Space Warships.

Lasers are an interesting conundrum. There's a rough calculation you can make determining the range at which you are guarenteed to hit a target, mathamatically speaking. It requires the radius of the target's crosssection and the relative velocities and accelerations between the target and firer.

Saying that (and plunking in some numbers), it is plausible to hit a ship a few million kilometres away with a laser. The problem then becomes making the laser powerful enough to do damage, since over that large distance the diffraction of the beam will be significant.

This means that either you need to stuff on your ship a lot of power reactors and the accompanying heat disposal systems (for your reactors and lasers, since lasers are not nearly 100% efficient) and all the trouble that entails...

... or you close the range, which poses its own problems since then you have to contend with enemy missiles with relatively short flight times. And may whatever ideology you believe in comfort you if a nuke actually manages to detonate close by. Even worse would be bomb-pumped lasers (each, despite the inefficiencies, probably having a greater power output than all of the ship's lasers combined) since those don't need to get close at all to cause distress. Technology depending, of course.

Ultimately, we come back to long range missile engagements. Sure, the missiles may take hours to get in range of the target, but it's not like the target is going to be able to get away. (One suspects the missile will be able to catch the ship, but not vice versa.) So within the confines of the technology involved, engagements lasting days may not be far out at all.

That will ultimately depend on the relative velocities involved. Any ship capable of withstanding near-detonations by nuclear weapons will shrug off low-velocity kinetic impacts.

After all, one expects that if a ship is designed to achieve 'high speed' interplanetary travel, it will have been designed to deal with space dust along the way. And orbital speeds tend to be somewhat slower.

Oh, no. You're understanding of this forum's mechanics is quite sound, I suspect. The 'post 68 and 69' comment was in reference to this site.

 

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lasers would probably be best, the highest velocity you can get out of a weapon. second best would probably a shotgun blast of very high velocity deuritium-tritium mixed pellets, shotguned so that it blankets a number of evasive thrusting a target ship may try to make.

since i heard a 1g pellet moving at a target-relative speed of 10km/s (earth LEO velocity is about 7.5km/s) would practically pulverize a tank, even if one of these pellets hit the target, it'd do some heavy impact damage. but since we'll say these pellets are moving at 150km/s relative, such speeds that the hydrogen in the pellets fuse in impact, you not only have insane amounts of kinetic energy, but an on-contact nuclear blast. extra-crispy.

that or a dual ion cannon. the idea being that positively charged ions are accelerated out one turret, and their negative counterparts (electrons) fired out a second cannon. the two beams would converge and neutralize in space (i could be wrong), but before that, a targeting formula could be used to aim the cannons so they converge right on the target ship. the massive electrical flow would superheat sections of the hull, and turn the ship into it's own EM distortion, frying sensors and electrical systems.

as for distance, there's no air distortion, no curvature of the earth's surface, so this isn't naval warfare. it's a milti-million-mile shootout.

I wouldn't be suprised if before battleships were built, sentrys were. you could have a war between earth orbital stuff and martian orbital objects just by high-velocity projectiles, or high energy beam weapons. a war mounted only on gargantuan energy cannons and mass-produced projectile launchers (for they'd probably blast themselves out of orbit after a few shots unless recoil-compensated)

 

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The shotgun blast idea is impractical at the scale required. You'd need a lot of 'pellets' to saturate the necessary volume. Best to stick with lasers and missiles.

A 2 g pellet impacting at a relative velocity of 200 kps will have just a bit more KE than a current 120 mm APDSR round. Needless to say, that's still insufficient energy to set off a thermonuclear reaction.

What you're talking about is a particle beam and none will do what you say. At best the particles impacting on the target will generate lethal radiation that will disable or kill the crew, assuming the target has really bad radiation shielding, or is using armour that results in such radiation.

Scrap the projectile weapons. Their effective range is far too short even against spaceships. About the only application for such things is to assist the launch of missiles (a 'cold launch' system, essentially.)

