But those bodies are at thermal equilibrium (more or less) with their deep-space environment. They are not generating their own heat internally (though they may still be cooling if large enough).
T4 Only: Some people say no stealth in space, a discussion.
- Thread starter warwizard
- Start date
But those bodies are at thermal equilibrium (more or less) with their deep-space environment. They are not generating their own heat internally (though they may still be cooling if large enough).
Marcatlas
SOC-12
Yes, apples vs road apples. A powered ship (or a ship at room temp for humans) shines like a bright beacon in space IR wise. You can see it all the way from Pluto's orbit to Earth without a problem.
Spinward Flow
SOC-14 5K
Is that a planet, a star ... or a starship?
Well, all of those things resolve to 1 pixel on the sensor scan, so ... {shrug}
{ supremely skeptical look }
Here are some ACTUAL images of planets (Uranus and Neptune) viewed with an actual IR telescope (James Webb).
Let's suppose, for illustration purposes that each of these 2 images contains a starship.
Pick the PIXEL of light that is ... not a star, not a planet and not a moon (and not a space station) ... in each of these images.
The officer of the watch on the bridge is going to want you to justify your interpretation of the sensor data, to make sure you've correctly interpreted the readings from your sensors.
If the moons of Uranus and Neptune look like single pixel dots of light in these images, what makes you think that a "smaller than a moon" starship will produce a brighter/higher signature IR signal than what you're seeing in these examples?
Show your work.
To expand on why the computer is the decisive element- as a previous person noted, that detection zone is a sphere that increases exponentially in volume the further out you have a good chance to newly detect contacts.
Since I use CT mostly HG computers, there are millions of credits to cover the sensor costs so they are just part of the buy. For Mongoose and others you’ll need to spec those better sensors, maybe more then the navigational/civilian/military ones.
Another variable if you go with the geekwonk versions of Traveller with a hard defined dish, that dish has to be rotating wildly to pick up everything, possibly with a ship roll added in. It’s got only a few seconds per pass to pick up whatever, so things can be missed.
I personally think it’s more rational to have arrays arranged to give continuous looks and the advantage of multiple sensor points on each contact to allow for more overall sensitivity and ability to range with all those ‘ears’. That way you aren’t dependent on one dish that can go out/be destroyed.
Individually they have less sensitivity then the big dish, but collectively they have more, where again the computer is there to stitch it all together.
Course you need a mechanic to degrade the sensors if you are taking hull damage.
Since I use CT mostly HG computers, there are millions of credits to cover the sensor costs so they are just part of the buy. For Mongoose and others you’ll need to spec those better sensors, maybe more then the navigational/civilian/military ones.
Another variable if you go with the geekwonk versions of Traveller with a hard defined dish, that dish has to be rotating wildly to pick up everything, possibly with a ship roll added in. It’s got only a few seconds per pass to pick up whatever, so things can be missed.
I personally think it’s more rational to have arrays arranged to give continuous looks and the advantage of multiple sensor points on each contact to allow for more overall sensitivity and ability to range with all those ‘ears’. That way you aren’t dependent on one dish that can go out/be destroyed.
Individually they have less sensitivity then the big dish, but collectively they have more, where again the computer is there to stitch it all together.
Course you need a mechanic to degrade the sensors if you are taking hull damage.
Sure, if you have a really good insulator above and beyond the vacuum itself. Just not with 100% efficiency. Then most of the heat stays inside the ship because it only radiates very slowly and builds up. And everything eventually cooks/boils/melts.
The idea is that you want to be producing heat at the same rate that you are emitting it while maintaining a particular equilibrium temperature (in our case, room temperature). If you retain the heat, you cannot do so with 100% efficiency, and your internal environment will find a new higher temperature at which heat production and radiation are at equilibrium.
That is what was suggested upthread about having some type of "heat-sink" to store aboard to dump the heat into (a "chill-can" so to speak). But it will have a capacity, and then will need to be dumped overboard. I made the point that in T5 that is one of the ways that Black Globes can deal with their energy absorption in the rules. But the "slug" needs to be ejected when it reaches capacity.
While the Black Globe itself is TL16 Standard, I do not know if that means a comparably rated and functional energy sink & slug mechanism would require the same TL or not in general.
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Daidoji Dave
SOC-12
Is there a book or edition that gives hard numbers on background system traffic? I haven't seen a hard figure in anything I've read. I'm guessing easily hundreds in trade traffic for most systems with a starport, and higher in high pop core worlds. And a worked asteroid belt adds thousands to tens of thousands of small craft and drones.
At this point you don't perfect literal stealth, just anonymity. Which the profile reduction some are arguing for would be enough to provide.
At this point you don't perfect literal stealth, just anonymity. Which the profile reduction some are arguing for would be enough to provide.
Marcatlas
SOC-12
not in realityland. If you could try you cook yourself and melt the interior of the ship in very short order. If you'd like to understand go here: https://www.projectrho.com/public_html/rocket/spacewardetect.php
Spinward Flow
SOC-14 5K
Camouflage.
You're detected ... but misidentified.
You're not "invisible" ... but rather "indistinguishable" from your surroundings, thus "blending into" them in ways that make identification difficult.
When the haystack gets big enough ... finding a needle, even with a magnet, can become quite challenging.
Note that signature reduction, camouflage, stealth, invisibility/cloaking devices, black globes, etc. ... all share a common purpose.
The design intent is to either "go unnoticed" or to "spoof" detection and identification, increasing the odds of misidentification (if detected) and/or thwart tracking once detected ("we've lost them").
