On Relative Sizes of Spacecraft

everything in space is huge

This was inspired by another topic, here, and was originally going to be my response, but I felt that its size and scope warranted a new topic.

Let us first assume that capital ships are quite large, as futuristic materials and construction methods, as well as the mining operations to support them, are advanced enough to produce classes of spacecraft that are not meaningfully limited on the interstellar scale. Within a solar system itself, if there are no mobility requirements and cost is no matter, of course these reasonable size limits are irrelevant, hence Schlock Mercenary-style UNS battleplates are a possibility in-system for defense. Where interstellar movement is concerned and you are trying to attack other systems with many ships, there are limits, but the limits are "high enough" that we can say that capital ships are very large. Hundreds or even thousands of crew, many weapon systems, and many weapon systems large enough to blow many ships out of the analogous water.

Let us also assume that since these large capital ships have the firepower to blow each other up effectively, in the interests of self-preservation of their crews, or at the very least preservation of the cost and materials to build such a spacecraft, or preservation of the mission objectives (bombard a planet after the fight for the sky), any fights between these capital ships will be done at range, with point-defense systems and a screen of smaller ships between them as they lob huge projectiles and missiles at each other. The range at which these combats will occur is such that each ship captain believes he can protect his ship, and get a reasonable chance at taking out the enemy. Yes, he could fly in at full speed towards the enemy and engage at point-blank, but that would be suicide (however it would be an effective tactic if you're losing, a la Return of the Jedi).

I see these large capital or super-capital ships as a way of carving out borders in space, where they would otherwise be meaningless empty space. A capital ship in effect controls a three dimensional field around it. In strategy board game language, a capital ship threatens a set number of squares around it, and thus the enemy may not move through those squares, at least without the capital ship being able to shoot at it. A naval analogy is also apt- capital ships are moveable air-fields and artillery, and do not attack each other in close range, but they do provide control or defense of land and water nearby in range of their guns and planes. Certainly no enemy shipping can occur in such areas.

So, the role of screen vessels becomes apparent, to either extend the range of fire of the capital ship, or protect it from harm. Screen vessels (these are your destroyers and cruisers, and perhaps even smaller vessels) may of course be found outside of a capital group, and packs of these might make daring raids against enemy outposts. But while a part of a capital group, their main concern is with protecting the capital ship, and that goal is accomplished in one of two ways. A defensive role, preventing enemy fire from reaching the capital ship, and offensively attacking the enemy screen, and once that is removed, attack the enemy directly. Being smaller and more numerous, these screen vessels would probably have some specialization. There would be anti-fighter classes, anti-destroyer classes, and anti-cruiser classes. There may even be some that would specialize in attacking enemy capital ships, although these would probably remain in reserve, as the weapons they would carry would be poorly protected, and thus too easily wasted on the front line. If your anti-fighter cruiser is destroyed, you've lost a ship, its crew, and only a bunch of small cheap warheads. If you lose an anti-capital cruiser, you've lost a bunch of large expensive anti-matter pods and a sophisticated delivery system.

The role of fighters becomes much more interesting in this kind of situation. A fighter is the pawn of this space-based chess game. Weak by itself, but with many others (especially when the enemy is low on their own pawns), it becomes very important. Fighters may be able to eliminate incoming large ordinance and serve as an outer line of point defense (think about Vipers in BSG taking out Cylon missiles), and of course they also attack other fighters. Interceptor-type fighters would have small missiles (think of an AIM-9 Sidewinder) or a quick-shooting canon, for which to dog enemy fighters. But fighters aren't just defensive. Strike-type fighters would be able to get through the front lines of the enemy capital's field of fire, deliver powerful explosives against the enemy screening vessels, and attack weak points on the enemy capital ship. They are able to do this through speed, superior maneuverability, and high pay-load capacity.

I've recently begun to think that fighters should be much larger than people generally think. They should be considerably larger than a cargo shuttle, I feel, just because of the technical limitations of the universe. Think about design considerations at Cargo Shuttles, Inc. versus Advanced Fighter Corp.

A cargo shuttle may come in several classes, from a simple puddle-hopper that only needs to take a few passengers or a couple tons of cargo, to a longer-range transport that will move maybe 20 tons of cargo (and unlikely any passengers). Speed is not a major issue, as the distances are short, so a slower, older-style engine will take up less space so that there's more for the cargo. Armament considerations are small, if any, although some hardpoints for extra fuel pods or specialized equipment for maybe scientific purposes might exist.

