Good astronomy in Homeworld 2 (Spoilers)

[freddo]

Yoshua you may enjoy reading this thread... We had a similar discussion about space weaponry.

[daver]

I think a projectile weapon would actually benefit from being in space.

Yes, it could. The question is whether it would benefit enough to be useful.

There are too many variables--it depends on the range of combat, the accuracy of the weapon, the speed of the projectile, the ease of detection of the firing of the weapon, the ease of determination of the probable projectile trajectory, the ease of detection of the projectile, whether the projectile can do active course correction, the ease of avoidance of the projectile, the ease of interception of the projectile, the possible damage caused by the projectile, the number of projectiles able to be carried, the ease of firing and rate of fire of the weapon, and a bunch of other stuff. Given all this, you can obviously set up whatever scenario you'd like.

Doc Smith's Lensman series was somewhat interesting in this regard--technology changed dramatically through the series; new technology kept making current weapons obsolete and occasionally made an update of an old weapon cutting edge again.

[Zamboni]

Disreguarding the linked thread (didn't bother to read it) I would say projectile weapons would be useless (and pointless) in any sort of realistic space combat.

Why, you might ask? Well because of the Newtonian physics, which states "for every action there is an equal and opposite reaction blah blah blah" (yes, the blahs were there, most people ignore it but it's there...). We use projectile weapons (ie. bullets, cannons, large pieces of stones) on earth becase of exactly that: we are ON EARTH (or if you're in a ship, on water). Gravity combined with solid ground (again, ships are in water) holds us still when we fire our precious metal billets. if we were in space, we would not be able to fire anything without either go into a spin or fly away in an unknown direction.

For example, WWII battleships fire cannons that make them bob back and forth in the water despite the counter weight, this effect would be amplified so much in space that every time they fire they will basically spin on its own axis (not very quickly but not very slow either). One way to counter this would be to time a booster burst (fire a rocket, what have you) in the opposite point on the mass centre; however this would be extremely inefficient on a smaller craft due to the continuous firing (unless future guns are all one shot wonders).

Further more, the reason why today's aerial combat does not favour projectile weapons is mainly because of one thing: it's heavy. Most fighters carry no more than a few seconds worth of ammunition. The rest of the mass capacity are devoted to missile weapons and more importantly, fuel. Again, in space this effect would also be greatly amplified because if you run out of fuel in space, you are done. You can't just crash land on some unknown planet like they do in movies, earth like planets aren't exactly that easily found; not to mention most stars are light years across.

All in all, I would argue that the future of space combat will be fought with missiles due to its ability to track enemies for great distances and energy weapons for its speed (most sub atomic particles fly at near light speed). Guns with bullets will probably be used ONLY on land combats or perhaps inside a starship.

[wedgebert]

Disreguarding the linked thread (didn't bother to read it) I would say projectile weapons would be useless (and pointless) in any sort of realistic space combat.

Why, you might ask? Well because of the Newtonian physics, which states "for every action there is an equal and opposite reaction blah blah blah" (yes, the blahs were there, most people ignore it but it's there...). We use projectile weapons (ie. bullets, cannons, large pieces of stones) on earth becase of exactly that: we are ON EARTH (or if you're in a ship, on water). Gravity combined with solid ground (again, ships are in water) holds us still when we fire our precious metal billets. if we were in space, we would not be able to fire anything without either go into a spin or fly away in an unknown direction.

For example, WWII battleships fire cannons that make them bob back and forth in the water despite the counter weight, this effect would be amplified so much in space that every time they fire they will basically spin on its own axis (not very quickly but not very slow either). One way to counter this would be to time a booster burst (fire a rocket, what have you) in the opposite point on the mass centre; however this would be extremely inefficient on a smaller craft due to the continuous firing (unless future guns are all one shot wonders).

