What sort of feel should I go for?

[Peter]

I've been thinking about this, and I'm wondering whether or not it would be better to cover a very small fleet (maybe even one ship) in exacting detail - sort of more like a roleplaying game or Star Trek - or to cover a large fleet.

The thing about the "small force in detail" plan is that with only two ships a side, the battles may have to take place in very 'dense' environments in order to get the most out of a board. I guess there is the point that it simply isn't worth fighting over big clusters of nothingness - most battles would be for a particularly important location such as a frequent jump point, and such areas would probably have large numbers of debris clusters and infrastructure pieces to hide behind.

This might also lead into 3d positioning rules, depending on how good a job I think I can do of them. At the moment, I'm thinking of considering the board to be part of a particularly important orbit over a planet or a star

[Peter]

Regarding science fiction hardness, I'm told that the best single piece of relatively hard science fiction literature (The Mote in God's Eye) called for spacecraft which were capable of generating 10 PW.

That's comparable to a 2.25 megaton nuke detonating every second according to projectrho.com

[dragonlord]

10PW is also almost 1000 times the average rate of energy use of human civilization on Earth, so getting sustained power production of that sort of level would be near impossible without some super-science source/actually having a small star in the back of your spacecraft. On the other hand if you only need that kind of power output in very short pulses it isn't so much of a problem, the most powerful laser currently in existence has a peak output of just over 1PW.

Regarding what sort of feel/scale you should go for as to size of fleet that's entirely up to you. I can't think of any other RPG style space battle systems though so you might have something fairly unique if you go down that route.
As to 3D positioning rules, I don't feel that it is worth it for most space battle games, it would be next to impossible to work out lines of sight if you wanted the 'terrain' to have a finite height and most ships would be able to spin on axis far faster than they could change course meaning they could reorient to deal with an enemy attacking from above or below quite rapidly.

[Peter]

That's a good point, although apparently a lot of people like to do things like work out where a shot came from and use that to allocate damage.

I'm still trying to work out a relatively firm idea for shields that isn't a blatant rip-off of the Langston Field. It's not going brilliantly so far.

I'm considering making this into a grid-based system, even though that's pretty much the standard for space battle games. It does offer a few advantages in the way things like debris clusters and gas clouds behave.

[Adam]

Interesting question. I think it might be worth going for not necessarily one, but (say) a flotilla of 3-4 ships, a la RPG parties. You've still got enough ships to pull off tactics and synergise with one another, but it's small enough to squeeze in far more detail than is usual.

BTW, that post on the 15 minute workday on your blog you made t'other day was actually quite a good read. If I/we ever get Word of Nerd off the ground, you should come write for it ;D

[Oliver]

For the shields, you could perhaps ditch the force-field thing entirely, and instead have large flat drones covered in mirrors, shaped charges etc. to physically get in the way and absorb the damage - perhaps have them magnetically held in place near the ship. That way you could include some interesting decisions about when to expend each shield drone. Also, chaff and flares, which would make the ship harder to target. It really depends on how magical you want your technology to seem - i must confess i haven't really read through the other threads in this section.

[Peter]

The Whipple shields carried by real space craft are basically made of tinfoil (most high-speed debris/projectiles explode when they hit something).

The 'space' between the shield and the hull plating is either filled with nothing, or with a fluid, depending on the job the shield is meant to do.

I'm pretty hopeful about being able to envision a self-repairing Whipple Shield assuming that custom materials are available, and that the spacecraft regularly stops off to replenish them.

However, 'cinematic' space combat requires, among other things, reasonably resilient craft, which are quite hard to justify, even when Whipple Shields are available - the self-repairing armour I just described would be completely raped by any self-respecting directed-energy weapon (admittedly, this could make for an interesting game mechanic).

Interestingly, the only warship designs really permitted in real-world physics are 'war machine' and 'bigger war machine' - I've seen a reasonably good argument for most wet-navy roles being pointless (none more so than the submarine, of course).

And the only reason for the "smaller war machines" was cost - a battleship will easily take on many frigates, but you can have far more frigates than battleships, which gives you a credible force in far more wells.

