Space Combat in the Human Sphere

IF there is a material which you can dump heat into then you could do short-term stealth Mass Effect style.

That's going to be my assumption walking in.

But, as I've pointed out previously, while the system does allow for spaceship "stealth" it does also make ships relatively easy to detect (in comparison to other vehicles which can be concealed quite easily).

 

Let's see if I can make this description work: Space is like someone walking in a pitch-black warehouse (or enclosed sportsball stadium) with a lantern. You can see them, or at least the light from the lantern, from a really long way away (you can see a single candle 10 miles away on a pitch-black night!). If you had a thermal imager, you could see them just from their body heat, from even farther (a human emits about 75 watts of heat, most lanterns don't emit that much light).

The Rocinante's drive emits as much power as is generated on Earth today, and the Roci is only 500 tons dry. I'm pretty sure the Roci is about the same mass as the Dolly Dagger, which makes a decent 'floor' for the size of a spaceship. The submarines I served on were about 19,000 tons, so in order to have the same acceleration as the Roci, they'd need to have a drive ~40x more powerful, call it 600 terawatts. An aircraft carrier is 100,000 tons, and would need a drive 2,000x more powerful, call it 30,000 terawatts. That's quite literally getting into (very small) stellar energy levels. (our Sun generates ~380,000,000,000,000 terawatts, and varies +/-0.1%, but there are stars 1/10 the size, I believe 1/1000 the mass/energy. There may be stars smaller than that, but the smallest possible brown dwarf star is still about 10x the mass of Jupiter and 3x the diameter)

How the hell do you hide a star? Particularly one that is mostly shining in X-rays, which happily go right through most materials...

OK, I must have missed that.

There is almost certainly some variety of 'thermal goo' you can dump your heat into during combat to prevent you have having to deploy radiators (which are terrifyingly fragile for most designs, and the ones that are relatively resistant to combat damage impose maneuverability limits). A car can't keep going for very long without any coolant, spaceships can't either.

 

Well lets run with this.
I am about to enter a pitchblack room with a lantern and I don't want the guy inside to easily spot me....
Options
I could put the lantern in a box first.
In spaceship terms maybe something about metamaterials and nanowires
" John Pendry, a professor of theoretical physics at Imperial College London, U.K. Besides making it possible to turn things invisible, the work could lead to ways to create heat shields by bending infrared light around objects, he says. Pendry’s initial research led to last year’s creation of the first working cloaking device, which operated in the microwave range."

And just like that we are in crackpot but still theoretical range of the target. IR heatshields on those engines keeping the crew from cooking sound pretty nice even without stealth in mind.

Other options include tricking you into putting on a blindfold or jabbing out your eyes.

 

Ok, so I think your assumptions about heat output might be off because your assumptions about how drive systems in Infinity work are off. We are told that:

"There is still a push to ensure that engines are as efficient and potent as possible, however, and most contemporary vessels made use of some variation of magnetoplasmadynamic thruster, or MPDT. These ionise a gas propellant mixture and accelerate it through a magnetic field, providing propulsion for the vessel. A few other forms of electromagnetic drive also exist, for various reasons, but these all work on a similar principle and rely on similar forms of propellant, some mixture of lithium, metallic hydrogen, and Nessium.

A few, typically high-priority, vessels employ thermal antimatter drives instead, which again use a hydrogen/Nessium propellant mixture, heated by a dense core being bombarded by an antiproton stream. These have higher performance than MPDT engines, but antimatter production, the engines, and the thermal and radiation shielding are costly and difficult to maintain."

So only the latter (rare and expensive and not common even on warships) type would be easily scoped at range. Basically most engines run much colder than you are assuming because they don't work the way you are assuming.

Yeah, actually this is a major issue and factors into ship combat in the RPG:

"While all this is going on, vessels are generating heat. In the cold of space and the fury of battle, a warship’s heat cannot be dispersed quickly, threatening vessel systems and the lives of the crew. This means vessels must make their attacks as quickly as possible, for a prolonged battle is unsustainable, and even the most capable warship must withdraw and cool down. A key element of warship design is
heat management, which translates directly into endurance."

 

*sigh* You didn't understand that analogy at all.

Let's try this again: You are the fire in the lantern in the dark. You cannot stop shining, you will die. How do you keep someone from seeing the heat you give off?

As you note, one way would be to convince the person looking that they can't see you. A book by Jay Posey called OUTRIDERS had that as a plotpoint (it's basically revealed in Ch4, so I don't think a spoiler tag is warranted), a nasty computer virus that made a space station not see the inbound rock that destroyed it and killed almost everyone on board.