Further more, the reason why today's aerial combat does not favour projectile weapons is mainly because of one thing: it's heavy. Most fighters carry no more than a few seconds worth of ammunition. The rest of the mass capacity are devoted to missile weapons and more importantly, fuel. Again, in space this effect would also be greatly amplified because if you run out of fuel in space, you are done. You can't just crash land on some unknown planet like they do in movies, earth like planets aren't exactly that easily found; not to mention most stars are light years across.

All in all, I would argue that the future of space combat will be fought with missiles due to its ability to track enemies for great distances and energy weapons for its speed (most sub atomic particles fly at near light speed). Guns with bullets will probably be used ONLY on land combats or perhaps inside a starship.

It all depends on your propulsion methods actually. Missiles are only good if they have fuel. Once they run out of fuel they basically become bigger bullets, except this time the enemy has had a nice exahust trail to follow (via whatever sensors necessary) and have a much easier time shooting it down.

Shells on the other hand don't do much to give themselves away. All you have then is the time it was fired and the estimated muzzle velocity. You might be able to get a good radar return, but since there's no friction in space, it's not inconceivable to build stealthy shells.

As to recoil, if you're firing along your direction of travel, you don't have to worry so much about it. You can easily just use spinal mounted or symetrically weaponry to keep from spinning off-axis. Broadsides can fire opposite weapons to keep from spinning as well (top-left + bottom-right, etc)

Large ships would suffer the same recoil penatlies from missiles as they would from guns, unless all the missiles are either externally mounted or ejected before they ignite their engines.

Finally, a shell can carry a significantly bigger warhead compared to a missile of the same mass.

It all depends on range though. Unguided ordinance won't be very effective past a few light seconds because the targets will have plenty of time to move out of the way.

The best bet would probably be a comprimise of the two. Short ranged missiles are fird like bullets, and after a predetermined time, they ignite their drives to do terminal guidance.

[Yoshua]

Well this is space we're talking about. We could probably use some kind of hybrid between artillary and missiles. Give the shell a radar/light absorbant outer layer and some type of basic rocket guidance for steering and launch it like an artillary shell to give it accelleration.

There's no reason for making something burn fuel constantly in space like a missile would on earth.

As for fighter craft, I think if they're firing into the direction they're accellerating, this would likely compensate no ? It'd slow'em down for sure, so they couldn't sustain fire for long. Though I do think your right that arming a fighter with missiles would be more practical. Though if a projectile weapon can disable a ship, it's a pretty cheap way to do it. This discussion started out talking about Homeworld. During the game, your struggling for resources, building lot's of missiles might not be practical under those conditions (though really I think the designers just wanted fighters able to dogfight).

[Comixx]

About constant acceleration of a projectile, I think this would actually be a favored thing. Imagine, your ship's delta V, added to whatever acceleration you can build from firing and the projectile's own propulsion. It could add up to fractions of c by the time you factor in the opposing ship's delta v, etc...So I'd want to pack as much propulsion into my projectiles as I could, giving them a kinetic potential for damage.

[Yoshua]

I'm no rocket scientist, but wouldn't an object fired from a spacecraft have to overcome it's initial acceleration for propulsion to be of any benefit ?

I'll admit this is just an intuitive guess and probably wrong.

[daver]

I'm no rocket scientist, but wouldn't an object fired from a spacecraft have to overcome it's initial acceleration for propulsion to be of any benefit ?

I'll admit this is just an intuitive guess and probably wrong.

Let's say you're south of the fleet moving north at 10 km/sec. In this case, so long as your projectile is moving a bit faster than you are it will have a chance of hitting.

If you're north of the fleet moving at 10 km/sec, you have to fire your projectile at at least 10 km/sec south before it could do damage.

Anyway, acceleration doesn't have too much to do with it so long as your target isn't accelerating--it's just your position and your relative velocities that you need to overcome.

[Zamboni]

@daver:

I think you are missing the point... Projectiles only do damage if they have sufficient momentum to transfer to the impact area. "A bit faster" won't do anything as most projectiles (ie. bullets) have little mass.

