the missile.
I can't imagine a KKM (or really any space based missile) without onboard sensors and tracking systems: that is after all the thing that differentiates missiles from rockets (or artillery shells for that matter) Given that requirement the light speed delay "you don't really know where the target is" problem is a non-issue: either your missile has lock (and will hit if you don't evade or shoot it down) or it doesn't and will miss. This will make life interesting for your anti-missile gunners...
...Especially if you do dirty tricks like interspersing Bomb pumped X-Ray laser warheads in with your KKM's: it that missile veering off target because it doesn't have lock, or because it is deploying laser rods?
Scott Martin
Yes, we are discussing the ability of KKM's to hit maneuvering targets.
At the kinds of velocities we are talking about, there is *no appreciable difference* in delivered energy whether the KKM "payload" is the most advanced chemical explosive you can name or a bottle of coke. At around 10 Km/second the kinetic energy (pound for pound) delivered is similar to that of current nuclear weapons (remember that you have to include the delivery package, electronics and trigger elements in the "weight" of a nuke) Having an explosive warhead means that your missile is a lot less "safe" to deal with in terms of loading, servicing etc, while an "inert" warheaded KKM could be subject to a lot more abuse without fear of it blowing holes in valuable equipment. This is doubly true if it's powerplant and drive are not live until it is launched. (Remember that unlike current missiles the only "volatile" is lHyd, and this can be loaded when the missile is in the launcher!) I'm in favor of missiles that my inept crew can drop without endangering the ship!
Ptah:
your "sidestep" idea only works at high relative velocities *if you are using a hex map* because hex maps require a quantized amount of "turn" energy for each 60 degree turn: a hex map can't handle less than 60 degree (or for some systems 30 degree) turn.
If my missile has generated a closing velocity of 50 km/second, and has a thrust capability of 12 gravities (120 m/sec/sec) and the "target" vessel has a "mere" 6 gravities of maneuverability, no matter what your ship does, it cannot generate a miss (make me miss it) because the *best* it can do is generate a vector at 90 degrees to the intercept vector, and I can match that until you have more thrust than I do. Let me know if you aren't following this, but in practice it means that a KKM will hit its target unless:
1) the missile has less fuel than your ship (Fuel reserve drops so low that you can "dodge" with more total Velocity change (Delta-V) than the missile can generate
2) your ship has more thrust than my missile (dodge at the ships convenience)
3) The ship does something to stop the missile (you shoot my missile down)
Think of the threat volume of my missile as a cone with the point away from your ship, and the avoidance area that your ship can maneuver into is a ball (sphere). If the sphere is completely within the cone, you can't avoid the missile, and I can prove mathematically that this is *always* the case unless you have more thrust than I do, as long as my start vector is pointing at the target. (since I fired the missile *at* you in the first place, for the vast majority of cases my start vector either intersects your ship, or isn't divergent enough to really matter)
More esoteric things to kill my missile (decoys etc) need to assume that I'm *really* stupid (Oh look, my targeting parameters are set in such a stupid way that I'll chase that decoy that looks a bit like my target, despite a drive putting out 4 orders of magnitude less energy!)
TheEngineer:
You're pointing out one of the issues I have with TNE "operator directed" missiles: without a sensor package, the missile "firing" is at a delay based on how far the controlling ship is from the missile.
I can't imagine a KKM (or really any space based missile) without onboard sensors and tracking systems: that is after all the thing that differentiates missiles from rockets (or artillery shells for that matter) Given that requirement the light speed delay "you don't really know where the target is" problem is a non-issue: either your missile has lock (and will hit if you don't evade or shoot it down) or it doesn't and will miss. This will make life interesting for your anti-missile gunners...
...Especially if you do dirty tricks like interspersing Bomb pumped X-Ray laser warheads in with your KKM's: it that missile veering off target because it doesn't have lock, or because it is deploying laser rods?
Scott Martin
Scott Martin
SOC-13
Oops, promised an explanation for the "extra" efficiency of the HEPLAR drive.
Option 1)
HEPLAR kicks out still actively fusing plasma: the extra energy is a result of fusion taking place in the drive plume.
Option 2)
The reason that your power plants have such crappy "efficiency" is because the vast majority of your power is being used to pump heat out of your ship / tank / whatever. If you are dumping enormous piles of hydrogen reaction mass out the back end of your ship, you don't need to use energy on containing the heat (or pumping it somewhere safe) you just eject the waste heat with the reaction mass. If this is the case, then you can easily get another order of magnitude of useful "power" out of your powerplant *for thrust purposes only*
I go for a combination of the two personally.
