Space naval combat (Segway from Antimatter thread)

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jsnead jsnead's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
The problem is that stealthing ships by radiating away energy so that enemy sensors fall into interference fringes probably doesn't work for simple geometric reasons. You need to keep the enemy in these bands, but you may not know or control how he is moving. He might also be far away, meaning that it matters where your fringes were at the point in time he is seeing - you would actually need to steer in certain directions to keep him in the dark, quite likely forcing you to move somewhere you don't like. Now add a second enemy sensor moving independently...
I've thought a lot about this issue. Stealthing a ship that's not under acceleration is difficult and requires either heat sinks (making it short term) or directional radiators, but it's possible. However, it's also often useless, since observers can simply calculate where the ship is based on it's last known position and velocity, when it was using it's drive. The only way I can see around this is to use either cold compressed gas thrusters (which has a truly pathetic ISP) or *maybe* a mass driver firing dense, heavy projectiles - if you used some sort of container to accelerate the mass inside, then the container would get most of the heat, and the mass would remain near ambient temperature. Of course, you'd need to recover and reuse the container, which would reduce the drive efficiency. I'd be shocked if you could do better than 200 ISP (less than half a H-O chemical rocket), but with either of these methods, a ship could maneuver enough while coasting to avoid being an obvious target. Of course, given that the velocity imparted by these means is so much less than the velocity imparted by a conventional drive, and that everyone will be aware of this tech, what this means is the position of a coasting ship will simply be known to be within a range of values, rather than being exactly located. Active sensors will be able to do the rest if it gets close, and sending out drones with active sensors within its possible position would find it further away, but it's position will be uncertain in the absence of either drones or a close approach to the people looking for it. Not ideal, but useful for some purposes. My best guess would be to use heat sinks combined with mass drivers to allow a ship to remain stealthy for a few hours. If those are the right few hours, this might be useful.
OneTrikPony OneTrikPony's picture
Re: Space naval combat (Segway from Antimatter thread)
So, "cloaking" your ship can only accomplished in relation to a portion of the sky. In comparison to trying to implement a radiator that ony emits energy in one direction, How effective would it be to simply hide behind a Solar Sail sized umbrella of smart materials? Your "Wake"--the exhaust of your engine--tells anyone with a telescope your mass, vector, DeltaVcapacity, the specs of your engine(s), and what color under wear you're wearing. How effective would it be to disburse little fusion fireworks into your wake to create some confusion in that data?

Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

valen valen's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
The problem is that stealthing ships by radiating away energy so that enemy sensors fall into interference fringes probably doesn't work for simple geometric reasons. You need to keep the enemy in these bands, but you may not know or control how he is moving. He might also be far away, meaning that it matters where your fringes were at the point in time he is seeing - you would actually need to steer in certain directions to keep him in the dark, quite likely forcing you to move somewhere you don't like. Now add a second enemy sensor moving independently...
Its also very likely that any fixed position worth attacking in EP will be able to cover a significant volume with cheap simple sensor platforms. These would be pretty easy to manufacture if you can make spaceships and then just scatter them across the system. It may take months or years to get them all into position, but once they are up they pretty much take care of themselves and could feed telemetry to your ships anywhere in the solar system. I would imagine that a sort of cold war is going on now in the deeps of the solar system and in the high and low elliptical orbits of the sun. The ones that pass above and below the system would be an ideal position for observation and all sides are probably sabotaging each others deep senor networks in untraceable ways hoping to degrade it enough to give them an edge if the shooting ever starts.
Xarei Xarei's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
The WMAP satellite has a sensitivity of around 1 milliKelvin per second in its measurements of the cosmic microwave background, so we should expect EP sensors to be at least that sensitive.
Ah, I should have looked into satellites rather than medical instruments, doesn't sound like that is really any leeway.
Arenamontanus wrote:
The problem is that stealthing ships by radiating away energy so that enemy sensors fall into interference fringes probably doesn't work for simple geometric reasons. You need to keep the enemy in these bands, but you may not know or control how he is moving. He might also be far away, meaning that it matters where your fringes were at the point in time he is seeing - you would actually need to steer in certain directions to keep him in the dark, quite likely forcing you to move somewhere you don't like. Now add a second enemy sensor moving independently...
Well, assuming for a second that a ship used a beam of collimated light for its propulsion system it wouldn't need to alter the vector of its thrust (much) to change which areas behind it were in the destructive interference bands; it could simply alter the distance between the emitters. Fundamentally though all of the radiation is going to be within a 180 degree arc perpendicular to the direction of thrust, and it is not really feasible to create more than 10-15 degrees of destructive interference* so a wide sensor network would be able to narrow down the direction of thrust to a 20-30 degree arc. Although... if instead of having the emitters on one vehicle, you had several vehicles each opening and closing emitters at random, you might be able to really confuse the issue. On the other hand, coordinating this sort of nanometer precision between multiple spacecraft may be beyond EP technology, or at least expensive in terms of Qbits. * This is based on dorking around with this http://www.falstad.com/ripple/ex-2source.html I'm sure that math could be done to get a better estimate.
The Sandman The Sandman's picture
Re: Space naval combat (Segway from Antimatter thread)
While it may not be possible to get strategic surprise, since there's no good way to disguise the IR emissions of your drives, I may have come up with at least one way to prevent your enemy from knowing exactly where your ships are going to be by the time they get within firing range of their target. Why not tether the ships of your fleet together, such that they're a single body for the purposes of firing their engines to reach cruising speed, then have them separate after they've finished boosting? It might be able to disguise the composition of the fleet, and assuming you spin the fleet as a unit before detaching the tethers you could probably spread your fleet out over an expanding cone-shaped region of space as you approach the target. Since the tether-related maneuvers are purely mechanical, they won't produce any EM emissions giving away the altered speed and trajectory of the vehicles involved.
OneTrikPony OneTrikPony's picture
Re: Space naval combat (Segway from Antimatter thread)
My understanding is that it's not just the wake that people are looking for. Any ship is hotter than space. Even if you could find a way to have 0 power consumption while you're coasting your ship will still pick up and reflect radiation from the sun.

Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
I'm working on a serious writeup of my take on this thread, and I am starting to think the detectability issue is more complicated than we tend to think. The atomic rocket estimate for detection seem to be a bit high and there are various tricky ways to get partial stealth. But in general anything heavy that accelerates will have an *amazing* power output - I think the destroyer has a *terawatt* reactor - and that means that big burns will be detectable from afar.
The Sandman wrote:
Why not tether the ships of your fleet together, such that they're a single body for the purposes of firing their engines to reach cruising speed, then have them separate after they've finished boosting? It might be able to disguise the composition of the fleet, and assuming you spin the fleet as a unit before detaching the tethers you could probably spread your fleet out over an expanding cone-shaped region of space as you approach the target. Since the tether-related maneuvers are purely mechanical, they won't produce any EM emissions giving away the altered speed and trajectory of the vehicles involved.
Yup. I think this could work. Of course "fleet" here is going to be a lot of submunitions, missiles, sensors, independent railguns and what have you. Capital ships in battle probably spread out their components over a big volume - that destroyer is more like an armored can containing useful parts. One idea suggested yesterday by a friend was that railguns could perhaps be built out of parts that could be separated (and some hefty batteries and sensors). They get launched into space, separate into a large volume yet remain connected by monofiliament wires. When there is a reason to try to fire the parts are dragged together, merge, fire and then separate. With enough smarts these medusa-guns could even switch parts if some have been destroyed.
Extropian
King Shere King Shere's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
One idea suggested yesterday by a friend was that railguns could perhaps be built out of parts that could be separated (and some hefty batteries and sensors). They get launched into space, separate into a large volume yet remain connected by monofiliament wires. When there is a reason to try to fire the parts are dragged together, merge, fire and then separate. With enough smarts these medusa-guns could even switch parts if some have been destroyed.
Imagine a"railgun" made by launchpads / massdriver catapults, "carriers" connect their "short" rail-guns or launchpads to make bigger ones, or one huge.
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
In my writeup (it is *so fun* to calculate when you can hide in the sun or how big fusion reactors are!) I have come to one big conclusion. There is one crucial EP tech that really gives the powers who have it a major tactical advantage: quantum entanglement. Space combat is going to be filled with sensors, missiles, weapons buses/fighters, decoys and whatnot. Being able to figure out where the enemy assets are and neutralizing them is highly problematic and requires a lot of comparison of observations. If you only have normal quantum encrypted laser links your comms are going to be sub-lightspeed *and* you are going to be revealing location by minor heat emissions when trying to signal (lasers have low efficiencies). With QE you know where everything is "right now" (modulo the lightseed delay from target to your sensor), you can give commands instantly and you do not have any comms emissions. For example, a sensor detects where a nearby ship is. With STL, first the message has to reach the nearest weapon, which fires. During the time the signal was going to the weapon the ship will be taking evasive action. So in order to hit the weapon better be very close. With QE the weapon can fire as soon as the message is sent. If we assume the weapon 10,000 km away, in the first case 0.03 seconds have been lost. The ship still has some chance of dodging while the weapon fire is approaching, but it has noticeably less (for a laser shot, we have halved its period of grace, which means 1/16 smaller area that has to be hit). If the weapon is steerable like a missile it can even be given updates on where to go in flight from the sensor. This makes qubits a much more strategic resource than before. Sure, being able to play on the stock market or send postcards to your aunt the exoplanetary explorer is nice. But given this, all military ships need to have a lot of qubits. Essentially every little device that is released into battle will be part of a qubit network, sending ultra-brief messages to each other. It is expensive, but being able to really cut communications lags matters enormously in the fast, deadly environment of a space battle - especially if the opponent haven't got them.
Extropian
valen valen's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
This makes qubits a much more strategic resource than before. Sure, being able to play on the stock market or send postcards to your aunt the exoplanetary explorer is nice. But given this, all military ships need to have a lot of qubits. Essentially every little device that is released into battle will be part of a qubit network, sending ultra-brief messages to each other. It is expensive, but being able to really cut communications lags matters enormously in the fast, deadly environment of a space battle - especially if the opponent haven't got them.
Also, since qubits allow communication between two fixed points only (think carrier pigeon), you need a central router to connect all your various fleet assets. That means that all your ships would have qubit reserves between them and a central command center. Possibly also a backup command center.
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
valen wrote:
Also, since qubits allow communication between two fixed points only (think carrier pigeon), you need a central router to connect all your various fleet assets. That means that all your ships would have qubit reserves between them and a central command center. Possibly also a backup command center.
You can set up your network in many different ways, actually. The central router linked to all assets minimizes the use of qubits, but all info has to go to it, be processed and then sent to other assets - it can get overloaded, and if it is hit the network crashes. If the network is a tree, sections of it can still function even if the hub is gone. Having all assets have a qubit link to all other assets maximizes resiliency but costs a lot. You can probably optimize things by considering which assets need to get what data where quickly, and estimate how long battles will take (measured in bits). The real question is how much you can remote control your assets from afar. Imagine having a fleet run by pilots sitting safely in New Shanghai. Unlike drone weapons there is not even a lightspeed delay. My guess is that normally you still want to have people in the actual fleet, since qubits can run out when missions get drawn out.
Extropian
valen valen's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
You can set up your network in many different ways, actually. The central router linked to all assets minimizes the use of qubits, but all info has to go to it, be processed and then sent to other assets - it can get overloaded, and if it is hit the network crashes. If the network is a tree, sections of it can still function even if the hub is gone. Having all assets have a qubit link to all other assets maximizes resiliency but costs a lot. You can probably optimize things by considering which assets need to get what data where quickly, and estimate how long battles will take (measured in bits). The real question is how much you can remote control your assets from afar. Imagine having a fleet run by pilots sitting safely in New Shanghai. Unlike drone weapons there is not even a lightspeed delay. My guess is that normally you still want to have people in the actual fleet, since qubits can run out when missions get drawn out.
Actually a tree makes a lot of sense as that would mirror an existing military hierarchy.
Dry Observer Dry Observer's picture
Re: Space naval combat (Segway from Antimatter thread)
I've been trying to stay out of too much military strategy, since space warfare, cyberwarfare, and WMD strategy are a lot closer to reality than even most EP tactical situations. Having said that...
Arenamontanus wrote:
In my writeup (it is *so fun* to calculate when you can hide in the sun or how big fusion reactors are!) I have come to one big conclusion. There is one crucial EP tech that really gives the powers who have it a major tactical advantage: quantum entanglement.
Yes. An one absolute, almost unstoppable threat faced by forces communicating at light speed becomes far easier to handle using quantum entanglement. Which is... What happens if someone simply fires a really powerful burst at you at either lightspeed or high relativistic speed? There are extremely potent weapons that could be used in this fashion, and some of them are even obvious. But if you can't even pick up the incoming attack, or be informed by your remote sensors, before it's right on top of you, then no matter how your response time is, you're already dead.* *Alright, technically there are still a few tricks you can pull. But there's a reason I don't put this kind of stuff online, or even on isolated computers. :p ;)
Arenamontanus wrote:
Space combat is going to be filled with sensors, missiles, weapons buses/fighters, decoys and whatnot. Being able to figure out where the enemy assets are and neutralizing them is highly problematic and requires a lot of comparison of observations. If you only have normal quantum encrypted laser links your comms are going to be sub-lightspeed *and* you are going to be revealing location by minor heat emissions when trying to signal (lasers have low efficiencies). With QE you know where everything is "right now" (modulo the lightseed delay from target to your sensor), you can give commands instantly and you do not have any comms emissions. For example, a sensor detects where a nearby ship is. With STL, first the message has to reach the nearest weapon, which fires. During the time the signal was going to the weapon the ship will be taking evasive action. So in order to hit the weapon better be very close. With QE the weapon can fire as soon as the message is sent. If we assume the weapon 10,000 km away, in the first case 0.03 seconds have been lost. The ship still has some chance of dodging while the weapon fire is approaching, but it has noticeably less (for a laser shot, we have halved its period of grace, which means 1/16 smaller area that has to be hit). If the weapon is steerable like a missile it can even be given updates on where to go in flight from the sensor. This makes qubits a much more strategic resource than before. Sure, being able to play on the stock market or send postcards to your aunt the exoplanetary explorer is nice. But given this, all military ships need to have a lot of qubits. Essentially every little device that is released into battle will be part of a qubit network, sending ultra-brief messages to each other. It is expensive, but being able to really cut communications lags matters enormously in the fast, deadly environment of a space battle - especially if the opponent haven't got them.
Yes, and it's one reason the big polities have an edge, but another reason why a bunch of cooperating habitats, otherwise small and isolated, can arguably still manage a decent defense in EP. That, and the simple fact that post-TITANs, pretty much everyone with a six-shooter and a shiny badge expects that they'll have to deal with [i]some[/i] kind of off-the-charts cataclysm... and for the most part, already have. Oh, and the incredibly strategic nature of qubits makes them a perfect unit of exchange in EP, at least until someone can mass produce them far, far more cheaply. After all, they're expended when used, the demand keeps expanding, and even if the market were flooded with them... you'd just end up with QE egocasting. And then QE egocasting for the masses. And then... for the Prometheans and the TITANs -- the [i]real[/i] data hogs. And then... [b]QE Spam![/b] ([b]Argh![/b] Basilisk hack! [i]The horror... the [b]horror![/b][/i])

-

OneTrikPony OneTrikPony's picture
Re: Space naval combat (Segway from Antimatter thread)
Actually I don't think there's any way to avoid having roughter situations. Since two entangled devices have to be entangled in close physical proximity there are some serious logistical implications. I think you'll end up with a roughter on a capitol ship or base for each fleet then each squadron, from Drednought to destroyer to missile, will have a tree configuration. the best thing about quantum entanglement is that it makes Space Marines and maned small ships tactically desireable! You'll always want to capture the enemy's entangled coms if possible.

