Space combat: Where does it end...

[RokkitVan]

I have been thinking about space combat for a while, and the current in-game balancing made me think of the "real-world" implications a bit. So I have some questions that can use some input or thoughts from the other esteemed members. This is in no way meant to tie in with the game, or do I have any expectations regarding implementation, but it just has me thinking a bit...

1. Assuming no friction or resistance in space, and you do not hit a random object, how far would ballistic weapons really be effective? 1km? 10? 100? 1000? Won't ballistic rounds just keep on traveling at the same initial velocity until it hits something? Is some poor Starliner going to get broadsided by rounds fired from half a star system away and many months ago?

2. Same for laser weapons. I am aware that there is dust, gas, radiation etc in space, so would this blast from a repeater eventually dissipate enough to just fade away? Would Roger Wilco lose an arm while sweeping the deck of an 890j somewhere?

Just curious. Perhaps there is someone here whose astrophysics is a bit more insightful than mine...

RV

 

[NaffNaffBobFace]

In regard to Ballistics, I think along the same lines as you, a mass in motion will continue until it hits something or is pulled into the sun or whatever - Compared to the velocities of other objects in space ballistics are crawling though. Any anti-kenetic shielding to cope with micro-meteorite or other space debris impact travelling at 30/40,000 m/s would shrug off ballistics like they were snow flakes falling on a child's shoulder.

We could hand-wavium it and say all rounds have a self destruct that vaporises them to keep space safe, but... yeah Ninetails goons are not going to waste their time fitting lead with a bye-bye button and then limiting its range to only a few thou meters, there are factions in the 'Verse who won't care or will see a benefit in rounds not restricted by civilizations arbitrary rules which they themselves glory in willfully not being a part of.

For energy weapons range is a little more logical, as you say energy disperses via entropy and at a critical point an energy bolt, even one which still has destructive potential, should not have enough energy left to retain cohesion with itself and falls apart rapidly.

Thinking this through logically, space is a hard place to loose energy because a vacuum has no/minimal particles to take on that energy so energy weapons are going to be viable up there. In atmosphere the decay rate of an energy round must be exponentially higher, but if an anti-kenetic shield system also has the requirement of a vacuum to function because of this high rate of energy loss in atmo...

Here is a thought:

If anti-kenetic impact shielding for ships is good enough for impact with naturally occurring space debris it'll shrug off bullets, but in atmosphere the energy required to sustain itself may bleed into the particles of the air so can't work/be sustained, and if that also holds true for energy weapons in atmosphere making their range tens of feet instead of thousands, it makes ballistics the only option in an atmosphere/high particle patch of space like gas/dust clouds... Could we end up with space fighters only flying with energy loadouts and atmospheric craft only carrying ballistics, and ships that spend a lot of time between the two or hiding to ambush in dust clouds, having a balanced loadout if that became a thing?

This, of course, would rewrite the whole balance of the game and pee a lot of people off, where fan favourites like the Mantis GT220 become tools to use only after you have lured a victim into an atmosphere or other anti-kenetic shield energy-leech like a gas cloud so I don't see this happening, as S42 would have to be rebuilt from the ground up... but it's fun to think about! :-)

Oooh, I do like a good theorycraft! Welcome to TEST, at some point when the mechanics are in (if they do ever come along) I hope to be part of TEST Weapons Research Lab (TWRL, if that ever happens), where we think about Science and the destructive defensive implementation of it, while theorycrafting. We'll be needing questions like this to ponder over

 

[Richard Bong]

Ignoring the game mechanics in Star Citizen and its artificial limitations.

Ballistics, due to speed restraints have a very limited effective range. How good your sensors are, how good their sensors are, relative speed and ability to dodge are all important in the calculation for how limited. A hyper velocity rail gun will be have much more effective range than any chemical propellent.

An exception would be a target that is stationary on a planetary or moon surface or a target traveling with zero self generated acceleration. For that range is, effectively, anywhere within the solar system.