Also, the projectiles themselves have to acheive quite a high speed before it can be utilizes as an effective weapons due to what Yoshua pointed out: they have no acceleration.

In fact if you take the point a bit further, you would realize that if the spacecraft acheives a sufficient accleration, it would render all projectiles useless. To put it in more understandable terms, as both crafts accelerate, the range of the bullet would decrease in exponential proportions. Eventually the attacker has to be right on the target's tail before it can fire and has any hope of damaging the enemy.

Now you *could* give the projectiles a very high initial speed (but nothing close to c though) in order to overcome this problem, however this again will slow down the craft too much as it fires continuously.

Also, reguarding missiles, they don't actually excert that much negative force on the firing craft. If you look at any modern day fighter missiles, you would see that they only use their own propulsion after they are released from the hardpoint (the rack they are fixed to).

To sum up my points against projectile weapons:
- they are heavy
- have to be carried in large quantities
- miss to hit ratio too high
- useless if given a low initial speed
- exerts too much negative force if given higher initial speed
- pollutes space
- requires manual aim, which is bad
- short range even if you ignore all the above points relative to missiles

Therefore I am right... Ha ha ha ha ha ha.

[Yoshua]

Actually I don't think the recoil would be such a big problem after all. It's all in how you maneuver, though it'd sure be a trick to learn.

If your firing into the direction your travelling, or away from it (directly behind you that is) wouldn't the recoil problem be diminished ? (actually, firing behind you is probably your best bet)

Does limit your field of fire though.

[wedgebert]

@daver:

I think you are missing the point... Projectiles only do damage if they have sufficient momentum to transfer to the impact area. "A bit faster" won't do anything as most projectiles (ie. bullets) have little mass.

Also, the projectiles themselves have to acheive quite a high speed before it can be utilizes as an effective weapons due to what Yoshua pointed out: they have no acceleration.

In fact if you take the point a bit further, you would realize that if the spacecraft acheives a sufficient accleration, it would render all projectiles useless. To put it in more understandable terms, as both crafts accelerate, the range of the bullet would decrease in exponential proportions. Eventually the attacker has to be right on the target's tail before it can fire and has any hope of damaging the enemy.

Now you *could* give the projectiles a very high initial speed (but nothing close to c though) in order to overcome this problem, however this again will slow down the craft too much as it fires continuously.

You're assuming that all projectile weapons would be inert bullets. Why not put explosives in then?

As to a bit faster, if you fire a shell at 1 km/sec and you're travelling at 10 km/sec, the shell now has a velocity of 11 km/sec. The shell is going to leave your ship at the same speed, not matter how fast you're travellling (barring relativistic effects). The targeting platform always adds its velocity to the base velocity of the shell. This also means firing backwards is bad.

Also, reguarding missiles, they don't actually excert that much negative force on the firing craft. If you look at any modern day fighter missiles, you would see that they only use their own propulsion after they are released from the hardpoint (the rack they are fixed to).

To sum up my points against projectile weapons:
- they are heavy
- have to be carried in large quantities
- miss to hit ratio too high
- useless if given a low initial speed
- exerts too much negative force if given higher initial speed
- pollutes space
- requires manual aim, which is bad
- short range even if you ignore all the above points relative to missiles

Therefore I am right... Ha ha ha ha ha ha.

If you just detach a missile and have it acclerate on its own, it's going to be a sitting duck for enemy point defense. They'll have plenty of time to track the missile as it accelerates.

Also, it's very unlikely (except mainly at the beginning of space warfare) that any weapon will require a direct hit to inflict damage. Space is just too big and the ranges too long to make that an effective way to do damage. Point defense weapons will have plenty of time to track incoming targets and shoot them down. Especially when you can just shoot a nuke out and use it as flak

What I think (barring some amazing propulsion discovery) will be the dominating weapon will be the (nuclear) bomb pumped laser. You just get that sucker within a certain range and have it explode. The warhead focuses the energy from the blast into powerful (if short lived) lasers, destroying itself in the process. This allows you to aim the warhead before detentation and reduce the chance of a miss and decrease the intercept time.

