@archon, on Jul 4 2008, 02:26 PM, said in On Relative Sizes of Spacecraft:

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

Sure, I don't mind.

The problem with designing missiles to be evasive means you're radically upping your costs for a one-time weapon. In order to make your missile evade, it needs thrusters all over it, as well as a sophisticated artificial intelligence, computer system, and sensors in order to detect threats and evade them, as well as being made even larger and sturdier to survive the additional, sudden forces evasion would require. This is a bunch of added cost and weight compared to just the usual components. Also consider that the missile already needs to have a powerful enough main thruster to allow it to travel at the super-high speeds and light-seconds to reach the target in the first place, sturdy enough so the force of it accelerating and potential gravity if you're close enough doesn't shred it, protected enough to survive unexpected collisions with space debris, and intelligent enough electronics and sensors for it to track a target. Adding all the other stuff you're proposing would make for some ridiculously expensive disposable weapons. For that cost, I'd rather make something that would last.

By the way, your missile bus is nothing more than a fighter (or maybe larger ship) using a A.I. instead of a human as the pilot. Just because the pilot is a program instead of a human doesn't make it any less a fighter. Though if you have A.I.s sophisticated enough to handle heavy combat situations well enough to replace human pilots, then you might as well just have A.I.s run all of your ships, not just a single class. Then you don't have to worry about human casualties in the first place.

@joshtigerheart, on Jul 4 2008, 05:45 PM, said in On Relative Sizes of Spacecraft:

The problem with designing missiles to be evasive means you're radically upping your costs for a one-time weapon. In order to make your missile evade, it needs thrusters all over it, as well as a sophisticated artificial intelligence, computer system, and sensors in order to detect threats and evade them, as well as being made even larger and sturdier to survive the additional, sudden forces evasion would require. This is a bunch of added cost and weight compared to just the usual components. Also consider that the missile already needs to have a powerful enough main thruster to allow it to travel at the super-high speeds and light-seconds to reach the target in the first place, sturdy enough so the force of it accelerating and potential gravity if you're close enough doesn't shred it, protected enough to survive unexpected collisions with space debris, and intelligent enough electronics and sensors for it to track a target. Adding all the other stuff you're proposing would make for some ridiculously expensive disposable weapons. For that cost, I'd rather make something that would last.

By the way, your missile bus is nothing more than a fighter (or maybe larger ship) using a A.I. instead of a human as the pilot. Just because the pilot is a program instead of a human doesn't make it any less a fighter. Though if you have A.I.s sophisticated enough to handle heavy combat situations well enough to replace human pilots, then you might as well just have A.I.s run all of your ships, not just a single class. Then you don't have to worry about human casualties in the first place.

You're making strange assumptions again, but the one that really jumps out at me is this:
Simply because you have a Missile-Bus computer that can evade properly does not equate to having a computer that can make strategic/tactical decisions for a fleet of battleships. I postulated an A.I. able to Random-Walk to a target, and that's a Very long way from being able to handle entire fleets.

One of the biggest benefits of using a computer over a Human pilot is processing time; being able to make thousands of simple decisions every second. Faster response times couple well with evasion, and with responding to high-intensity AA fire.

Yet, for all the processing power in the world, no one has yet programmed an A.I. that can play Go at better than an intermediate level. Until you have an A.I. able to play Go well, replacing Human Command Officers with machines is a genuinely bad idea. And if you lack FLT communications, it's outright impossible. No one is going to put A.I. in charge of every strategic/defense decision, and leave it to its own devices unattended.

A Missile-Bus is a compromise between an actual missile, and a fighter-craft. Instead of pouring all of the effort required into making each missile get to the target, pour all that effort into the one Missile-Bus, and have that fire a bunch of cheaper missiles.

Two major differences between a Fighter and a Missile-Bus are these:

1. No Human Pilot
2. Because of 1), you don't care if it ever comes back or not.

This may not seem like much of a difference, but they change the design philosophies between Fighters and Missile-Buses quite a bit.

