T4 Only: Some people say no stealth in space, a discussion.

[Badenov]

This is now THE question.

A 400dT ship can operate for 4 weeks using 40dT of fuel. This is about 1.65E-8kg of H2 per second. Let’s assume all this energy becomes heat eventually. It doesn’t, but let’s look at a worst-case scenario. Using E=mc2, this means the ship runs on 1.49 GW.
This is pretty close to IRL scenario suggested by TheDS and Rupert.

But this means that the overall emissions can be greatly reduced by reducing the power consumption. Now, all the tactics learned from submarines “running silent” are relevant. Like coasting, lowering the lights, ZeroG, …

So that's not quite right, but I like the analysis strategy.

<Rambling analysis that accomplishes nothing>

Fusion doesn't get E=mc² energy out of fuel, that figure is for total conversion of mass to energy. Google tells me one kg of D-T (deuterium-tritium) fuel can release 3.37 x 10¹⁴ Joules of energy, so 40 tons, 40,000 kg, would deliver about 5.4x10¹⁷J or 2.1x10¹¹ joules every second of the day for 30 days. (This is ignoring how much of your scooped fuel is actually deuterium or tritium, I'm assuming that fuel processing means that 100% of your fuel is usable.) Since 1J/s=1W, you're producing about 2.1x10²GW per sec. Multiply by 3600 to get ~750,000 GWH. That's a lot of energy to dissipate, but it's not all heat. There's motion from the energy used by the engines, ship's utilities like life support that don't directly produce heat, and so on. So, I realize I need an efficiency rating to complete this calculation to tell me how much energy is lost to heat.

So, generally the more efficient your gear is, the less waste heat it produces. Interesting assumption: presuming max possible efficiency goes up as TL increases, that would correlate to the Computer Rating being a factor in LBB5 combat, as max available Computer rating is also tied to TL and affects your to-be-hit number in LBB5 combat. So the net effect is that your computer manages your Power Plant, Engines, and gear to run efficiently, affecting your detectability.

So, it seems like what I'm suggesting is that stealth and detection are already incorporated (however crudely) into the LBB5 rules, which kind of makes me happy because I feel like I've discovered something. I understand that this negates 16 pages of discussion because people want more crunch in rules and more things to put into their ships, and I totally see room for upgrades or downgrades to the standard performance, so feel free to ignore my ramble. And of course civilians don't much care about stealth, so LBB2 ships don't get it.

 

[Dragoner]

So, it seems like what I'm suggesting is that stealth and detection are already incorporated (however crudely) into the LBB5 rules, which kind of makes me happy because I feel like I've discovered something. I understand that this negates 16 pages of discussion because people want more crunch in rules and more things to put into their ships, and I totally see room for upgrades or downgrades to the standard performance, so feel free to ignore my ramble. And of course civilians don't much care about stealth, so LBB2 ships don't get it.

Stealth is already incorporated in the rules, the two sides are those of us saying it's ok, even if not perfect, and the others, I don't know what they want, just to drag it down, I guess. The idea that stealth equals invisibility is a strawman argument people are creating, because as the rules stand it is just a modification on the sensor roll, or that stealth is a signature reduction, which tracks to the real world.

 

[Spinward Flow]

A 400dT ship can operate for 4 weeks using 40dT of fuel.

That's ... not exactly the right formula to be using for that, in terms of fuel consumption rate.

I personally prefer to use the fuel consumption formula presented in CT Beltstrike ... refactored to determine consumption rates by hull tonnage and by EP.

The formula (re)computes into being:

• 2000 tons of hull consumes 1 ton of fuel per 7 days for "basic power" (housekeeping, life support, etc.)
• 1 EP continuous output from a power plant consumes 0.35 tons of fuel per 7 days (maneuver/agility, computer, weapons, screens, etc.)

So a 100 ton Scout/Courier that generates 2 EP (maximum) will consume:

• 100/2000 = 0.05 tons of fuel per 7 days while "idling" on intertial
• 2*0.35 = 0.7 tons of fuel per 7 days while continuously maneuvering @ 2G/Agility=2

Combine these two consumption rates and a 100 ton Scout/Courier will consume 0.05+0.7=0.75 tons of fuel per 7 days of continuous maneuvering.

But a 100 ton Scout/Courier has a fuel tankage of 40 tons ...