Either of these ideas mean that a ship under HEPLAR sticks out like a sore thumb (This would be an enormous Mother****** of an X-Ray source in a drive plume thousands of Kilometers long) but since the HEPLAR drive is an enormous X-Ray source anyway the emissions due to this "extra" energy aren't really going to add a lot to the ease of detection (I can't remember where someone calculated that current sensors would be able to pick up a scout's drive exhaust from Alpha Centurai)
If you want an explanation of why this exhaust is so "noticable" remember that you are accellerating charged particles to an obscene velocity, which generates EM radiation. because of the velocity that these particles *must* be to accellerate your ship, an awfully large percentage of that is in the energetic (and easy to detect) bands.
For a refresher on why your exhaust must be going really *really* *REALLY* fast.
In TNE a 50% fuel ship with a nominal mass of 10T/displacement ton has 56 g-hours of thrust available: delta-V of the ship is 56*10*3600 (a bit over 2 million) meters/second so the exhaust, which weighed 0.5T per displacement ton must be moving at an average velocity of a bit over *40 million* meters per second (the energy required to do this is pretty mind-boggling, and is why a lot of people have commented on traveller drives being "broken")
and HEPLAR is 50% as efficient *based on POWER USAGE* than thruster plates. Maybe you are sinkng all the extra heat into some wierd gravitic sump, I don't use reactionless drives so I don't have to justify this one...
Scott Martin
Option 1)
HEPLAR kicks out still actively fusing plasma: the extra energy is a result of fusion taking place in the drive plume.
Option 2)
The reason that your power plants have such crappy "efficiency" is because the vast majority of your power is being used to pump heat out of your ship / tank / whatever. If you are dumping enormous piles of hydrogen reaction mass out the back end of your ship, you don't need to use energy on containing the heat (or pumping it somewhere safe) you just eject the waste heat with the reaction mass. If this is the case, then you can easily get another order of magnitude of useful "power" out of your powerplant *for thrust purposes only*
I go for a combination of the two personally.
Either of these ideas mean that a ship under HEPLAR sticks out like a sore thumb (This would be an enormous Mother****** of an X-Ray source in a drive plume thousands of Kilometers long) but since the HEPLAR drive is an enormous X-Ray source anyway the emissions due to this "extra" energy aren't really going to add a lot to the ease of detection (I can't remember where someone calculated that current sensors would be able to pick up a scout's drive exhaust from Alpha Centurai)
If you want an explanation of why this exhaust is so "noticable" remember that you are accellerating charged particles to an obscene velocity, which generates EM radiation. because of the velocity that these particles *must* be to accellerate your ship, an awfully large percentage of that is in the energetic (and easy to detect) bands.
For a refresher on why your exhaust must be going really *really* *REALLY* fast.
In TNE a 50% fuel ship with a nominal mass of 10T/displacement ton has 56 g-hours of thrust available: delta-V of the ship is 56*10*3600 (a bit over 2 million) meters/second so the exhaust, which weighed 0.5T per displacement ton must be moving at an average velocity of a bit over *40 million* meters per second (the energy required to do this is pretty mind-boggling, and is why a lot of people have commented on traveller drives being "broken")
and HEPLAR is 50% as efficient *based on POWER USAGE* than thruster plates. Maybe you are sinkng all the extra heat into some wierd gravitic sump, I don't use reactionless drives so I don't have to justify this one...
Scott Martin
Scott Martin
SOC-13
3 in a row: I really need to get out more
An easier example of how to figure out if my KKM will hit you
Project a sphere around my ship with a radius equal to the distance that my missile will travel under maximum thrust
project a sphere around the target equal to the distance that it can travel before my missile runs out of fuel.
If the "target" sphere is entirely contained in the "missile" sphere, then the missile will hit it unless the missile is shot down or diverted in some other way.
If I have a lot of fuel in the KKM, then the only question is who has more raw thrust, because that "missile" sphere will be really really big.
This is the simplest case (launching when the target is too close to evade) but still gives an idea of the envelope of operation. for maximum damage in the "simple" case you want to launch the missile as soon as the "target" sphere is entirely enclosed: if the target runs exactly away, you reach your max velocity, and impact velocity is
Vmax (missile) - Vmax (target)
if the target thrusts directly towards you then impact velocity is
Vmax(target) + (Vmax (missile) x (Vmax(target)/Vmax(missile) )
and if the target thrusts on a 90 degree tangent then the impact velocity involves a pile of trigonometry, but will be more than
Vmax(missile) - Vmax(target)
Actual operations of KKMs will be a bit more complex, and will tend to be a balance between too few missile to be a credible threat (you shoot all of them down with ease) and emptying your magazines and being a sitting duck until you can resupply. I'm also trying to figure out how the anti-missile stuff will interact, since this is really what the excercise (for me) is all about.