This post has been edited by Eugene Chin : 04 July 2008 - 06:52 PM

Regardless of the fact that I misread your A.I, you'd still need one that's more advanced. With weapons potentially traveling at the speed of light,, such as lasers, you'd need to program the A.I. to anticipate and how to at least gauge the situation on the basic level whether it is safe to move in and fire or better to break off, which targets provide the best opportunity should it not be pre-assigned or the target destroyed before your bus arrives, how to deal with damage, and a couple of other things that escape me at the moment. But even still, we're looking at an expensive, disposable craft since it needs to maneuver like a fighter, be as protected as a fighter (maybe), have a similar power supply as a fighter, be as sturdy as a fighter, and the same weapon systems as a fighter. Unless your bus is bigger than a fighter, but then it's even more costly! The only things it is lacking are life support, some, if not all, inertial dampening (some might be necessary to merely hold the craft together), and an ejection system. I suspect those would be the cheaper components too.

Out of sheer speculation, I'm going to guess the cost ratio for comparison, excluding costs for training a pilot and for designing, debugging, and testing an A.I., to be 4/5, maybe 3/5 if we're generous. Eh, lets go with 7/10. So if your fighters cost 100,000 to produce, that would make your missile bus 70,000 to produce. Let's say you have a budget of 1,000,000. That's ten fighters or fourteen missile busses. Let's say in battle we loose three fighters, since they're designed to come back if they take damage and eight busses, since we don't care if they return. That's 300,000 to replace the fighters, but 560,000 in missile busses, excluding repair costs on what returns, rearming the survivors, replacement pilots, and the costs of programming new busses.

This, of course, assumes the bus is as protected as the fighter. If you cut your defense, you'll cut costs and be able to field more, but you'll also loose more busses. Say if we take off the shield generator on our bus, costs drop to 1/2 of a fighter to produce, minus all the programming, debugging, and testing, we then have twenty busses. But since defense is reduce, they're more likely to get shot down, regardless of evasive programming. Even still, if we loose six busses, we match costs with the fighters. And we already lost eight with shield generators, so we may be loosing up to fifteen busses, which is 750,000, more than double the cost to replace the fighters. Though your busses will be able to do more damage on that first run, the seven remaining fighters will be able to rearm and inflict more damage than your five (or six if they have shield generators) busses. And if the attrition rate remained constant, you're going to have five fighters and two busses (both ways), then about three fighters and one bus, then two fighters and no busses. Or if we upped this to more reasonable numbers by tacking on a zero to the numbers for a single cap ship, we have twenty of a hundred fighters left, and zero of two hundred busses left. Multiplying that by five, a fleet may have a hundred fighters of five hundred left, and no busses left. The costs we're looking at here is in the millions.

Of course, as there is absolutely nothing to check my numbers against other than pure fiction, I could be radically wrong. Busses could be many times cheaper than fighters, or they could end up being more expensive. However, as I see it, I don't see the missile bus being a cost-effective weapon. Disposable weapons, like bombs and missiles, need to be cheap to be practical compared to reusable alternatives. If I have a higher ratio of returning fighters that can go out and cause more damage once rearmed, then that's what I'm going to use, human or A.I. piloted.

A fighter will be designed to maximize its acceleration, meaning very high thrust and very little mass. Size is a constraint of sorts, since the fighter will have to be small enough to fit in the bay of its carrier and also be able to maneuver through small places in the defense fire grid. Mass however, becomes an extremely important constraint.

Depending on what type of propulsion system is being used, most fighters are probably stripped down to bare min life support for pilot, propulsion, and single weapons package. Fighters probably wouldn't contain a FTL drive.

Random thought: capital ships probably wouldn't deploy fighters from maximum range. Rather, since the bigger ship is considerably more durable, it'd move as close as it safely could before deploying to decrease the distance the fighters have to go.

Okay, I read a bunch of posts...and then it looks like it turned into bickering.

Mrxak...your argument looks fine except for one huge glaring flaw...and I think it is following all the arguments from there.

Imagine this, whatever you have, your opponents have.

aka you build a capital ship, what are its benefits? As you noted, it is basically a compilation of a base/planet/(everything needed to survive in empty space for a longtime). Thus the capital ship is basically containing ships, much like a planet would to defend it. Now if we think of capital ships from that perspective it makes a lot less sense for them to be used as weapons in the first place.