40 / 0.75 = 53.33333 * 7 days = 373d 8h of maneuver endurance under continuous 2G acceleration.
Which seems excessive ... until you realize the "granularity" of fuel hit damage results are the loss of 10 tons (minimum) of fuel supply. So really, that "excessive" fuel load requirement is really there as a safety margin against mishaps.

A 400dT ship can operate for 4 weeks using 40dT of fuel.

Using the fuel consumption rate from CT Beltstrike, a 400 ton starship will consume 0.2 tons of fuel per 7 days for "basic power" (keeping the lights/internal gravity on, etc.), which equates to 1 ton of fuel per 35 days with the craft "idling" in space. If not maneuvering ... a 40 ton supply of fuel would be enough for 1400 days of continuous operation while "idling" in space (power plant output: zero EPs).

Last I checked, 1400 days is a little bit longer than 4 weeks ...

Now, granted, having enough life support reserves to sustain any crew/passengers that long would be a different problem.

 

[whulorigan]

Stealth is already incorporated in the rules, the two sides are those of us saying it's ok, even if not perfect, and the others, I don't know what they want, just to drag it down, I guess. The idea that stealth equals invisibility is a strawman argument people are creating, because as the rules stand it is just a modification on the sensor roll, or that stealth is a signature reduction, which tracks to the real world.

Stealth (that is signature reduction) is already in the rules, and it is ok within reason (i.e. it is not perfect). The issue is how is it achieved within the setting?

What those of the rest of us want is people to utilize plausible rationales for the effect, and not state scientifically inaccurate explanations for an effect while digging in their heels and knee-jerk reacting when someone tries to point out that there are misconceptions in their understanding of a phenomenon. There are ways within the "SciFi" to explain the "stealth" already incorporated in the rules, some of which have already been pointed out, and which are often casually dismissed as "magic-tech" (despite the fact that the setting already utilizes some of that very tech for many other things, because the presupposition is that in the future we will have discovered certain things in Science that we do not yet know today - i.e. SciFi). To then proceed and say that a harder scientific basis is desired for the explanation and then provide an explanation that gives evidence of basic misconceptions about the science in question requiring even bigger "magic-tech" without credibly describing what that "black box" is that permits it, I find rather disingenuous. Especially when efforts by people on the board to try and engage the discussion are met with snarky "you don't know as much as we obviously do" language every time someone points out a problem.

There are board rules here that forbid assertions of authority and professional credentials by posters (because they cannot be proven and should not be used as a means to shut down discussion in any event). Nevertheless, more than a couple of the people that some of you have been engaging with just might have done so should it have been permitted. Which doesn't mean that nobody else can have a brilliant idea, but it does mean that some should perhaps cool their jets a bit and take time to consider and think thru what others are trying to constructively point out. It actually is possible to arrive at a good solution for the question at hand, if people are willing to take the time to think the ramifications thru, and what is required.

 

[Dragoner]

Stealth (that is signature reduction) is already in the rules, and it is ok within reason (i.e. it is not perfect). The issue is how is it achieved within the setting?

What those of the rest of us want is people to utilize plausible rationales for the effect, and not state scientifically inaccurate explanations for an effect while digging in their heels and knee-jerk reacting when someone tries to point out that there are misconceptions in their understanding of a phenomenon. There are ways within the "SciFi" to explain the "stealth" already incorporated in the rules, some of which have already been pointed out, and which are often casually dismissed as "magic-tech" (despite the fact that the setting already utilizes some of that very tech for many other things, because the presupposition is that in the future we will have discovered certain things in Science that we do not yet know today - i.e. SciFi). To then proceed and say that a harder scientific basis is desired for the explanation and then provide an explanation that gives evidence of basic misconceptions about the science in question requiring even bigger "magic-tech" without credibly describing what that "black box" is that permits it, I find rather disingenuous. Especially when efforts by people on the board to try and engage the discussion are met with snarky "you don't know as much as we obviously do" language every time someone points out a problem.

There are board rules here that forbid assertions of authority and professional credentials by posters (because they cannot be proven and should not be used as a means to shut down discussion in any event). Nevertheless, more than a couple of the people that some of you have been engaging with just might have done so should it have been permitted. Which doesn't mean that nobody else can have a brilliant idea, but it does mean that some should perhaps cool their jets a bit and take time to consider and think thru what others are trying to constructively point out. It actually is possible to arrive at a good solution for the question at hand, if people are willing to take the time to think the ramifications thru, and what is required.

Please don't ever post to me again, thanks.

 

[whulorigan]

Please don't ever post to me again, thanks.

Then I suggest you click on my username and choose "Ignore".