A fighter though, has completely different needs, and its size is therefore very different. First and foremost, is speed. While the sophisticated tracking systems of the enemy fire control can easily track and put ordinance in front of incoming fighters, if the fighter remains inside the enemy field of fire for a shorter time, it becomes more difficult to shoot down. Maneuverability is the next factor. Changing course quickly causes the firing control computers of the enemy to shoot in the wrong place. Payload is another major sticking point, since there's no point in being fast and agile enough to get within range of the enemy capital ship if you can't hurt it when you get there. The bomb you're dropping or the missile you're shooting is likely many tons in weight. Speed, of course, is requires a good balance between mass and acceleration. High-powered engines, and really over-powered engines, is a must. Plus you need the fuel to hit your afterburners on your way in and out. Rapid changes in your vector is how you survive in the kill zone. So, you can pretty much expect your fighter to be mostly engine and payload. You probably have some thrusters all around your ship to change your direction. Payload increases mass, decreases your velocity, but as I said, there's no point in going in if you can't cause some damage, so strike fighters would be equipped with heavy rockets, bombs, or blasters to get the job done. Again, this just makes the size of your fighter larger. I don't think it's so hard to imagine fighters being much larger than a 747, maybe twice or three times as large. Remember that space is big. Yes, you seem like a bigger target, but the precision needed to hit you when you are a whole planets-width away and traveling at .7c is just crazy. Sure, if you get hit, you're probably dead, unless it was just an interceptor that got you, but if you're good enough, you'll be fine. Nobody said being a fighter pilot was safe, after all.

So, I don't think it's so wrong that fighters are large. I think it's the only thing that makes sense. The real question is, how do we translate this all to a game like EV? The answer of course is, suspension of disbelief.

Yes, the planet on your screen looks tiny compared to your cargo shuttle. Just think of it as "in the distance". It's just background to the epic battles going on in space. The same can be said of capital and screening sized vessels. They however, are shrunk down on purpose. Does it really make sense that a ship as big as an island is only going to have 10 guns on it? Of course not. But we only have 10 guns on it in the game because it makes sense relative to everything else. In "real life" it would have hundreds of cannons of all shapes and sizes, shooting ordinance of every type for every situation. That's the advantage of flying around your own personal star base. But the disadvantage, of course, is that you aren't as fast and much easier for you to get hit. So in essence, capital ships are an abstraction. You get 10 guns because realistically you miss a lot of the time, and you really can't fend off 10 fighters and destroyers buzzing around you. That's why you had your screening vessels and fighters of your own.

I think the solution to scaling in EV is not about making fighters smaller, it's about realizing that larger ships are far larger than you can realistically make them and still have a balanced, playable game. And also realizing that fighters are way bigger than you think they are. Think of it like a logarithmic scale of sorts. As your ships get bigger in the "real world", they don't get as bigger on the screen, nor do their armaments get massively overpowered.

In conclusion, here's how I see the scales of various ships in a realistic universe. These are lengths.

|--------------------------------------------------------------------------------------------------------------------------------------------| capital ship
|---------------------------------------------------------------| escort carrier
|------------------------------| heavy cruiser
|------------------------| light cruiser
|---------------------| heavy freighter
|----------------| destroyer
|----------| light freighter
|------| strike fighter
|----| interceptor
|---| heavy shuttle
|-| light shuttle

Now, for actual graphics, you might want to scale it such that you can pretty much tell how big a ship is by its size, but each ship is mostly on its own scale. Notice that in this example, I have freighters on a slightly different scale (a civilian scale, as it were, since these ships have limited defenses and should be easier to hit anyway), and strike fighters and below are larger on the scale.

|---------------------------------------------------------------| capital ship
|------------------------------------------| escort carrier
|----------------------| heavy cruiser
|------------------| light cruiser
|---------------------| heavy freighter
|----------------| destroyer
|------------| light freighter
|------| strike fighter
|-----| interceptor
|----| heavy shuttle
|--| light shuttle

I feel this is a reasonable relative size for the various ship classes, but of course your mileage may vary, and you may have your own classes, etc. But, using a kind of logarithmic scale, you can create a reasonable difference in size, and require minimal suspension of disbelief. People like seeing details, so let them, make your tiny ships big enough to see. And think about sizes relative to armaments and roles. Nobody's going to build a freighter that can transport so much of a material as to destroy the price of the material when it gets there and floods the market. And nobody's going to pay to maintenance keeping it running for the entire year it takes to mine enough ore to fill it. Similarly, nobody's going to build a fighter so small that it can't deliver a weapon large enough to damage its target in the enemy fleet. Remember that space is big, and in the kinds of actual distances being fought between, you're going to need a fighter with enough speed and fuel to span that distance, so you'll need a much larger engine than in a cargo shuttle. That means a much bigger fighter than you're used to seeing on TV or in the movies, or even on Earth today. An F/A-18 can only fly a bit over 300 miles and it can only reach Mach 1.8. Space is way bigger and combat would be way faster than that, so even with futuristic fuels and engines, you would still expect a space fighter to be much larger, especially if the ordinance you're carrying is going to be much much heavier. Space is HUGE, you can afford to make your smallest craft just as huge if it gets the mission done.

I am using something rather similar to your second scale. However, I disagree with your conception (which I may be misinterpreting) that there will not be a maximum size for a 'space navy', or spacic, capital ship. For a variety of reasons I feel that spacic ships won't be much larger, and probably smaller, than twice the size of a modern 'super carrier', IE six hundred meters or so.