[Oliver]

I would think there would be two main ways of making resilient spacecraft - make them hard to target, or make them hard to damage. The former method would probably lead you to producing a large number of small, apparently-identical drones, each with at most one weapon, coordinated like the internet so any of them can go down and the swarm still function. They'd probably either be automated or have a very small crew. They'd also be as camouflaged as possible - using tight-beam lasers to communicate, painted black or using active camo.

Making ships hard to damage would send them the other way - you'd balance an asteroid, slap some engines and weaponry on and put your crew and systems right in the middle. Presumably an interstellar fleet would use both - the miles-long asteroid ships transporting the car-sized drones. The problem with both being maneuvrability - the drones don't have room for much fuel and the asteroid has to burn craptons of it to make noticeable course adjustments. And this is where mid-sized ships would come in - light enough to be agile, and big enough to be able to power their movements. So there you have three different useful sizes of ship already. Maneuvrability being useful for getting out of the way of warheads, of course, and making your plans harder to predict, which would probably be the better part of space warfare - putting your firepower where the enemy is going to be, since it's very hard to cover large volumes of space.

[Adam]

^ Good post from Ollie there. I second it.

[Peter]

Bear in mind that stealth is rather difficult - that's why we don't have space submarines. Coasting under radio silence is a good way to paint a giant target on your ship ("Sir, we've detected a ship trying to sneak into the system undetected"). There is a lot of heat around, and it has nowhere to go. At best, you might have a few seconds of stealth.

About the only thing you can really sneak into a system is an R-bomb (the famous 10,000 ton torpedo, which happens to be carrying the equivalent of a 3.6 kiloton perfect matter/antimatter warhead.)

Burning is even worse - your ship can be identified at least to within a particular class by analysing a burn, and a decoy would cost nearly as much as another ship.

You'd basically have to find and hack all of the enemy's sensors in order for stealth to work.

Sure, this is only 'firm' science fiction (i.e. nanotechnology is not magic), but there are limits.

[Oliver]

The whole form of the spacefleets obviously depends on the technology around. If we're talking about stealth at a distance of a few thousand kilometres, obviously you'd need much more advanced technology than if you were trying to disguise your ship at a dozen AU off. With regards to analysing a burn, I should think if all your ships had fairly standardised engines it might be possible to disguise even their class at a distance. (For example, an idea I had was of needle ships - very long, thin vessels designed to look a lot smaller than they are from certain perspectives. Simply present the small profile as you enter the system, and hope they can't get a good side view. It would also make them harder to hit from that direction than a normal ship of comparable class, because the targetting would have to be more precise to hit them, although side-on hits would be more damaging because of their propensity to snap.) Of course, asteroid ships would be completely obvious, what with their size and unusual regularity. But an automated drone ship might get away with pretending to be a space rock for quite a while.

What scale in terms of battlefield size do you have in mind? I've got some ideas i think might be quite neat if the game's designed for ones bigger than a couple of planets - 2-20 AU on a side, at a guess - where the length of the 'battle' is measured in weeks or months, related to the idea of fuel consumption and spaceships being hard to identify at range.

[Peter]

The problem is that the enemy has a rough idea of your engine output, exhaust velocity, and resulting acceleration just by looking at your burn. Finding out the mass of the spacecraft is pretty trivial from there.

You can disguise your ship as "generic thingy with a thrust of 34 TN and an exhaust velocity of 500,000m/s, and an acceleration of 4g" for a while, but that stops working quite quickly.

You can't really get much better than a six-month planning cycle without making a visible burn.

While spacecraft do tend to use dark matter as propellant, even that has to radiate something, otherwise the ship will cook. If you can find exploitable dark matter of this type, you can spot its radiation.

[Adam]

Pete, have you seen the spaceship fluff for Mass Effect? There's plenty of stuff to do with heat there. Have a peek - it's probably on the internet somewhere, unless you have the game.

Jan 23, 2010 15:36:14 GMT -5 Peter said:

While spacecraft do tend to use dark matter as propellant, even that has to radiate something

Well, no. That's kind of the point of dark matter, isn't it?