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Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
OneTrikPony wrote:
Actually I don't think there's any way to avoid having roughter situations. Since two entangled devices have to be entangled in close physical proximity there are some serious logistical implications.
Yes, but as described in EP once the pair is entangled they can move freely. So you have a qubit factory at your fleet base, and before each mission you tank the ship containers full of linked qubit pairs [*]. As you are preparing for battle the qubits are distributed between the assets - either so they link to a qubit in your C3I system or so they link to each other. After the battle you recover the remaining qubits, if it is worthwhile. No need for a central router, although I can imagine it to be desirable for some systems. [*] Or triples, quadruples etc - I really should check the limitations of extended entanglement in my textbook; my guess is that it can be collapsed far too easily.
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the best thing about quantum entanglement is that it makes Space Marines and maned small ships tactically desireable! You'll always want to capture the enemy's entangled coms if possible.
But qubits are the easiest thing in the world to destroy, too. I think information security and getting into enemy systems play a huge role in space battles, but you capture the comms by hacking his computers.
Extropian
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
Dry Observer wrote:
What happens if someone simply fires a really powerful burst at you at either lightspeed or high relativistic speed? There are extremely potent weapons that could be used in this fashion, and some of them are even obvious. But if you can't even pick up the incoming attack, or be informed by your remote sensors, before it's right on top of you, then no matter how your response time is, you're already dead.*
Yes, I wrote up the relativistic kinetic kill system in my unconventional weapons post. But you actually poked a beautiful hole into it! If the Consortium have sensors near Jupiter or Saturn telling them that the Junta or Commonwealth have launched a relativistic attack, they have many *minutes* do do something. The weapon goes from "surprise megakill" to "expected megakill" - which makes a lot of difference if you can egocast your leadership to safety, launch retaliatory systems or do other responses. However, relativistic kill still works fine against enemies not using extended QE spysats - like all the minor powers.
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[b]QE Spam![/b] ([b]Argh![/b] Basilisk hack! [i]The horror... the [b]horror![/b][/i])
And given the FTL/timetravel issues, it could even come from the future! "This is not a hoax: I am really sending you this message from the future to tell you that you *must* invest in this stock in order to become as rich as I am!" "Next week Mohammar Yasin, the despot of Bostrom 5 will die. He will have deposited 50 million credits in a lunar bank account bearing a certain number. if you act now and get the account, you will be able to launder the money for the Planarian Liberation Army and earn 3 million yourself!" "Mammal, we provide you with Civilization Enhancer - discreetly delivered for happiness and epistemic integrity!"
Extropian
nezumi.hebereke nezumi.hebereke's picture
Re: Space naval combat (Segway from Antimatter thread)
The question of relativistic speeds brings up some interesting questions. As most people know, if I approach lightspeed, my timeline moves slower relative to a stationary observer. We see this in practice when highly volatile particles with lives measured in seconds manage the trip from the Sun to the Earth which takes 8 minutes. I've not figured out how to use this yet, but for an illustration, imagine I have a warhead which explodes so quickly that its destructive potential is reduced by its speed. If I take this warhead, accelerate to close to c, and detonate it en route, that process which normally takes half a second will be spread out across minutes or even hours - spreading out the destructive strength and, hopefully, the damage to the target. (Also interesting to note that guided projectiles will have less time to react to stationary defenses.)
OneTrikPony OneTrikPony's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
So you have a qubit factory at your fleet base, and before each mission you tank the ship containers full of linked qubit pairs [*]. As you are preparing for battle the qubits are distributed between the assets
If I can rephrase that to something that my redneck intelect will wrap around; You got a big box o' Q-bits at the base. Before everyone heads out you take some o' the Q-bits out of the box and put them in everyone's radio. Then when one radio squaks all radio's hear it including the base. That's not a network, that's a frequency. Isn't it? Seems like that's going to use up a shitton of Q-bits all the way around given that every bit sent from one unit will use up one bit from the reservoirs of every unit. I can't decide if that's a good idea or not. It's desirable that everyone have the total tactical picture but it seems to me that the tree config would be more Q-bit efficient.
Nezumi wrote:
that process which normally takes half a second will be spread out across minutes or even hours - spreading out the destructive strength and, hopefully, the damage to the target.
Isn't time a component of power? i.e. if you increase the time component of the equasion you decrease the force component? Or is there some relativistic effect I don't understand? PS> just a thought; but isn't the production of Q-bits likely to require a really big accelerator like the LHC or bigger? Cuz that would seriously impact the logistics of Q-bit production; Like you couldn't produce them onboard a ship or at a forward operating base. And you'd need either a lot of sunlight or a lot of reactor fuel. Does anyone know what the energy cost of isolating quarks is like compared to antimater production?

Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
OneTrikPony wrote:
Arenamontanus wrote:
So you have a qubit factory at your fleet base, and before each mission you tank the ship containers full of linked qubit pairs [*]. As you are preparing for battle the qubits are distributed between the assets
If I can rephrase that to something that my redneck intelect will wrap around; You got a big box o' Q-bits at the base. Before everyone heads out you take some o' the Q-bits out of the box and put them in everyone's radio. Then when one radio squaks all radio's hear it including the base.
Nononono... qubits are *pairs* (leave out my speculations about triples etc). You can do something to one qubit in the pair and the other responds. So you can only signal to me if I have some qubits paired with some of yours. In practice I expect that we even have to decide to use some of the pairs for my messages to you (I keep my end in the sender device and you keep your end in the receiver device), and some of the pairs for your messages to me. Nobody else can listen in.
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Nezumi wrote:
that process which normally takes half a second will be spread out across minutes or even hours - spreading out the destructive strength and, hopefully, the damage to the target.
Isn't time a component of power? i.e. if you increase the time component of the equasion you decrease the force component? Or is there some relativistic effect I don't understand?
Suppose you build a bomb that normally would explode after 1 second. You accelerate it to 85% of c, and now you will see it explode after 2 seconds. The explosion also seems to take twice as long - the same amount of energy gets released, but more slowly. Now, this is pretty irrelevant to the damage it will do. Because when it slams into anything it will have a kinetic energy equal to its own mass: even if it was made of marshmallows it would detonate as if it was antimatter.
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PS> just a thought; but isn't the production of Q-bits likely to require a really big accelerator like the LHC or bigger?
Nope. Current qubits are mainly made by shining lasers at quantum dots. What tech is required to make EP qubits is unclear, but it it is expensive and likely requires some very sensitive equipment. I think it is likely that you cannot make them on a ship, you probably need something like the orbital qubit factory Nimbus operates in Mars orbit (mentioned somewhere) full with experts and expensive equipment. So for practical purposes it could just as well be the LHC.
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Does anyone know what the energy cost of isolating quarks is like compared to antimater production?
You cannot isolate quarks. Because of the strong nuclear force they are held together into hadrons ridiculously strongly - so strongly that when you pull one out you have to supply more energy than it takes to make a quark-antiquark pair, which immediately appear, turn your quark into one part of a meson (a quark+antiquark particle) and the original particle into some other particle. Of course, as mentioned in Greg Bear's "Anvil of Stars", a weapon that could convince two quarks on opposite sides of a planet that they had a strong force link would be *very* devastating... But that is currently outside EP tech, and Firewall will likely fight tooth and nail to keep it that way.
Extropian
icekatze icekatze's picture
Re: Space naval combat (Segway from Antimatter thread)
hi hi I think exploding a warhead before impact at relativistic speeds would probably increase the damage it would deal to a spaceship or space station, but would be mostly irrelevant to the damage output on a planet. A projectile moving at relativistic speeds like that is likely to pierce straight through the entire thickness of a ship before the explosion has much of a chance to expand. However, if it is exploded ahead of time the impact area is going to be much larger. At that speed even the smallest fragment is going to cause massive damage. The best way to reduce damage is to reduce the projectile speed. Perhaps the projectile is a particle beam or powerful accelerator that fires just after it passes by the target, hitting the opposite side at a much lower speed.
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
icekatze wrote:
I think exploding a warhead before impact at relativistic speeds would probably increase the damage it would deal to a spaceship or space station, but would be mostly irrelevant to the damage output on a planet.
Yes. At hypervelocity impacts it only matters how much mass is striking you, not what kind of mass it is or even how hot it is. But the width of the mass matters a lot to whether you get hit or not, so blowing up missiles a short while before a hit makes sense: it is harder to stop all the individual fragmentswith point defences, and harder to evade.
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A projectile moving at relativistic speeds like that is likely to pierce straight through the entire thickness of a ship before the explosion has much of a chance to expand.
The penetration depth is going to be roughly equal to the length of the impactor times the ratio of its density to the ship. Typically, a solid impactor is going to embed itself fully in the hull. An explosion is going to be much thinner than the ship and pancake along the surface.
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The best way to reduce damage is to reduce the projectile speed. Perhaps the projectile is a particle beam or powerful accelerator that fires just after it passes by the target, hitting the opposite side at a much lower speed.
That is going to be very wasteful, since you need to not just armor it against very hard impacts but supply it with an energy source and targeting.
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nezumi.hebereke nezumi.hebereke's picture
Re: Space naval combat (Segway from Antimatter thread)
re: hyperspeed projectiles - I don't think this would make much difference if we're talking about just shooting rocks at the enemy. I'm trying to think of something more out of the box. For instance, instead of detonating your high-radiation explosive at a single point, accelerate it so it smears the radiation across a wide area. To make things more interesting, since the most potent forms of radiation lose their power so quickly, adding time dilation may make it more effective to deliver these forms of radiation directly to the target (obviously, the radiation can't be moved any faster - it always goes at c - but if we smear out the process of generating that super-gamma radiation, it may have a positive impact). But I feel like there's another brilliant application there, I'm just not seeing it.
icekatze icekatze's picture
Re: Space naval combat (Segway from Antimatter thread)
hi hi Arenamontanus: I don't know why someone would want to attempt to lessen the damage of a relativistic weapon, I was just trying to come up with examples of how you would do it for the sake of argument. I figure that anything that is going that fast is probably going to be a big long rocket, big enough to cut though a ship if it is hit perpendicularly. Nezumi: Perhaps it would be easier to make a laser out of that radiation?
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
Relativistic weapons are likely useless against ships because you need a very big launcher that you cannot easily bring to the battlefield. And you can only hit things that you know are going to be in the path of the weapon, and this makes an evading spaceship a rather hopeless target. Meanwhile, habitats and defense emplacements make much better targets. Still, if you impact a *small* 1 kg projectile on a ship at 0.99c, the typical result would be that after traversing about 7 kg of hull it would have turned into a nuclear fireball. The kinetic energy is more than enough to blow through the ship in a few tens of nanoseconds, but during this time the fireball also expands to a size comparable to the ship, depositing its energy into ship material (i.e. blowing it up). I think most of the energy does end up in the ship. A heavier projectile at the same speed would shoot through it, turning into a fireball but not slowing enough to deposit all its energy in the ship - the ship would likely be about as nuked, but most weapon energy gets turned into a relativistic fireball shooting off on the other side. The temperature of relativistic objects is by the way a bone of contention, with several major physicists giving entirely different answers: http://www.ipc.bas.bg/PPages/Avramov/lectReliv.pdf For our purposes there is no problem, since we consider only the *effects* of relativstic weapons on more or less stationary structures. But the temperature of that fast-moving fireball is somewhat mysterious.
Extropian
jsnead jsnead's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
Relativistic weapons are likely useless against ships because you need a very big launcher that you cannot easily bring to the battlefield. And you can only hit things that you know are going to be in the path of the weapon, and this makes an evading spaceship a rather hopeless target. Meanwhile, habitats and defense emplacements make much better targets.
Of course, if a habitat has a relativistic launcher and a cloud of QE targeting sensors, then vaporizing an attacking vessel wouldn't be all that difficult. I can see Luna or Mars having such a defense, and Titan is also a good candidate. A lot of how useful such a weapon would be depends upon how far away large ships have to be from their target to attack. If the weapons actually manage to accelerate a small projectile to 0.8 C+ or so, and ships need to be within a few thousand km to attack, then with FTL comms on a cloud of targeting drones, hitting a large ship won't be all that difficult. One shot kills on any attacking ship, with no hope of point defense, isn't a bad thing for a large and wealthy habitat to spend money and resources on.