First, the larger a ship the longer it takes to build. Especially in a real wartime scenario you need rapid turn-around on construction to replace lost hardware. The more mass a ship has increases exponentially the time it takes to construct I would expect. Even with the greatest of construction efforts that I can cite (http://en.wikipedia....ki/Liberty_ship) the fastest the ships were produced was on the order of more than a month (read carefully- I know the exception), and that was for cargo ships, not warships, which I imagine would require significantly more advanced construction techniques and a much higher level of outfitting. As it is now, it takes the USN five years (http://en.wikipedia....ki/Nimitz_Class) to produce a Nimitz class carrier, which is totally out-of-pace to replace wartime attrition (albeit this is at a somewhat relaxed pace and could likely be sped up dramatically if need arose- still I can't see a ship of this size and technical capacity being fully laid out and outfitted in under two years).

Second, making a ship larger does not necessarily make it more combat effective. In my opinion, after a certain amount of mass, the slow response time and immaneuverability of a ship versus combat effectiveness will bring diminished returns. Any warship has to be able to maneuver responsively to some extent or another, regardless of how effectively it's screened or guarded by auxiliary ships. When factoring that it takes nuclear reactors to make a modern supercarrier, as immaneuverable as they are, as responsive as they are, especially when compared to smaller ships, the (speculative) power required to maneuver a two-thousand foot, 200,000 ton displacement (my math should be easy to discern) is astronomical (no pun intended), and leads into my point three.

Third, the cost involved in building a ship of my proposed size, again using easy to relate math, would be out of the ballpark. Using what I consider to be conservative math I come up with a cost of $8,242,000,000 to produce a 2000 foot, 200,000 ton displacement ship. However, I would consider a better estimate to be closer to twenty billion dollars for a variety of reasons. First, a space vessel would probably have to be better armored over a greater percentage of its' surface to be survivable, not only versus ordnance, but versus space debris and accidental impact. When a plane coming in for landing on a sea-based carrier crashes on the flight deck it does not risk the decompression of the whole ship like it would in space (even a segment of a spacic ship loosing compression, as envisioned by emergency bulkheads closing and preventing full decompression, would be perhaps fatally damaging to the ship if it is unable to reproduce atmosphere fast enough. Even as well-made as modern ships are they still have bilge pumps to remove water that leaks in from somewhere or another, and in space you would probably need to replace atmosphere in a similar idiom as removing water). Secondarily, I would think that the costs involved in keeping such a huge ship operational and staffed with qualified personnel would be insane. Sure, a modern jet fighter can get away with having a 300 (as mrxax cites) mile range. But in space I would expect travel times and distances to be much greater by orders of magnitude: the fleets squaring off against each other in ROTJ at such close ranges would never happen I imagine. The fuel cost would be enormous to keep a fighter wing supplied, let alone the fuel cost for the ship itself. I'm sure that even the below-average imagination can come up with other examples of cost overrun in this vein.

Fourth, I don't see how any right-minded space fleet manager would want to put so many of his or her eggs in one basket as to produce so investment-heavy vehicles as these. When you spend twenty billion dollars on a ship it would be like spending one hundred fifty thousand on a Ferrari- you wouldn't just take it out everywhere. Spreading out that twenty billion to produce three smaller ships, cumulatively probably more of a realistic threat than your one super space battleship or carrier, is a much smarter idea. Even the Death Star, for all of what it represented, was more of a mental threat than a military one ("Fear will keep the local systems in line- fear of this battle station..) Such a large ship cannot be everywhere at once, and with the price tags attached a spacic navy could not afford to produce and keep a large number of them around enough to be a real, credible threat. One or two symbolic vessels, yes, but a fleet built around them? No.

I agree with rmx. In terms of naval combat he is absolutely correct. All we have to do is look at the failed attempt of a massive "super" ship with the Japanese battleship "Yamato" (http://en.wikipedia....lass_battleship) It was extremely expensive to build and didn't affect the war much at all. It only ended up destroying an escort carrier and a destroyer. It ended up getting destroyed with massive amounts of fighters and only about 300 of its 3000 man crew survived. But enough about history all we need to do if we wanted to create a "realistic" EV universe we just need to look at the naval battles and economics behind WW2, dump the ships in space, and give the ships and aircraft missiles.

I believe space will still follow the principle of cramming as much as you can into as little room as you can. Rather than making bigger and bigger ships and guns, I see a major focus on making things as tiny as possible to cut costs and resource usage. Granted, there'll still be some larger, capital class ships, obviously, and things probably will be a bit bigger than average for atmospheric and naval combat. But the small you are, the harder you are to hit. Also, larger ships would have considerably more trouble dealing with gravity should going into a planet's atmosphere be necessary.

I think you're probably right about the sizes, rmx256, although I do have some disagreements which I'll get into a bit later, but I'm not sure if the Yamato is an appropriate analogy. The Yamato was a huge ship, easily out massing all other warships of that time. But it was sent on a deliberate suicide attack against an enemy fleet that comprised of over twice as many vessels. The Yamato did have escorts, true, but it wasn't designed for fighter defense. It carried a mere seven fighters (in contrast, modern Nimitz-class carriers carry a total of 85 aircraft. WWII HMS Illustrious carried 57.) It was mainly armed with deck guns, and had very little in the form of AA defense. A super ship might work if it was better designed.
You're right about big ships being very expensive and hard to build. The US currently has 11 aircraft-carriers in service, with one more under construction. I haven't been able to find construction costs in five minutes, but the operating cost per ship is $160 million annually. But keep in mind, the Federation is a much bigger government, with more resources. It might be capable of fielding hundreds or thousands of carriers. In addition, they might be able to build a new carrier in as little as two or three years with more effiecient manufacturing, and have it armored very well against fighter strikes with QLBT's and heavy armor. In addition, it seems to me that weaponry increases at a faster rate than armor when going up in size, but that armor still goes up enough to make smaller weaponry ineffective. So a large ship can destroy many smaller ships with ease, as well as taking very little damage from them.