"Jabbing out your eyes" would imply destroying the telescopes that are used to track objects. You could use a laser to do that, and because stealth in space is so problematic that it's effectively impossible you should know where the various telescopes looking for you are. That's not impractical for tactical stealth, preventing someone from shooting at you. It's downright contra-indicated for strategic stealth, since destroying someone's tracking systems is an act of war. So I guess it's still useful for events once the shooting has already started.

I could argue that the computer virus from Outriders is also an act of war, but it's a bit more of a gray area today. My guess is that the first time a nationally-organized hacking attack kills civilians, it will get added to the laws of war (the Geneva and Hague Conventions).

OK, not a fusion-thermal rocket, though technically the Epstein drive starts with a fusion-thermal drive and further accelerates the exhaust like an MPD. You might as well, since you've got a running fusion reactor to make electricity for you! (I'm assuming that you're using whatever cooling you need to keep the fusion plant from melting down to generate power, since the easier way to generate power from a rocket exhaust is to use an MPD thruster in reverse to slow the exhaust down slightly)

But drive energy (thrust power) is a function of exhaust velocity and thrust force. (mathematically, Drive Power = 0.5 * Thrust in kg * exhaust velocity in m/s). High exhaust velocity, like the MPD thrusters, gives low mass flow (= good remass efficiency) but almost always gives low thrust force. Low exhaust velocity, like ye olde Saturn 5's Kerosene-Liquid Oxygen, almost always gives high mass flow with good thrust force. Once you're in space, you can optimize for high exhaust velocity to minimize reaction mass use, but getting off the ground requires high thrust force. Any drive that gives you both high exhaust velocity and high thrust force is called a torchship (yes, the Epstein Drive is a Torchship), which do end up with pretty obscene drive powers as a result.

An MPD thruster is really heavy for it's thrust, since it needs a rather massive electricity source. Atomic Rockets gives an MPD thruster capable of 20,000Newtons a drive energy of 3.1gigawatts (due to the relatively high exhaust velocity of 314km/s), and it requires 4GW of electricity to power it. Said drive including power reactor masses 1,540tons. Now, 1 Newton is enough force to move one kilogram 1 meter in one second, so that drive is capable of pushing itself (as a kinetic kill missile) at 0.013m/s/s (discounting the reaction mass). Yup. 1.3 Centimeters per second^2 of acceleration. No wonder you need those Vila Boosters to get anywhere in a reasonable time!

Huh... OK, that's a Solid Core Antimatter drive. That's actually capable of boosting a payload into Earth orbit! I wouldn't want to be around the launch site, there's a lot of antimatter in there that would make a launch accident rather ... energetic. Earth-shattering kabewm, even.

Note the exhaust velocity is not quite 11km/s, with a thrust force of 440,000 newtons for a drive power of 2.7 gigawatts. Compare that to the measly 20,000 newtons of the MPD thrusters at 3.1 gigawatts.

Dimmer, not colder.

If those MPD thrusters CB is writing about are capable of pushing a 1500-ton ship at 0.25gee, they will still be really bright. Epstein Drive has an exhaust velocity of ~12,000km/s, while MPDs run ~300km/s. So, 1/40 the drive power. A 'mere' 250gigawatts or so drive energy, for a ship about the size of the Dolly Dagger. To put that in perspective, that's still more than 10x the power generated at Three Gorges Dam!

The higher your drive exhaust velocity, the higher up the sprectrum you will emit. Most of the drives we are talking about will be emitting X-rays in their drive plume, not visible light.

The gas-core power reactors of these spaceships, whether fission or fusion, will be running at about 1600Kelvins, their lifesections at about 300K. If, by some miracle you could get a pressurized water fission reactor to work in space, it would be running about 600K and need radiators ~6x the size (it's a square function).

 

Except none of that maths is relevant because, as you have pointed out, that would mean these ships are automatically visible from a distance of entire star systems.

And we know that is not accurate.

The system makes hiding a ship as challenging as an unaided person hiding in a normal room, not one with especially good conditions for hiding, but not one with terrible conditions for hiding either.

That is clearly not a ship radiating like you assume.

 

Mass Effect dealt the problem of stealth that way: you still generate huge amount of energy, but you use a heat tank. And the drawback: don't go past the tank limit, or you're fried.

In my opinion, the whole "how spaceships can fight " also and even mostly depend on the speed spaceships can reach.
For example, ok, you can shoot laser at them, but ... where do you shoot ? If your opponent is at 300 000 km, that is, roughly Earth-Moon distance (so, a small distance in space), what you see (or what your sensors are seeing, if you prefer) is the position and situation of your target 1 second before. And if you shoot, your laser will reach the target 1 second after. If they are doing evasive maneuvers (anything like a non predictable fly path), hitting them at that range is pure luck since you can only guess a conic area (the volume that contain all their possible paths with their max acceleration).
If you want to use any kind of active sensor device, it is even worse, since your signal needs to reach it first ...

