[General Battuta]

Lasers don't obey the inverse square law. They do drop off by distance due to beam area dispersion, but it's not by inverse square.

Common misconception.

[StarSlayer]

Would there even be a reason to bother with lasers?  Wouldn't kinetic energy weapons be cheaper and more effective?

[Ghostavo]

Lasers would be much more accurate and difficult to avoid.

[General Battuta]

Would there even be a reason to bother with lasers?  Wouldn't kinetic energy weapons be cheaper and more effective?

No. They make awesome knife-fighting weapons because they can't be dodged and they strike faster and more efficiently than kinetic weapons. A good laser can get through a meter of graphite (probably the best laser armor known to man) in a second at 5000 KM. At half a light-second you can get through one millimeter per second, which is pretty good.

However they produce a ton of heat - basically, they're blast furnaces that produce laser light as a byproduct - and they're quite short-ranged.

Plus you can shoot down missiles.

At range however, Trashman's right, coilgun/railgun/shrapnel launches from aforementioned system (or even from a chemical gun) would be the way to go. Missiles too. EDIT: I take that back. Thinking about the distances, kinetic energy weapons probably suck. The only way to get a hit is to calculate the target's potential vectors (given a low-acceleration environment where he can't alter vector too rapidly) and just fill every potential space in his path with junk. That might work.

The usual metaphor is that you've got a cop with a revolver (you can't dodge it, but it might miss), a shotgun (it's got a wider spread and a lot of stopping power, and in our metaphor, it doesn't lose power with distance, unlike the revolver), and an attack dog, which takes a long while to get there and can be shot but doesn't stop.

[StarSlayer]

So a reasonable weapons mix would be guided missiles and UASV drones for long range, some type of KEW for medium range and lasers for short range?  With ECM, counter missiles and point defense lasers for defense?

[General Battuta]

In a realistic environment, a manned ship would carry massive numbers of drones for long-range fights (99% of engagements, probably), maybe some KEWs (maybe railguns if you had awesome fire control or for planetary bombardment), and a lot of point defenses, including some lasers.

If ships actually met each other more often they might carry more straight-up weapons like missiles and lasers. Shrapnel missiles are probably the way to go.

ECM is actually kind of dubious in space.

[TrashMan]

It's a possibility. We don't really know how effective laser weapons will be. A pulsed laser weapon can saw through stuff pretty fast.

Not fast enough. Especially since you can make armors designed to withstand lasers longer. Carbon armor has a high vaporization energy and is great for that purpose.

You've got some stuff backwards, though. Railgun/coilgun effective range is far longer than laser range. You can use your railgun/coilgun to fire shrapnel all over the target's vector.

A sapce shotgun would be terribly ineffective. The spread of shrapnel would be too great at the distances invlolved. It wouldn't hit anything. A "smart" bullet would be a far better solution.

Keeping a laser on a ship that's only moving at several Gs wouldn't be a tremendously difficult task.

Oh no?

And don't think that lasers will automatically hit their targets either. There are many factors that can cause a miss. Off the top of his head, Dr. John Schilling mentions:

Uncertain target location due to finite sensor resolution
Uncertain target motion due to sensor glint or shape effects
Sensor boresight error due to finite manufacturing tolerances
Target motion during sensor integration time
Analog-to-digital conversion errors of sensor data
Software errors in fire control system
Hardware errors in fire control system
Digital-to-analog conversion errors of gunlaying servo commands
Target motion during weapon aiming time
Weapon boresight error due to finite manufacturing tolerances
Weapon structural distortion due to inertial effects of rapid slew
Weapon structural distortion due to external or internal vibration
Weapon structural distortion due to thermal expansion during firing
And we haven't even begun to include target countermeasures...

[Ghostavo]

Let's put it this way, aiming a laser would be much easier than aiming any other "projectile" weapon, since the errors you pointed out make much matters much, much worse for stuff like say, railguns.