I think JTH is pretty much spot-on. Sure, a larger craft will most likely be able to destroy a smaller one, but at the end of the day, the question is how can you get the most bang for your buck. And since inefficiency decreases ship size (I'm not buying the "larger ships are inherently harder to destroy" argument; the same amount of material more highly concentrated in a smaller craft would be much more durable not to mention harder to hit), they are less economical. Remember that you don't have to entirely demolish a hull to destroy a ship; all you have to do is destroy something vital (bridge or propulsion perhaps, or generator or ammunition storage to get the job done quickly). So that in mind, a ship that is simply twice the size of another that uses twice the resources will be just as easy to destroy, or perhaps easier since it would be harder to miss.

For example, unless you want to lose speed, you need to create more powerful propulsion. This results in a net loss. Even if the material cost is small, the monetary cost for a larger reactor would be quite high. So a ship that's twice the size and twice the potency carries more than twice the cost. Of course there is no "one unit of material yields one unit of power" ratio; that's just a rough depiction.

In most sci-fi, you also have shields to take into consideration. A shield would lose potency (I think) geometrically as the protected surface area increases. So again, the cost would skyrocket as the craft gets larger. This of course is the opposite in the the Langsten Field system, in which larger shields can bleed off heat more quickly, and therefore are more resilient to implosion. But assuming traditional conception of particle shields, larger is much, much worse.

Now of course, there would be a use for a large range of ship sizes. You're always going to want small, quick picket ships for scouting if nothing else, perhaps gunship roles, missile intercept (although given the near-universality of energy-based weapons in sci-fi, I don't see how a large ship shooting down a missile or fighter would be difficult) etc. You're always going to want capitals that can hold weapons that are too large for the fighters, and probably carriers. And some things in between.

Finally, huge ships do possess a few great advantages. If fire isn't concentrated against it, it can be highly ineffective (see: Star Trek: First Contact ). Intimidation can cause some slip-ups even if it doesn't result in stupid orders. And if a larger ship is used in place of several smaller ones the sum of whose power is identical to that of the capital, there's the chance that whereas one or two of the smaller ships would have been destroyed, the larger ship will survive, albeit with some damage. This would result in lower costs, less loss of life, and greater morale.

Still though, my personal opinion... well, you'll see what it is as soon as I'm finished with Anathema. This is actually more or less what the entire end of the series revolves around (as if nobody saw that coming).

(tangent)I believe that Destroyers are actually larger than Cruisers, at least in modern naval classifications.(/tangent)

This post has been edited by Archon : 03 July 2008 - 03:40 PM

I think there are advantages and disadvantages to having a larger vessel.

The main advantage, I would think, would be in armoring the vessel. When you scale something up by x, the volume (and mass) will increase by x^3, whereas the surface area increases by x^2. You have less area you need to protect for a given mass. Also, a larger reactor would likely be more efficient, thermodynamically speaking, since it could run hotter. At worst you just use a number of smaller reactors of the right mass and your power generation scales fine.

Now for the downsides. Propulsion itself may not directly be as much of an issue as one might think depending on the source use, simply add some heavier elements into the plasma or ion thrusters, make 'em a bit longer so you can add enough speed to the exhaust at the same power, and your set. That is going to make the reaction mass slightly more expensive, but it isn't going to directly impact the performance of the vessel. The problem comes with the structure holding the vessel together. For mere forward/backward motion, a proportional size increase to the supports might be sufficient. But they are likely going to have to be built bigger and sturdier than a linear increase to account for the torque in turning, or even to account for partial engine failure. So a larger ship is either going to have to have less maneuverability (though not necessarily speed), or have more of its mass taken up by structural elements, which is essentially a waste.

The size issue would not matter as much for long ranges where guided/area weapons are needed to hit anything, but it would increase the ease of hitting with more concentrated beam/projectile weapons.

Larger ships would also be slightly harder to construct, logstically speaking. Smaller or medium ships could be built on ground based facilities, but building a large ship in strong gravity isn't going to work out so well, and it would likely have to be built using orbital facilities which require a higher level of infrastructure.

So in conclusion I think large, heavily armored battleships would be the mainstay for heavy fleet battles, being able to go toe to toe in long range missile confrontations, and basically being able to wipe the floor with anything too much smaller than it. However, small or medium sized gunships and cruisers would also be involved, more heavily armed but more lightly armored, trying to get in range of the battleships to use heavy beam weapons or railguns on them, or for fighting each other. I'm not sure there would be much need for any real fightercraft as we think of them, as it would likely be more effective to simply use the space it would take for a fighter as missiles instead. Using them as point defense platforms like in Galactica is a possibility, I suppose. Also if there was a tremendous expense for high end propulsion, or unjammable sensors that would be prohibitively expensive to put on a missile, fightercraft might be a worthwhile investment, provided they have a good chance of coming back/being salvageable. Either way the smallest ships are likely to be much larger than the airborne fightercraft of today.