Most of all orcaloverbri9 limit argument probably is the best analogy (although he didn't use it as such, but instead simply used it to show off :p).

Just like weapons today, your opponents as well as yourself will constantly be trading superiority back and forth. Just as carriers grow bigger and fighters get more stealthy or smaller, everything goes to nil. That is, in a competition for superiority between to relatively equal sides, technology will stay roughly the same between the two sides. Thus it took us 15 years (in the U.S.A) to develop the F-22 raptor (more like 25 actually). South Koria, Japan, and China have all put forward test beds to equal the feet, working off the F-22's technology, to build generation 5 fighters in the next 5 to 10 years. Why? Because as technology becomes developed it is very hard initially (much like breaking the glass ceiling), but for those that follows reverse engineering, and simply release of technology means new models have the advantage of copying or tweaking the previous models.

Why is this important?

It means that the reason you can't build a bigger fighter is because someone else will build a smaller faster fighter to shoot that fighter down. Thus the advantage from having fighters in general, eventually goes to nil. Same thing with capital ships. They are probably made bigger and (bigger shields, larger crews for boarding purposes, larger weapons, more engines) eventually the fighting capability of a capital ship becomes nil as well and they become ineffective as a warship altogether. Thus between the extremes you have this gulf, eventually fighters are just used to fight fighters, and warships (capital ships) are just used as either stations or just used to fight warships.

Anyway, not hacking on anyones day, but of course the bail clause here is that simply by nova's time, all these problems would have been thought out and fixed. You'd probably have inertia-less movement, tiny weapons with huge payloads, planet sized microwaving devices, etc... I imagine the universe extremely unstable where an advantage is extremely destructive, but primarily, all sides are at a stalemate 99% of the time. You don't get large oscillations in superiority at such times because the destructive effects would be epic, much like we have today with nuclear weapons. Although, anyone of 9 nations could at anyone time destroy anyone else in the world, it would be to their own detriment because the world would be a vast waste land and then what would you have?

Much like in the EV scenario you might have planet destroying devices...but then you lose a planet to farm for resources and the people to do it. Thus I envision a universe in a stalemated, almost certain peace...much like we have now in the world, where globalization begins to take hold, and everyone comes to the realization that it is in their interest to not blow the planet to smithereens.

P.S. In terms of the bigger weapons on the fighter, one might surmise that precision is more important. It is likely that a capital ship would make a frontal assault on another capital ship with most of the vitals of the ship wrapped behind. thus the fighter could attack the "exposed" vitals more easily and more precisely with smaller weapons. The previous point still stands, however, in my own mind.

This post has been edited by Swithich : 05 July 2008 - 02:08 AM

All you people are talking about being able to detect and evade attacks in space.

I say the moment you're seen, you lose most of your chances at winning.

-Most of our current stealthing tech works in space. You cover every ship you've got in materials that absorb or deflect 99% of every bit of light that strikes them.
-When you accelerate, you cool your emissions to as close to background as you can before it exits.
-In combat, you either talk with cables (imagine that for space fleets!) or not at all. Rather than worrying about the enemy listening in, you have to worry about them shooting at encrypted radio sources. I'd imagine most battles would be 1v1 affairs. Too troublesome to keep track of what near-invisible shape is a friend and which is an enemy, unless you are cabling your ships together, and if you lose a ship, it's too risky that the light from the hits and detonations will reveal the rest of your fleet.
-Under no circumstances should you use active sensors. Those are suicide.
-If you think you may have been seen, change course.
-If you you've done something that might allow you to be seen, change course.
-If you think you haven't been seen, change course.
-If you are hit, you are dead. If you aren't dead, you will be soon: launch everything you've got.

When you shoot a projectile, you eject it from your ship using mechanical force: a spring or railgun. Oh right, you put stealthing materials on these too, and you change your vector immediately.

Homing missiles don't work well in space. They'd have to have multiple thrust vectors to move right, and altering course significantly is prohibitive. Instead, you give them a target and send it roughly towards a location where the target will be (roughly) around the time the missile gets close. This was all done launcher side, here's where the AI comes in. The missile monitors the target the entire time. When it's close enough, it uses a gyroscope to alter it's orientation to point at the target (again, preceding the target along its current vector, and of course compensating for its own initial vector,) and ignites the thruster.

