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Post by tukuro on Jan 20, 2017 19:51:15 GMT
If the missile acceleration is at least equal to the target acceleration, it can follow the target in all its moves. At least within the limitation of it's turnabout time, so your "put engines on both ends so that the direction you're going to dodge can't be known" strategy could actually work, at least against a single missile. Faster intercepts actually help, assuming the target starts dodging 1000 km out, because then the missile doesn't need as much Δv. If the missile acceleration is much greater than the target acceleration, and the missile guidance can perfectly predict how the target will dodge, it only needs to expend half the Δv. But in practice, the guidance can't perfectly predict the target, so the target can force the missile to piss away it's Δv. Also the attitude controller isn't stable with very short turnabout times, so a higher acceleration missile can't turn proportionately faster, so it spends a lot more of its fuel on turning. I think this is a better way to put it. It really depends on how fast the missile can adjust thruster angles and change course. Right now, because we cannot easily change orientations so they match the direction of the ship we're attacking, we run into the problem where even with high G micro missiles they cannot correct their intercept fast enough to hit the enemy ship. To really see what is the most effective though we'd need greater control of (missile) formations (Rings, lines, wedges, pyramids, etc. including distance between vessels), the ability to randomize orientations (similar to scattering) and more sophisticated targeting for CIWS. I think rings could be one of the most effective formations here, with the the missiles oriented inwards right before impact. This way if a ship attempts to dodge there is a much higher chance for a successful intercept. |
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Post by midnightdreary on Jan 20, 2017 20:46:48 GMT
I thought the general strategy was to have a wide range of different missiles, some very fast to break through defense lasers, then have "slower" ones that can't be dodged as easily because they keep a lot of fuel for the terminal phase. I think it's like a fisherman using the correct hook and bait for the type of fish they are catching.
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Post by tukuro on Jan 21, 2017 0:51:06 GMT
I thought the general strategy was to have a wide range of different missiles, some very fast to break through defense lasers, then have "slower" ones that can't be dodged as easily because they keep a lot of fuel for the terminal phase. I think it's like a fisherman using the correct hook and bait for the type of fish they are catching. You don't need kilometres of spare delta v for an intercept, at least if you're intercepting at several km/s. What you want is multi-G missiles and fast (thousands of RPM) gimbals. |
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Post by newageofpower on Jan 21, 2017 1:36:47 GMT
I don't buy your statements either way. Missiles with overtuned drives can break 20G of acceleration, and can hit (or close enough, for standoff payloads) manouvering targets even with a closing velocity >10 km/s. For warships/drones with MPD, you can always do a deceleration burn prior to entering combat envelope. In fact, by taking a fuel mass ratio closer to a NTR/other fuel warship you can easily exceed 100 km/s; in this case, if you want an extended combat window you burn 25km/s to close the distance, then spend another 24.5 km/s to bring the approach velocity down to 500m/s for some lovely 200+ second engagement window. In this scenario, you still have half your dV remaining even after chasing down (and presumably crushing) the NTR fleet. I'm not contesting that missiles/drones can catch up to a ship for an intercept. What I am referring to is what happens when the intercept actually takes place. As in seconds before impact. In this frame of reference the ship is effectively standing still, and the missiles are traveling at high velocities to overcome the laser death zone (especially with Cerium doped lasers), interceptor missiles, interceptor drones and and array of cheap sandblaster CIWS. What a ship can do in those few seconds before impact is fire it's engines, and assuming it has a sufficiently high trust to weight ratio change its relative position by dozens or even hundreds of meters. Those missiles now have to change course. But this takes time, and when you are already traveling at 10+ km/s, takes a lot of deltaV. Notice how difficult it is to change course if a multi-G enemy ship evades minutes from the intercept when your missiles are traveling at over 10 km/s? This is even harder if this happens two seconds before impact. Even more so if their relative velocity is dozens of kilometres per second. Even if your missiles can pull 20Gs and have a few kilometres of delta V left they're going to miss. Now, of course we could spread out the missiles or have them travel in a line. In the first case we can just focus on the missiles that are most likely to impact the ship, and then repeat the last second manoeuvre and combine it with front and rear mounted directional thrusters to further reduce the chance of a successful impact. In the second case we will have an easier time to destroy the missiles individually, because for this formation to be effectiveness you need significant distance between the missiles for them to still reliably get an intercept with their multi-G propulsion. The formation system is difficult to test in the first case, and highly impractical in the second case (Unless you have the time to space a thousand or so 1 missile fleets 1-2 kilometres apart). But the whole act of dodging at the last second is already possible in game. ... Nothing you've stated here counters my point: What stops my MPD (primary) drones from decelerating before entering combat range? As for targets moving 1-2+ Gs vs a 10km/s interceptor, I've managed to achieve hits on them. Even then, they may dodge direct impacts, but NEFP and near-10 MT weapons can inflict damage at kilometers of range. |
