RKV weapons suite

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Prophet710 Prophet710's picture
RKV weapons suite

For those not geeky enough, RKV is Relativistic Kill Vehicle.

Anyway, my question is, is such a concept more powerful than already established Kinetic weapons or is this a completely different concept along the same lines of science?

"And yet, across the gulf of space, minds immeasurably superior to ours regarded this Earth with envious eyes. And slowly, and surely, they drew their plans against us."

The Enemy The Enemy's picture
It is both more powerful, and

It is both more powerful, and another different concept- Relativistic Kill Vehicles are simply kinetic projectiles going at a significant fraction of the speed of light. This opens a whole new can of worms, like the doppler effect with light instead of sound, that sort of thing. In fact, once you throw something at 96% the speed of light, then it holds as much energy as it's rest mass- IE, it holds as much energy as a bomb made purely of antimatter/matter.

Almost impossible to stop, due to the lightspeed lag- by the time you see it, it is already upon you, you have no time to react.
That said, just like any other non-explosive kinetic weapon, you have to put as much energy into accelerating into it, as you get out of it.

Insanity is the Spice of Life.
Gun-totin Texan.

Tnargraef Tnargraef's picture
Killer Space Death Buses is
Arenamontanus Arenamontanus's picture
Worth checking the archives,

Worth checking the archives, we have discussed them before. I think my take home message is:

Horribly big and expensive to launch.
Works against targets that move in predictable ways.
Very good armour penetration.
Energy density can be made several times higher than corresponding antimatter mass.
QE comms reduces their surprise utility: big powers have remote sensor networks that can see them coming. Over interplanetary distances there will may be time for evacuation or emergency egocasting with this warning.

Extropian

Xagroth Xagroth's picture
The only Setting I can

The only Setting I can remember having these is David Weber's Honorverse, and more like a concept than a usable thing, and it works the following way:

- Premise: FTL travel is possible by Hyperspace "cheat", but gravity is related: you cannot jump unless you are a very long way from the local star (in EP, at least on Uranus or even Eris' distance from the Sun). There is also the possibility of using wormholes, but less than two dozen of such can be used (the rest are not stable or connected to nothing at all).
- Premise: spaceships use a "gravity wedge" that, aside from generating a gravitational distortion that can be picked FTL (in-system), is completely unpenetrable. The Gravity Wedge is composed of two defined and limited planes (that would cross themselves on the aft of the ship if prolongued) at thousands of gravities.
- Defensive Premise: Top and Bottom of ships are protected by the Wedge and are, thus, invulnerable. Sides are protected with force fields (with openings to fire onboard weapons) and armor, but the front and back of the ships have only armor, because the back has to be clear for the Wedge to provide accceleration and the front has to be clear not only because of that, but also for the sensor systems.
- Energy source: hidrogen-based (from one point onwards, nuclear for some small "fighters" and missiles).
- Premise: FTL Comms are not possible (until a point, and only for one faction... until another point, then it is avaible for two factions. In all cases, this can only works inside of the solar system).
- Premise: all ships and missiles have a top speed they cannot surpass, even with constant acceleration, without suffering damage to the frontal systems
- Effect: Missiles use this same system for propulsion (but at one time, they get a second and then a third reaction drive). A drive cannot be turned off and then reignited, and some energy in the propulsion system is needed for a missile to not go "ballistic" (straight line. Missiles are programmed to self-destruct to not ruin somebody's day millions of years after launch). Also, the propulsion system has to be on at launch.
- Limitation: missiles are very limited by space: they are essentially controlled/aided by the launching ship, meaning distance has an effect on accuracy (once the in-system FTL comms and multiple drices missiles are researched, this becomes irrelevant).

- Relativistic kills: a ship accels to its max (about 500 gravities in the first books, about 600 or so in the later ones) in a collision course with its target, and then launches its missiles configured to get most speed. 0.96c is possible, but the missile will go in ballistic, and the propulsion system can be tracked while engaged. Since the missile has to go ballistic and you had FTL warning of its launch (and even at lightspeed, lag is there: it takes hours at a constant acceleration of 500 gravities to cross a solar system).

Conclussion: in this Setting, relativistic Weapons are only useful against targets that cannot dodge, like space stations or planets.
Habitable planets are protected from orbital bombardment by an edict enforced by the biggest navy in the setting, by the way.

Prophet710 Prophet710's picture
OK, so

OK, so

Next question. Could you miniaturize this, something the size of say, a Javelin (the ballistic missile launcher suite, not the spear you throw). Obviously not a one shot kill, but more like a recoil-less 20 cal. ??

"And yet, across the gulf of space, minds immeasurably superior to ours regarded this Earth with envious eyes. And slowly, and surely, they drew their plans against us."

Arenamontanus Arenamontanus's picture
Prophet710 wrote:Next

Prophet710 wrote:
Next question. Could you miniaturize this, something the size of say, a Javelin (the ballistic missile launcher suite, not the spear you throw). Obviously not a one shot kill, but more like a recoil-less 20 cal. ??