Now, your missile buses are more efficient for this method. Rather than spending precious resources developing ever more complex evasion AIs, make the bus as close to undetectable as you can. You'll be researching the same materials for your own primary ships, so you're spending the money already. Like the missile, the bus drifts close on initial mechanical acceleration, then opens it's ports and fires its missiles. You can leave these unstealthed if you prefer, but then you'll have to launch all at once, because only an idiot won't immediately shoot at a point that just launched 10+ missiles at him. As long as you don't mind losing the bus, it only matters that you were not pinpointed by the trajectories of your projectiles.

As for warheads, those are pretty straight-forward. Except the antimatter one. For that, you have to hold the antimatter within a magnetic cage, and one would expect that triggering the warhead would be like letting it connect with regular matter. Have some fun. Make antimatter ball bearings and take a page from Swordfish's opening scene. Point the cage at the target and open that end. A few antimatter balls exploding directly on the hull of a craft is probably going to cause more damage than just detonating it while the target is in the blast radius. This is a benefit of a material that is inherently explosive. It'd probably be best if you didn't use these near planets that are inhabited or habitable.

In my opinion, if you couldn't tell by now, space-borne combat will be more like submarine combat and Battleship than *Wars.

In this paradigm, the bigger you make a ship, the more likely it is that it'll occlude some stars, and you can bet every targeting system is going to be paying close attention to the stars, as well as any other indirect detection method the scientists can come up with. Aside from that disadvantage to large ships, the design is completely up to the military engineers.

The first side that comes up with a gravity sensor capable of resolving ships wins.

@artanis, on Jul 5 2008, 12:35 AM, said in On Relative Sizes of Spacecraft:

All you people are talking about being able to detect and evade attacks in space.

I say the moment you're seen, you lose most of your chances at winning.

-Most of our current stealthing tech works in space. You cover every ship you've got in materials that absorb or deflect 99% of every bit of light that strikes them.
-When you accelerate, you cool your emissions to as close to background as you can before it exits.
-In combat, you either talk with cables (imagine that for space fleets!) or not at all. Rather than worrying about the enemy listening in, you have to worry about them shooting at encrypted radio sources. I'd imagine most battles would be 1v1 affairs. Too troublesome to keep track of what near-invisible shape is a friend and which is an enemy, unless you are cabling your ships together, and if you lose a ship, it's too risky that the light from the hits and detonations will reveal the rest of your fleet.
-Under no circumstances should you use active sensors. Those are suicide.
-If you think you may have been seen, change course.
-If you you've done something that might allow you to be seen, change course.
-If you think you haven't been seen, change course.
-If you are hit, you are dead. If you aren't dead, you will be soon: launch everything you've got.

When you shoot a projectile, you eject it from your ship using mechanical force: a spring or railgun. Oh right, you put stealthing materials on these too, and you change your vector immediately.

Homing missiles don't work well in space. They'd have to have multiple thrust vectors to move right, and altering course significantly is prohibitive. Instead, you give them a target and send it roughly towards a location where the target will be (roughly) around the time the missile gets close. This was all done launcher side, here's where the AI comes in. The missile monitors the target the entire time. When it's close enough, it uses a gyroscope to alter it's orientation to point at the target (again, preceding the target along its current vector, and of course compensating for its own initial vector,) and ignites the thruster.

Now, your missile buses are more efficient for this method. Rather than spending precious resources developing ever more complex evasion AIs, make the bus as close to undetectable as you can. You'll be researching the same materials for your own primary ships, so you're spending the money already. Like the missile, the bus drifts close on initial mechanical acceleration, then opens it's ports and fires its missiles. You can leave these unstealthed if you prefer, but then you'll have to launch all at once, because only an idiot won't immediately shoot at a point that just launched 10+ missiles at him. As long as you don't mind losing the bus, it only matters that you were not pinpointed by the trajectories of your projectiles.