So space fight is only doable in short range, that is, a few 10 000 km range at best, so going stealthy until range is no small feat if even possible.

 

Macguffins indeed. A certain amount of handwavium is required to keep a space setting from being very boring. (At least boring for people who find math boring. Now if you find math exciting, space is very exciting!) And at the risk of being pedantic, we do have antimatter. In 2011, CERN was able to perserve a sample of antimatter for 17 minutes! Although I am not sure the sample would have been visible to the naked eye. Well, beyond the fact that the ability to observe the material would also cause it to explode, I just meant it was not very big.

I have read about these experiments, and they are very interesting. However they are an attempt to bend light around an object, so that light will not bounce off the object, rendering it visible. However with spaceship stealth, you are not trying to stop reflected light (which is still a problem) but trying to hide generated light. And that is an entirely different, and much more difficult task. It practically requires some sort of Handwavium heat sink. Which causes other interesting issues. Any material that can absorb that much heat that quickly, can be easily weaponized by a creative individual. I would love to read a short story, were 'super-heat-sink' is weaponized.

 

Strictly for sake of the conversation, but does the experiments dictate that the light has to go back into the same direction, or can it be used in a slightly dumber mode where it re-directs the IR waves in a predictable direction. Where I'm going? Well, if you simply make sure you don't radiate any IR in the direction where the enemy has sensors, you're effectively invisible as far as heat is concerned.

 

It's called "absorb all radiation that comes your way and make sure none gets to the enemy's sensor". I've heard about it in Eclipse Phase, but only at "S2" scale: having good enough processing power, emitters and absorvers lets you absorb the radar/lidar active pulse (coming from a sacrificial enemy sensor) and send back the response that sensor expects if your body was not there (the background you are covering).
In space, that is not usually an option unless you are moored to a meteorite or something similar.

And for the gases, well, Mutara Nebulas! The to-go hiding place in Star Trek! XD

 

The experiment I read about, bent the infrared light around the object in a curve, and the 'unbent' it again so it left the experiment going the same direction as when it entered. Rendering the object in the center 'invisible' The interesting side effect of this, is that it would also render the object 'dark' Eyes, or other sensors, require light, or other electromagnetic rays, to detect things. Bending them around the object to make it 'invisible' would also blind any sensors on the object itself.

This effect could be used to make for some interesting dramatic stories. Entering into stealth mode could force a ship to go blind. Take your readings before you enter stealth, plot the course, and hope things don't change too much while you are not watching. However this is again dealing with reflected light, not generated light.

Bending the IR waves in a predictable direction so that the enemy doesn't see your heat signature might work, if you had enough handwavium. Unfortunately, it also requires you to know where all the enemies sensors are located. Warships rarely work alone, and often have a network of support craft/sensors. Difficult, but perhaps not impossible.

I think a double agent, who can insert a virus into the system to get the sensors to lie, would be a more cost effective solution, but would require a great deal more long term planning.

 

*shrugs*

Heat retention, some kind of system akin to the light bending system described by @xagroth and straight up engines and power generators not putting out the kind of waste heat that is common to similar systems today are all perfectly satisfactory answers within the setting.

Just as Outrage likely shows us an example of:

"Others still use diamagnetism to simulate a gravitational force, though typically at less than 1g due to power consumption."

As an "artificial gravity" solution, making perfect sense on a space station where power consumption is less of a concern.

 

Because it's easy to tell stories like Das Boot or Hunt for Red October if you file the serial numbers off. Even if it's impossible according to the laws of physics.

How do you tell an interesting story when you can say, "The ship will go to battlestations in 3 weeks, half an hour before battle is joined."? That's so far outside everyone's frame of reference that it's almost impossible to relate to.

I'm not discounting thermal superconductors, they are possible to exist (or at least aren't prohibited by the laws of physics) and we know how the math says they'd behave. Thermal superconductors would make excellent space armor, BTW, so I rather assume that they are part of the Infinity setting. (Teseum could be a thermal superconductor, among other properties, it wouldn't surprise me in the slightest)

I can even tell you what properties a material would require to use as a 'heat sump' material, it would need a very high specific heat (taking immense energy to raise the temp of the material by one degree), as well as density greater than 0.5g/cm^3. Ironically, basic H2O is one of the best heat sumps per unit mass (needing ~4 joules per gram per degree), regardless of density. Hydrogen gas has much higher specific heat (~14 joules per gram per degree), but has terrible density (one ton of liquid hydrogen is ~14,000liters!). In comparison, uranium takes very little energy to increase it's temperature, only 0.1 joules per gram per degree! So our "thermal goo" would ideally have a specific heat over 4.4 joules per gram per degree and a density higher than molten lithium' 0.5g/cm^3 (while being liquid at less than ~450K).