Space is very empty. Lasers, presuming you have a weapon grade power source, not only have effective ranges measured in light seconds, but the only warning that you are being shot at, is when you are hit. Lasers in atmo suffer scatter effects but not, generally, in space and not enough scatter in atmosphere that they wouldn't be effective in line of sight. In fact back before the 1969 moon landing NASA used a laser, from the surface of the Earth, to measure the exact distance to the moon.

Ship speed, by itself, is not really important and has to be measured relative to something. You are mostly fuel limited, for how fast you can get but Einstein might have a word with you once you start getting near the speed of light.

Accelleration, on the otherhand, is the important measure. Here your limit is g forces, mostly based on what a crew can sustain.

Drones and missiles are likely to be highly effective, especially if they can be semi autonomous. They will have much higher gforce tolerance than piloted craft. They can carry guns, warheads, missiles, countermeasures or any combination. Or they can just use their kinetic energy to damage a target.

While Nukes have limited effect in space, other than contact detonation, one interesting weapon use case is the "bomb pumped laser." Surround your nuclear warhead with a crystal lattice designed to focus the flash of a nuke into very powerful lasers. Preferably directional, in the correct direction. Put one or more of those on a missile, detonate at half a light second and watch ships get shredded. Note a Size 9 torp is about the same size as a Polaris SLBM, which carried three independently targeted 150KT (city buster) warheads.

 

[Bambooza]

Both @NaffNaffBobFace and @Richard Bong have great answers.


While there is friction in space it's so low as to be considered non-existent (1.322 × 10−11 Pa ) there would still be a slight drag on the projectiles over a very long duration. The other aspect is that space is very empty and the chances of it hitting something is also almost non-existent. So much so that when NASA launches probes that have a trajectory through the asteroid belt they don't even worry about hitting anything in it. So yes a Balistic projectile would mostly maintain its initial inertia relative to the frame it was launched in which could significantly increase or decrease in potential energy when compared to potential impacts on other objects as they move around in their own frames.

I am looking for the speed calculation of projectiles in SC but I am wondering if they have enough speed to even escape the solar system.

As for Lasers, they would have an effective range as the beam would start to spread out over time and thus the effectiveness would decrease (total energy wouldn't just the energy per cm would) and thus it would become part of the background em and thus indistinguishable from other energy sources. Of course, if you could create perfect reflectors and put all of the laser energy into a perfect parallel stream then, in theory, it would travel outward maintaining its energy potential until it hit something.

 

[Richard Bong]

Both @NaffNaffBobFace and @Richard Bong have great answers.


While there is friction in space it's so low as to be considered non-existent (1.322 × 10−11 Pa ) there would still be a slight drag on the projectiles over a very long duration. The other aspect is that space is very empty and the chances of it hitting something is also almost non-existent. So much so that when NASA launches probes that have a trajectory through the asteroid belt they don't even worry about hitting anything in it. So yes a Balistic projectile would mostly maintain its initial inertia relative to the frame it was launched in which could significantly increase or decrease in potential energy when compared to potential impacts on other objects as they move around in their own frames.

I am looking for the speed calculation of projectiles in SC but I am wondering if they have enough speed to even escape the solar system.

As for Lasers, they would have an effective range as the beam would start to spread out over time and thus the effectiveness would decrease (total energy wouldn't just the energy per cm would) and thus it would become part of the background em and thus indistinguishable from other energy sources. Of course, if you could create perfect reflectors and put all of the laser energy into a perfect parallel stream then, in theory, it would travel outward maintaining its energy potential until it hit something.

My understanding of lasers is that they only disperse when they pass through a medium that disperses them. A Prism, for example. Atmosphere for another. In a vacuum there is no medium to disperse the laser. From a weapon fired in space, to a target, also in space, the only dispersal effect would come from a focus error. I am not saying there wouldn't be focus errors. I would think you would be more limited by sensor range, and ability to predict a moving target's motion (at range) than laser dispersal, with a properly tuned laser weapon. Which is why I suggested Light Seconds effective range. A Light Second is about 186,000 miles/300,000 KM. It takes light roughly 2.5 seconds to make the round trip from the Earth to the moon. I would think anything much more than 2 light seconds would be difficult to hit a maneuvering target. This is especially true since lasers tend to be in very short shots (hundredths of a second or less), not the long beams of most science fiction due to energy requirements.