Thinking about it, since dark matter is invisible in all thus-far-readable spectra (ie. to our knowledge, it emits no energy), could you enfold/fill a ship in/with the stuff and (somehow) direct heat into it? For that matter, how do the people in your universe detect dark matter, never mind interact with it? I suppose its mass could be detected by very finely analysing gravity acting on a number of sensors and comparing it to the expected gravity from stellar bodies within some obscene distance, but that would require ridiculous computing power and extremely detailed knowledge/observations of the (current) masses of stars. It would also get messed up by other ships nearby that you had no knowledge of, passing comets, etc, unless you had an absolutely huge conglomeration of the stuff.

Is dark matter even theorised to have a material presence in this universe - ie, occupy one of the states of matter (gas, liquid, solid, plasma)? Can a ship fly into it? Hit it? If so, since it radiates no energy, where does energy go when it strikes dark matter? (Conservation law says it doesn't just disappear.)

I think we need Dragonlord on this one... ;D

[Peter]

A dark matter rocket would basically chuck dark matter out of the back. Your drive power is greater than the rate at which you're imparting kinetic energy to dark matter, so you have to work out where that's going.

Maybe it does give you an invisible burn, but I don't see a drive using a propellant that can barely be interacted with being all that efficient. So let's say your drive has a useful output of 1 TW and produces 9 TW of waste heat.

Now, with any luck, most of that waste heat is leaving the ship with your exhaust, because if it isn't then you get sautéed. So what does dark matter do when it heats up?

I don't really see all of this dark matter being invisible to people who were able to exploit it to start with.

[dragonlord]

Speak and the Dragon cometh...

Regarding Dark Matter, the entire point of dark matter and hence the epithet 'dark' is that it does not interact with anything, or at least only very, very, ridiculously weakly, other than through gravity. Energy does not 'hit' dark matter it just goes through it. A dark matter rocket that simply throws dark matter out of the back is an essentially flawed idea, it is not going to be any more efficient that chucking normal matter out of the back, and is almost certainly going to be less efficient owing to the difficulty of working with dark matter. I don't know exactly how dense the dark matter halo of the Milky Way is supposed to be in the solar neighbourhood, but it is quite possible that if you found a way to interact with dark matter reliably the most efficient way of powering a ship would be using some form of dark matter 'propeller' that would push your spacecraft through space in the same way as a ship is pushed through water.

Regarding stealth, how easy it is to be stealthy is entirely dependent on how good your enemies sensors are/how complete their coverage of the sky is. A spacecraft that is not in a burn is not going to radiate brightly and is also not going to be that large (other than asteroid ships). If you think about our current knowledge of potentially hazardous near Earth objects, that is ones largely than 150m, and how long it has taken us to get to the level of knowledge we have, you can see that a moderately sized spacecraft at a reasonable distance that is not actively burning is not going to be easy to spot. During a burn that would be somewhat different, but it would still be a fairly small source and you would have to have sensors looking in the right direction at the right time as a course correction burn is not likely to last for long.

[Peter]

I generally assumed (for EV purposes) that dark matter interacted with other dark matter, and very small quantities of it could also interact in mundane ways with mundane materials - so you could find dark matter using custom materials that emit light when exposed to 'dark radiation', for example.

Assuming high technology, a full sky sweep might take only as long as a minute, if not less (it's only four hours right now). There would be about a terabyte of information to process per sweep.

Even worse, the orbits which allow the most coasting take ages and are easily predicted and patrolled. Not to mention the network of sensor platforms and picket ships that have a decent chance of seeing you during your transfer.

Tactical stealth can be managed for a few minutes I guess, but that's not really useful.

Also, the general depiction of a warship is a torchship, which has a multi-terawatt drive and gets around using a Brachistochrone transfer, which involves constant burning.

[dragonlord]

I generally assumed (for EV purposes) that dark matter interacted with other dark matter, and very small quantities of it could also interact in mundane ways with mundane materials - so you could find dark matter using custom materials that emit light when exposed to 'dark radiation', for example.

I still can't really see what would be attractive about using dark matter even if you did have a way of interacting with it, that is unless the dark matter in the surrounding environment is dense enough to use a dark matter propeller.

Even worse, the orbits which allow the most coasting take ages and are easily predicted and patrolled. Not to mention the network of sensor platforms and picket ships that have a decent chance of seeing you during your transfer.