And since this discussion was for plausible scenarios as far as current science can see, you really should use the term 'laser' instead of 'energy cannon' or 'beam weapon.'

---

Enlighten yourself on the elements of spaceship operations here.

And if you're brave enough, search through this group.

 

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I would not opt for any of these solutions. I would go with missles that act as mines and are designed to penetrate the hull then seal the breach. The missles then release robotic "soldiers" that use computer hacking/ hand-to-hand/ guerilla warfare techniques to neutralize the crew without destroying the ships integrity. In space resources would be a rare commodity, I could not see wasting the material resources (the ship), the biological resources (food stores and crew remains) or the chemical resources (water and atmosphere). Not to mention the information contained in the computer systems. These mines could be fired from a ship like a missle or left to drift indefinitely as mines...

Even if the battle is lost, the soldiers (some of which may only be dedicated AI virus programs, and others could be mechanized fighting machines) would still be on board the enemy ship.

Here is an interesting idea that I had once, cacti have evolved to have an outer shell that does not allow moisture evaporation...imagine a genetically engineered cactus that grows on the surface of the moon, or in deep space as long as it is "fed" mineral resources. The eventual goal could be a hollow "living" ship that acts symbiotic to its crew. O2 - co2 cycle, food - waste exchange (with the help of specialized bacteria to break it down), etc.

I just thought of another weapon that I have not heard yet. The ship itself. If it was made with a super massive armored "nose cone", it could just aim at its enemy and turn on the engines. If the cone or ram shield can withstand he effects of raming another ship then who knows, perhaps it could also withstand the effects of any weapons fired at it (from the front anyway). A stellar icebreaker...oh, there goes the chaff idea...

- KitNyx

 

Fun, fun...I like this game.

- KitNyx

 

this is how I see it.

1. missile will be out because you can take them out with a quick laser blast as soon as you detect them.
2. projectiles would be too hard to aim (even a shotgun type burst) at the ranges we are talking.
3. it would be so hard to find someone in space that the only place you would fight would be where there were precious natural resources (asteroid fields rich in U235 would be valuable if you had a fission powered ship).
4. lasers would be a last resort, an EMP to knock out their defenses would be best, because a pirated ship would probably be quite valuable.
5. if you want to kill them, lasers are the way to go.
6.

a very good idea if you are taking out a stationary (moon base) target. I think you could probably manage the momentum enough to cause fusion upon impact (given enough time.)

 

Only if you fight at ranges of a sliver of a light second. Which is not likely to happen.

You won't get an EMP in space unless you're within a very strong magnetic field or atmosphere present. Even then, you'd need to detonate your bomb real close to the target, which could be difficult.

 

I don't get it, why would I need to be so close? you just watch for rocket bursts in all directions. the moment you spot something that is coming at you, blast it.

you can generate the magnetic field you need. just make a strong magnetic field around a nuke and detonate it (a little more complicated than that, but you get the idea). and yes, it would have to be close, but its hard to watch that much space, and since it does not need to impact, you could have it detonate as soon as someone's lasers hit it. they might get it in time, they might not.

 

projectiles would not be bad if you knew where the target was going. ultimately, nothing is sationary, a space station is just a space ship without an engine. it can't chane it's deltaV, just follow where gravity takes it. ploting it's location in the time it takes to fire a round into it, even at extreme distances, would only be a few calc. problems away, nothing a computer couldn't handle. a ship would be hard to hit because it CAN change it's deltaV. so, if you wanted to make sure it was dead, fire away with lasers until you either destroyed it or disabled it. if diabled, a deadlier projectile round can be fired, since you can plot it's direction easier. you could use this in several different scenarios, including firing EMP-mounted missiles to disable the target, request a surrender, etc. etc.

projectiles wouldn't be dead, they would just be regarded as a heavy ordinance, with massive damage potential and limited targeting abilities. plus, the fact that they won't use as much energy (or make as much heat) as a laser would probably make them appealing in certain scenarios.

but then again, if ships commonly employ mirrored surfaces, a laser would be pretty much useless unless you hit critical parts (a rocket nozzle or an outlet somewhere). i guess a maser would have to be the norm.

