Newtonian Space Combat

[drachefly]

Yes.

As for space combat being like submarine warfare, OK..

except that there is no thermocline to reflect sonar waves, and since the background is 0.4 kelvins it's hellishly difficult to get your emission profile low enough to go stealthily (see the atomic rocket links for more info; though they don't consider certain possibilities for enhancing stealth, it's still freaking hard)

Basically, submarines only, except stealth is not the default.

[Gunhead]

In a "submarine" style of space combat decoys and ECM/ECCM would play an important role since it's kinda hard to hide yourself. So just saturate the area with multiple targets.

-Gunhead

[RedImperator]

In a "submarine" style of space combat decoys and ECM/ECCM would play an important role since it's kinda hard to hide yourself. So just saturate the area with multiple targets.

-Gunhead

No good. For the cost of building a decoy that can imitate the thermal signature of a warship, you might as well just build another warship. As for ECM, jamming radar is all well and good, except:

1. The jamming emitters will function as radio beacons

and

2. Infrared, especially from the rocket exhaust, is the real giveaway, and the only way to hide that is to stick close to a larger infrared emitter such as a star, which has obvious and non-obvious drawbacks, or saturate the area with other heat sources, which requires detonating nuclear weapons like strings of fireworks.

Basically, in order to achieve the kind of thrust necessary to make space combat possible, let alone economically worthwhile, you need engines which heat your propellant to the point it's impossible to hide. The thermal signature of an antimatter rocket would be visible from Alpha Centauri; even a chemical rocket is visible from multiple AUs away. For a starship under thrust, ECM is mostly irrevelant.

[drachefly]

And the moment they accelerate it's easy to tell what's what, since exhaust signatures give away how much thrust is being applied... so you need to make your decoys have the same mass. Awkward...

If you're just going by the IR and visual signature, and there's no air to scatter the light, I don't see what one can do to interfere with their scans, short of destroying their sensors.

[Gunhead]

I know all that. You're right though, it still requires handwavium to work.
I mainly brought it up because I'm somewhat of a submarines in space fan, and fighthers in space are just so..... last century.

-Gunhead

[Battlehymn Republic]

I've read that the game Terminus has Newtonian physics. Allegiance wasn't, though, right?

I'm trying to make a list of all commercial computer games that had Newtonian physics.

[Centurian99]

I'd suggest you read the "Dread Empire's Fall" series by Walter J. Williams. That's got about the only possible realistic depiction of "fighter" type craft in a newtonian space combat situation.

Basically, cap ships will occasionally launch "pinnaces" (small, one-man craft) that will accompany flights of missiles/torpedoes. This allows them to fire at longer ranges, while still maintaining the ability to give the torpedoes new instructions without the lightspeed lag.

[Sarevok]

Consider another thing about detection in space. Once a warship is detected it could be tracked with a telescope. Have not we detected and tracked many far away asteroids in the hundred meter range using telescopes ? I think once a ship is detected its position is comprised for a very long time. No matter where it goes the telescope can see it. In terms of the big picture if 2 space powers have a cold war in space its possible within years both powers could know where large portions of the other powers ships are. A war might begin within the position of most enemy warships already known.

[drachefly]

That is why you need to make your warships with as few surfaces as possible, each surface being a flat mirror cooled to liquid nitrogen temperatures (or cooler). That will minimize the chance of detection and make telescope tracking hellishly difficult.

[fgalkin]

That is why you need to make your warships with as few surfaces as possible, each surface being a flat mirror cooled to liquid nitrogen temperatures (or cooler). That will minimize the chance of detection and make telescope tracking hellishly difficult.

You'll still need to vent the heat somehow, and that will give you away.

Have a very nice day.
-fgalkin

[phongn]

That is why you need to make your warships with as few surfaces as possible, each surface being a flat mirror cooled to liquid nitrogen temperatures (or cooler). That will minimize the chance of detection and make telescope tracking hellishly difficult.

And those mirrors are cooled how? You'll have to dump heat somwhere.

[GrandMasterTerwynn]

That is why you need to make your warships with as few surfaces as possible, each surface being a flat mirror cooled to liquid nitrogen temperatures (or cooler). That will minimize the chance of detection and make telescope tracking hellishly difficult.

