Standard Sci-Fi Fleet

[Patroklos]

In a short term battle situations heat sinks can get you a few shots off or taken on your shields before you have to radiate depending on how powerful your weapons and your capacity to absorb heat. You can actually use reaction mass if you don't want to have more a more sutiable substance dedicated to this purpose and just make the calculated cost benefit of future engine burns vs combat staying power. That's not a long term solution but when you are being hit by projectiles at the speed he has stated you only have to get one to the hull to instakill. Depending on his world's combat mechanics that might work.

You vent the coolant in an emergency to maybe get one more shot given/taken. Ideally you can fire and then lower shields to use normal radiators as long as you can. If his shields are directional as opposed to a bubble this will work better and could allow for interesting formation issues as each side tries to keep a threat axis and a radiation axis and prevent either from coinciding. If they are more like a bubble vending coolant won't work as you are just putting it back into your shields if you are enclosed.

It should be remembered that without magic shields are basically always a heat sink. Both in whatever it generates just be being in operation while it encloses you, then via whatever damage it ends up absorbing.

[Corvus 501]

As you said, "sweating" (not exactly) uses mass. THATS WHY THERE ARE NORMAL RADATORS! When you get into a fight, you recess the radators into armored compartments, and flush out heat with coolent as needed. You don't want the delicate radators getting shot off, so you "sweat" off heat during battle.

[Lord Revan]

As to the radation problem, well, the shields don't do much, that's what the armor's for. With the cooling issues that brings up, (and the general cooling issues that you run into with spaceships) the solution is surprisingly simple. Just borrow the little quirk of human anatomy known as sweating. Just vent coolant through "pores" in the armor to cool it. Under normal circumstances, use normal radiators to conserve coolant.

...You do know that in space, that coolant is effectively radiators, right? You dump heat into the coolant, you eject the coolant, it radiates away the heat. Granted, the heat is no longer your problem, but you're spending a lot of mass on what is effectively single-use heat sinks.
Human sweating works because it uses convection/evaporation cooling. Out in space...not so much.

or to put in other terms I'd probably get hypothermia sooner if I stepped outside in my current essentially summer clothing, then I would if I was exposed to hard vacuum in deep space and FYI it's about 277 K atm outside while deep space is about 3 K or so (when not near a large body that's giving off heat), I might be exagrating but the point stands easier to cool things when it's surrrounded by matter.

[Jub]

As you said, "sweating" (not exactly) uses mass. THATS WHY THERE ARE NORMAL RADATORS! When you get into a fight, you recess the radators into armored compartments, and flush out heat with coolent as needed. You don't want the delicate radators getting shot off, so you "sweat" off heat during battle.

How do your passive radiators work? In atmosphere you transfer the heat to the air, in space sweating or firing off extra heat as energy are your only options. Passive radiators don't tend to work very well when they have nothing to transfer energy to.

[Batman]

What in Valen's name is a 'passive' radiator? Radiating heat away is active by definition. I assume this to mean 'unpowered'.

[Simon_Jester]

You can still radiate away heat thermally via blackbody radiation; it's just slower. Painfully slower. So just having big slabs of metal at the same temperature as your hull, free to radiate heat into space, will cool your ship down- as long as those slabs of metal aren't parked in direct sunlight, or at least not sunlight intense enough to heat them faster than they can cool down.

EDIT:

That said, I wish Corvus would actually address some of my questions or comments.

[Corvus 501]

Operative word: radation. Otherwise known as one of a few ways that heat is transmitted, as any 5-6th grade physics textbook will tell you.

[Corvus 501]

Actually this problem is discussed in John Ringo and Tarvis S. Taylor's Voyage of the Space Bubble series, where the radators/heat sinks where large glass rods that would be pushed out of the ship to cool the ship, called in series Chilling.

[Jub]

What in Valen's name is a 'passive' radiator? Radiating heat away is active by definition. I assume this to mean 'unpowered'.