You are trying to "mission kill" these when they are far enough away from your ship that you can maneuver out of the way of the (soon to be ballistic) KKM, but the longer you wait, the better targeting solution you will have. If you seed the KKM barrage with bomb-pumped laser heads, then these are almost guaranteed to be effective, unless the "interdiction" zone is moved out enough to get them before they deploy, which reduces the probability of KKM kills.This gets even further muddied if you are having KKM submunitions, since you then need to take out the KKM's before they can burst...
If it's any consolation, I've been working on this off and on for a few years now, and it's still a nasty problem: I figured that maybe I should try figuring out how I would write the rules to simulate this (tied in to FF&S/Brilliant Lances) and see if that "granularity" made it easier (unfortunately hex map "artifacts" make it more complex again...
Anyway, enough of the brain hurting for tonight
Scott Martin
An easier example of how to figure out if my KKM will hit you
Project a sphere around my ship with a radius equal to the distance that my missile will travel under maximum thrust
project a sphere around the target equal to the distance that it can travel before my missile runs out of fuel.
If the "target" sphere is entirely contained in the "missile" sphere, then the missile will hit it unless the missile is shot down or diverted in some other way.
If I have a lot of fuel in the KKM, then the only question is who has more raw thrust, because that "missile" sphere will be really really big.
This is the simplest case (launching when the target is too close to evade) but still gives an idea of the envelope of operation. for maximum damage in the "simple" case you want to launch the missile as soon as the "target" sphere is entirely enclosed: if the target runs exactly away, you reach your max velocity, and impact velocity is
Vmax (missile) - Vmax (target)
if the target thrusts directly towards you then impact velocity is
Vmax(target) + (Vmax (missile) x (Vmax(target)/Vmax(missile) )
and if the target thrusts on a 90 degree tangent then the impact velocity involves a pile of trigonometry, but will be more than
Vmax(missile) - Vmax(target)
Actual operations of KKMs will be a bit more complex, and will tend to be a balance between too few missile to be a credible threat (you shoot all of them down with ease) and emptying your magazines and being a sitting duck until you can resupply. I'm also trying to figure out how the anti-missile stuff will interact, since this is really what the excercise (for me) is all about.
You are trying to "mission kill" these when they are far enough away from your ship that you can maneuver out of the way of the (soon to be ballistic) KKM, but the longer you wait, the better targeting solution you will have. If you seed the KKM barrage with bomb-pumped laser heads, then these are almost guaranteed to be effective, unless the "interdiction" zone is moved out enough to get them before they deploy, which reduces the probability of KKM kills.This gets even further muddied if you are having KKM submunitions, since you then need to take out the KKM's before they can burst...
If it's any consolation, I've been working on this off and on for a few years now, and it's still a nasty problem: I figured that maybe I should try figuring out how I would write the rules to simulate this (tied in to FF&S/Brilliant Lances) and see if that "granularity" made it easier (unfortunately hex map "artifacts" make it more complex again...
Anyway, enough of the brain hurting for tonight
Scott Martin
TheEngineer
SOC-14 1K
Hi Scott !
So Your KKM is a kind of very agile active missile.
To out-maneuver such a thing might really be impossible.
Now, IMHO defense against this type of missile would be possible just in the same ways as it is possible against other standard missiles.
ECM could be used to take out electronics. Lasers or other beam wespons could be used to disrupt locomotion.
I would consider repulsors to be less efficient here, because of the high velocities...
But even dampers might be usable here, because they could be able to disrupt the fusion/locomotion process.
As soon this type of missile is not able to maneuver, it should not be of much use any more. At least, if it should hit a mobile target.
A more sophisticated way and a kind of typical weapon/defense evolution might be a anti-KKM drone, equipped with a sufficient locomotion and the task to match vector with the KKM, dock and change vector...
Anyway its a real alternativ for the destruction of static (or better excactly calculatable) targets.
To put it into available rules in MT, I would treat them as missiles, "disturbable" just by beams or dampers (not by repulsors, sand, desints or proton screen) of a mobile target and with a hit effect of a nuclear missile.