As for warheads, those are pretty straight-forward. Except the antimatter one. For that, you have to hold the antimatter within a magnetic cage, and one would expect that triggering the warhead would be like letting it connect with regular matter. Have some fun. Make antimatter ball bearings and take a page from Swordfish's opening scene. Point the cage at the target and open that end. A few antimatter balls exploding directly on the hull of a craft is probably going to cause more damage than just detonating it while the target is in the blast radius. This is a benefit of a material that is inherently explosive. It'd probably be best if you didn't use these near planets that are inhabited or habitable.

In my opinion, if you couldn't tell by now, space-borne combat will be more like submarine combat and Battleship than *Wars.

In this paradigm, the bigger you make a ship, the more likely it is that it'll occlude some stars, and you can bet every targeting system is going to be paying close attention to the stars, as well as any other indirect detection method the scientists can come up with. Aside from that disadvantage to large ships, the design is completely up to the military engineers.

The first side that comes up with a gravity sensor capable of resolving ships wins.

They already have gravity sensors, they use them to detect gravitational waves in other solar (or bisolar) systems.

Also, you assume the ship's stealth capabilities would come before a gravity sensor.

Another thing, there are (I believe) about 10,000 particles per square foot of space. Couldn't you just map known particles and then look for a gap?

I mean at worst, you could send out some really powerful energy beam (one that could not be absorbed) and just look for where it reflects. Just because radio waves (radar) on earth can be absorbed, doesn't mean that all waves can be absorbed.

Really all this talk is just speculation of course. As I was pointing out, anything one side develops will either be copied and/or defended against very quickly after the discovery (probably before a productions model) especially with telipaths running all over the universe.

@guest_swithich_-, on Jul 5 2008, 02:39 AM, said in On Relative Sizes of Spacecraft:

They already have gravity sensors, they use them to detect gravitational waves in other solar (or bisolar) systems.

Also, you assume the ship's stealth capabilities would come before a gravity sensor.

Another thing, there are (I believe) about 10,000 particles per square foot of space. Couldn't you just map known particles and then look for a gap?

I mean at worst, you could send out some really powerful energy beam (one that could not be absorbed) and just look for where it reflects. Just because radio waves (radar) on earth can be absorbed, doesn't mean that all waves can be absorbed.

Really all this talk is just speculation of course. As I was pointing out, anything one side develops will either be copied and/or defended against very quickly after the discovery (probably before a productions model) especially with telipaths running all over the universe.

I know we have gravity sensors. I also know that they can only resolve stars and larger planets, when they work at all. Gravity's a hard field to nail down.

Well, pretty much, yeah. This is materials stealth, not some clever device that grabs photons and moves them around. Just absorb them and let the background of space do all the work.

It'd be easier to map densities and look for variations, but particles move, and so do densities. And a ship could attempt to refill the particle wake behind it. Too much room for error.

No, not all waves can be absorbed. Gravity waves for example, but then you need a gravity generator as well as a sensor capable of resolving an object slightly larger than a spaceship. All waves useful for locating things rapidly (light) can be absorbed, unless they go right through, in which case they are useless as detection. I suppose you could scatter lamps around the predicted battle field, but they'd illuminate you just as well.

Of course, it is left unsaid that the first side to develop telepathy wins.

I have a few ideas on ship size. A cessna 172 can fly at 123 knots (140 mph) and weighs 2.25 tons. A F15-C Eagle can fly at mach 2.5 (1650 mph) and has a max gross weight of 20 tons. A Nova spaceship needs to be able to leave Earths atmoshere so it must be able to achieve 18,500 mph. The space shuttle can do so and weighs 1,600,000 lbs, or 800 tons and can carry 25 tons payload. A fully loaded 747 weighs 800,000 lbs. So, accounting for futuristic improvements such as more effecient engines, but adding weight back on for armor, shields, and weapons, I could see a space fighter being an 800 ton monster easily. Modern naval carriers displace 100,000 tons and carry 85 aircraft. Since going from F15 to space shuttle is an increase of a factor of 40, I believe a space carrier carrying 85 fighters would weigh 4,000,000 tons.