Yes, it is called a particle rifle. Of course, the missiles are now individual protons.

The problem with RKVs is how to spend the energy needed to accelerate the projectile without vaporising it. And if you can get that much energy, you also need to consider whether it is best to just beam it straight at the target instead. RKVs do not make sense in all settings.

(The classic RKV novel is Pellegrino's "The Killing Star")

Extropian

Prophet710 Prophet710's picture
OK so, if you needed more

OK so, if you needed more power obviously you're going to have something that needs to hold the power source. Like a beefed up exoskeleton? Or even a highly specialized synthmorph.

Is anyone familiar with the Glitterboy Boom Gun?

Would this even be possible to engineer? Throwing a small tungsten slug at .96c using power armor that is basically a mobile fusion reactor.

"And yet, across the gulf of space, minds immeasurably superior to ours regarded this Earth with envious eyes. And slowly, and surely, they drew their plans against us."

NewAgeOfPower NewAgeOfPower's picture
Existing superconducting

Existing superconducting batteries could do one shot (assuming 50 kilos of batteries, and future batteries 50x better than today's best; 1.01 Mj/KG), but your problems are weapons efficiency and projectile size.

A 1 gram projectile travelling at .96c would develop an energy equal to 2.288E+15 Joules. This is beyond the energy possibly generated by a humanoid sized system, but perhaps in EP Tanks and other vehicles could generate this much power.

For comparison, a .50BMG rifle round weighs over 50 grams and delivers about 18,000 joules.

Your issue now is how much energy actually bleeds into the target- I can see it simply punching a hole through the target without significant damage- but even a 1% energy dump would result in a localized explosion.

As mind to body, so soul to spirit.
As death to the mortal man, so failure to the immortal.
Such is the price of all ambition.

Xagroth Xagroth's picture
Just one detail... Recoil do

Just one detail... Recoil do exist. So if you shoot a bullet at 0.96c (please notice the missiles I mentioned before were launched from a "slow" ship at its max speed, then they accelerated all they could until burning themselves and the fuel: blind, but still powerfull) what will happen to you?
And also... a gun makes that thundering noise thanks to the bullet exiting at supersonic speeds. Imagine the kind of damage to the surroindings a 0.96c projectile can cause just by passing by. As a sidenote, a military aircraft cannot engage its afterburners near a city to avoid breaking all glass around it (I was in an air exibitioin this saturday... the Harrier was interesting, but...).

Prophet710 Prophet710's picture
As far as shockwaves are

As far as shockwaves are concerned. I know a great deal about that from my military days. Being unable to engage ground soft and air soft targets with anything larger than a standard small arms round. The resulting concussive waves from something like a .20 or even a .50 cal can crush a human being in close proximity (at least internally).

But, I'm not concerned about all that in EP, I'm wondering IF it can be done given the technologies, not wondering about its repercussions...yet.

"And yet, across the gulf of space, minds immeasurably superior to ours regarded this Earth with envious eyes. And slowly, and surely, they drew their plans against us."

NewAgeOfPower NewAgeOfPower's picture
Prophet710 wrote:As far as

Prophet710 wrote:
As far as shockwaves are concerned. I know a great deal about that from my military days. Being unable to engage ground soft and air soft targets with anything larger than a standard small arms round. The resulting concussive waves from something like a .20 or even a .50 cal can crush a human being in close proximity (at least internally).

But, I'm not concerned about all that in EP, I'm wondering IF it can be done given the technologies, not wondering about its repercussions...yet.

That not only sounds outrageous but is complete BS. Firstly, even lightly armored helicopters are practically immune to the standard 5.56 NATO round, which, is by the way, supersonic. Even the standard 9mm Parabellum pistol round is supersonic.

You also have an effective 0% chance of actually damaging a fixed wing aircraft with a 5.56mm weapon.

Modern attack helicopters are armored against 23mm (.90 Cal) fire, and even their GLASS is proof against .50 BMG fire.

Even massed .50 cal machine guns mean nothing to fixed-wing assets, because they can easily fly 2 km or higher, after which .50 BMG rounds suffer a very radical drop off. The chance of getting hit by such weapons is minimal.

There are videos of people standing next to passing .50 BMG rounds without suffering internal organ damage.

Mythbusters also had an Supersonic Aircraft vs Glass test.

http://tinyurl.com/d3dogtf

As mind to body, so soul to spirit.
As death to the mortal man, so failure to the immortal.
Such is the price of all ambition.

Prophet710 Prophet710's picture
Hey that's just what I was

Hey that's just what I was told. You don't engage soft air or ground targets with anything heavier than a .50 without prior-auth. Something about Geneva Conventions.

"And yet, across the gulf of space, minds immeasurably superior to ours regarded this Earth with envious eyes. And slowly, and surely, they drew their plans against us."

NewAgeOfPower NewAgeOfPower's picture
Okay. But don't go around

Okay. But don't go around claiming the military taught you that the sonic boom from a .50 cal round is going to crush bystander's organs, unless you were trained by a Third World military.

