The Practicality of various futuristic weapons.

[Noctis]

Well, I was talking in an earlier thread about what sort of weapons would exist in a real battle between space based battleships. Anna decided to simply insult me and lock the thread rather then allow me to argue a point, so I've come here. Here I can't derail anything and there should be no reason to have to lock the tread.

Now, we were debating the practicality of Kinetic based weapons verse directed energy weapons. I was arguing for the kinetic weapons, while Anna seemed to prefer Energy weapons, specifically NPB's or Neutral Particle beams. I argued that any energy based weapon will use more energy then a Kinetic weapon. He responded as such

"... The power requirements for a laser would be pretty high compared to the energy requirements of hurling a 1 ton slug at nearly light speed!? Are you high? Plasma weapons just plain don't work, and yes, while charged particle weapons have a problem with blooming, neutral particle weapons suffer less from it.

Jesus Christ, Noctis, sometimes you say the most retarded things."

Well, while the ad hom is uncalled for, I have to say that he is more then likely right in some ways; just not in all ways. I feel I must add qualifications to my statements.

Firstly, lets say we're comparing my example, (a one ton slug fired at a significant fraction of light speed) to his example of a NPB capable of equal destructive force. Now, I believe we can all agree that a NPB capable of causing equal damage is going to be larger, perhaps much larger, then an equivalent Mass Accelerator system. The simple fact is that a Kinetic weapon will always have a larger area of effect simply because of it's method of attack. While a laser causes damage through the rapid heating of the target substance, a Kinetic weapon simply hurls one substance into another at massive speeds, causing blunt trauma. For a energy weapon to have the same effective destruction radius as a kinetic weapon, it's beam must be equal or at least close to the desired effect radius.

Secondly, we come to the power consumption. Several things must be taken into account when considering the energy usages of both systems; the first constraint being the size. Once again, a energy weapon capable of the destructive force of the example kinetic weapon would need to be unwieldy large. For this reason we'll scale the examples back so that the kinetic cannon fires a projectile roughly the size of a cannon ball, so the energy weapon can be of a reasonable size. Now, our Kinetic weapon is based off the concept of a railgun, that is to say it uses powerful magnetic fields to accelerate the projectile. We'll also assume that the NPB is the standard model, using enormous electrical current to accelerate negatively charged hydrogen or deuterium ions into it's target at near light speed.

If we look at the power usages over time then we can see that a Kinetic cannon would use a massive amount of energy in a quick burst to accelerate it's projectile. Comparatively, the energy used to generate the NPB would be lower, on that time scale. However, while a Kinetic weapon expends a great amount of energy in the short run, its more then likely that a Energy weapon will expend an equal or greater amount in order to do the same amount of damage. This is because an NPB would have to concentrate it's energy on a single spot for a period of time in order to do damage equal to that of a kinetic cannon. For a NPB to use less overall power then a Kinetic cannon it would need to do an equal amount of destruction before it's continuous power consumption equaled or exceeded the "start up" power consumption of the Kinetic cannon. This seems unlikely in a practical situation.

Lastly, we have the Logistics of actually building, maintaining and operating either of these weapons. A Kinetic cannon would be highly ammo dependant, as well as requiring "rails" which could withstand the repulsive forces of the firing sequence. More then likely these rails would have to be replaced regularly, to prevent failure or bending which would reduce the weapon's effectiveness. An energy weapon would not be confined to these limitations, requiring only energy and the necessary gas to fuel it's ion projection. A Hydrogen NPB would have practically endless ammunition and as long as power was available it could be used indefinately.

A NPB would more then likely never be able to match the sheer destructive force of a Kinetic weapon, while a Kinetic weapon would never be as maneuverable or compact as a energy weapon. Because of these aspects their individual roles would be limited and very different. Energy based weapons would probably be most effective against smaller targets and would deployed in large numbers across a ships hull, rather then using a single large cannon. A Kinetic cannon would most likely be a large, semi-fixed weapon which would see use only in special weapons platforms or on large ships; it's targets would be large and ideally relatively stationary. These aspects mean that large scale kinetic cannons would most likely see use more as a planetary bombardment tactic then a ship to ship weapon, however small scale Kinetic guns could be used on ships to a similar effect as machineguns.

I hope that this lays out my opinion better then I did so before. If there are any errors in this please feel free to correct me, as I'm not a rocket scientist and am very capable of error. Please, to everyone, try not to resort to Ad hom or random insults; both seem to be needlessly prevalent here and do little more then make this place hostile and drive away potential players.