But let me lay down some Nova assumptions
1. Ships of all sizes can land on planets
2. Shields are advanced enough to offer protection from just about anything
3. Even small ships can achieve FTL travel

Now in terms of futuristic starship defenses, here are my basic ideas. Shields in Nova seem to be very similar to the shields in Star Wars, capable of stopping lasers, projectiles, whatever. Also the shields in Nova scale with the ship, the larger ships are able to project stronger shields. My thoery on armor is based on NASA's Deep Impact mission when they crashed a probe in to 9P/Tempel. To protect the probe on final approach to the comet, they used several thin sheets of copper spaced out in layers on the front of the probe. For a few kilograms it could stop a ball bearing moving at 60,000 mph. Now imagine a capital ship layered in dozens of layers of armor that are several inches thick. Anything passing through would suffer from refraction. It would take weapons of catastrophic power to penetrate that kind of defense, especially after defeating an energy shield. It should take an entire swarm of strike craft to take a capital ship down.

As for weapons, small ships would probably try to deliver missile or torpedo based weapons because they would lack the powerplant for excessively overpowered energy weapons. Large ships would use more energy based weapons because they could support the power requirements and that would extend their battlefield endurance. Capital ships would also likely carry missiles and torpedoes as fire and forget weapons for hit and run or nuclear ordnance for orbital bombardment. Capital ships would also be very dependent of point defense weapons for protection.

In space tactics, there would likely be two phases: the stealth phase, and the engagement. In the stealth phase, the opposing sides manoeuvre on each other silently, hunting and hiding. Once contact is made, they turn over to active scanning and jamming. Decoy craft, small pods that broadcast ship like signals, would be effective because visual confirmation of targets would be nigh impossible at space combat ranges.

In strategic terms, even if strike craft could achieve FTL, carriers would be important as a refuel/rearm station in enemy territory. Otherwise the small craft would have to jump all the way home before returning to the action. That would make the carrier the center point of the fleet. As carriers would have obscene defenses, direct combat capital ships would likely be required to engage them. Supercapital ships would likely be rare, as rare as carriers, but medium capital ships would likely be common because of thier survivability and versatility. Fleets would have ships of all sizes up and down the scale to operate effectively in the game of space rock, paper, scissors. Strike craft swarm counters destroyer, destroyer swarm counters heavy cruiser, heavy cruiser counters carrier.

Stealth in space, while fun, doesn't make much sense. I did some research on it once and discovered that it isn't very likely. If your ships have enough temperature for life support, a reactor that produces a reasonable amount of power, and a thruster able to move your ship fast enough, you WILL get detected. Why? If the spacecraft are torchships (aka they don't have some sort of cold engine), their thrust power is several terawatts. This means the exhaust is so intense that it could be detected from Alpha Centauri. By a passive sensor. The Space Shuttle's much weaker main engines could be detected past the orbit of Pluto. The Space Shuttle's manoeuvering thrusters could be seen as far as the asteroid belt. And even a puny ship using ion drive to thrust at a measly 1/1000 of a g could be spotted at one astronomical unit. The life support for your crew emits enough heat to be detected at an exceedingly long range. The 285 Kelvin habitat module will stand out like a search-light against the three Kelvin background of outer space. And your reactor to power your ship is going to be many times hotter. And if you are hoping to lose your tiny heat signature in the vastness of the sky, well, that won't work either. Current astronomical instruments can do a complete sky survey in about four hours, or less.

This is with modern technology used from Earth , by the way. Having multiple ships and dedicated platforms in space for detection will just make canceling stealth all the easier. Now if you can come up with a way to keep your ship at an extremely low temperature at all times, you can use your cloaking fields and what not. Though exactly how that would be achieved is beyond me.

Though even if you could hide your ships, the moment you fired, you'd be spotted.

However, even with this problem, stealth would still work in atmospheric combat, near high sources of heat, such as a star, and hiding ships under the heat emissions of a larger one (where did that heavy cruiser get all those frigates?). It just won't be a game of hide 'n seek with bazookas.

Are we building ships that require reaction mass, or magic reactionless drives that can modify your ship's velocity and/or heading as long as your reactor has enough energy? Because whether you're constrained by the laws of physics (especially Newton's third law) also makes a difference as to how you'd design ships (especially fighters, which can't carry much reaction mass). (If you want to make ships that accelerate at 1000G, like the ones in Star Wars, you probably have some sort of physics-breaking technology like a gravity damper so your crew and electronics don't become meat-and-silicon pancakes whenever your ship speeds up or slows down. It's hard to get to a really high velocity quickly accelerating at 1-2G.)