Regards,
Mert
So Your KKM is a kind of very agile active missile.
To out-maneuver such a thing might really be impossible.
Now, IMHO defense against this type of missile would be possible just in the same ways as it is possible against other standard missiles.
ECM could be used to take out electronics. Lasers or other beam wespons could be used to disrupt locomotion.
I would consider repulsors to be less efficient here, because of the high velocities...
But even dampers might be usable here, because they could be able to disrupt the fusion/locomotion process.
As soon this type of missile is not able to maneuver, it should not be of much use any more. At least, if it should hit a mobile target.
A more sophisticated way and a kind of typical weapon/defense evolution might be a anti-KKM drone, equipped with a sufficient locomotion and the task to match vector with the KKM, dock and change vector...
Anyway its a real alternativ for the destruction of static (or better excactly calculatable) targets.
To put it into available rules in MT, I would treat them as missiles, "disturbable" just by beams or dampers (not by repulsors, sand, desints or proton screen) of a mobile target and with a hit effect of a nuclear missile.
Regards,
Mert
Scott Martin
For example, as the missile approaches the target the angle subtended by the cone doesn't change if the velocity remains constant (if velocity increases the angle decreases), but the area covered by the "base" decreases because the "height" of the cone is getting shorter as the missile gets closer. Thus, the distance the target needs to get out of the way of the missile becomes shorter, much shorter. At some point the target does not have enough time to get out of the way, engines or pilot can not react fast enough. If the base of the traveling cone is on the target at this point the hit occurs.
Now the abstracted movement in a game may not reflect this, especially one that needs to look at movement on the light second scale. However, all that is required for a KKM missile to miss is movement on the meter scale. Hence, such things are usually reflected in targeting, hit tables, agility, etc.
Further, even if the missile can turn at the last "minute" and hit. This will seriously degrade its performance because it is the component of velocity directed at the target at the time of impact (not simply from firing position to final target position) that is important for KE imparted. An extreme example to illustrate the point, if a missile proceeds at a speed of 50 hexes/turn towards the target jukes and the missile needs to turn 90 degrees and proceeds 1 hex in 1 turn to hit. The KE is not the velocity vector from the launch site to the target, it is the velocity vector from that last 1 hex per turn. Trigonometry gives the reduction for other angles. So instead of the KE being based on a 50 hex/turn velocity, it is based on a 1 hex/turn velocity.
The above is working in the artificial game mechanic of turn based movement at the vast scales used for game play reasons. In actuality, the target is continually moving and the relevant scale is on the order of meters or less as the weapon must contact the target and the impact velocity determines the damage. Being off by 1 meter is a miss. I will completely agree that the KKM is also continuosly moving and can adjust. From a damage point of view though the starship doesn't care if it is hit by the KKM as long as the impact velocity is low. The way to do this is to force the missile to turn as much as possible. Each 90 degree turn means the initial velocity vector was brought to zero (or otherwise you don't turn) and all the KE in that vector is gone for damage purposes. Now the missile needs to build up velocity again to have effective KE. Even smaller turns are going to reduced the KE.
The question is do you wish to take these factors into account. The game mechanics are set up as turn based moved meant to capture light second scale combat. If one calculates impact KE based on this alone, then the minimum KE will be determined by the length of the turn, i.e., your game mechanics.
I'd suggest that dodging the KKM and the damage of KKM be assessed without regard to turn length or game hex scale if you are looking for some hard numbers.
As to defenses. An anti-KKM missile should be very effective as it does not need to intercept the KKM it only needs to protect/screen the location the ship is going to be at. Since the KKM must contact the target to hurt it, the anti-KKM needs to only put up a "wall" of ball bearings between the KKM and the place the ship is moving to. The KKM may or may not be able to see this wall in time to steer around it, but any steering wastes the all important velocity needed for damage. The walls do not even need to be that big, the closer to the starship they are the smaller they need to be.
Lastly, a real world example (although antedotal) is the way helicopters avoided SAMs in Vietnam. Now these are just stories mind you but from my best friends father who was a helicopter pilot in Vietnam so I trust them (since SAMs were fired at them and he survived 2 tours in one piece). I think no one will argue that a helicopter can't out thrust a SAM but these guys used to avoid them by pulling sideways at the last second. (If I recall, once they saw the flash they'd start counting then when they got to a certain number they'd pull hard sideways.) The missile could not make the tight turn due to its speed and would shoot past the target. This is a matter of reflexes and the degree of guidance of the missile. And hard to do with modern missiles because of the times and distances involved.