Ballistics escaping a solar system isn't really the trick. :) After all even the slow moving Voyager probe can escape the solar system. The trick is hitting a maneuvering target.
Most ballistics should be limited to a muzzle velocity of around Mach 5, or (roughly) 5500 fps or 1715 m/s. You tend to melt barrels at around Mach 4, but I figure we have better materials by then.
Now that is muzzle Velocity. You also have to take into account the work of Sir Isaac Newton and Albert Einstein. The barrel is likely moving relative to the target and that makes a difference.

Now comes some fun options, strap a rocket to your projectile that ignites after the projectile leaves the barrel and you have increased the speed in relation to the target.
Use some handy gravity wells between you and the target and you get more velocity. (The shortest distance is not necessarily the fastest distance between two points in space.)

Hitting a non-dodging target should be fairly easy with ballistics. Throwing rocks or I-Beams at surface targets on a planet is a long time staple of Science Fiction and the theoretical work has been studied by Rand Corp and the USAF, among others. So, yes, letting rocks go against Earth from the asteroid belt is not as far fetched as you might imagine.

Hitting a maneuvering target would be much more difficult with a ballistic weapon at range, than a laser mostly because the ballistic weapon projectile is traveling slower than the speed of light and sensors can detect them. I wouldn't expect them to be effective at more than 5,000 km.

The math on this stuff gets really interesting and really nasty very quickly. :)

 

[Bambooza]

My understanding of lasers is that they only disperse when they pass through a medium that disperses them. A Prism, for example. Atmosphere for another. In a vacuum there is no medium to disperse the laser. From a weapon fired in space, to a target, also in space, the only dispersal effect would come from a focus error. I am not saying there wouldn't be focus errors. I would think you would be more limited by sensor range, and ability to predict a moving target's motion (at range) than laser dispersal, with a properly tuned laser weapon. Which is why I suggested Light Seconds effective range. A Light Second is about 186,000 miles/300,000 KM. It takes light roughly 2.5 seconds to make the round trip from the Earth to the moon. I would think anything much more than 2 light seconds would be difficult to hit a maneuvering target. This is especially true since lasers tend to be in very short shots (hundredths of a second or less), not the long beams of most science fiction due to energy requirements.

If the laser beam was perfectly parallel then yes it would continue on until it hit something indefinitely, but that requires perfect optics which I figured even in the year of SC was not achievable and so the light beam would gradually spread apart, much like a flashlight just over a far greater distance.

Ballistics escaping a solar system isn't really the trick. :) After all even the slow moving Voyager probe can escape the solar system. The trick is hitting a maneuvering target.
Most ballistics should be limited to a muzzle velocity of around Mach 5, or (roughly) 5500 fps or 1715 m/s. You tend to melt barrels at around Mach 4, but I figure we have better materials by then.
Now that is muzzle Velocity. You also have to take into account the work of Sir Isaac Newton and Albert Einstein. The barrel is likely moving relative to the target and that makes a difference.

Now comes some fun options, strap a rocket to your projectile that ignites after the projectile leaves the barrel and you have increased the speed in relation to the target.
Use some handy gravity wells between you and the target and you get more velocity. (The shortest distance is not necessarily the fastest distance between two points in space.)

Hitting a non-dodging target should be fairly easy with ballistics. Throwing rocks or I-Beams at surface targets on a planet is a long time staple of Science Fiction and the theoretical work has been studied by Rand Corp and the USAF, among others. So, yes, letting rocks go against Earth from the asteroid belt is not as far fetched as you might imagine.