I'll jump on the "have you thought this through" bandwagon and say that mirrors are not 100% reflective, and you'll be left soaking up the difference. Not to mention you'll somehow have to keep the heat generated onboard the ship from leaking onto your mirrors. Essentially, you're going to need some area to get rid of the heat, since it has to go somewhere and can't be made to magically disappear.

[Battlehymn Republic]

What about a ship rotating in a fixed position in space? is that against Newtonian physics?

[GrandMasterTerwynn]

What about a ship rotating in a fixed position in space? is that against Newtonian physics?

Uhh, no. There's nothing to stop a vessel or object from sitting there and spinning as fast as you're willing to spin it. In fact, an uncontrollable spacecraft spin almost killed Neil Armstrong in his first foray into space on Gemini 8.

[drachefly]

Heat dumping:

If you are running on low power (remember, this is for the long period of stealth prior to the beginning of engagement, no thrust to be used etc.) then there does not need to be much heat generation on board. That which is generated can be used to melt and then evaporate containers of, say, water.

Once the gas has been evaporated it can be dumped into space, which will adiabatically cool it to near absolute zero anyway.

Suppose that each crew member has a 2000 kilocalorie-per-day diet, and the machinery they use is made very efficient (for this purpose), and produces, say, another 2000 kilocalories per day.

That is enough heat to raise 4 metric tons of water by 1 kelvin each day, or to melt 1/20 of a metric ton of ice at 273 kelvins, or to raise 8 metric tons of ice by 1 kelvin.

So, if we have two thermoses with a variable thermal contact between them; and in one thermos is a crew member and its support machinery, and in the other is ice, how much ice must we bring in order to keep them cooped up for, say, one month?

melting point of ice = 273 kelvins
room temperature = 300 kelvins

mass = 30 days*(4 megacalories per day) / (273 kelvins / 2 kelvins megagrams per megacalorie + 80 megacalories per megagram + 17 kelvins / 1 kelvin megagram per megacalorie) = 0.513 megagrams

so each crew member and his support machinery would only need to be assigned a ONE TON of coolant for a stealth journey of two months. Compared to the rest of the stuff the ship is carrying around, that's insignificant.

Now, things get better if we swap out water for, say, Chlorine... then it evaporates at a low enough temperature that we can take advantage of its similarly enormous latent heat of evaporation. But you can't drink chlorine and you can't feed it to a fusion reactor.

How do we keep the outside down at liquid nitrogen or helium temperatures? Well, merely remember that we have our crew and coolant in two thermoses. On an outer layer, use liquid N2 as coolant. As it evaporates, let it go, it'll quickly cool to near absolute zero.

Now, what are the holes? I assumed that the support machinery could do the job with just 2000 kilocalories. Maybe it would need ten times that. Well, okay, 5.5 tons of bulk coolant to carry around per month still isn't that big a deal. If we're talking a hundred times that, it gets to be a problem.

[drachefly]

Oh, on the evaporation front I raised in the beginning and forgot to follow up on:

That could be used to cool machinery which runs hotter than room temperature. So we gain an additional factor of two (roughly) when speaking of such temperatures.

[Arrow]

Ok, I might be smoking ignorance here, but wouldn't an IR strobe be a good way to fool or blind IR sensors? Something cheap and expendable to make it harder for the enemy to spot you. Doing the same in the visible spectrum would reduce the effectiveness of telescopes.

[drachefly]

Now, what are the holes? I assumed that the support machinery could do the job with just 2000 kilocalories. Maybe it would need ten times that. Well, okay, 5.5 tons of bulk coolant to carry around per month still isn't that big a deal. If we're talking a hundred times that, it gets to be a problem.

OOPS -- arithmetic error. Before it was 0.25 tons per month for human and machine at 2000 kilocalories per day. Now we're multiplying the machine by 10 so it totals out to 2.75 tons per month, not 5.5

BTW, if people are thinking that mere lighting would cost that much or more, there are creative ways to limit the need for light -- use light-amplification goggles.

External observation can be effected by looking out through a glass surface at room temperature, through a contained vacuum, onto a window in the outer surface, which is kept at low temperatures.



A strobe wouldn't do much good unless it was insanely powerful -- powerful enough to saturate the detectors. A lased signal aimed directly at the sensing ship might do the trick, depending on various factors... it seems to me that countermeasures to this would be easy to develop, though.