Keldor has a good point about the gunships and smaller ships. They probably won't be as heavily armored, since one or two shots from a battleship could destroy one regardless, but would instead focus on high speed and maneuverability so they won't get hit by those shots and/or extremely powerful weapons, preferably with long range, that can hurt a battleship. They wouldn't be gunships so much as mobile weapon platforms. In fact, I'm making a ship based on that. It's pretty clumsy, but is armed with huge railguns, rockets, missiles, and all sorts of really powerful weaponry. This would probably also change the game for fighters. They probably would be considerably bigger, but would mainly dump the small scale weaponry. Example: an F-16, which carries two 20 mm, about .8 inches, cannon, attacking a battleship which has guns of 406 mm, or 16 inches. The battleship probably won't hit the fighter, and the fighter will successfully hit the battleship, but won't do any damage. I'm disregarding the missiles right now. Unless they were specialized, they wouldn't kill it anyway. The thinnest armor on the ship is 7 inches thick. But take the F-16's cannon off, as well as the missiles, armor, and a lot of other systems that aren't needed if it can't be hit, and replace it all with a huge gun, on the order of 200 mm. Suddenly, it can do damage to the battleship, but the battleship still can't hit it. Needless to say, the fighter won't be able to carry more than one or two shells (a 16 inch shell weighs in at about one metric ton), but each of those will hurt, and will be much cheaper than a missile. And if they are being launched from a carrier or groundbase, the ship can stay out of the battleship's range, and still be able to rearm each of the fighters in maybe ten minutes. With seventy or so of these, they can easily take down the battleship without getting damaged at all. However, refitting the battleships with those 20 mm cannon would allow them to take down several of the attacking fighters, if not defeat all of them.

What about recoil on your fighter- even a Boeng 777 sized fighter- firing a 200mm cannon? I would think that one or two shell capacity wouldn't matter too much if the gun shot out the back of your ship when you fired it.

I would write a longer reply but I am quite busy.

Don't discount fighters so quickly. Remember, modern aircraft carriers can hold 80+ fighter craft, more than enough to kill themselves several times. One or even a few fighters will just be laughed at by a capital craft. But fighters will be traveling in packs. Or, more accurately, swarms. Say you have eighty fighters with two heavy, short ranged missile on board, in addition to smaller guns for shooting other fighters, missiles, and some of the not-too-much-larger craft. That swarm potentially has 160 heavy shots they can fire simultaneously, or in two salvos, depending on how they're loaded. That capital ship will be pretty darn hard pressed to shoot down 160 missiles along with the 80 fighters. Fighters aren't about small squads somehow owning everything, but are rather about fire saturation. And even if they couldn't do enough damage to a capital ship, they could still cripple it. Or aim at the cap ship's defense line, clearing the way for the larger craft to attack without as much interference.

Think of fighters as killer bees and the capital ship as a bear. That bear could easily smack around a few killer bees without much trouble. It'll get stung, likely, but wouldn't come close to suffering any sort of minor injury. However, if a whole swarm attacks that bear and it can't get away, that bear is screwed. It could easily kill a bunch of the attacking bees, but the bees will win.

Also, don't forget atmospheric battles. Orbital bombardment isn't always feasible, and some would argue that such a thing isn't even physically possible to do. Huge capital ships would have a difficult time dealing with gravity and maneuvering around the planet, if they can even maintain flight like that. Fighters, however, being so small, could easily get in there with little to no trouble and navigate tight passages such as canyons.

This post has been edited by JoshTigerheart : 03 July 2008 - 07:19 PM

I would worry about fighters being able to re-achieve orbit after atmospheric battle. Orbital bombardment would require a specialized type of bomb, which would probably work more by falling mass than by explosive charge for its damage induction, and be delivered by smaller ships specialized in 'skimming' the atmosphere. Keeping a one to two thousand foot ship on station anywhere near a planet without having the luxury of forward speed would be probably prohibitively dangerous structurally or would require too much fuel.

@0101181920, on Jul 3 2008, 11:24 PM, said in On Relative Sizes of Spacecraft:

Suddenly, it can do damage to the battleship, but the battleship still can't hit it.

As I've stated several times before, I've never found the concept that a larger ships can't hit fighters to be even slightly believable (although I'm not sure if you're extending this part of the analogy into space. But just in case you are.) 😉

Certainly, the majority of a capital ship's weapon allotment is likely going to be taken up by anti-capital weapons, which will likely be larger, longer-range, and can afford to have a fair amount of inaccuracy. But given how much smaller anti-fighter weaponry would be and how lightly armored they (fighters) are, it seems unlikely that they won't slap a few on at the cost of a Turbolaser Battery. Hmm. I never noticed how stupid that name sounded until right now.

There's also a problem with the naval-fighter-to-space-fighter translation. Fighter planes have a distinct advantage over naval craft of mobility in that they can move in three dimensions and, due to their method of propulsion and the wind/water drag that is conspicuously absent in space. (Well, I guess a lot of ships do end up moving in three dimensions eventually... ;)) Space fighters will still be faster than capital starships, but they won't have the same advantages over capital starships that planes enjoy over wet navies. Doesn't really refute anything, but it's something to keep in mind.