valen valen's picture
Re: Space naval combat (Segway from Antimatter thread)
I don't know if anybody in EP actually has relativistic weapons. They would require a LOT of energy. Think about it. We use the LHC at CERN to accelerate a single atom of gold to relativistic speed. Now scale it up in your mind to the kind of machine and power source required to accelerate a couple kilograms to relativistic speeds.
nezumi.hebereke nezumi.hebereke's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
Relativistic weapons are likely useless against ships because you need a very big launcher that you cannot easily bring to the battlefield. And you can only hit things that you know are going to be in the path of the weapon, and this makes an evading spaceship a rather hopeless target. Meanwhile, habitats and defense emplacements make much better targets.
You're still thinking very old-school - accelerate object A so as to impart the maximum damage on object B. But what if instead of that, we accelerate nanomachine A in order to complete X critical function in a non-Newtonian way, so it causes Y undesired effect on object B? Y could be something like desynchronizing q-bits, altering planar coordinates, creating visual obfuscation, etc.
Rhyx Rhyx's picture
Re: Space naval combat (Segway from Antimatter thread)
Hmm so if you would need nuclear or antimatter as a propellant, ultimately doesn't that mean the relativistic cannon (let's say) pretty much gets destroyed in the firing process? Are relativistic weapons one shot deals?
icekatze icekatze's picture
Re: Space naval combat (Segway from Antimatter thread)
hi hi I'm pretty sure humanity doesn't have relativistic weapons in EP. However, the TITANs or the Factors may be a different story, so I don't think it is entirely academic. Even with qubits, I don't think humanity is well prepared for a dedicated attack by relativistic weapons. Ships might be able to move out of the way and survive, but pretty much every habitat in the solar system could be wiped out in an instant. Defense against relativistic weapons would probably involve disabling the weapon before it is able to fire (or for rockets, before it goes ballistic) Arenamontanus: I was figuring a relativistic weapon would mass a good many tons, but for little itty-bitty ones, I concede that you are correct. For the larger ones, I guess even if they cut straight through, there would still be sufficient boom to destroy a ship anyway.
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
In my write-up of relativistic weapons (in this thread) I assumed them to be launched (if indeed anybody has built a launcher; I think this is a fun area to be uncertain about) through a series of antimatter detonations. In a later version (soon to arrive on my site) I mention some speculations that there might be a railgun-like way of launching them - we can certainly do it using particle accelerators (true itty-bitty relativistic projectiles), but whether macroscale projectiles can be launched like that is anybody's guess. A relativistic projectile has kinetic energy many times its mass-energy. It can do more damage than antimatter. But the acceleration process is going to be imperfect, leaving a sizeable multiple of that energy as waste heat in the "gun" - very likely blowing it up. It also obviously needs to have more energy than the projectile to do it, so it requires some very hefty power sources. The multi-terawatt fusion reactors of large spaceships are likely puny in comparison. QE comms actually reduce the utility of relativistic weapons a lot. They are still impressive and impossible to defend against, but no longer the perfect surprise weapon.
Extropian
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
nezumi.hebereke wrote:
You're still thinking very old-school - accelerate object A so as to impart the maximum damage on object B. But what if instead of that, we accelerate nanomachine A in order to complete X critical function in a non-Newtonian way, so it causes Y undesired effect on object B? Y could be something like desynchronizing q-bits, altering planar coordinates, creating visual obfuscation, etc.
Fine, describe the constraints on doing Y. In my ongoing writeup on space warfare (essentially this thread but with all the math worked out) one clear result is that clever methods *if they work* are much better than brute force. But clever stuff only works under certain conditions, while heating something beyond its vaporisation temperature always works. If you can desynchronize the qubits of a spaceborne asset you break a node in the enemy communications network and slow things down a bit - but to do that you need to get some kind of device close to the asset and hope the asset is not shielded against that interference (it will also still be able to function). If the device is instead a pinch of antimatter no shielding is going to save the communications through the asset or its functions. A clever hacker who suborns enemy comms is worth their weight in qubits - but there is no way I or anybody else can estimate the likelihood of it working or how that changes naval strategy beyond even more concern for encryption and hidden QE comms (I do note that the Brooks–Iyengar algorithm for distributed sensor networks can handle that a third of the nodes are faulty or suborned).
Extropian
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
I am putting in the last steps in my calculations about EP style space combat, and realized that I need help with some of the assumptions: how heavy and large are spacecraft? Based on this we get a lot of constraints on energy, weapons, detection distances and from that of course strategy. Here is my current estimates, and I would like to hear if anybody thinks they are completely absurd (and why): Ship, mass, volume, cross-section area, length Bulk Carrier: 100,000 ton, 1,000,000 m^3, 10,000 m^2, 100 m Destroyer: 10,000 ton, 40,000 m^3, 1200 m^2, 34 m Fast Courier: 1,400 ton, 5,600 m^3, 320 m^2, 18 m Standard Transport: 2,000 ton, 20,000 m^3, 740 m^2, 30 m LLOTV (MH): 300 ton, 10,000 m^3, 450 m^2, 40 m LLOTV (HO) 300 ton, 10,000 m^3, 450 m^2, 40 m SLOTV (MH) 100 ton, 3,000 m^3, 200 m^2, 20 m SLOTV (HO) 100 ton, 3,000 m^3, 200 m^2, 20 m SCUM Barge 20,000 ton, 150,000 m^3, 2,600 m^2, 50 m Fighter (MH) 10 ton, 40 m^3, 14 m^2, 2 m GEV: 15 ton, 26.4 m^3, 13.2 m^2, 6 m The length is obviously very debatable, since many ships will be strongly elongated (and will anyway extend enormous heat radiators and Whipple shields). In general I am pretty confident in the mass estimates as making some sense (they produce engine requirements that fit with the ships, IMHO) but volumes are much harder to estimate.
Extropian
OneTrikPony OneTrikPony's picture
Re: Space naval combat (Segway from Antimatter thread)
It looks like you're proposing something other than the 'Lollypop' configuration for your big ships. I'd love to know more about your thoughts on that because I've been entirely unable to come up with a more efficient design. I do think I might have proved that a hemispherical shadowshield would be lighter than a big thick plane of radiation soaking material. Question: in your listed masses are you talking "Dryweight" or are you including propellant? you allready know I'm not very learned about this stuff but I have spent some skull-sweat on it so I'll give you my thoughts if for no other reason than you could rule them out. A bulk carrier doesn't need internal cargo space. This is one ship where I'm certain that the configuration will be a lollypop design. All it needs are Spars to attach cargo modules and cables to stabilize those spars under the slight acceleration that it will achieve. Everything could be entirely modular even the crew compartment (if it even has one). In my mind's eye a bulk carrier has a lot of similarities to the rigging on an 18th century sailing ship. Everything is built inside the space version of Conex containers even habitable modules. Standard transport; the same as a bulk carrier except some of the larger ones have the extendable passenger modules for artificial G. And really big ones have a torrus like the Song Cai Flower from the Glory adventure. To me fighters will all be some variation of the Tie Fighter. I think Lucas got this one right. All the mass is centralized for quick and responsive maneuvering. Spherical ships turn better than long ones. They're also very efficiently shaped for storage as cargo. On your LOTV's; I've been unable to track down any information on the expected density of metallic hydrogen. If you have any information about this I'd really appreciate if you could share. If you've listed a dry weight I'd say you're pretty close to correct for ships that are capable of atmospheric re-entry. The space shuttle, (with all of it's heat shielding), has a dry weight of 75 tons. I figure that's about the size of an SLOTV. I think the average 747 has a dry weight of 181 tons. LOTV's that are designed for airless moons or just work in vacuume as tugs will be much lighter. As to the actual math that I've done: The atomic rockets page; engine listing has listed He3-D fusion rockets as having a thrust of 49000 newtons. Correlating this to the EP listing of fusion rockets thrust of .05G, which would give a standard transport an acceleration of .49m/s This leads me to believe that jsnead gave his standard transport a GTOW of 100,000 kg, with a fuel mass ratio of 1.5, It would have a dry weight of 67 tons. But I'm probably wrong.

Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

nezumi.hebereke nezumi.hebereke's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
Fine, describe the constraints on doing Y.
The only real limitation is that it must confer a practical advantage to the engagement. I don't think I'm the right person to say what Y must be constrained to (and really, trying to constrain Y is exactly the limiting of options we want to be careful about). Simply said, I'm looking at this situation and saying 'hey, if we do this, we can break the conventional laws of physics! How can we leverage this?' But I'm not at this point seeing a way that slowing time on my own weapons is advantageous. Part of that is because I'm not a physics nut, and I have a lot of trouble inventing things on my own, and part of it is because I don't know the history of engineering enough to know what weapons or tools were tossed out because they're too fast.
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
OneTrikPony wrote:
It looks like you're proposing something other than the 'Lollypop' configuration for your big ships. I'd love to know more about your thoughts on that because I've been entirely unable to come up with a more efficient design. I do think I might have proved that a hemispherical shadowshield would be lighter than a big thick plane of radiation soaking material.
The estimates were based on a rather compact spherical or conical shape. As I see it, most of the fusion and antimatter ships probably do extend a long tail when boosting to full velocity (that exhaust is *nasty* radiation-wise, and a weapon of mass destruction in its own right). But it is likely suboptimal to have extended in combat, and then it might be worth the mechanics to withdraw the drive spine. Most of the ships require a shield against hypervelocity micrometeors in full flight, and in battle you want to enclose most of your ship with it (Whipple shields look pretty good against lasers).
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Question: in your listed masses are you talking "Dryweight" or are you including propellant?
This is largely dryweight. Some handwaving here, since I do not want to run the full equations (my paper is bad enough as it is, I estimate reactor powers from what is necessary to produce the stated accelerations and delta-v). (JSnead has clearly done his homework, the fun part is to figure out what he is assuming)
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A bulk carrier doesn't need internal cargo space. This is one ship where I'm certain that the configuration will be a lollypop design. All it needs are Spars to attach cargo modules and cables to stabilize those spars under the slight acceleration that it will achieve. Everything could be entirely modular even the crew compartment (if it even has one). In my mind's eye a bulk carrier has a lot of similarities to the rigging on an 18th century sailing ship. Everything is built inside the space version of Conex containers even habitable modules.
Yup. This is also how I envision most scum habitats - they are also containers. There might be some need for shields protecting the containers though - a micrometeor hitting you at 400 km/s is going to explode like a pretty big bomb. Along the spar you have the *enormous* heat radiators. The big cargo ship and destroyer requires a simply titanic cooling system. Even the fighter is going to have tungsten wings glowing orange when in full flight.
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To me fighters will all be some variation of the Tie Fighter. I think Lucas got this one right. All the mass is centralized for quick and responsive maneuvering. Spherical ships turn better than long ones. They're also very efficiently shaped for storage as cargo.
Yup. They might be having thrusters on spines to turn really fast, and may use some cooling surfaces as extra shielding (generally, the shielding is against remote laser scorching and being hit by debris, rather than serious weapons - against those no armour is enough by my calculations).
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I've been unable to track down any information on the expected density of metallic hydrogen. If you have any information about this I'd really appreciate if you could share.
Same here, actually. I was surprised by the scarcity or obscurity of the subject. This paper http://prl.aps.org/abstract/PRL/v76/i11/p1860_1 seems to give us a density of 0.28–0.36 mol/cm3, which would be close to the density in grams per cm3.
Extropian
Extrasolar Angel Extrasolar Angel's picture
Re: Space naval combat (Segway from Antimatter thread)
valen wrote:
I don't know if anybody in EP actually has relativistic weapons. They would require a LOT of energy. Think about it. We use the LHC at CERN to accelerate a single atom of gold to relativistic speed. Now scale it up in your mind to the kind of machine and power source required to accelerate a couple kilograms to relativistic speeds.
I have to agree with that. A glance at speeds available to spacecraft suggests that a truly relativistic weapon(even assuming projectiles can reach much faster speeds than spacecraft) is beyond the technology available to navies in EP. Of course a epic super-project by one of the factions for one-shot relativistic weapon is a good idea for adventure.
[I]Raise your hands to the sky and break the chains. With transhumanism we can smash the matriarchy together.[/i]
jsnead jsnead's picture
Re: Space naval combat (Segway from Antimatter thread)
OneTrikPony wrote:
A bulk carrier doesn't need internal cargo space. This is one ship where I'm certain that the configuration will be a lollypop design. All it needs are Spars to attach cargo modules and cables to stabilize those spars under the slight acceleration that it will achieve. Everything could be entirely modular even the crew compartment (if it even has one). In my mind's eye a bulk carrier has a lot of similarities to the rigging on an 18th century sailing ship. Everything is built inside the space version of Conex containers even habitable modules.
Agreed, when I created that ship, I assumed it was designed to carry external cargo containers.
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Standard transport; the same as a bulk carrier except some of the larger ones have the extendable passenger modules for artificial G.
When I created them, I assumed that all of them had the passenger modules. Also, I think the cargo would be a mixture of internal (in cargo holds) and external.
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On your LOTV's; I've been unable to track down any information on the expected density of metallic hydrogen. If you have any information about this I'd really appreciate if you could share.
IIRC, given a lack of data, I assumed something like 50% the density of water. It's a solid, and it makes sense to me that it would be a relatively low density solid. I've run into the prediction of 0.8g/cc (80% the density of water) in several places, but I don't know if this is remotely accurate.
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The atomic rockets page; engine listing has listed He3-D fusion rockets as having a thrust of 49000 newtons. Correlating this to the EP listing of fusion rockets thrust of .05G, which would give a standard transport an acceleration of .49m/s This leads me to believe that jsnead gave his standard transport a GTOW of 100,000 kg, with a fuel mass ratio of 1.5, It would have a dry weight of 67 tons.
I went more conservative on the engines that many of the designs on the Atomic Rocket site - for example their listed ISP for a He3-D rocket is 780,000, and mine is only 100,000. Of course, I also think that much of the hype around He3 is nonsense + wishful thinking.
OneTrikPony OneTrikPony's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
Most of the ships require a shield against hypervelocity micrometeors in full flight, and in battle you want to enclose most of your ship with it (Whipple shields look pretty good against lasers).
Stuffed whipple shields too. I'm thinking layers of meta-metals and metallic foam would work really well vs. both lasers and the smaller railgun stuff. I had never thought about retracting the engine cluster while coasting. Wouldn't that also require batteries since you still have power draw? Or is it cheaper to haul around a fission reactor so you don't have to run your fusion drive all the time? As far as shielding, seems to me like you really only have to shield the ship from impacts from one direction; the front. The shadow shield will do a pretty good job of shielding the engine cluster and there are several configurations that can make shielding other parts of the ship more efficient; I've allways loved this picture by Adam Burch http://www.projectrho.com/rocket/7-20-07.jpg You can find more of his stuff here http://www.projectrho.com/rocket/rocket3aq.html I think that narrow crew section is pretty clever. You don't get the optimal volume/surface area of a sphere but you're probably not worried about that in a warship, or a bulk freighter for that matter. In a freighter you'd really only need to impact shield that narrow front end. Of course he's hasn't included the couple square klics of radiators that ship would need. Speaking of radiators; A couple months ago I read two papers about something like 'hot bead radiation' or something like that I can't find them now and I never did get all the way to the end to figure out if it actually worked. the basic premise was like the 'droplet' type radiators but instead of packing disposable mass on the ship and then using it to shed heat like sweat you dump the heat into micro beads of some magnetic material dump those into space till they cool down then collect them again with a magnet so they can be recycled. All I can remember is that they were from the USAF and one was written in 1962. Even if that scheme wasn't as efficient as fabric radiators it could still have military applications because instead of 30 football fields of radiator to target you just have a huge field of floating beads for your enemy to shoot through. Have you ever heard of anything like that. Do you know if it works? @ jsneed: As always thank you much for the info. So, are you saying you used a benchmark mass of less than 100,000kg for your standard transport? Thank you both jsneed and Arenamontanus for the info on metallic Hydrogen. Looks like I'm going back to the drawing board on my pictures of shuttles. the word metallic had lead me to hope that it was a lot more dense then it apparently will be. ++R-rep for both of you. :)

Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

jsnead jsnead's picture
Re: Space naval combat (Segway from Antimatter thread)
OneTrikPony][quote=Arenamontanus wrote:
Speaking of radiators; A couple months ago I read two papers about something like 'hot bead radiation' or something like that I can't find them now and I never did get all the way to the end to figure out if it actually worked. the basic premise was like the 'droplet' type radiators but instead of packing disposable mass on the ship and then using it to shed heat like sweat you dump the heat into micro beads of some magnetic material dump those into space till they cool down then collect them again with a magnet so they can be recycled. All I can remember is that they were from the USAF and one was written in 1962. Even if that scheme wasn't as efficient as fabric radiators it could still have military applications because instead of 30 football fields of radiator to target you just have a huge field of floating beads for your enemy to shoot through. Have you ever heard of anything like that. Do you know if it works?
I've run into this before, and have read that it would work quite well. It seems an especially good military design, since it would be easy to retract and also easy to carry spare beads.
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@ jsneed: As always thank you much for the info. So, are you saying you used a benchmark mass of less than 100,000kg for your standard transport?
Here are the full design stats that I used for all of the ships - I forgot that I hadn't posted them before: [B]Large Lander and Orbit Transfer Vehicle (LOTV)[/B] Dimensions: 25 m tall, 16 m in diameter (for LOTVs with hydrogen-oxygen engines) 19 m tall, 12.5 m in diameter (for LOTVs with metallic hydrogen engines) Fully Loaded Mass: 450 tons Empty Mass: 26 tons Maximum Acceleration: 2 Gs Performance & Payload: [I]Hydrogen-Oxygen Engine[/I] High Velocity Configuration (total Delta V = 11 km/s) 1 pilot, 6 passengers, 7 tons cargo or 1 pilot, 20 passengers, 4 tons of cargo. Low Velocity Configuration (total Delta V = 7 km/s) 1 pilot, 100 passengers, 40 tons cargo [I]Metallic Hydrogen Engine[/I] High Velocity Configuration (total Delta V = 17 km/s) 1 pilot, 250 passengers, 70 tons cargo Low Velocity Configuration (total Delta V = 8 km/s) 1 pilot, 350 passengers, 120 tons cargo [B]Small Lander and Orbit Transfer Vehicle (LOTV)[/B] Dimensions: 17 m tall, 11 m in diameter (for LOTVs with hydrogen-oxygen engines) 13 m tall, 8.5 m in diameter (for LOTVs with metallic hydrogen engines) Fully Loaded Mass: 150 tons Empty Mass: 11 tons Maximum Acceleration: 2 Gs Performance & Payload: [I]Hydrogen-Oxygen Engine[/I] High Velocity Configuration (total Delta V = 11 km/s) 1 pilot, 2 passengers, 200 kg cargo Low Velocity Configuration (total Delta V = 7 km/s) 1 pilot, 30 passengers, 11 tons cargo [I]Metallic Hydrogen Engine[/I] High Velocity Configuration (total Delta V = 17 km/s) 1 pilot, 70 passengers, 20 tons cargo Low Velocity Configuration (total Delta V = 8 km/s) 1 pilot, 100 passengers, 40 tons cargo [B]General Exploration Vehicle (GEV)[/B] Size: 6 m long, 2.2 m wide, 2 m high 5.5 tons fully loaded, 3 tons empty. Fully Loaded Mass: 5.5 tons Empty Mass: 3 tons Maximum Acceleration: (space) 0.1 Gs Performance: (space) Total Delta V of 3.6 km/sec from metallic hydrogen rocket (land) Top speed 200 kph from wheels or 40 kph from legs. (sea) 60 kph on the surface or 40 kph submerged. Payload: up to 6 human-sized morphs + 1 ton of cargo [B]Fighter[/B] Size: 4.5 m long, 3 m wide, 3 m high, 7 tons fully loaded, 3 tons empty. Fully Loaded Mass: 7 tons Empty Mass: 3 tons Maximum Acceleration: 3 Gs Performance: (space) Total Delta V of 11 km/sec (using metallic hydrogen rockets) Payload: weapons + 1 synth morph (optional). Carrying a synth morph reduces the missile launcher to holding only 4 missiles. [B]SCUM Barge[/B] Size: 300 m long, 70 m wide, 70 m high Fully Loaded Mass: 180,000 tons Empty Mass: 80,000 tons Maximum Acceleration: (space) 0.003 Gs (0.015 Gs using a Fusion Rocket) Performance: Total Delta V of 80 km/sec (using plasma rockets) Ships refitted with Fusions rockets have a Total Delta V of 400 km/s Payload: 20 crew + 20,000 humanoid passengers in cramped long term occupancy, and 4,000 tons cargo [B]Standard Transport[/B] Size: 150 m long, 25 m wide, 25 m high (80 m wide and high with rotating booms fully extended) Fully Loaded Mass: 10,000 tons Empty Mass: 4,500 tons Maximum Acceleration: (space) 0.02 Gs Performance: Total Delta V of 400 km/sec (using fusion rockets) Payload: 13 crew + 200 humanoid morphs in long term comfortable occupancy and space for 1,000 tons cargo [B]Bulk Carrier[/B] Size: 150 m long, 25 m wide, 25 m high + externally mounted cargo pods Fully Loaded Mass: 90,000 tons Empty Mass: 4,500 tons Maximum Acceleration: (space) 0.002 Gs Performance: Total Delta V of 40 km/sec (using fusion rockets) Payload: 10 crew + 100 passengers in comfortable long-term occupancy, and 80,000 tons of bulk cargo [B]Fast Courier[/B] Size: 75 m long, 13 m wide, 13 m high Fully Loaded Mass: 1,000 tons Empty Mass: 300 tons Maximum Acceleration: (space) 0.2 Gs Performance: Total Delta V of 1,600 km/sec (using anti-matter rockets) Payload: 3 crew + 10 passengers in comfortable long-term occupancy, and 100 tons of valuable cargo [B]Destroyer[/B] Size: 150 m long, 50 m wide, 50 m high Fully Loaded Mass: 40,000 tons Empty Mass: 25,000 tons Performance: Total Delta V of 800 km/sec (using anti-matter rockets) Payload: 70 crew and 20 fighter pilots in military style long-term occupancy, + 1,000 tons of weapons & 20 fighters and metallic hydrogen fuel to refuel them twice. [B]Note:[/B] I specifically did not make the destroyer long and thin, in order to make it less fragile - having a ship that you can easily cut in half seemed problematic to me.
icekatze icekatze's picture
Re: Space naval combat (Segway from Antimatter thread)
hi hi I'm pretty sure if you have the technology for fusion reactors, you have the technology to suspend plasma in a magnetic bubble. That would make a pretty good radiator if you ask me.
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
jsnead wrote:
Here are the full design stats that I used for all of the ships - I forgot that I hadn't posted them before:
Yule came early this year! Thank you so much! This is really going to help my analysis. (That destroyer is going to have a *frightening* power plant... about 76 TW. When the fleet leaves a naval base everybody will sit up and notice.)
Extropian
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
OneTrikPony wrote:
I had never thought about retracting the engine cluster while coasting. Wouldn't that also require batteries since you still have power draw? Or is it cheaper to haul around a fission reactor so you don't have to run your fusion drive all the time?
I would think a small reactor would do. Most main engines will anyway have to be designed in a special way to transmit a lot of energy into the propellant, so they are less than ideal as coasting power generators. Charging up batteries is not a bad idea either - while insufficient to drive the ship forwaed and to power big weapons they are good for everyday use, especially when you want to limit emissions.
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Speaking of radiators; A couple months ago I read two papers about something like 'hot bead radiation' or something like that I can't find them now and I never did get all the way to the end to figure out if it actually worked.
There are some fun discussions about molten droplet radiators. Microbeads is a cute solution but will not work magnetically (above the Curie temperature it is non-magnetic, and for iron this is a mere 770 C, for cobalt 1130 C). Having a sheet of droplets (and catching it for recycling) is going to be a mechanical mess and you cannot use it while changing course, but you can do fun stuff with it too: http://www.youtube.com/watch?v=HAITYFkICEc ("Sir, the enemy warship is scrolling adverts at us!") See http://www.projectrho.com/rocket/rocket3e.html#radiator for some sketches. As far as I know, nobody has tried it yet.
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Thank you both jsneed and Arenamontanus for the info on metallic Hydrogen. Looks like I'm going back to the drawing board on my pictures of shuttles. the word metallic had lead me to hope that it was a lot more dense then it apparently will be.
Yep, that metal is pretty light. Still, it is 100 times denser than the gas.
Extropian
jsnead jsnead's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
jsnead wrote:
Here are the full design stats that I used for all of the ships - I forgot that I hadn't posted them before:
Yule came early this year! Thank you so much! This is really going to help my analysis.
Glad to help.
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(That destroyer is going to have a *frightening* power plant... about 76 TW. When the fleet leaves a naval base everybody will sit up and notice.)
Indeed, it's really an insanely powerful vessel, and I wouldn't expect anyone to bother building anything like that - except for the threat that the TITANs might return. Of course, once built, such weapons are tempting to use for less dire threats, and I'd expect that the Jovians, the PC, and Titan all have a number of these. I'm not certain who else does. I'm certain that some people on Venus want some, but am equally certain that the PC doesn't want Venus to have any. What other groups do people think are likely to be able to afford one or more destroyers?
nezumi.hebereke nezumi.hebereke's picture
Re: Space naval combat (Segway from Antimatter thread)
Arenamontanus wrote:
There are some fun discussions about molten droplet radiators. Microbeads is a cute solution but will not work magnetically (above the Curie temperature it is non-magnetic, and for iron this is a mere 770 C, for cobalt 1130 C).
But does magnetism return after the temperature drops? If so, it's not an issue. You only need it magnetic for recovery (was my understanding).
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
jsnead wrote:
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(That destroyer is going to have a *frightening* power plant... about 76 TW. When the fleet leaves a naval base everybody will sit up and notice.)
Indeed, it's really an insanely powerful vessel, and I wouldn't expect anyone to bother building anything like that - except for the threat that the TITANs might return. Of course, once built, such weapons are tempting to use for less dire threats, and I'd expect that the Jovians, the PC, and Titan all have a number of these. I'm not certain who else does. I'm certain that some people on Venus want some, but am equally certain that the PC doesn't want Venus to have any. What other groups do people think are likely to be able to afford one or more destroyers?
I get the impression the Titanian Commonwealth *might* be able to build one, but sensibly they moved moons instead (!) and set up their insanely well-defended orbital space. A lot of the sheer macho absurdity of the Destroyer is that it has to be a rocket, with all the problematic issues of reaction mass: putting equivalent weapons on moonlets might not allow you to roar towards troublespots, but you get enormous firepower. Still, they have other craft. I wonder if the Ultimates are also interested. Maybe not a huge destroyer, but something fast and dangerous allowing them to push around in the outer system. Getting to Eris is hard enough in the first place, doing military operations there is every trickier. One of the amazing things about the destroyer is its main armament, the engine. Considered as a particle beam it is very powerful. It does have some serious collimation issues, but I think the engine has been designed to allow non-thrust uses where smaller amounts of heavy reaction mass (like mercury) is dumped at a lower temperature. The range is in the thousands of kilometres at least, and the damage pretty epic (unlike most weapons it doesn't try to blow things up, this is something that melts and vaporises its targets at a rate of meters per second - and it can keep it up for minutes at the very least, possibly hours).
Extropian
OneTrikPony OneTrikPony's picture
Re: Space naval combat (Segway from Antimatter thread)
jsnead wrote:
Here are the full design stats that I used for all of the ships - I forgot that I hadn't posted them before:
:D Thanks man :D This information is, indeed, alot like a crismass present. To me this is critical to figuring out a very important component of what EP 'looks like'. I don't know if anyone else get's that but I really hate the random starwars/trek design of ships based on coolfactor. And apparently I was WAY, WAY off about the scale of things.
Arenamontanus wrote:
Having a sheet of droplets (and catching it for recycling) is going to be a mechanical mess and you cannot use it while changing course, but you can do fun stuff with it too:
Thats what I was thinking too but there are a couple other benefits that make me think the idea's got legs.
Dr. John Schilling from the atomic rockets page wrote:
f liquid metal is used as the coolant, MHD pumping can be used at the collector arms, resulting in a simplified design with no moving parts. Indeed, in such a case the coolant could also be used as the working fluid in an MHD generator, resulting in a single-fluid, single-cycle power system from primary energy generation to waste heat radiation. Again, a simple, efficient design with no moving parts.
Plus, it's fun to try to draw ;)
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One of the amazing things about the destroyer is its main armament, the engine.
Ha! I KNEW this could work. I'd love to know more about how difficult it is to overcome the calumniation issues. I've been thinking for a while that terrorists or small political blocks like Locus. Perhaps thats why the first noctis/PC foray against Locus failed?