[GrandMasterTerwynn]

Ok, I might be smoking ignorance here, but wouldn't an IR strobe be a good way to fool or blind IR sensors? Something cheap and expendable to make it harder for the enemy to spot you. Doing the same in the visible spectrum would reduce the effectiveness of telescopes.

Sure, if you're dealing with spaceships with weak engines. If you're dealing with a high-performance sci-fi starship with big hot engines and high-power reactors, you're going to need a big strobe. Think tactical nuclear weapon in the size you'd stuff into a large briefcase or artillery shell. It isn't enough to just blind a sensor. They'll recover extremely fast once you stop oversaturating them (a target tracker on a missile like that will probably have a sensor capable of generating thousands or tens of thousands of frames per second.) You have to hit it with a big enough pulse that enough energy gets focused on the sensor, in a short enough period of time, to physically damage it, or its optics. And you have to physically damage it enough to render its imagery completely worthless.

[Battlehymn Republic]

What about a ship rotating in a fixed position in space? is that against Newtonian physics?

Uhh, no. There's nothing to stop a vessel or object from sitting there and spinning as fast as you're willing to spin it. In fact, an uncontrollable spacecraft spin almost killed Neil Armstrong in his first foray into space on Gemini 8.

How would you cause a spacecraft to start spinning without having it move away from its original position?

Think Asteroids. When the S.S. Triangle starts, it can rotate however it wants to without moving anywhere. However, in real space, wouldn't that be impossible?

I know this is a stupid line of questioning.

[RedImperator]

Heat dumping:

If you are running on low power (remember, this is for the long period of stealth prior to the beginning of engagement, no thrust to be used etc.) then there does not need to be much heat generation on board.

Your whole scheme crashes right here, because how do you plan to engage in combat with no thrust? I know you're thinking you'll thrust up to engagement speed ahead of time and coast the rest of the way, but with the ranges at which your thrust exhaust can be detected, you'd have to do that months ahead of time. Unless you have fortune tellers on your crew, there's no way to know where the enemy is going to be far enough in advance to make that work.

[Nephtys]

What about a ship rotating in a fixed position in space? is that against Newtonian physics?

Uhh, no. There's nothing to stop a vessel or object from sitting there and spinning as fast as you're willing to spin it. In fact, an uncontrollable spacecraft spin almost killed Neil Armstrong in his first foray into space on Gemini 8.

How would you cause a spacecraft to start spinning without having it move away from its original position?

Think Asteroids. When the S.S. Triangle starts, it can rotate however it wants to without moving anywhere. However, in real space, wouldn't that be impossible?

I know this is a stupid line of questioning.

This is totally possible. It's a simple matter of vectors. If you thrust a port-aft turning jet, and a starbaord-forward jet, then you'll spin really without shifting your course any noticible amount.

[Admiral Valdemar]

Your whole scheme crashes right here, because how do you plan to engage in combat with no thrust? I know you're thinking you'll thrust up to engagement speed ahead of time and coast the rest of the way, but with the ranges at which your thrust exhaust can be detected, you'd have to do that months ahead of time. Unless you have fortune tellers on your crew, there's no way to know where the enemy is going to be far enough in advance to make that work.

They can always use cold thrusters like hydrogen peroxide or CO2, that's even an option in I-War 2 where you need as much stealth as possible. Assuming you have them set to low expulsion so no giant cloud erupts from the exhausts, you should be able to have a slow ability to manoeuvrewhich doesn't involve venting plasma at several thousand Kelvin.

[drachefly]

I know you're thinking you'll thrust up to engagement speed ahead of time and coast the rest of the way, but with the ranges at which your thrust exhaust can be detected, you'd have to do that months ahead of time.

Thrust exhaust is much harder to detect if it's very tenuous (there is a quadratic dependence on the density of particles). High efficiency drives produce very tenuous exhaust. High efficiency drives which emit nonthermal exhaust (i.e. the differences in the exit velocities are much smaller than the exit velocities) produce even dimmer exhaust.

Unless you have fortune tellers on your crew, there's no way to know where the enemy is going to be far enough in advance to make that work.

or if you're attacking a fixed installation...

[Battlehymn Republic]

Does anyone have links to footage of newtonian space combat? Like clips from B5 or something?