Don't ask me, it seems like Corvus thinks that his normal radiators don't need to eject mass to cool his ship.

You can still radiate away heat thermally via blackbody radiation; it's just slower. Painfully slower. So just having big slabs of metal at the same temperature as your hull, free to radiate heat into space, will cool your ship down- as long as those slabs of metal aren't parked in direct sunlight, or at least not sunlight intense enough to heat them faster than they can cool down.

That hardly counts at sci-fi levels of energy generation. Just firing your engines would cook you if that's the best you had to deal with heat. Hell normal operating heat from cooking and the crew moving about would likely build up faster than you could radiate it unless you had a giant radiator.

[Corvus 501]

Read the series. The co-author may suck as a standalone author, but he knows his stuff, and John Ringo more than makes up for Taylor's lacking where it comes to writing.

[Jub]

Read the series. The co-author may suck as a standalone author, but he knows his stuff, and John Ringo more than makes up for Taylor's lacking where it comes to writing.

This is really the first time you've given us a clear picture of how you expect things to work.

What you need to do now, is gather all your ideas into one well written post with good formatting and grammar so we can give you ideas on where to go next. So step one, clearly articulate your ideas; step two, tell us why you like those ideas and how you plan to use them in your story; step three, answer questions that come up from the first two.

If you're going to tell a story, you need to start with an idea that people can understand.

[Corvus 501]

Thanks Jub, but the cooling issue seems to be the real hang up for every space thread. I'm trying to avoid any "space magic" handwaves, with the exception of things like "how is that alloy so strong", "how does that reactor work," and "how the hell does artificial gravaty work?" Mostly, I'm using the vaguely hard sci-fi handwave of "Science Marches On".

Mostly, because I don't want to end up with egg in my face because somone came up with a real world version of one of my concepts, one they works completely differently than a painstakingly planned out fictional technology.

[Batman]

If you don't want to end up with egg on your face how come you refuse to properly spell 'gravity' even after Simon called you out on your atrocious spelling?

[Zeropoint]

Don't ask me, it seems like Corvus thinks that his normal radiators don't need to eject mass to cool his ship.

Well, they don't. Check out the radiators on the Space Shuttle or the ISS. Open-cycle cooling is for emergencies and very low endurance craft.

Also check out Liquid Droplet Radiators, which present several advantages over the old-school pipes & panels type.

[Jub]

Well, they don't. Check out the radiators on the Space Shuttle or the ISS. Open-cycle cooling is for emergencies and very low endurance craft.

Also check out [url]Liquid Droplet Radiators[/url=http://en.wikipedia.org/wiki/Liquid_droplet_radiator], which present several advantages over the old-school pipes & panels type.

I think that if you're talking about running shields and accelerating to high fractions of c in hours or less, you'll never be able to get by with just that. You're just going to burn too much power and make too much waste heat.

[Simon_Jester]

What in Valen's name is a 'passive' radiator? Radiating heat away is active by definition. I assume this to mean 'unpowered'.

Don't ask me, it seems like Corvus thinks that his normal radiators don't need to eject mass to cool his ship.

While he may have profound trouble writing or responding to my questions, he's actually right about this part. A radiator radiates; it does not necessarily have to eject mass to cool things down.

If you take a hunk of red-hot metal in space, it is glowing with its heat. Glowing takes energy. Eventually your red-hot metal will cease to be red-hot. Eventually it will become colder still, and colder than that, until it reaches a temperature at equilibrium with the background radiation. In the depths of interstellar space, background temperature is extremely low; in direct sunlight in the habitable zone of a star it's actually rather hot- but the principle remains.

That hardly counts at sci-fi levels of energy generation. Just firing your engines would cook you if that's the best you had to deal with heat. Hell normal operating heat from cooking and the crew moving about would likely build up faster than you could radiate it unless you had a giant radiator.

Space stations manage just fine with people cooking and moving about and operating normal scientific equipment. In, as often as not, direct sunlight.