Besides, when we're talking about the ever-popular "beam of light" weapons, inaccuracy and target mobility aren't going to be an issue (you point, pull the trigger, and it's there. Well, almost). Like JTH said, fighters are harmless. But a lot of fighters will kill you. (Nice analogy by the way).

This post has been edited by Archon : 03 July 2008 - 08:12 PM

Well mobility is still likely to be an issue in space battles, simply because the speed of light. You see a ship and you know you're in weapons range, you start moving erratically, and it's physically impossible to track you that well until you get within a light-second or two. Nova has to obviously be somewhat unrealistic about this, since a general relativity physics engine for a game would be interesting to program to say the very least.

And Josh, the point I was making about fighters, was why bother with having 80 fighters with 2 short range missiles each when having 300 long range guided missiles for much cheaper? Space is big and empty, much easier to target and hit things--you won't need individual pilots or sensors to pick out and target enemy ships. Whereas on Earth, you pretty much need to have some sort of intelligent person there to find and confirm targets because there's so much terrain and clutter around.

Now for patrol missions you might want a small scoutship, and planetside battles will surely continue to use air power. But as far as pure space superiority goes, fighters are not necessarily going to be as useful or cost effective as loading up on missiles.

@rmx256, on Jul 3 2008, 07:37 PM, said in On Relative Sizes of Spacecraft:

I would worry about fighters being able to re-achieve orbit after atmospheric battle.

I don't think that's much of a problem, especially on worlds with low gravity and/or weak or no atmospheres. I naturally assume that, if we're already on a scale big enough to engage in interstellar warfare with massive capital ships, a fighter engine should be strong enough to bring it out of the atmosphere, assuming the structural integrity of the fighter isn't low due to combat damage.

@keldor-sarn, on Jul 3 2008, 08:21 PM, said in On Relative Sizes of Spacecraft:

And Josh, the point I was making about fighters, was why bother with having 80 fighters with 2 short range missiles each when having 300 long range guided missiles for much cheaper? Space is big and empty, much easier to target and hit things--you won't need individual pilots or sensors to pick out and target enemy ships. Whereas on Earth, you pretty much need to have some sort of intelligent person there to find and confirm targets because there's so much terrain and clutter around.

Missiles can be jammed, missiles don't know evasive maneuvers, missiles would be easier to shoot down because they'd have predictable flight paths, missiles can be duds, missiles can be detonated on-board, missiles cannot be equipped with smaller guns to hunt and kill other missiles and fighters, missiles can only be used once, and, unless you have three hundred individual launchers, you're not going to be able to fire 300 missiles at once. You'd need eighty separate firing mechanisms just to match a single volley of the fighters (assuming they don't mount their missiles in a way that allows them to fire both at once). And having a ton of launchers would take up a considerable amount of space, more than a couple of bays to cram fighters in. Most depictions of space fighter bays waste too much open space to make sense. Instead, fighters would be very cramped while in their bay. I don't remember where I saw it, but I recall seeing a bay somewhere that had a ton of fighters on a folding rack that would be lowered out of the ship and unfold, allowing for many fighters to be crammed into a tiny area.

Again, it's all about saturation. Whereas firing a missile, or even a bunch of missiles, from far away would give the enemy time to react, 80+ at short range delivered by fighters are much more likely to get through. Plus, those fighters can then shoot down missiles and other fighters, and perhaps shoot at some of the larger craft, on their way back to rearm. You could also arm fighters with a bunch of nuclear bombs and launch them at capital ships by using some sort of propulsion out of the bomb bay, such as magnetic acceleration.

I simply see fighters being more likely to get past the enemies defenses and actually do damage. Of course, I'm not saying missiles should be eschewed. You also want variety in your firepower if you're a big, hulking capital ship.

@rmx256, on Jul 3 2008, 05:04 PM, said in On Relative Sizes of Spacecraft:

What about recoil on your fighter- even a Boeng 777 sized fighter- firing a 200mm cannon? I would think that one or two shell capacity wouldn't matter too much if the gun shot out the back of your ship when you fired it.

I introduce to you two concepts. One, the muzzle brake. Two, the patented "Big Hunk of Heavy Stuff to Reduce Backwards Acceleration In Accordance with A=F/M." Wonderful, isn't it? The concept is simple: if you make an object heavier, then it won't accelerate as much when you apply a given force. And you don't have to apply this by hanging a huge chunk of iron off the side of the plane. You could put it as armor. In this way, armor might be a good thing, even though it would lower the ships acceleration.

@archon, on Jul 3 2008, 06:03 PM, said in On Relative Sizes of Spacecraft:

Certainly, the majority of a capital ship's weapon allotment is likely going to be taken up by anti-capital weapons, which will likely be larger, longer-range, and can afford to have a fair amount of inaccuracy. But given how much smaller anti-fighter weaponry would be and how lightly armored they (fighters) are, it seems unlikely that they won't slap a few on at the cost of a Turbolaser Battery. Hmm. I never noticed how stupid that name sounded until right now.