As mind to body, so soul to spirit.
As death to the mortal man, so failure to the immortal.
Such is the price of all ambition.

DivineWrath DivineWrath's picture
Xagroth wrote:Imagine the

Xagroth wrote:
Imagine the kind of damage to the surroindings a 0.96c projectile can cause just by passing by.

The webcomic xkcd did cover what would happen if a baseball was thrown at 0.9c (ignoring how that was achieved). The effects are not pretty. You would probably be creating a creating a nuclear explosion in the barrel of the gun.
http://what-if.xkcd.com/1/

Xagroth Xagroth's picture
Prophet710 wrote:Hey that's

Prophet710 wrote:
Hey that's just what I was told. You don't engage soft air or ground targets with anything heavier than a .50 without prior-auth. Something about Geneva Conventions.

Yes, because that kind of weapons are considered "anti-material" ones, and cannot be used against personnell. Funny thing, a uniform is a "material", or a vehicle too. The Geneva Convention also forbids to shoot against medical vehicles if they sport the Red Cross (or equivalent) symbol and are unarmed and used for medical purposes. I think in WW2 some of the "hospital ships" sunk by the Germans were in fact being used to move troops and supplies, and today we have the Merkava version that exchanges the explorer's space for medevac stuff and its, therefore, unprotected by the Convention (because it is a tank!).

I think the only "relativistic" weapon we can implement in EP without breaking the setting's atmosphere of "hard" sci-fy would be laser weapons and the kind.

NewAgeOfPower NewAgeOfPower's picture
Xagroth wrote:

Xagroth wrote:

Yes, because that kind of weapons are considered "anti-material" ones, and cannot be used against personnell. Funny thing, a uniform is a "material", or a vehicle too. The Geneva Convention also forbids to shoot against medical vehicles if they sport the Red Cross (or equivalent) symbol and are unarmed and used for medical purposes. I think in WW2 some of the "hospital ships" sunk by the Germans were in fact being used to move troops and supplies, and today we have the Merkava version that exchanges the explorer's space for medevac stuff and its, therefore, unprotected by the Convention (because it is a tank!).

I think the only "relativistic" weapon we can implement in EP without breaking the setting's atmosphere of "hard" sci-fy would be laser weapons and the kind.

I've done the calculations before, but clearly I need to expand on them.

It is possible (theoretically) to build railguns that are 50% efficient, but no rail material would ever survive blasting something at .9C.

A coilgun is never in contact with the projectile, and therefore could hypothetically launch this relativistic projectile.

A 1 gram .96c projectile would have an energy of ~2.28E15 Joules, I compared it to a .50 BMG round, but perhaps a more suitable comparison is tons of TNT;

One ton of TNT (metric) has energy equal to 4.18E6 Joules.

Thus, our hypothetical projectile has more energy than 545 Kilotons of TNT! Thats 545,000 Tons of TNT! For reference, the Hiroshima nuclear device yield was ~20,000 tons of TNT! This is over 27 Hiroshimas and change!

Another comparison would be the American Minuteman III warheads- each MIRV's warhead is a mere 330 kilotons!

Assuming a coilgun efficiency of around 30%, you only need your capacitors/other energy jars to hold about 7E15 Joules of energy. Thats less than 2 Megatons of TNT! Or the energy supplied by joining 50 grams of Antimatter to normal matter.

Of course, Antimatter-Matter reactors can hardly be expected to even approach 50%, forget 100% efficiency... but it shows you, in EP, it is quite possible to use relativistic weapons. If you are willing to accept even smaller projectile weights, even the EP equivalents of Tanks could theoretically fire relativistic ammunition.

As mind to body, so soul to spirit.
As death to the mortal man, so failure to the immortal.
Such is the price of all ambition.

Xagroth Xagroth's picture
Mmm I think the Starship

Mmm I think the Starship Troopers videogame, with the SWARM engine, had some weapon like that. From what the friend that played it (and lent me his copy... now if I only manage to find time to play it... XD) told me, he managed to die five or so times before managing to fire the weapon without being caught in the shockwave of the projectile reaching the target. He was about 5 or more Km. from the aforementioned target...

So I'd say that this weapon, if used, would be a strategical one because of the distances involved, and would be better on orbit than on the ground, to maximize range.

nick012000 nick012000's picture
NewAgeOfPower wrote:Of course

NewAgeOfPower wrote:
Of course, Antimatter-Matter reactors can hardly be expected to even approach 50%, forget 100% efficiency... but it shows you, in EP, it is quite possible to use relativistic weapons. If you are willing to accept even smaller projectile weights, even the EP equivalents of Tanks could theoretically fire relativistic ammunition.

Though doing so in an atmosphere would cause a nuclear fireball with the tank at ground zero, which isn't survivable.

+1 r-Rep , +1 @-rep

NewAgeOfPower NewAgeOfPower's picture
Many EP locations don't have

Many EP locations don't have an atmosphere. Of course, there really isn't a point in having tanks in EP anyways...

As mind to body, so soul to spirit.
As death to the mortal man, so failure to the immortal.
Such is the price of all ambition.