 

Have we already gone over nukes?

Just have drone nukes, heavily armored and with huge energy yields. Like in the gigaton range. The inside of the drone could be mostly plutonium.

Then have them attack enemy craft. They could be launched from a planet or orbiting station at incoming craft.

There could also be lightly armored very fast drones with lasers, chaff, pellets and a grappling claw to take out nuclear drones. The lighter drones could be released defensively to intercept incoming drones by using lasers, firing chaff, and even grabbing on the enemy's hull and detonating.

 

Run the calculation yourself.

(Time it takes for the target to move the radius of cross-section) = (Time it takes for sensor data to reach attacker and attacker's fire to reach the target)
Since r=vt+(1/2)a(t^2), t=(-v+(v^2+2ar)^(1/2))/a [by the quadratic equation]
(-v+(v^2+2ar)^(1/2))/a=d/s+d/w
(-v+(v^2+2ar)^(1/2))/a=d(s+w)/sw
d=[(-v+(v^2+2ar)^(1/2))/a][sw/(s+w)]
where:
d is the distance in light seconds in which one is guarenteed statistically to hit the target.
r is the radius of the target's cross-section in metres (decrease to decrease range)
v is the target's initial 'relative lateral velocity' (RLV) in metres per second (increase to decrease range)
a is the lateral acceleration of the target in metres per second per second (increase to decrease range)
s is the speed of your sensor in number of times the speed of light (decrease to decrease range, but generally is light speed)
w is the speed of your weapon in number of times the speed of light (decrease to decrease range, generally equal to or less than light speed)

If you want to find the maximum range at which you can hit something, replace 'r' with '2r' (calculate for the diameter, not the radius.)

It's a rough calculation, but it gives you idea just how close 'close' is. I assume a missile with a crosssection radius of 1.5 metres, a RLV of about 200 m/s, and an acceleration of 1 m/s/s. With light speed sensors and weapons, point blank range is just over 1000 kilometres. Max range is perhaps 2500 to 3000 kilometres.

(The same missile, assuming it starts from an RLV of 0 m/s, and an acceleration of a mere 100 m/s/s, will still be 'unhittable' at a range of some 40000 kilometres, still very very close in terms of space warfare. If the enemy launches from 1 light second away...)

Since I'm not a fan of contact-detonated nukes, I also assume that the enemy is using bomb-pumped lasers. And 3000 km is a comfortable range for a bomb-pumped laser. Going to need counter-missiles.[/quote]

You'd need an Earth-strength magnetic field to produce an EMP.

(EDIT: For more on EMPs and space, I refer you to this little search.)

IR detection would disagree with your assessment.

 

I have not followed or read all here, but perhaps can help. As I recall you need D/T at about 10e8 degrees to get fusion going. Once it is going, it makes heat if not too small and the yield you get will depend upon how long the plasma can met the "Larson criteria", which I forget. As temperature is average of KE and all the particle in the "fuse on impact" pelet have the same KE, it should not be hard to calculate the speed relative to target required to start fusion if one can assume the pelet stops on target quick enought and does not disperse too rapidly. I have strong doubts either of these "if conditions" can be met. I think the pelet wil "incorporate" whatever target mass is in front of it and cool as it heats this accquired mass, so a much higher invitial relative impact speed will be required that the simple calculation just out lined. I suspect that this higher speed wil just let it acquire more target mass in the same time so perhaps no relative impact speed will permit it (With the acquired target mass reach 10e8 degress)

All of the "inertial confinement ideas I know of trying to make fusion on Earth have the D/T pelet stationary and blast it with with powerful lasers from all sides (try not to knock it out of the multi-laser beam focus.) If pelet with KE were a route to fusion, I would think a pair of oppositely charged ones in some classing beam accelerator (pair of accelerators?) wold have a better chance of fusion than pelet on target does and hve been tried. (Not that I think such an approach could ever yield net energy.)