If you are looking for a quick way to determine what distances are too short for a pilot/craft to react. You could take the firing distance of modern air-to-air missiles, assuming relative attack and dodging abilites remain the same. I don't know what it is but lets say it is 100 miles, that's 160 km. That's about 0.0005 light seconds.
I see what your talking about. That certainly determines if the missile is even a threat. "Sidestepping" has the possibilty of working because it is the cone that travels with the missile, not a static one projected from the firing site, that determines whether a hit actually occurs. The job for the missile is keeping the base of this traveling cone on target not knowing where that target will be from second to second. The static cone from the firing position to target only indcates that it is possible to hit the target not that a hit is guaranteed. In other words, the target does not need to get out of the initial target cone for the missile to miss.
For example, as the missile approaches the target the angle subtended by the cone doesn't change if the velocity remains constant (if velocity increases the angle decreases), but the area covered by the "base" decreases because the "height" of the cone is getting shorter as the missile gets closer. Thus, the distance the target needs to get out of the way of the missile becomes shorter, much shorter. At some point the target does not have enough time to get out of the way, engines or pilot can not react fast enough. If the base of the traveling cone is on the target at this point the hit occurs.
Now the abstracted movement in a game may not reflect this, especially one that needs to look at movement on the light second scale. However, all that is required for a KKM missile to miss is movement on the meter scale. Hence, such things are usually reflected in targeting, hit tables, agility, etc.
Further, even if the missile can turn at the last "minute" and hit. This will seriously degrade its performance because it is the component of velocity directed at the target at the time of impact (not simply from firing position to final target position) that is important for KE imparted. An extreme example to illustrate the point, if a missile proceeds at a speed of 50 hexes/turn towards the target jukes and the missile needs to turn 90 degrees and proceeds 1 hex in 1 turn to hit. The KE is not the velocity vector from the launch site to the target, it is the velocity vector from that last 1 hex per turn. Trigonometry gives the reduction for other angles. So instead of the KE being based on a 50 hex/turn velocity, it is based on a 1 hex/turn velocity.
The above is working in the artificial game mechanic of turn based movement at the vast scales used for game play reasons. In actuality, the target is continually moving and the relevant scale is on the order of meters or less as the weapon must contact the target and the impact velocity determines the damage. Being off by 1 meter is a miss. I will completely agree that the KKM is also continuosly moving and can adjust. From a damage point of view though the starship doesn't care if it is hit by the KKM as long as the impact velocity is low. The way to do this is to force the missile to turn as much as possible. Each 90 degree turn means the initial velocity vector was brought to zero (or otherwise you don't turn) and all the KE in that vector is gone for damage purposes. Now the missile needs to build up velocity again to have effective KE. Even smaller turns are going to reduced the KE.
The question is do you wish to take these factors into account. The game mechanics are set up as turn based moved meant to capture light second scale combat. If one calculates impact KE based on this alone, then the minimum KE will be determined by the length of the turn, i.e., your game mechanics.
I'd suggest that dodging the KKM and the damage of KKM be assessed without regard to turn length or game hex scale if you are looking for some hard numbers.
As to defenses. An anti-KKM missile should be very effective as it does not need to intercept the KKM it only needs to protect/screen the location the ship is going to be at. Since the KKM must contact the target to hurt it, the anti-KKM needs to only put up a "wall" of ball bearings between the KKM and the place the ship is moving to. The KKM may or may not be able to see this wall in time to steer around it, but any steering wastes the all important velocity needed for damage. The walls do not even need to be that big, the closer to the starship they are the smaller they need to be.
Lastly, a real world example (although antedotal) is the way helicopters avoided SAMs in Vietnam. Now these are just stories mind you but from my best friends father who was a helicopter pilot in Vietnam so I trust them (since SAMs were fired at them and he survived 2 tours in one piece). I think no one will argue that a helicopter can't out thrust a SAM but these guys used to avoid them by pulling sideways at the last second. (If I recall, once they saw the flash they'd start counting then when they got to a certain number they'd pull hard sideways.) The missile could not make the tight turn due to its speed and would shoot past the target. This is a matter of reflexes and the degree of guidance of the missile. And hard to do with modern missiles because of the times and distances involved.
If you are looking for a quick way to determine what distances are too short for a pilot/craft to react. You could take the firing distance of modern air-to-air missiles, assuming relative attack and dodging abilites remain the same. I don't know what it is but lets say it is 100 miles, that's 160 km. That's about 0.0005 light seconds.