[General Battuta]

Not fast enough. Especially since you can make armors designed to withstand lasers longer. Carbon armor has a high vaporization energy and is great for that purpose.

Not as good as graphite, see the earlier remark about a meter of graphite armor at 5000 k (which is knife fight range.)

A sapce shotgun would be terribly ineffective. The spread of shrapnel would be too great at the distances invlolved. It wouldn't hit anything. A "smart" bullet would be a far better solution.

A 'space shotgun' isn't a shotgun at all. The objective is to deny an area of space by flooding it with shrapnel. It doesn't have to be fired all at once, shotgun-style; you just need to put a lot of crap into the target's flight path. You can use missiles to get a shrapnel warhead closer. Great way to get a kill, especially if you're scattering a ton of dust.

A smart bullet is just a missile. Already addressed. You can launch it from a coilgun if you like, though.

Oh no?

Followed by a laundry list from the website I linked earlier.

Those factors are all explanations for why lasers won't constantly hit. As I said time and again earlier, lasers can miss. Keeping a laser on a target, however, is not particularly difficult - it's one of the easier parts of the challenge today.

It's a hell of a lot easier than aiming a kinetic energy weapon, and at knife fight range the laser is a better bet. Every kind of weapon has its place. KEWs are the trickiest to make useful, though.

Please read what people post.

[NGTM-1R]

A sapce shotgun would be terribly ineffective. The spread of shrapnel would be too great at the distances invlolved. It wouldn't hit anything. A "smart" bullet would be a far better solution.

Not really. The concept that's being looked for here is called "ideal contact ellipse" and is one already routinely tackled in modern gun systems. (Some, not many, missiles have the option of being able to conduct evasive manuvers; the ideal contact ellipse concept is a direct response to that and the reason why most missiles don't.) It is, of course, infinitely more manageable at short range, but since a ship commited to battle is already going to be in motion at fairly high speed and thus his manuvering options will be somewhat limited, and we have at our disposal already weapons with ridiculous high fire rates (like the Metal Storm system), it would be entirely feasible for relatively short range combat in space terms. Orbital combat would probably play out at suitable ranges for projectiles to play a significant role.

[TrashMan]

Lst time I checked graphite is a allotrope of carbon... so it pritty much is a type of carbon armor.

And no. A smart bullet is not really a missile. Missile is self-propelled. A smart bullet isn't and can only make minor course corrections. It effectively gives a railgun a cone-like field of fire..altough you'd still fire it when almost perfelcy alligned, to maxime the chances of a hit.

[General Battuta]

A sapce shotgun would be terribly ineffective. The spread of shrapnel would be too great at the distances invlolved. It wouldn't hit anything. A "smart" bullet would be a far better solution.

Not really. The concept that's being looked for here is called "ideal contact ellipse" and is one already routinely tackled in modern gun systems. (Some, not many, missiles have the option of being able to conduct evasive manuvers; the ideal contact ellipse concept is a direct response to that and the reason why most missiles don't.) It is, of course, infinitely more manageable at short range, but since a ship commited to battle is already going to be in motion at fairly high speed and thus his manuvering options will be somewhat limited, and we have at our disposal already weapons with ridiculous high fire rates (like the Metal Storm system), it would be entirely feasible for relatively short range combat in space terms. Orbital combat would probably play out at suitable ranges for projectiles to play a significant role.

Yep, that.

Lst time I checked graphite is a allotrope of carbon... so it pritty much is a type of carbon armor.

Precisely. And did you read the post? A good laser will blow through a meter of it (a meter!) in a second at knife fight range.

And no. A smart bullet is not really a missile. Missile is self-propelled. A smart bullet isn't and can only make minor course corrections. It effectively gives a railgun a cone-like field of fire..altough you'd still fire it when almost perfelcy alligned, to maxime the chances of a hit.