Also, if the technology exists, adding some sort of linear accelerator onboard the firing ship (like a rail gun or mass driver) would allow you vastly increase the missile's initial speed for "free". This reduces the firing arc of missiles, but decreases travel time.

[Madcat]

Actually, it's not hard at all to make a recoilless projectile weapon. Soldiers have used them for many years to fight tanks. Basicly, you take an ordinary shell (well, it's got a modified case so it can be set off by an electric charge instead of a striker) and put it in a gun barrel that's open on both ends. Ignite the charge. The force going out each end is roughly equal and there is little recoil to speak of. The catch? You lose a lot of force this way. A recoilless version of say, a typical 100mm cannon needs twice the amount of propellant the non-recoilless version would need to get the same velocity from the same projectile. If it helps you to picture this, think of launching a rocket from the inside of a tube that's open on both ends. Your rocket will go straight because the tube guided it a bit, but it's not going to take the tube with it as it goes. There's no recoil.

Now would these get used in space? Maybe for a while. If we're talking about interstellar, sci-fi warfare I'd guess no; if you can get to your enemy in another planetary system fast enough that you will actually still remember what you're mad about when you arrive you would probably have much better toys. If we had a war in the near future, say in LEO, with ships that can't manuver all that much, than why not? Putting a lot of shrapnel out in front of a craft that's in a different orbit than you sounds rather nasty. That sounds kind of jerry-rigged though. For the forseable future, it costs so much to send something up there that I'd expect something more effective. Probably a missile of some sort. Maybe people will use these if we ever start mining the moon or something like that.

[The Supreme Canuck]

Here's an example of a recoilless projectile weapon:

http://www.army.forces.gc.ca/lf/English/3_2.asp#

Click on "Carl Gustav"

[daver]

@daver:

I think you are missing the point...

I don't. As i mentioned earlier, since you're making up the technology for space warfare, you can make up the technology in such a way that it supports projectile weapons.

To sum up my points against projectile weapons:
- they are heavy

The cannon may be heavy. The individual projectiles may be light.

- have to be carried in large quantities

That's an advantage, not a disadvantage.

- miss to hit ratio too high

That depends on the engagement distance and whether the projectiles have terminal guidance

- useless if given a low initial speed

As are bullets

- exerts too much negative force if given higher initial speed

See the A-10

- pollutes space

I can see ways around this, which almost certainly wouldn't be used.

- requires manual aim, which is bad

Most likely they would require aiming the entire ship (at least for small ships), which is bad.

- short range even if you ignore all the above points relative to missiles

Yes.

Therefore I am right... Ha ha ha ha ha ha.

Oh yeah? Bowby humans got B.O.! So there!

Again, it all boils down to technology. If you can bottle up the enemy fleet--confine them to a limited range of positions and velocities, then projectile weapons become ideal. Planetary orbits, landing, takeoff, for instance. Projectile weapons would likely be used for point defense.

[Moose]

About constant acceleration of a projectile, I think this would actually be a favored thing. Imagine, your ship's delta V, added to whatever acceleration you can build from firing and the projectile's own propulsion. It could add up to fractions of c by the time you factor in the opposing ship's delta v, etc...So I'd want to pack as much propulsion into my projectiles as I could, giving them a kinetic potential for damage.

Well, actually, be careful there.

The moment you fire the projectile, it is no longer accelerating. If you continue to accelerate along the same trajectory, you will end up catching up with the projectile and possibly self-inflicting damage.

The other thing I should mention is that accelerating the ship (relatively very heavy) + (heavy) launcher + (light) projectile takes more fuel than accelerating the projectile alone, plus the fuel it has to carry to do the job.