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Post by jasonvance on Jan 21, 2017 1:55:26 GMT
I'm not contesting that missiles/drones can catch up to a ship for an intercept. What I am referring to is what happens when the intercept actually takes place. As in seconds before impact. In this frame of reference the ship is effectively standing still, and the missiles are traveling at high velocities to overcome the laser death zone (especially with Cerium doped lasers), interceptor missiles, interceptor drones and and array of cheap sandblaster CIWS. What a ship can do in those few seconds before impact is fire it's engines, and assuming it has a sufficiently high trust to weight ratio change its relative position by dozens or even hundreds of meters. Those missiles now have to change course. But this takes time, and when you are already traveling at 10+ km/s, takes a lot of deltaV. Notice how difficult it is to change course if a multi-G enemy ship evades minutes from the intercept when your missiles are traveling at over 10 km/s? This is even harder if this happens two seconds before impact. Even more so if their relative velocity is dozens of kilometres per second. Even if your missiles can pull 20Gs and have a few kilometres of delta V left they're going to miss. Now, of course we could spread out the missiles or have them travel in a line. In the first case we can just focus on the missiles that are most likely to impact the ship, and then repeat the last second manoeuvre and combine it with front and rear mounted directional thrusters to further reduce the chance of a successful impact. In the second case we will have an easier time to destroy the missiles individually, because for this formation to be effectiveness you need significant distance between the missiles for them to still reliably get an intercept with their multi-G propulsion. The formation system is difficult to test in the first case, and highly impractical in the second case (Unless you have the time to space a thousand or so 1 missile fleets 1-2 kilometres apart). But the whole act of dodging at the last second is already possible in game. ... Nothing you've stated here counters my point: What stops my MPD (primary) drones from decelerating before entering combat range? As for targets moving 1-2+ Gs vs a 10km/s interceptor, I've managed to achieve hits on them. Even then, they may dodge direct impacts, but NEFP and near-10 MT weapons can inflict damage at kilometers of range. I think the real problem is people are assuming last second maneuvering or zipping a ship around really fast actually does anything. A ship making an emergency thrust 2 seconds before intercept from a drone moving 10km/s is only 20km away. You have to think of drones (and even missiles) in terms of their sphere of influence. Most weapons are effective at about 100km (even with projectiles) and you have to dodge the entire sphere of influence to stay "safe" with high thrust movement. Even if you did hit your burn from a super powerful 20G acceleration rocket (which would kill the occupants of the ship) you only managed to move yourself ~400 meters off your current course in those 2 seconds which is nearly meaningless in terms of effective ranges of weaponry. You wouldn't even be able to move that far in actuality since you need to make randomized defensive maneuvers by changing trajectory every few mili-seconds to make your acceleration path non-linear and that non-linear path would have to have greater variance than your ships cross-section (if your ship is a sphere of 10 meters you need to make your projected trajectory move yourself back and forth in addition to away by greater than 10 meters to make shots miss). You aren't going to be escaping a sphere of influence doing that. You will dodge a few shots from projectile weapons and maybe prolong your ships life and buy time for CIWS but you won't dodge it and as the drones close the effect of dodging maneuvers becomes less and less as the relative time to target from projectiles will out weigh your acceleration's ability to move your cross section out of the way. I think everyone can agree how useless evasive maneuvers would be against lasers and the drones using them with millions radius spheres of influence. The point is you can't out accelerate combat you have to out delta-v it and dodge it before combat occurs. I personally don't see the use of projectile weapons though their spheres of influence are too small to make sense when compared to laser weaponry. |
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Post by theholyinquisition on Jan 21, 2017 2:02:10 GMT
So you agree with newageofpower?