This post has been edited by UE_Research & Development: 05 July 2008 - 11:21 AM

3 Kelvin? Pardon, but shouldn't space, having no heat energy by definition, be 0 Kelvin?

@orcaloverbri9, on Jul 5 2008, 11:50 AM, said in On Relative Sizes of Spacecraft:

3 Kelvin? Pardon, but shouldn't space, having no heat energy by definition, be 0 Kelvin?

That's be absolute zero and everything in space would be frozen in place. Well, all matter would anyways. A situation like that would be the Big Freeze. Don't forget we have stars and other things to keep space above that temperature. The fact that we can see starlight from lightyears away suggests the heat from said light, however little and diminished, can go very far, to say the least.

@orcaloverbri9, on Jul 5 2008, 09:50 AM, said in On Relative Sizes of Spacecraft:

3 Kelvin? Pardon, but shouldn't space, having no heat energy by definition, be 0 Kelvin?

Ya, the temperature of space is about 3 Kelvin.

Here is an article for ya.

http://en.wikipedia.org/wiki/Cosmic_microw...round_radiation

@joshtigerheart, on Jul 5 2008, 01:59 PM, said in On Relative Sizes of Spacecraft:

That's be absolute zero and everything in space would be frozen in place. Well, all matter would anyways. A situation like that would be the Big Freeze. Don't forget we have stars and other things to keep space above that temperature. The fact that we can see starlight from lightyears away suggests the heat from said light, however little and diminished, can go very far, to say the least.

Technically speaking, space, being a complete vacuum, is the absence of matter, and there's nothing to be frozen in place, but I hadn't considered the various waves. On the other hand, a theoretical place with no light or radiation of any kind would, in fact, be 0 Kelvin, though we might as well be talking about a place where all gases are ideal.

There's supposed to be a very minute amount of matter floating around out there (aside from stars, planets, and the like). I assume it'd be stuff like little bits of rock from asteroids and other things. Though this isn't something I've looked into much since I've never been interested in. I just recall reading about it on a website about how to destroy the Earth.

I point out, gentlemen, that there is friction in space - gravity is a serious impediment to small projectiles, even if they're moving quickly. For example, when in orbit of a planet (or anything like close by), small projectiles will suffer severe internal friction and losses from the gravity of the larger body. Even a railgun slug travelling at thousands of kilometers per hour will quite rapidly be affected and perturbed by gravity.

The maths would get even worse in a planetary ring system like Saturn's. Lots of little small objects all acting on the slugs would seriously impact their accuracy and would eventually trap them as part of the system. Even if they didn't, the slugs most certainly wouldn't reach escape velocity of Saturn proper. Even in-system, I don't know of any slug-propelling technology that would allow something to reach solar system escape velocity.

The only things I know of that have enough speed to get out of this system are the Voyager probes, and they got their speed via a gravitic (oddly enough) slingshot from both Jupiter and Saturn. Lord knows we haven't got anything big enough to duplicate that kind of energy.

@orcaloverbri9, on Jul 5 2008, 04:30 PM, said in On Relative Sizes of Spacecraft:

Technically speaking, space, being a complete vacuum, is the absence of matter, and there's nothing to be frozen in place, but I hadn't considered the various waves. On the other hand, a theoretical place with no light or radiation of any kind would, in fact, be 0 Kelvin, though we might as well be talking about a place where all gases are ideal.

I believe I once heard that there are about 10,000 particles per square foot of space...

That said...here is another link for you...

http://en.wikipedia....iki/Outer_space

Interstellar space is a very good vacuum, although it is not quite perfect.

And by the way Pipeline, I don't think you can technically classify gravity of an object as "friction" although it would be a major impediment to mass based weaponry in space, I definitely agree with you there.

It would also be a huge problem to larger ships. If you can imagine a capital ship would, in its self create a large amount of attraction between it and another large object, thus affecting its course a lot more. Therefore if we want to be pseudo-realistic, it would be extremely impractical for a capital ship to ever visit a planet or even a large stellar object (astroid or a moon).