Are you sure you want to burn that much of your ship's fuel to give your projectile a relatively slight boost? (no pun intended)

[Comixx]

I was talking about the missile accelerating constantly, not the ship...forgive me if I was unclear on this point.

I favor fire-and-forget type projectiles for space warfare, instead of inert projectile-type weapons which rely on saturation and the initial firing mechanism + the ship's inertia for their speed and destructive capability.

[Madcat]

Quote:

- short range even if you ignore all the above points relative to missiles


Yes.

NOT AT ALL!

If you know roughly how many newtons of force will be imparted to each bullet as it leaves the gun barrel and you know your own velocity then you can easily do a quick orbital-translation calculation and set it up so the new orbit of the fired projectiles intersects with your enemy's orbit. It's mean, it's nasty, it imparts energy greater than the initial charge of propellant contained in most cases, and better yet it will come out of nowhere as far as your enemy is concerned. You could set this up so the shot hit days later and no one even know who did it.

[wedgebert]

I was talking about the missile accelerating constantly, not the ship...forgive me if I was unclear on this point.

I favor fire-and-forget type projectiles for space warfare, instead of inert projectile-type weapons which rely on saturation and the initial firing mechanism + the ship's inertia for their speed and destructive capability.

The problem with self-guided weaponry is that unless you aim them very carefully before firing, they require loads of fuel to correct their course.

And if you fire one while orbiting a target against another target in orbit, you can almost forget about having the fuel if improperly aimed.

Hence why I would prefer bomb-pumped lasers. They would have a good range when detonated and so wouldn't have to get all that close to their target.

[Zamboni]

The International Space Station endures hundreds of projectile hits EVERYDAY ranging from screw, debris, to frozen human waste. Last time I checked, the ISS is still there and the engineers found a way to minimize the damage. Don't you think an advanced spare faring culture would have eliminated ALL such damages from pure impacts?

The "nuke in space" theory just doesn't work as you would probably kill every ship in the vicinity, including your own. As for the self-guiding bullets and the explosive bullets; you know what we call them? MISSILES!!!

And Madcat's idea is just that: mad! Since when do fighters sit around in stationary orbits when engaged in a dog fight? It ain't chess!

And lastly, toward wedgebert's idea, I assumed that we are talking about weapons used in deep space, not in orbit of some intersteller object.

BOTTOM LINE (sorry I had to resort to using caps but)
Evolution of weapons = stones > arrows > bullets > missiles > energy basedd weapons; not the other way around. If you can show me ANY current army still using stones and arrows instead of bullets and missiles then I'll admit I was wrong, otherwise, projectile weapons have no place in space! Muwhahahahaha...

[freddo]

Don't you think an advanced spare faring culture would have eliminated ALL such damages from pure impacts?

The question is how would they do this? We minimise the damage - we don't eliminate it... Forcefields appear to be impossible. All you've got to go on is an argument from incredulity.

The "nuke in space" theory just doesn't work as you would probably kill every ship in the vicinity, including your own.

Big range involved - you far away from the bomb - they're close to the bomb.

Since when do fighters sit around in stationary orbits when engaged in a dog fight?

Changing your orbit is not overly easy - requires lots of fuel... You have a perpetual motion drive?

show me ANY current army still using stones and arrows instead of bullets and missiles then I'll admit I was wrong

Your progression is flawed. Bullets and missles are stones and arrows - just faster and smarter. We still use projectiles like stones - only in the bullets case they're harder and supersonic - and in a missles case - they're guided.

[Zamboni]

Actually I made a mistake in my last statement of my previous post; I meant to say "bullets" have no place in space, not "projectiles"...

I was pointing out that unguided projectiles would be practically useless in space, instead of all projectiles.

Sorry... I was hit by a large piece of projectile in the head. LOL

[The Supreme Canuck]

Ouch. Hope it didn't leave a mark...

[Zamboni]

It did actually... ever since grade 3... Which explain why I do not make any sense at all most of the time... Actually, all of the time.