Mea Culpa: My mode of speech can make others feel uninvited to argue or participate. This is the EXACT opposite of what I intend when I post.

King Shere King Shere's picture
Re: Space naval combat (Segway from Antimatter thread)
Touching a related topic from another thread, http://www.eclipsephase.com/construction-time How long do you think those ships take to construct. For example If Titanian Commonwealth decides to build destroyer ships, how long would it take them to do so (without breaking "sweat" or alerting to much attention) Another ship I can imagine is a "carrier"/"missile" ship that physically carries few fighter/missiles/ shuttles (if any). Choosing instead to construct them when needed, in battle, or while in transit. Not expecting any "child ships" to return to it. Perhaps more of a Titan ship, one version could cannibalize itself when making the "child ships" choosing to end itself with its remaining scraps & reaction mass in a high-speed suicidal collision.
valen valen's picture
Re: Space naval combat (Segway from Antimatter thread)
King Shere wrote:
Choosing instead to construct them when needed, in battle, or while in transit. Not expecting any "child ships" to return to it.
This idea doesn't make a lot of sense for a military vessel. You'd have to carry all the components, or at least raw materials for your Missile/Drones around then why not just carry completed Missile/Drones. It might make sense for a civilian or scientific ship to be capable of constructing missiles/drones out of stocks, since that type of ship would have other uses for those stocks and wouldn't necessarily want them "tied up" as Missiles/Drones.
Arenamontanus Arenamontanus's picture
Re: Space naval combat (Segway from Antimatter thread)
Preparing to manufacture equipment on the fly makes sense when you know you will not have the optimal arsenal, but will discover what it is en route. This may happen in deep space combat where you are picking up intel before battle, but in orbital combat things will be flying hot from the first moment and you have little time to adapt. By the way, I have now run the numbers on the ships. I found my earlier reactor estimates to be a bit high, and now the top power of the destroyer is 800 GW - still monstrous, but not in the tens of terawatt range. Most of the numbers make sense, with one exception: the fusion-retrofitted scum barge is now 135 GW. This is pretty hefty: the fast courier is just 20 GW, the standard transport 10 GW and the bulk carrier just 9 GW. I wonder if the stated max speed/acceleration is simply too high. There is after all little need to move barges ridiculously fast.
Extropian
icekatze icekatze's picture
Re: Space naval combat (Segway from Antimatter thread)
hi hi I made this little sketch of a battleship that I had thought up earlier. [url=http://knhauber.phpwebhosting.com/scraps/ep_bs.jpg]battleship[/url] It is depicted here separating the combat module from the strategic module. It's main armament is a massive laser turret that can hit targets from very long distances, I borrowed the concept from the airborne laser system. It has a set of blast shields that open for it to fire and close again to protect the lens. For cooling, it uses super hot plasma suspended in magnetic bubble tubes (the orange lines going front to back). Four turrets can be equipped with railguns or point defense weapons. Not sure how to stat out it's other features. The combat module would have acceleration comparable to a fighter, while the strategic module would have acceleration comparable to a destroyer. I don't know what size naval weapons usually run, though I'm sure it isn't relevant to game play anyway. The important features is that it is dangerous, the combat module has no living space, it is piloted by AGI or forks, it is not in common use (generally used in defense by a handful of big powers) and most people don't think they're worth the cost.

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