The engines, and waste heat from the engines, is problematic. But without figures for the actual power generation of those engines or the configuration of the ship, it's hard to say how much of a problem it is. For example, the engines could be mounted in a thermally isolated, insulated pod that is structurally separate from the bulk of the ship- in which case the temperature of the engines might be a lot higher than that of the crew compartment.

Thanks Jub, but the cooling issue seems to be the real hang up for every space thread. I'm trying to avoid any "space magic" handwaves, with the exception of things like "how is that alloy so strong", "how does that reactor work," and "how the hell does artificial gravaty work?" Mostly, I'm using the vaguely hard sci-fi handwave of "Science Marches On".

Mostly, because I don't want to end up with egg in my face because somone came up with a real world version of one of my concepts, one they works completely differently than a painstakingly planned out fictional technology.

See, that's not really a problem. For one, because we all know heating is a problem and it's hard to solve from an engineering standpoint, people are relatively forgiving of handwavium.

Meanwhile, it is NOT a problem if someone comes out with a clever way of accomplishing something you stressed about how to make happen in fiction. That's not going to make anyone think less of you.

What's causing you to embarrass yourself is:

1) Technical writing- your posts are badly spelled. Persistently so. As though you really believethat "radiation" is spelled "radation" and "gravity" is spelled "gravaty." If you have some kind of problem that actually stops you from spelling words correctly in English, tell us. If you don't, then please pay attention to your spelling.

And you seem to keep formatting them in pairs rather than stopping to combine multiple posts into one passage of text before hitting "submit." That's a lesser issue.

2) In addition to this, I personally am upset because you are not responding to what I say, and are often not really responding to what anyone says. You're just... making up more stuff, and putting it out there, without stopping to think seriously about the questions people put to you.

What do you want from us? If you want ideas, critiques, and different points of view, you need to listen when those things are offered. If you just want to recite all the stuff you've thought up for your Mass Effect fanfiction, and aren't prepared to modify your ideas in response to others' comments... then you should be clear about that from the beginning.

[Patroklos]

A third and final point is that you have to remember that in space warfare, there are very few reasons to fight a battle in open space. Armies marching on land can bump into each other at any old place because there's only so much room to move around. Space is huge. Almost any combat will take place around some physical thing, or because some physical object is threatened and your fleet is intercepting my fleet before it gets there.

I wanted to return to this point by SJ, not because I disagree with it but just to expand on it a bit.

I am not sure just how capable the drives and FTL in Covus's universe are, but while SJ is correct that physical objects will very often dictate why and where enemy ships fight, that doesn't mean you have to be physically near those objects. If your propulsion systems are limited enough that there is a great advantage in using things like LaGrange points and transfer orbits. These things are not stationary just like the planets and other objects themselves and can be "in the middle of space." You can have lots of fun having your opposing Admirals debate about whether to power through without assistance between Mars and Earth and accept that it makes it a one way trip, total victory or total defeat, situation or if they progress down a predictable orbital transfer path that allows more ready interception.

This also allows you to keep things in the orbital plane for the most part. While space is 3D orbital mechanics are for the most part not. There is a lot of angst about 2D "star maps" but in a world where every pound of reaction mass is golden maneuvering outside the orbital plane and then back in becomes a very expensive endeavor. Certainly possible, but not just a trivial exercise like in an Star Trek type universe. I mention this because it allows you to keep local 3D tactial combat while operational level stuff remains in a 2D plane. Its hard enough to describe a dynamic 2D plane like a solar system to readers or other participants in your world, the orbital workings of planets are not readily understandable to even the astronomy inclined casual reader.

This all comes back to Simon's original point of form follows function. Don't limit yourself by designing your ships first and then creating a universe in fan service to this small part of it.

[Corvus 501]

What in Valen's name is a 'passive' radiator? Radiating heat away is active by definition. I assume this to mean 'unpowered'.