Why? That's farcically ineffective. It can reach a tiny fraction of the range a missile can and it'll almost certainly never hit. Why not just fire a missile from the railgun?

Unlike lasers, KEWs are slow. Unlike missiles, they can't adjust course or coast-until-burn to engage a maneuvering target.

KEWs make a lot of sense using the ideal contact ellipse concept NGTM-1R outlined, though.

[StarSlayer]

Would drones (I'm assuming there would probably be bomber version analogous to a Backfire and some type of multi role fighter/interceptor like a F-16?) be able to operate within the range an enemy capital ship's point defense lasers?  Would we still see a standard battle group mix of CVs, CGs, DDGs, FFGs or would ships have basically the same capabilities only different tonnages?  Finally would warships be high performance or still relatively lumbering?

[General Battuta]

It's not going to be navy in space. In a realistic setting, it's all unmanned, all the time. I doubt we'd see any classifications that firm - just a lot of drone vehicles that might or might not be recoverable. Big ships to carry little ships across long distances might make sense, as might tankers (though fuel is massive, which in turn demands even more fuel). Big ships could mount bigger lasers and more armor and missiles and parasite ships.

Warships would be 'high performance' in the sense that they would go really fast after a lot of acceleration, but maneuverability would be quite limited in terms of altering one's vector, probably. Zero-zero engagements just aren't likely to happen.

In the near future, the whole 'stealth in space' debate aside, it really may be a lot like submarine warfare.

[StarSlayer]

Even unmanned capital ships?  I assume that would mean your depending on AI since having ground based controllers would be inefficient due to the signal travel times?

[General Battuta]

Y'know, that's actually a pretty fair point. You might need manned warships as control stations.

But given lightspeed lag your drones will be operating autonomously anyway, so...I dunno.

Life support sucks. It sucks really, really hard. It means you need air, water, radiation shielding, crew spaces, and G limits.

[StarSlayer]

Yeah, though sometimes I think we are stepping on the edge of the precipice with unmanned/automated warfare.  And not for the Skynet reason, I just tend to worry it makes war easy.  On one hand its removing troops from the front lines which is a good thing, an AWACs UAV gets shot down you lose a piece of hardware rather then 24 aircrew.   
On the other hand conventional war is hard to wage, the government generally needs to convince the populace that its a needed operation, they need to conscript and train troops, deploy them to the combat zone and support them.  If your having kids come home in body bags people are going to stand up and question its legitimacy.  The cost in sweat and blood makes conducting war hard and something to be avoided as a last resort.  If we get to a point where most of our forces are unmanned or automated will it remove those roadblocks to combat?  Will governments need wrack their conscience or have to sell the war to the populace if all they have to do is let loose their robot MBTs and UAVs? 

In the short term it seems like a damn good idea, I just wonder if in the long term its a dangerous can of worms.

[swashmebuckle]

Can't space dudes all just get along?

[Thaeris]

ECM is actually kind of dubious in space.

I disagree. Weapon systems which need to close to short range to attack/hit need to have a way of not being blasted to hell by point defense lasers or projectile weapons. Some means of giving a false reading to hostile sensors must therefore be achieved... that, and high speed/agility. If your missiles keep getting shot down because of radar/[insert sensor type here] guided weapons, you'll need to invest in a similar weapon that can pump that sensor array full of noise so it can get close enough do damage.

@ StarSlayer:

Those are my thoughts exactly. Dehumanizing the battlefield desensitizes the combatant who's got noting but cheap [compared to actual lives] toys with guns on them to loose. Thus, the lives of the enemy become quite expendable as well. The truth is that war and politics are the same in the end. When the morals of the ones who've got nothing real at stake fade, we're all in trouble.

[NGTM-1R]

I disagree. Weapon systems which need to close to short range to attack/hit need to have a way of not being blasted to hell by point defense lasers or projectile weapons.

Saturation is, was, and pretty much forever shall be the one truly reliable method of doing this.