Scott Martin
SOC-13
Unfortunately aircraft combat is not a good example for how to dodge missiles.
Dodging missile in air combat takes advantage of the fact the the craft you are in has large lifting and control surfaces (wings or rotors) while the missile does not: as a result, at short ranges and high closing velocities, "max performance" maneuvers give the "target" vehicle a greater ability to change vector. Basically the missile has more brute power, the aircraft has better maneuverability. The trick is to let the missile build enough velocity that it can't track your last-second course change. A better way of thinking about this is submarine combat: A sub and a torpedo both have the same method of propulsion: what are the chances of a sub "dodging" a torpedoe without employing some kind of counter-measures?
Your example of "correcting" by 1 (velocity unit) giving a (1 velocity unit) relative velocity is incorrect: take a look at the resultant vector: it will still be on the order of 50 (velocity units) with the vector normal directly through the target. This gives you a binary "hit or miss"
I had some thoughts about the possibility of using ESA (electrostatic armour) as a defence, but this is probably a seperate post topic...
Scott Martin
Dodging missile in air combat takes advantage of the fact the the craft you are in has large lifting and control surfaces (wings or rotors) while the missile does not: as a result, at short ranges and high closing velocities, "max performance" maneuvers give the "target" vehicle a greater ability to change vector. Basically the missile has more brute power, the aircraft has better maneuverability. The trick is to let the missile build enough velocity that it can't track your last-second course change. A better way of thinking about this is submarine combat: A sub and a torpedo both have the same method of propulsion: what are the chances of a sub "dodging" a torpedoe without employing some kind of counter-measures?
Your example of "correcting" by 1 (velocity unit) giving a (1 velocity unit) relative velocity is incorrect: take a look at the resultant vector: it will still be on the order of 50 (velocity units) with the vector normal directly through the target. This gives you a binary "hit or miss"
I had some thoughts about the possibility of using ESA (electrostatic armour) as a defence, but this is probably a seperate post topic...
Scott Martin
I agree a 1 hex correction on a 50 hex vector is about a 1 degree turn and the impact velcoity is still about 50. My example, actually was meant to be an extreme one that assumed a 90 degree turn (not correction) by the missile. So my example is a correction by 51 hexes, 50 to shed the velcoity in the x direction, and 1 to add 1 hex velocity in the y direction. My example only has a practical impact if the starship is viewed as comparably or more maneuverable than the KKM is at high-V. I've also glossed over how the missile got that 50 hex velocity and what teh starship was doing in all that time, hopefully it should have been adding V itself.
I'm not sure about the analogy to submarines, but all analogies have their limitations and benefits. Submarines do not have means of applying thrust perpendicular to their direction of motion as a space craft can, and their speeds do not admit for hydrofoil controls that could do the same like aircraft. In addition, the drives of a submarine can not provide the kind of acceleration that the drives of a torpedo can given the large mass difference (and being that they are not reactionless drives.) I'm assuming that your KKM are based on reactionless drives otherwise one could not provide enough fuel to get them to the velocities we are talking about. In space without air/fluid resistance a reactionless drive on a starship can readily provide a component of velocity perpendicular to the path of the oncoming missile. Thus, in my view, the comparison to aircraft is a more apt analogy than submarines. Nevertheless, I agree that it does depend on how you view the relative manueverability of the target and missile.
I view the missile as not being very maneuverable, to get the high-G drives on such a small package they are concentrated on providing thrust in 1 direction. On ships, I don't view these as lumbering behemoths, I assume (and it is my assumption) that drive plates are mounted so thrust can be applied in orthoganol directions.
If you view ships as submarines, unable to avoid missiles, I thinks it's clear that KKM will dominate the battle space. Ships will load up on KKM and anti-KKM weapons. Fighters will dominate as a single KKM, if it hits, can take out anything.
If a single KKM missile as an uber-weapon against moving targets seems unrealistic, it is. It's taking advantage of a loop-hole in how the energy required for G drives in the game does not depend on velocity, which violates the conservation of energy. If you allow missiles to exploit this loop-hole then ships should be able to take advantage of it as well. Our conversation on tactics will turn to how close to the speed of light can we get and combat is about who is moving fastest. If my fuzzy memory serves correctly this very topic was covered heavily on the TML.
I'll leave it at that. I prefer a tact where missiles need to trade something for being able to achieve high-G and high-V, that something is maneuverability. It still doesn't solve the violation of the conservation of energy problem or the violation of the conservation of momentum problem, but that's another topic.
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