[unsunghero10]

You sir, did your homework.
new award maybe?


The only problem is, in a realistic space battle, ships would be so veeeery far away that unguided kinetic weapons would be useless no matter how fast.

Rays and beams are the only practical weapons for such distances.
Anybody read "The Gripping Hand" or "The Mote in God's Eye"?

[Swamp Fox]

Noctis, I just wish to point out one little thing. Whenever you speak of railguns or RKVs, you seem to be assuming stupidly huge ammunition. There is no reason whatsoever to be firing a "one-ton slug at nearly light speed." There just isn't. If you actually assume you can get your projectile to that velocity, then it would be much easier to just fire a tiny little ball-bearing. Hell, let's get extravagant, and fire a whole bunch of unnecessarily heavy ones. Fifty 0.5-kilogram ball-bearings fired at the target any respectable speeds whatsoever, even at a mere 0.5c, which is far below what you proposed, in a tight spread, would do the job nicely, and at a far lower cost in terms of energy and mass. If you can actually aim worth a damn, there's no reason to even use anywhere near that many. Hell, near c a snowflake has enough energy to cause some serious damage.

[Noctis]

You sir, did your homework.
new award maybe?


The only problem is, in a realistic space battle, ships would be so veeeery far away that unguided kinetic weapons would be useless no matter how fast.

Rays and beams are the only practical weapons for such distances.
Anybody read "The Gripping Hand" or "The Mote in God's Eye"?

A good kinetic weapon could be fired at close to the speed of light, so it would be near the same speed as a laser. If you had accurate enough tracking systems and perhaps some small thrusters on the round itself to provide minor trajectory changes then it shouldn't matter. Notice that I said the greatest applications of such systems would be in planetary bombardment or against very large ships. Planets are predictible and ships can only move so fast.

Noctis, I just wish to point out one little thing. Whenever you speak of railguns or RKVs, you seem to be assuming stupidly huge ammunition. There is no reason whatsoever to be firing a "one-ton slug at nearly light speed." There just isn't. If you actually assume you can get your projectile to that velocity, then it would be much easier to just fire a tiny little ball-bearing. Hell, let's get extravagant, and fire a whole bunch of unnecessarily heavy ones. Fifty 0.5-kilogram ball-bearings fired at the target any respectable speeds whatsoever, even at a mere 0.5c, which is far below what you proposed, in a tight spread, would do the job nicely, and at a far lower cost in terms of energy and mass. If you can actually aim worth a damn, there's no reason to even use anywhere near that many. Hell, near c a snowflake has enough energy to cause some serious damage.

I assumed that the one ton slug would be used in planetary bombardment, while the smaller shells would be used in ship to ship battles. We have to assume that actual space battleships, assuming they can't stop the projectile, will be built to withstand as many hits as possible before being destroyed. They will more then likely be heavily sectioned and have powerful manuvering thrusters to inch them away from a potentially fatal blow. A RKV "shotgun" would definitely more effective then a single shot.

[HorseMonster]

Extremely heavy projectiles being accelerated by electomagnetic means to high fractions of c? I think you took the codex entries in mass effect to seriously, Noctis.

[Noctis]

Extremely heavy projectiles being accelerated by electomagnetic means to high fractions of c? I think you took the codex entries in mass effect to seriously, Noctis.

Mass effect is just copying from a vast history of scifi and theoretical science. The actual problem with Railguns is the rail part. The forces exerted by the firing are tremendous and the faster the projectile the more powerful the repulsive forces. We would need a substance that could withstand the forces needed to accelerate a projectile at near light speed, and so far we just don't have one. Too hard and it will shatter, too flexible and it bends, not to mention the heat that would be generated.

Might simply be easier to have drones catch meteors and hurl them into things. You don't need to be going super fast of you're already super huge.

[HorseMonster]

You seem to have missed my point there. I invoked mass effect because it's what all the kids these days get their erroneous ideas about what a "realistic" depiction of space combat is, and that the content of your post echos that.

And I don't know why you're telling me about railguns, I know what a railgun is.

[Noctis]

You seem to have missed my point there. I invoked mass effect because it's what all the kids these days get their erroneous ideas about what a "realistic" depiction of space combat is, and that the content of your post echos that.

And I don't know why you're telling me about railguns, I know what a railgun is.