Summary: I don't think the D/T pelet inpact fusion bullet will work, but I surely could be wrong before the emeny gets near good old solar system

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you're assuming an alien attack, eh? i think in that case, ifthey could go interstellar, the could develop full-spectrum cloaking systems and wield antimatter weapons, and maybe the aliens would have evolved technologically to be postalien, like an equivalent of posthuman. Then, they could handle very high gees, think faster, react quicker, figure out an attacker's strategy and adapt, and etc., making targeting even tougher. We'd be screwed, if we could even detect them.

I figured we were assuming the traditional humans-angry-at-other-humans way of life we all have come so fond of...

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A thorough two-part article recently published on this exact subject, from Strange Horizons ezine:

http://www.strangehorizons.com/2005/20050606/hunter-1-a.shtml

http://www.strangehorizons.com/2005/20050613/hunter-2-a.shtml

 

I personally believe that nukes are out of the question in space warfare.

The majority of the damage a nuke does is in the blast wave, which you will not get it space because of the lack of an atmosphere.

The EMP from a nuclear blast is a result of the Compton effect when the radiation from the nuke knocks electrons out from air molecules. This, when combined with the Earth's magnetic field produces the EMP blast. However in space there is no atmosphere nor a magnetic field.

So the only damage a nuke would be able to do in space would be by the radiation. But even so the lethal radius of the blast would be at the most a few kilometres to take out an armoured spacecraft, maybe even less if it is radiation shielded.

Projectile weapons actually seem quite feasable if the target is not too far away, perhaps within a thousand kilometres or so. Still, the velocities of the projectile would have to be at least 10km/s to be effective.

As for the accuracy part, since projectiles are relatively cost effective, you could simple fire tens of thousands of relatively small projectiles and one of them hitting the target would be enough to take it out if the velocity it is fired at them is high enough. The rule of space warfare regarding projectile weapons states that: An object impacting at 3km/s delivers kinetic energy equivilent to it's mass in TNT. Because of this, it doesn't really matter the size of the projectiles you are firing so long as they are fired at a high enough velocity.

Another advantage of projectile weapons would be that in space, there is no atmosphere to slow the projectile down so theoritically a bullet could go on for eternity till it hits something.

However for projectiles the relative speeds of the 2 fighting spacecraft are very important, since the velocities most spacecraft travel at in space are quite high. For example you could leisurely toss a 1kg projectile at 10m/s into the path of a spacecraft flashing by at 25km/s and the impact should be more than enough to destroy, if not cripple it.

The opposite is also true. If you fire a 1kg projectile at a speed of 1 000 000m/s at a spacecraft moving at 999 999m/s, it would only impact at a speed of 1m/s, which would at the most cause a small dent unless it ends up in the engine or something.

I think as this discussion goes on, we will simply wind down to this conclusion: Space warfare is impossible.

 

Still if you asked me what weapon I would say to be most effective in space combat I would say the laser.

 

"And what better way to launch missiles than with autonomous fighter drones"

it would be considerably simpler, cheaper and more effective to put expolsive charges in these 'autonomous fighter drones' to create long range missiles, rather then firing drones which fire missiles

 

woudln't that be a guided missile?

 

a posibility

i predict ships that have thick extremeley dense exteriors and multichambered interiors so that a single penetration wouldnt be catastrophic. titanium or something similar would be used. mabey they would fire tungsten projectiles via large scale magnetic propultion tracks, the projectiles would be designed to penetrate superdense armor, and then nuclear missles or something that could finish the already opened up ship.

military ships would probably be alot like the giant aircraft carrying ships that sail the seas now. they would operate like a miniature city and need lots of maintenence.

mabey....

 

a ship with that much armor would be tough to maneuver, and would have to be all armor and propellent (little room for anything else) to be able to do anything. sounds more like a very safe station to me.