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Post by jasonvance on Jan 21, 2017 2:11:58 GMT
So you agree with newageofpower? I think if you spent billions designing a drone or missile with the purpose of intercepting and destroying capital ships thrust isn't going to save you delta-v might though to stay away from it. Relying on tanking damage through evasive maneuvering or CIWS is not a good strategy those should all be last ditch efforts when all else has failed. The main goal should be to evade intercept completely and the only way that can be done is through high delta-v not high thrust. If you have high thrust at the cost of delta-v you can get burned out by the interceptor and be "dead in the water." |
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Post by tukuro on Jan 21, 2017 2:53:50 GMT
I'm not contesting that missiles/drones can catch up to a ship for an intercept. What I am referring to is what happens when the intercept actually takes place. As in seconds before impact. In this frame of reference the ship is effectively standing still, and the missiles are traveling at high velocities to overcome the laser death zone (especially with Cerium doped lasers), interceptor missiles, interceptor drones and and array of cheap sandblaster CIWS. What a ship can do in those few seconds before impact is fire it's engines, and assuming it has a sufficiently high trust to weight ratio change its relative position by dozens or even hundreds of meters. Those missiles now have to change course. But this takes time, and when you are already traveling at 10+ km/s, takes a lot of deltaV. Notice how difficult it is to change course if a multi-G enemy ship evades minutes from the intercept when your missiles are traveling at over 10 km/s? This is even harder if this happens two seconds before impact. Even more so if their relative velocity is dozens of kilometres per second. Even if your missiles can pull 20Gs and have a few kilometres of delta V left they're going to miss. Now, of course we could spread out the missiles or have them travel in a line. In the first case we can just focus on the missiles that are most likely to impact the ship, and then repeat the last second manoeuvre and combine it with front and rear mounted directional thrusters to further reduce the chance of a successful impact. In the second case we will have an easier time to destroy the missiles individually, because for this formation to be effectiveness you need significant distance between the missiles for them to still reliably get an intercept with their multi-G propulsion. The formation system is difficult to test in the first case, and highly impractical in the second case (Unless you have the time to space a thousand or so 1 missile fleets 1-2 kilometres apart). But the whole act of dodging at the last second is already possible in game. ... Nothing you've stated here counters my point: What stops my MPD (primary) drones from decelerating before entering combat range? As for targets moving 1-2+ Gs vs a 10km/s interceptor, I've managed to achieve hits on them. Even then, they may dodge direct impacts, but NEFP and near-10 MT weapons can inflict damage at kilometers of range. In case of long range drones and NEFPs you're right, it won't matter. If however you are dealing with hypervelocity missiles or small (non-NEFP) nukes, it becomes feasible. ... Nothing you've stated here counters my point: What stops my MPD (primary) drones from decelerating before entering combat range? As for targets moving 1-2+ Gs vs a 10km/s interceptor, I've managed to achieve hits on them. Even then, they may dodge direct impacts, but NEFP and near-10 MT weapons can inflict damage at kilometers of range. I think the real problem is people are assuming last second maneuvering or zipping a ship around really fast actually does anything. A ship making an emergency thrust 2 seconds before intercept from a drone moving 10km/s is only 20km away. You have to think of drones (and even missiles) in terms of their sphere of influence. Most weapons are effective at about 100km (even with projectiles) and you have to dodge the entire sphere of influence to stay "safe" with high thrust movement. Even if you did hit your burn from a super powerful 20G acceleration rocket (which would kill the occupants of the ship) you only managed to move yourself ~400 meters off your current course in those 2 seconds which is nearly meaningless in terms of effective ranges of weaponry. I guess I should've stuck to drones in the example. Indeed, even a microdrone and its sub-hypervelocity wafer gun will be able to hit you at those velocities (10km/s, 2 sec out). But flak, KKVs and nukes will have a problem if they can't turn and burn fast enough. Actually, projectile weapons can be competitive, both in terms of mass and cost. Your projectiles aren't effected by fall off, but they will suffer from inaccuracy and will take time to travel to their target. However an almost 40 km/s amorphous carbon/titanium-aluminide coilgun and 10,000 metglas rounds cost less mass and credits than a comparable laser system, and is really just about as effective. I've found that such a system is effective even at 1000 km, and probably even beyond that. |
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Post by jasonvance on Jan 21, 2017 3:03:34 GMT
... Nothing you've stated here counters my point: What stops my MPD (primary) drones from decelerating before entering combat range? As for targets moving 1-2+ Gs vs a 10km/s interceptor, I've managed to achieve hits on them. Even then, they may dodge direct impacts, but NEFP and near-10 MT weapons can inflict damage at kilometers of range. In case of long range drones and NEFPs you're right, it won't matter. If however you are dealing with hypervelocity missiles or small (non-NEFP) nukes, it becomes feasible. I think the real problem is people are assuming last second maneuvering or zipping a ship around really fast actually does anything. A ship making an emergency thrust 2 seconds before intercept from a drone moving 10km/s is only 20km away. You have to think of drones (and even missiles) in terms of their sphere of influence. Most weapons are effective at about 100km (even with projectiles) and you have to dodge the entire sphere of influence to stay "safe" with high thrust movement. Even if you did hit your burn from a super powerful 20G acceleration rocket (which would kill the occupants of the ship) you only managed to move yourself ~400 meters off your current course in those 2 seconds which is nearly meaningless in terms of effective ranges of weaponry. I guess I should've stuck to drones in the example. Indeed, even a microdrone and its sub-hypervelocity wafer gun will be able to hit you at those velocities (10km/s, 2 sec out). But flak, KKVs and nukes will have a problem if they can't turn and burn fast enough. Actually, projectile weapons can be competitive, both in terms of mass and cost. Your projectiles aren't effected by fall off, but they will suffer from inaccuracy and will take time to travel to their target. However an almost 40 km/s amorphous carbon/titanium-aluminide coilgun and 10,000 metglas rounds cost less mass and credits than a comparable laser system, and is really just about as effective. I've found that such a system is effective even at 1000 km, and probably even beyond that. Could I get some cost / mass numbers on those AC/TiAl coil guns? I've built some really cheap lasers and I'm actually curious because I haven't been able to build anything close to the lasers at 1,000km performance. My current go-to laser is 25,000c and 3 tons (with power and radiators). |
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