But that still means that you're radiating at ~300K (your lifesection) against a 50K background. If you're lucky, since deep space is 5K. You can detect that kind of temperature difference halfway across the solar system.

If *you* can hide, how do you know what the safe direction is?

Because if I can set up some variety of stealthy telescope, I'd be deploying them about every 30 light-minutes or less. That is, I'd have an Iridium-style satellite array orbiting about the distance of the Asteroid belt (3AU), in solar-polar orbits. That's 80 satellites in criss-crossing orbits. Anything in the inner solar system would be visible from all sides.

 

O/T From the spaceship talk (so skip this part if you want).

I love it when someone says that we can't base any of the Infinity stuff on our world. Where do you think Guitier gets his ideas from? He can only pull from what he knows and understands (and sometimes does not). Storytellers are not Nostradamuses nor is everything original. Infinity pulls from a lot of sources with its ideas (GiTS, Altered Carbon, Appleseed, Arabian Nights, Dune).

Infinity in its current timeline is in a cold war very similar to our Cold War. Replacing the Soviet Union and the USA is Yu Jing and PanO. Nomads, Haqq, and Araidna don't have direct analogues but they would represent the powers below the supers (ie. UK, France, Israel, etc.). Infinity has had its world war equivalents with the Neocolonial Wars. When the dust settled no one wanted to do that again and set out with low intensity black ops. We even got a proxy conflict with Ariadna with the Commercial Wars. The EI throws a slight wrench into this but the Human Sphere is carrying on with doing the same thing they were doing before so... *shrug*

Infinity draws from our world and it is fair to assume some of our "old" Earth ideas carry over into other realms. It isn't as separated as some think...

Moving out of O/T

Moving into the future it makes sense for old Earth habits to follow along. Laws of the Sea make natural transitions to space travel. Warning systems to help aid in commercial shipping (that's what it's primarily for) and not providing info about the current "weather conditions" would be saying "we're not doing business". YJ and PanO might not be buddies but they do business between one another and the other powers as well. You know the Nomads would be the first people to voice a concern about a warning/weather system in place being a space faring people. As @Shiwen has pointed out O-12 even has a bureau for facilitating such tasks in the Human Sphere.

People are also free to see fit how much they want to use cannon ideas. For me I edge to the harder side of sci-fi when it comes to Infinity. All space stations in Infinity are spun for gravity. Ships provide gravity when accelerating or they use mag boots when they are not. Stealth is provided by electronic warfare and misdirection rather then the usual idea of stealth.

 

I think it's more amusing to assume infinite resources to construct perfect whole-system sensor nets over ship-based developments in a setting with FTL travel.

That's my whole point.

There's little to no point in getting technical with real-world space related data, because it's clear that basically none of it has any bearing on Infinity.

The setting just doesn't work the way spaceships we would build today would work, and it's not even "close enough" like The Expanse.



And there's nothing wrong with homebrewing your setting, but hard sci-fi is not the actual Infinity setting as described in the RPG or the Wargame.

 

It draws from pulp, anime, and hard sci-fi. Throws those into a blender and you get Infinity in one form or another. I embrace the pulp and anime but I dumb them down (point in case being my PbP on this forum). It's kind of cool it gives you a mix as that will attract a good chunk of people. Some will come for the pulp, the anime, the hard-ish sci-fi, or maybe all of it. The official setting gives you all those flavors. Don't like sci-fi elements all that much? Well then Ariadna is for you. Like the dull boring boys in blue? PanO. Furries or just want to say fuck it to the man in some sort of style? Nomads!

 

I get that.

And that is how any good RPG group should be.

But that doesn't change the setting.

*shrug*

 

No, but at the end of the day the setting is what the player gets out of it. S9 is an ex-submariner (among other things) and that influences his thoughts on ideas in Infinity. He draws a harder sci-fi line then you like. You seem to role with the more pulpier and softer sci-fi side of Infinity and kind of toe the line on keeping everything within the setting lines so to speak.

I never once though S9 was saying that Infinity needs to do stealth like how it is supposed to be (which is more hypothetical cause we have no real world examples with ships in space yet). He's just pointing out Infinity takes a pulpier handwavy approach to treating it in the official lore. He'd prefer that but at the end of day I think he'd settle in with what they have (he plays the game and likes the fluff, mostly, overall). I can't speak for him but that's what I get from his posts.

 

That's as may be, but I ultimately don't care enough about the real physics of theoretical real space combat anymore.

And it has little to no bearing on the game.

My biggest takeaway is the comment on how rare space combat was, not because of difficulties but because of cost.

The top end Dreadnoughts and Supercarriers cost the total annual GDP of entire planets. And they can be destroyed by a properly equipped skilled gunner in seconds.

Only in the most full on of direct showdowns between the G5 did they happen regularly.

But now that's totally out the window because of the Combined Army.