Hitting a maneuvering target would be much more difficult with a ballistic weapon at range, than a laser mostly because the ballistic weapon projectile is traveling slower than the speed of light and sensors can detect them. I wouldn't expect them to be effective at more than 5,000 km.

The math on this stuff gets really interesting and really nasty very quickly. :)

The slow-moving voyager is on a highly elliptical path that was able to achieve solar escape velocity after getting a number of planet gravitational assists. But even still it's not slow going Voyager 2 is escaping the solar system at a speed of about 3.3 AU per year or 55,230 km/h.

 

[Richard Bong]

If the laser beam was perfectly parallel then yes it would continue on until it hit something indefinitely, but that requires perfect optics which I figured even in the year of SC was not achievable and so the light beam would gradually spread apart, much like a flashlight just over a far greater distance.

I get that it is a question of focusing error. Given some improvement, a couple of light seconds should still be very lethal.

The slow-moving voyager is on a highly elliptical path that was able to achieve solar escape velocity after getting a number of planet gravitational assists. But even still it's not slow going Voyager 2 is escaping the solar system at a speed of about 3.3 AU per year or 55,230 km/h.

Speed is, of course relative. The Earth travels at roughly 110,000 km/h around the sun.

 

[NaffNaffBobFace]

If the laser beam was perfectly parallel then yes it would continue on until it hit something indefinitely, but that requires perfect optics which I figured even in the year of SC was not achievable and so the light beam would gradually spread apart, much like a flashlight just over a far greater distance.



The slow-moving voyager is on a highly elliptical path that was able to achieve solar escape velocity after getting a number of planet gravitational assists. But even still it's not slow going Voyager 2 is escaping the solar system at a speed of about 3.3 AU per year or 55,230 km/h.

What of energy weapons which aren't laser based, such as Plasma and Neutron canon and repeaters? Some of these like the Neutrons have some of the shortest ranges in their classes.

 

[Richard Bong]

What of energy weapons which aren't laser based, such as Plasma and Neutron canon and repeaters? Some of these like the Neutrons have some of the shortest ranges in their classes.

No such things currently exist, so judging them is a bit difficult.

The closest thing to a "neutron canon" is likely to be a particle accelerator but those are generally kept confined with their target in the same tube as the stream. I have only seen one in Science Fiction, as a weapon, in Traveller. They were large, bulky, and had similar range to a laser.

IIRC the only use I have seen for plasma, out side of pure science fiction, is theory about using it for rocket fuel. In most science fiction (Traveller, again, comes to mind) they are, generally, relatively short ranged weapons.

 

[Bambooza]

No such things currently exist, so judging them is a bit difficult.

The closest thing to a "neutron canon" is likely to be a particle accelerator but those are generally kept confined with their target in the same tube as the stream. I have only seen one in Science Fiction, as a weapon, in Traveller. They were large, bulky, and had similar range to a laser.

IIRC the only use I have seen for plasma, out side of pure science fiction, is theory about using it for rocket fuel. In most science fiction (Traveller, again, comes to mind) they are, generally, relatively short ranged weapons.

Indeed, as much as it is a trope of sci-fi weapons it's one of those things that seems to get a lot of handwaving as to how it works if there is even an attempt at it. Even wiki just has a tag that says this section needs expansion.

Weapons in science fiction - Wikipedia

en.wikipedia.org

 

[Jolly_Green_Giant]

Newtons first law of motion dictates that an object at rest will stay at rest, and an object in motion will stay in motion unless acted on by a net external force. Both the laser and projectile will go on forever unless gravity catches them or the infinitely small amount of particles in "empty" space can slow them down. There's also the extremely unlikely scenario of them running into anything with mass, other than your target that is.

 

[Richard Bong]

Newtons first law of motion dictates that an object at rest will stay at rest, and an object in motion will stay in motion unless acted on by a net external force. Both the laser and projectile will go on forever unless gravity catches them or the infinitely small amount of particles in "empty" space can slow them down. There's also the extremely unlikely scenario of them running into anything with mass, other than your target that is.