Don't ask me, it seems like Corvus thinks that his normal radiators don't need to eject mass to cool his ship.

While he may have profound trouble writing or responding to my questions, he's actually right about this part. A radiator radiates; it does not necessarily have to eject mass to cool things down.

If you take a hunk of red-hot metal in space, it is glowing with its heat. Glowing takes energy. Eventually your red-hot metal will cease to be red-hot. Eventually it will become colder still, and colder than that, until it reaches a temperature at equilibrium with the background radiation. In the depths of interstellar space, background temperature is extremely low; in direct sunlight in the habitable zone of a star it's actually rather hot- but the principle remains.

That hardly counts at sci-fi levels of energy generation. Just firing your engines would cook you if that's the best you had to deal with heat. Hell normal operating heat from cooking and the crew moving about would likely build up faster than you could radiate it unless you had a giant radiator.

Space stations manage just fine with people cooking and moving about and operating normal scientific equipment. In, as often as not, direct sunlight.

The engines, and waste heat from the engines, is problematic. But without figures for the actual power generation of those engines or the configuration of the ship, it's hard to say how much of a problem it is. For example, the engines could be mounted in a thermally isolated, insulated pod that is structurally separate from the bulk of the ship- in which case the temperature of the engines might be a lot higher than that of the crew compartment.

Thanks Jub, but the cooling issue seems to be the real hang up for every space thread. I'm trying to avoid any "space magic" handwaves, with the exception of things like "how is that alloy so strong", "how does that reactor work," and "how the hell does artificial gravaty work?" Mostly, I'm using the vaguely hard sci-fi handwave of "Science Marches On".

Mostly, because I don't want to end up with egg in my face because somone came up with a real world version of one of my concepts, one they works completely differently than a painstakingly planned out fictional technology.

See, that's not really a problem. For one, because we all know heating is a problem and it's hard to solve from an engineering standpoint, people are relatively forgiving of handwavium.

Meanwhile, it is NOT a problem if someone comes out with a clever way of accomplishing something you stressed about how to make happen in fiction. That's not going to make anyone think less of you.

What's causing you to embarrass yourself is:

1) Technical writing- your posts are badly spelled. Persistently so. As though you really believethat "radiation" is spelled "radation" and "gravity" is spelled "gravaty." If you have some kind of problem that actually stops you from spelling words correctly in English, tell us. If you don't, then please pay attention to your spelling.

And you seem to keep formatting them in pairs rather than stopping to combine multiple posts into one passage of text before hitting "submit." That's a lesser issue.

2) In addition to this, I personally am upset because you are not responding to what I say, and are often not really responding to what anyone says. You're just... making up more stuff, and putting it out there, without stopping to think seriously about the questions people put to you.

What do you want from us? If you want ideas, critiques, and different points of view, you need to listen when those things are offered. If you just want to recite all the stuff you've thought up for your Mass Effect fanfiction, and aren't prepared to modify your ideas in response to others' comments... then you should be clear about that from the beginning.

The spelling problem is partly because I'm writing from an iPad, and partly because I suck at spelling. As for not responding, usualy I'm in the middle of responding, but end up only responding only to one or two points in your post. Sorry, I'll try to do better.

[Simon_Jester]

Corvus-

You know you can save drafts and work on them a piece at a time, yes?


Patroklos-

On the other hand, you get a very specific 'flavor' out of that kind of rocketry environment. Ships have very limited mobility and flexibility, travel times are measured in months; it is possible and even likely that you will see a threat coming months in advance and have no way to respond to it. There is very little that skill and daring and resourcefulness can do to counteract the laws of ballistics or of travel from place to place.

Some stories benefit from not being told this way.

[Patroklos]

Oh sure, no objection from me there. Star Trek for instance would not work if you had months between cuts dozens of times an episode. I prefer a mix, where you could just rocket yourself from planet to planet in straightish lines relatively quickly but the cost is such that it is beneficial not to. Which choice do you make and why. It lets you have your technobabble and real hard scifi orbital mechanics. OH THE DRAMA .