Yes, Mass effect's whole "dog fight" thing is rather, well, stupid. Actual space based combat would involve fighting over millions of miles away from each other, unless we consider some sort of individual space craft, but even then there's no reason for it.

I don't know how exactly you got "bombastic dogfights" out of a discussion of the physical dilemmas and logistical problems involved in planetary bombardment and long distance space combat.

[unsunghero10]

Sorry, I mis-judged your argument.
What is it?

[Noctis]

Sorry, I mis-judged your argument.
What is it?

Well, basically, that kinetic weapons do more damage then energy weapons. Also that large kinetic weapons are unfeasible on anything smaller then a mini deathstar and are best used against other large targets.

[firevikin125]

Well, basically, that kinetic weapons do more damage then energy weapons

Well part of that makes sense.
Any sized object traveling at extremely
high speeds would punch strait through
a ships hull and cause blowouts all over
the ship from hull breaches.
An energy weapon, depending on
what type you use, would instead
splash across the hull, slowly melting
it over a larger area but also not effecting
the sections of systems that are deeper in.
bbbbbbbbbbbuuuuuuuuuuuutttttt...........
you would need a dam good targeting system
to actually hit anything.

Yes, Mass effect's whole "dog fight" thing is rather, well, stupid. Actual space based combat would involve fighting over millions of miles away from each other, unless we consider some sort of individual space craft, but even then there's no reason for it.

Not necessarily.

[thanto_]

I think we're forgetting a very important concept when speaking about coilguns here, and that is the effect of firing that weapon on the ship. Whatever work (Joules) is done to move that mass is equally imparted on the ship. The effect is somewhat negligible on earth, because weapons can be braced against things which are connected to the ground (either people or bipods, etc.), so the work is transferred to the earth, which has such great mass that the effect is negligible. Also, since we move relative to the earth, we wouldn't even notice it anyway.

But when you apply the same principle to space ships, you start running into problems. Keep in mind how current space ships move: by pushing reaction mass away from the ship. This can be done with explosions or electromagnetism, but the effect is the same: the energy of propulsion is equivalent to the work done to push the reactive mass away from the ship. So, a kinetic cannon shooting a particle of some mass M at some speed V is going to impart kinetic energy on that object of 1/2 MV^2. That same kinetic energy is going to be applied to the ship as well. Presumably it would have significantly higher mass, but velocity would be imparted upon it proportional to the velocity and mass of the projectile. So, the only way to remain stationary is to push mass in the opposite direction with equal kinetic energy. Basically, you'd have to fire the exact same projectile from the exact same kinetic cannon in the exact opposite direction.


This problem does not exist for directed energy weapons (that I'm aware of - I may be wrong on this).

[HorseMonster]

I don't know how exactly you got "bombastic dogfights" out of a discussion of the physical dilemmas and logistical problems involved in planetary bombardment and long distance space combat.

At this point I have no idea who you're actually talking to. You're the only person in this thread who's actually mentioned fighters or dogfighting in any context.

[thanto_]

I also wanted to point out that the problem with a railgun is indeed the rails, but it has nothing to do with the force of repulsion. It's friction. Railguns accelerate projectiles by running current through the projectiles via contact with the rails. So, right there, you have contact, which means you have friction, which means that you have heat. You ideally want a lot of current so you have a lot of speed, which means you'd need superconducting rails. Problem is that superconducting materials tend to be either super-low temperature, or high temperature, but eventually, it's just going to melt if you try for fractional C speed, because the friction is just going to be ridiculous.


This is why you use coilguns. The projectile can be shot between the coils with zero contact meaning no friction, which means no heat, which means you're free to use superconducting coils of any temperature or construction, really. These could be held in place with non-conducting materials, like nickel steel. The problem I see is the coils wanting to stick together when current is run through them, so they'd have to be held apart with some very strong materials such that the coils don't break under load. But I'm sure materials science can take care of that.


Of course, that still runs into the same problem I mentioned earlier of masses pushing against eachother.

[Noctis]

I don't know how exactly you got "bombastic dogfights" out of a discussion of the physical dilemmas and logistical problems involved in planetary bombardment and long distance space combat.

At this point I have no idea who you're actually talking to. You're the only person in this thread who's actually mentioned fighters or dogfighting in any context.

*sigh*
Ok let me explain that to you then ok? You said I took my ideas from mass effect. I said that mass effect had space dogfights and that that was not a realistic take on space combat. If you say I'm getting anything my ideas of combat from mass effect then you're saying I believe that space dogfights are the realistic idea.