There's also a problem with the naval-fighter-to-space-fighter translation. Fighter planes have a distinct advantage over naval craft of mobility in that they can move in three dimensions and, due to their method of propulsion and the wind/water drag that is conspicuously absent in space. (Well, I guess a lot of ships do end up moving in three dimensions eventually... ;)) Space fighters will still be faster than capital starships, but they won't have the same advantages over capital starships that planes enjoy over wet navies. Doesn't really refute anything, but it's something to keep in mind.

Besides, when we're talking about the ever-popular "beam of light" weapons, inaccuracy and target mobility aren't going to be an issue (you point, pull the trigger, and it's there. Well, almost). Like JTH said, fighters are harmless. But a lot of fighters will kill you. (Nice analogy by the way).

You're right about ships having AA weapons. The Iowa-class battleship I was using as a comparison in fact had significant AA weaponry for defense. But it does become significantly harder to target in space, for a reason I'll get into next point, as well as some simple aiming problems. What do you do when you're fighting right above a planet? You've got fairly heavy gravity fields, certainly heavy enough to make problems aiming. There are a lot of little quirks in space that make it very hard to accurately aim the shot for small objects.
One key advantage that fighters have in space that they don't over the sea: they can go beneath the ship. You can't just mount a few AA turrets on top and have them cover the whole thing. You now have a full 360 degree sphere you need to cover. Sides, top, back, front, bottom. Fighters can take advantage of any holes in defense. In the ocean, two turrets can cover your whole ship.
About your last point: the thing is, beam weapons won't have 100% accuracy, ever. They don't fire at the fighter, but where you're aiming. Hopefully, it hits, but chances are you'll be off just enough to miss, since the fighter is probably moving, and also most likely quite far away.

@0101181920, on Jul 4 2008, 03:56 AM, said in On Relative Sizes of Spacecraft:

You're right about ships having AA weapons. The Iowa-class battleship I was using as a comparison in fact had significant AA weaponry for defense. But it does become significantly harder to target in space, for a reason I'll get into next point, as well as some simple aiming problems. What do you do when you're fighting right above a planet? You've got fairly heavy gravity fields, certainly heavy enough to make problems aiming. There are a lot of little quirks in space that make it very hard to accurately aim the shot for small objects.

One key advantage that fighters have in space that they don't over the sea: they can go beneath the ship. You can't just mount a few AA turrets on top and have them cover the whole thing. You now have a full 360 degree sphere you need to cover. Sides, top, back, front, bottom. Fighters can take advantage of any holes in defense. In the ocean, two turrets can cover your whole ship.

About your last point: the thing is, beam weapons won't have 100% accuracy, ever. They don't fire at the fighter, but where you're aiming. Hopefully, it hits, but chances are you'll be off just enough to miss, since the fighter is probably moving, and also most likely quite far away.

The first point is very true, but it works both ways. Besides, I don't think it's very likely that any ships would fight that close to a gravity well since it would take immense amounts of energy as opposed to staying in orbit or moving far enough away to marginalize the gravity's influence.

The second point is also valid, but since larger ships are likely sluggish, I always operate under the assumption that all capitals will have their weapons spaced evenly around the hull. So I've already taken that into account. 😉

As for the final point, I'm a little more skeptical. Because energy-based weapons are going to be dependent on either energy reserves or energy generators (likely reactors), and because fighters have very little room for either compared with their larger cousins, it's likely safe to assume that the primary weaponry of a fighter will be shorter-range than that of a capital (or really lower powered, which translates into shorter range to cause the same damage). So the capital is going to get off quite a bit of fire before the fighter can close in. And it's likely going to take a while before the fighter, constrained by linear acceleration, is going to be able to close that gap when the 2 light-seconds that were mentioned before amount to nearly 200,000 miles.

But again, if you're not talking about one fighter, but a couple hundred... things change.

That could actually create an interesting predicament: do you use your larger, longer range weapons on the horde of incoming fighters in the hopes of killing enough to keep you alive? Or do you wait for them to close in to use your smaller, more efficient weaponry, exposing you to more initially but saving on energy?

Ahh, you've come across one little quirk in space that is completely different from an atmosphere: range. The fact that railguns or chainguns decay at all is ridiculous. There's no friction in space, besides small bits of matter on the scale of a few molecules. They'll keep on going. And going. And going. And going. Do I need to continue?
Anyway, in theory, I could sit on the other end of the universe and throw rocks, and they'd eventually hit you, without decreased velocity or kinetic energy at all. It doesn't work that way in practice, of course, because I'm going for a moving target, and the time it takes to travel the length of the universe is a long time for you to drift. A battleship under full power could easily evade something from a quarter million miles, even if it's moving at a hundred miles a second. It'd take nearly an hour to get there. Obviously and ships have to get a bit close unless they're firing missiles, in which case it would be practical to fire from across the universe, so long as it's got a big enough power source. But a battleship isn't going to have anywhere near the acceleration of a fighter. (Just like to make the distinction between top velocity and acceleration. Everything in space has the same top velocity. That is, .9999 repeating C. It's the acceleration that's different.) So the fighters could shoot accurately from significantly farther away than the battleship. If it's armed with beams, and we're two light seconds away, then it will take two seconds to travel to us. You'd be surprised how long that is in aerial combat. A wary fighter could dodge it even after it started firing unless it's thirty meters in diameter, which I doubt. As they get closer, true, they have less time to dodge, but they are moving faster as the gunners will see it. If they don't travel in a straight line towards the ship, then their drifting to the side will appear to accelerate and become harder to compensate for.

