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".

 

[Black Vulmea]

I think it simply comes down to not so much about "stealth in space".

I addressed the thread on its own terms; I'm not interested in the semantic argument.

With distance and clutter and such, very possible for things to hide in the MASSIVE volume.

As noted in Grand Survey, one can "hide" in an EM source greater than one's own - the spacer version of "attacking out of the sun" - behind clouds (at certain wavelengths), or behind matter like asteroids, moonlets, &c; solar flares and nuclear explosions also make detecting something more difficult with EM sensors.

With this in mind, it's not difficult to see what IN fleet escorts like the PF Sloan-class do: jump to points around a star system to create a web of overlapping sensors in support of squadron and fleet ops; while a ship may be able to position itself through very careful navigation with "the sun at its back"- to obscure its own tiny star - relative to a target, multiple ships looking from multiple directions provide an effective counter.

I'm sympathetic to the folks who are asking for some sort of cheat code to get around IR signatures - yes, I do think ships operate with the power plants at low levels and cruise with the plant off altogether, with the barest minimum battery power and in vacc suits for extended periods - but at best they may make detection more difficult. With the sensor rules in GS, detection is a task, and like every other uncertain task it's possible to get a result of "SOME TRUTH" or "NO TRUTH," so imperfect knowledge or erroneous interpretation is A Thing, playing by those rules.

And again, the focus on IR signatures and EMS sensors overlooks neutrino sensors and densitometers. IMTU you can spoof them a bit, too - change your power plant signature through careful engineering, add mass to your ship to change its configuration, like Rocinante disguised as a gas hauler - but at the end of the solar day . . .

. . . there's no "surprise" in space. By the time a ship gets close enough to be a threat, close enough to do ANYTHING, targets will know it's there.

If you're looking to play "Balance of Terror," well, TTB's detection rules kinda get you there, but those rules snap my suspenders of disbelief a little too hard and that's neither my goal nor my expectation.

I know this is a T4 thread, but since we seem to be discussing Traveller generally, I want to drop a quote from another source I don't recall seeing mentioned:

When completely buttoned up, the entire ship appears to be an ordinary nickel-iron asteroid. Carefully sculpted shutters close off the boat well openings and the turret location; even the maneuver drives are covered by camouflaged shutters. If the ship has been powered down, the only way that it can be identified as a ship is by close inspection of the exterior by individuals in vacc suits actually on the asteroid surface. Of course, clues that the asteroid is a ship can be gotten by a good navigator based on the asteroid's course or orbit, or by the fact that the asteroid is unusual in its current location. (The Asteroid Ship, p 22; emphases added - BV)

The significance of the tiny star that powers Rock isn't overlooked in what is the only "stealth ship" I recall from canon CT, and plotting is a good way of handling "SOME TRUTH" sensor results.

One last thought: I'm with @mike wightman - I like to lean into the known technology of the Third Imperium, applying deductive and inductive reasoning about how the fictional science works. That gravitic heat sink's going on my list of "prototype tech of the 3I," along with tractor beams and sensors for detecting ships in jump space, because "magitech" gravitics made of "handwavium" is one of the key speculative departures separating Charted Space from our own.

I've never played a Traveller game that wasn't at heart mostly crapsack ships visiting craphole worlds; any sort of advanced stealthing tech, whether it's gravitic heat sinks or laser exhausts - why not microwaves, I wonder? - is at best a macguffin, at worst a red herring.