Or you can do the warp point thing where you have expensive slow inter planetary movement but quick or instantaneous interstellar movement.

In any case, I was just trying to illustrate that details such as this dictate how your fleet works.

[Corvus 501]

Oh sure, no objection from me there. Star Trek for instance would not work if you had months between cuts dozens of times an episode. I prefer a mix, where you could just rocket yourself from planet to planet in straightish lines relatively quickly but the cost is such that it is beneficial not to. Which choice do you make and why. It lets you have your technobabble and real hard scifi orbital mechanics. OH THE DRAMA .

Or you can do the warp point thing where you have expensive slow inter planetary movement but quick or instantaneous interstellar movement.

In any case, I was just trying to illustrate that details such as this dictate how your fleet works.

Nice idea, but I'm going more for Halo style interplanetary movement, relatively fast, though you still have hours to prepare. Of course, that dosn't always help, sometimes you are just outnumbered, outgunned, and will be outfought. Of course, because most fleet engagements would take place around gas giants, stars, and planets, it's possanble that the defenders can just call up swarms of fighters, interceptors, torpedo boats, and maby some corvetts from the planet or Belt mining colonies, if only to harass the enemy and thicken point defence screens.

[Patroklos]

So fighters are viable in your universe?

[Simon_Jester]

Observation:

For fighters to be viable, you need a few things.

One is very compact one-person life-support, with an endurance measured in many hours. Unless of course you mean robotic or drone fighters, which simplify matters greatly.

Two is that you need either technomagic drives (that miniaturize well), or very efficient rocket engines, so that rocket fuel makes up only a small fraction of the total mass. The reason for this is that if you need to make, say, 50% of the fighter's mass be fuel in order for it to accelerate to attack speed, decelerate, and come back to the mothership... well, it can a lot more sense to build the unmanned version of the same fighter, with only a quarter as much fuel, but not designed to come back. In other words, a missile bus. The unmanned missile buses will have 2/3 the weight, OR will be able to devote far more payload to big nasty warheads and ECCM and so on.

Three is that you need munitions the fighter can fire at the enemy effectually other than a ramming attack; this is tricky if you need a multimegaton nuclear warhead to seriously damage enemy spacecraft.

...

It just occurred to me that most of these objections are irrelevant if your "fighters" are actually, say, five thousand ton patrol craft that just happen to have a crew of one.

[Patroklos]

This is where an in universe contrivance regarding AI comes in handy. Perhaps there is some weapon that easily incapacitates them. Make them so prohibitively expensive to create/build/maintain that they can be casually installed for every military application. Perhaps the expectations of when AI becomes capable of such things were wildly off by centuries. Perhaps there is an engineering or physical limitation you can introduce to the mix? Maybe your AIs refuse to engage in base human destructive activities in short order after activation?

The simple fact is that even beyond fighters the reasons to have people on combat space craft of any type dwindle once competent AI is available. They exist but they are generally not due to the limitations of the AI itself, but rather some human factor whether political/emotional. Things like "there must be a human pilot to pull the trigger because AIs should never become comfortable killing humans!" sort of thing. Outside physically move dudes from place to place for non in vacuum purposes space flight quickly becomes like current flight, space ships will become people busses (piloted by AI of course) to the vast majority of those who will experience them.

[Eternal_Freedom]

I would also think that for single-person manned fighters you would need some kind of technomagic inertial compensator to match your technomagic engines. Sure, a human might reasonably be able to survive an hour or so of relatively high-g accelerations, but if you can have an AI that doesn't worry about that, even better.

Compare (numbers pulled from thin air) a manned fighter that can pull 4g's acceleration and carry one megaton-range nuke, to an AI drone that can pull 8 g's and carry two megaton-range nukes. It's an easy choice, especially as having them be drones means you aren't losing highly trained pilots even in a successful attack.