@0101181920, on Jul 4 2008, 05:44 AM, said in On Relative Sizes of Spacecraft:

Everything in space has the same top velocity. That is, .9999 repeating C.

.9999~ = 1. Additionally, there is no such thing as a top velocity. Are you familiar with mathematical limits? The idea is that something can approach a number (0, -73, infinity, it doesn't matter) without ever reaching it; it literally gets infinitely close. That's the case here. There is no such thing as a specific number that is infinitely close to anything without being it.

@joshtigerheart, on Jul 3 2008, 10:43 PM, said in On Relative Sizes of Spacecraft:

I don't think that's much of a problem, especially on worlds with low gravity and/or weak or no atmospheres. I naturally assume that, if we're already on a scale big enough to engage in interstellar warfare with massive capital ships, a fighter engine should be strong enough to bring it out of the atmosphere, assuming the structural integrity of the fighter isn't low due to combat damage.

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Missiles can be jammed, missiles don't know evasive maneuvers, missiles would be easier to shoot down because they'd have predictable flight paths,

The idea that you can't program a decent A.I. to a missile, and TEACH it evasive maneuvers, even as simple as Random-Walking, is simply false. The "Predictable flight paths" argument depends on the same assumption.

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missiles can be duds, missiles can be detonated on-board,

Depends upon payload-type, and warhead quality-control. Better technology and better quality-control means fewer duds, and fewer premature-detonations.

Payload Type: While Plutonium bombs require much finer precision in their construction, Uranium bombs are damn near idiot-proof, and an Antimatter warhead Will detonate - it's just a matter of when.

(In settings where velocities over 3 km / sec are easily attained, chemical warheads can be safely dismissed from consideration as weapons)

And while carrying a larger number of warheads does increase the chance of a premature detonation, your Fighter's are carrying the same yield of warhead, no? If Those go off before Fighters launch, your Fighter-Carrier is just as screwed as a Missile-Carrier would be, should the Missiles go off before They are launched.

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missiles cannot be equipped with smaller guns to hunt and kill other missiles and fighters,

A Missile-Bus can.

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missiles can only be used once,

So what? Neither can your Fighter's ordinance. Neither can a Fighter that gets shot down, for that matter.

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and, unless you have three hundred individual launchers, you're not going to be able to fire 300 missiles at once. You'd need eighty separate firing mechanisms just to match a single volley of the fighters (assuming they don't mount their missiles in a way that allows them to fire both at once). And having a ton of launchers would take up a considerable amount of space, more than a couple of bays to cram fighters in.

Where are you getting these assumptions?

If your Fighter-Carrier can launch all 80 Fighters at once, it isn't a great stretch do design a Missile-Carrier that can launch 80 Missiles at once; this is assuming that the Missiles would be the same size as the Fighters, and they'd likely be Smaller.

Let me toss out a concept I've seen in other places: The Missile-Bus.

The Missile-Bus is an A.I. controlled spacecraft that carries missiles to a target, and fires them.
There is no Human pilot on the Missile-Bus, so there's no need for Gyroscope / comfy chair, air / life-support, ejection system, inertial dampening (No need to protect a pilot from 100G accelerations), or any of the requirements for supporting a Human Pilot.

All of the volume/mass thus saved can be put to carrying more missiles.

Evasive maneuvers, flight paths, swarming targets with multiple Missile-Buses, all depend upon how much you're willing to invest into the Missile-Bus A.I.

Like a Missile, since a Missile-Bus has no Human pilot, recovering the bus is not a strict requirement, saving space on both the Firing-Ship, and on the Missile-Bus. (e.g. Since a Fighter has to both Get There, and Come Back, and a Missile-Bus just has to Get There, it already saves about half the space on its fuel tank.)

Actually, on the "shorter range to do the same damage" point, I was referring to energy weapons, which diffuse over distance and lose potency. You're right; railguns won't decay in space, but they also need to be powered by something, and a capital's reactor is going to be able to push it a lot faster than a fighter's.

Of course, with those, the fighter can move out of the way much more easily than a large capital, but because of the time it would take for a railgun shot to travel that far, like you said, they would be totally impractical until you closed the distance somewhat unless the larger ship is essentially immobile. In the end, you're going to be able to shine a light on something long before you can hit it with a bullet.

@eugene-chin, on Jul 4 2008, 03:52 PM, said in On Relative Sizes of Spacecraft:

There is no Human pilot on the Missile-Bus, so there's no need for Gyroscope / comfy chair, air / life-support, ejection system, inertial dampening (No need to protect a pilot from 100G accelerations) , or any of the requirements for supporting a Human Pilot.

Hey, I didn't think of that one! Mind if I throw that into a dësc or two in Anathema?

This post has been edited by Archon : 04 July 2008 - 01:29 PM