While this is true, it does assume that the system is under the control of the defending fleet, since such monitoring networks cannot be set up that rapidly. There is also the possibility of hiding your burn by executing it when there is a planet or large asteroid between you and the enemy fleet, assuming of course that you know where they are, likewise coming in from the direction of the system's star would make it easier to hide such things.

Also, the general depiction of a warship is a torchship, which has a multi-terawatt drive and gets around using a Brachistochrone transfer, which involves constant burning.

I agree that if you are using a warship of this type it would be almost impossible to hide.

[Adam]

Yeah, you might actually want to drop the dark matter idea completely. Antimatter's a nice easy sci-fi drive technology to use if you want it.

A thought: dark matter could simply be matter that's displaced from us in a dimension we can't experience. Isn't there a current postulation in some branch of advanced science (string theory, I think) that suggests existence actually has eleven dimensions? Why 11, I don't know, but dark matter could just be matter that's on/in another 3D plane, one displaced from ours in one or more of the other eight dimensions. If the 11 dimensions form a cohesive whole and obey the laws of physics properly, then the mass of this extra matter could still affect the motion of the universe as a whole.

This suggests that if you have dimension-crossing technology, you can harvest dark matter. As it would probably just be normal matter, though, you'd essentially be harvesting either bits of planet or bits of sun. Not so great. Dimension-crossing technology does provide an amusing way of stealthing ships though - send your fleet to where it needs to be in another plane of existence and then pop back in. Ships on patrol would no doubt station themselves across different planes (I'm assuming there might be five different ones, including our own, because dark matter is supposed to represent 4/5ths of the matter in our universe IIRC), but it means that until the others can translate themselves, you only have to fight one fifth of their fleet.

Interesting ideas. It ties in to your wormhole technology. It would have to be done over short distances, though, as the other planes would be completely different in their distributions of matter and would thus be very hard to navigate on an interstellar level, because we don't know where everything is. It would also take up craptons of energy. It also means you can have aliens from other dimensions... I imagine it's only a matter of time before someone wormholes into the airspace of a really angry alien race and starts an interdimensional war...

[Peter]

The current plan is for it to be possible to create wormholes specifically in places that are rich in dark matter (presumably, such places are rich in the exotic matter you actually need). In those places, you can also use impellers to get around, as Dragonlord suggested.

Because there is often only one such area near a system, that's quite easy to picket.

The idea behind using dark matter remass is basically that I'm not sure I really want to fit a small star to the back of a torchship. Dark matter can presumably be used at much higher mass ratios with the same amount of engineering skill, allowing for higher thrust drives to be used (high exhaust velocity drives invariably have low thrust - eventually coming to a head with laser drives with an output of 1 PW). It also doesn't murdelise anyone approaching the back of the craft, making civilian torchships a bit easier to justify.

It is worth pointing out that most systems in the void are neutral, however - even then, though, a picket sphere doesn't necessarily cost much effort.

I'll probably let you roll to see if your ship managed to coast in undetected, but I'm not going to allow cloaking devices. Painting your ship black or silver isn't really going to make much difference either.

It's certainly hard enough to hide that active sensors are worthwhile.

[Oliver]

Although it may be easy to picket a wormhole, although it's relatively easy to see a spaceship, it's a lot trickier to tell it's a warship. Disguise your frigate as a freighter - or inside a freighter - and your enemies may take a lot longer to discover your true intentions. Similarly, disguising space defenses as civilian stations would make it a lot harder to successfully invade because you can't be sure where you should be avoiding. Hence espionage would be very important in space warfare. Similarly, it would be quite easy to disguise the armament of a ship, which is a very important issue in working out how to counter it. Does it have hidden booster drives? Lasers? Nuclear explosives? Seismic warheads? Of course, you would likely need all three in a fleet (I imagine drones/fighters would be vulnerable to nukes, asteroids to seismics and medium-sized ships to lasers) and probably lots of other fun stuff i haven't thought of, but the general point stands that having a system of hidden armaments (probably scribbled on index cards, assigned hidden-ly to ships before deployment, points totals totted up at the end to make sure noone's cheating) could both be characterful and add tension to the game. A similar face-down-card system of espionage and subterfuge might let you do fun things like sabotage enemy stations, reveal armaments, or deploy ships where the enemy doesn't expect them (subverted asteroid miners building a lo-fi asteroid ship, anyone?)