Lasers, will disperse, over distance, because focusing is not perfect, not really due to the miniscule amount of particles. :)


Otherwise, exactly.

 

[Shadow Reaper]

What of energy weapons which aren't laser based, such as Plasma and Neutron canon and repeaters? Some of these like the Neutrons have some of the shortest ranges in their classes.

High power laser weapons have a beam divergence measured in thousanths of a radian, or mRad; however real world figures are usually classified. Point is the beams always diverge at some angle and so eventually become less useful. DoD is not going to tell us what the state of the art is here.

All energy weapons ought to diverge over distance. What we call lasers in game are certainly not that, as they're far too slow. Lasers appear as a beam you can see or not. You don't see them move forward. Sci-fi has "blasters' and other types of energy weapons that appear to move slower than the speed of light in order to be interesting.

 

[NaffNaffBobFace]

High power laser weapons have a beam divergence measured in thousanths of a radian, or mRad; however real world figures are usually classified. Point is the beams always diverge at some angle and so eventually become less useful. DoD is not going to tell us what the state of the art is here.

All energy weapons ought to diverge over distance. What we call lasers in game are certainly not that, as they're far too slow. Lasers appear as a beam you can see or not. You don't see them move forward. Sci-fi has "blasters' and other types of energy weapons that appear to move slower than the speed of light in order to be interesting.

So would an energy weapon which fired a ball or packet of super heated plasma or ionised radiation be able to fire at the speed of light? Would such a thing even be possible within the laws of physics?

 

[Shadow Reaper]

No. Plasma is electrically charged matter, and matter is constrained to always move below the speed of light. As it approaches light speed the energy needed to increase the speed asymptotically goes to infinity.

 

[Zookajoe]

Perhaps what CIG refers to as Laser Weapons are actually a type of laser charged ions. Which could explain the speed and range we are seeing?

 

[Shadow Reaper]

I think they have owned the issue by simply saying "we know this isn't accurate but it is a game, and this is more fun". Fact is faster weapons are easier to hit with and when they tried the instant to target Singe 2 Tachyon Cannons, they hit so often they created huge play imbalance. They ended that pretty quickly.

I get they need to make it fun, but I don't get how making most of the weapons slower to target than the ships that fire them is actually working. I think it's because almost all combat kills are in jousting, when the velocity of the projectile or energy is added to that of the ship firing. It does make one wonder whether it is even possible to shoot down fast moving targets from behind. There is a limit to the realism sought somewhere. Just FYI, 700 mps is slower than many different kinds of real world ammo.

On the issue of charged particle beam weapons, this is very old tech. The Cathiod Ray Tubes in the back of old CRT displays (early TVs and monitors) were charged particle rays, but at low power. They shot electrons at the TV screen inner surface with fantastic precision. The Hyperion Ion Cannon used in hydrogenating crystals for precise fracture use similar tech. (The notion is, bend the beam twice, once removing ions lower than a single energy, and once removing ions above that energy, and all the hydrogen beam ions (protons) then have the same energy and will penetrate crystals like sapphire to the same precise depth. They create a "hydrogenated layer" in the crystal that can then be fractured along the layer and get a molecularly smooth, fantastically thin sheet of crystal for use in cell phone screens, with NO WASTED material from dicing, cutting, grinding or polishing. BTW, sapphire is the "transparent aluminum" that Scotty supposedly invented in Star Trek 4.)

High power weapons of this type have been in development since the Reagan (Star Wars) years, but virtually all that research is classified (and done at Kirtland Air Force base). Many types of particle accelerators exist to research particle physics, and these often have power densities high enough to be used as a weapon. See: https://en.wikipedia.org/wiki/Particle-beam_weapon

Final BTW, all particle energies scale quadratically with velocity, meaning that in order to make a particle twice as fast, you need to put in four times the energy. Goes as 1/2MV^2, and as the velocity approaches the speed of light, the energy needed approaches infinity, so very high speeds require increadible energy input.