That's not a multi-million dollar armed craft on your sensor readout ... it's a "natural phenomenon" (such as a bird, or a whale or a rock in orbit).
Using multiple sensors across multiple bands makes it harder to pull off this trick ... but NOT IMPOSSIBLE.
It's been interesting to watch people AVOID admitting the truth of this point.
We've all seen entertainment media ranging from swords 'n' sandals to hypertech where the results of damage are BINARY.
Either an attack does NO DAMAGE or it does completely LETHAL damage (usually "dying" instantly) ... leading the phenomenon of "crunchy henchmen" where all the extras in a scene simply exist to be destroyed in 1 hit. Only main characters have "wound levels" or take damage (and keep going) when hit, everyone else is just "instadead" when hit (because there's no kill like OVERKILL).
People who say that "there is no stealth in space!" just automatically assume that sensors are EVERYTHING ... signature reduction engineering DOESN'T WORK ... so ... "LIGHTSABER!" sensor detections are just automatic and PERFECT and there's nothing that anyone can do about it ... so NYAH, NYAH!
It's the same "bad script writing/choreography" thinking that weapons/sensors are INVINCIBLE
and that armor/signature reduction is WORTHLESS 
.
mike wightman
SOC-14 10K
You can't camouflage yourself as a 3K object when you are radiating to maintain 291K without an internal heat sink (temporary at best) or space magic.
You could try to pretend to be a different ship.
You could try to pretend to be a different ship.
Even if you "reduce your signature" in some meaningful way so as to be "missed" by a sophont SensOps for some time, how long will it be between the time when you actually are spotted as a foreground object (with parallax) and the time that you are within meaningful engagement range? Hours? Half-a-day? Day-and-a-half?
Remember that unless the stealth ship has just "jumped-in", it is originating and coming from somewhere else in the system and astrogating thru deep space the entire time along a trajectory. It just doesn't "pop up" at the beginning of the encounter.
Remember that unless the stealth ship has just "jumped-in", it is originating and coming from somewhere else in the system and astrogating thru deep space the entire time along a trajectory. It just doesn't "pop up" at the beginning of the encounter.
Marcatlas
SOC-12
Well, let's say with TL 12 (the Imp avg) sensors and you reduce your IR sig to room temp (it is normally much higher with a fusion PP) you will be detected within an hour and at a distance of at LEAST 1 A.U. (~150,000,000 km). At 6Gs with turn over at half way point, the travel time is about 27 hours. 1G = ~68 hours
The best approach would be to base it off of trade volume numbers.
Interstellar trade traffic would be different from in system traffic. That depends on how busy the internal system is, how much travel is done through sub light vs just jumping to the outer system, etc.
The key things to note is the majority of traffic is predictable. These are long trips, people value time, they take the shortest route. As a general rule, space is REALLY boring. It's also, still, REALLY dangerous, and nobody really just wants to be out there. If you look at most modern shipping, they take common, known routes from port to port across the wide open oceans.
Same thing would happen for most space traffic.
That means that if you want to find the vast majority of the system traffic, it's not scattered all over the system, it's in just a few places, just a few trade lanes or trade routes. Meaning that the little blips that may pop up outside of those major traffic patterns, those might well get an extra glance over as who they are, and why they're there.
Also, all traffic has some kind of identity transponder, actively pinging. If some background cosmic anomaly stands out on a scanner, it better be pinging back to make it less of one, or its going to gather even more interest. Particularly if it wasn't there yesterday.
We don't do daily sky scans because we don't have too. We try to keep track of the potentially dangerous rocks out there that might prove cataclysmic, and we do detect most of them. Sometimes, one sneaks in an startles the astronomers. And, yes, its fair to say you don't know what you don't know, and there are very likely ones we've missed completely. Thankfully, they've missed us, so, no harm no foul.
But we do look.
At the same time, our security situation, outside of a rogue rock, which by definition needs to be pretty big to bother with in the first place, doesn't warrant a more detailed, or timely view of the sky. We don't have space traffic to monitor.
That said, I'm pretty sure everything in orbit is, literally and figuratively, on somebodies RADAR. As a rule, I think those working in space have detailed knowledge of everything floating around up there, from space stations, to satellites, to rogue nuts, bolts, and wrenches.
In a future situation with a lot of space traffic, we'll have to set up some kind of more robust, more up to date status of the sky, requiring more scans, and more power, and, likely, some work on instrument sensitivity. We don't have that now because its simply not needed.
If we start needing to care if a pixel dot in deep space is important for us to keep track of, we'll start putting out deep space sensor platforms to make those dots easier to pick up and identify.
Daidoji Dave
SOC-12
Yeah I get that. That part's self evident.
But that being the case, it seems like maybe someone would have done the work already, and save reinventing the wheel. GURPS if no one else.
Flipping through GURPS Far Trader though I don't see it. I see numbers you could work it out from, but I'm reminded why I'm not using Far Trader even after the GURPS fans' glowing recommendations - the thing is both crunchy and doing its own thing. Would take a while to work out.
If I ever get it I'll post it, but I'd rather do more immediately useful game prep.
To save yourself some time, you could just use the trade maps (link below) and sector data (links from the sector's page or through the trade map page) on the Wiki:
Category:Trade maps - Traveller
Marcatlas
SOC-12
Well, in order to blend in you have to be running with a normal or seemingly normal transponder and traveling on a course that makes sense flight plan wise. That's no problem depending on what exactly you are trying to pull off.
Enoki
SOC-14 1K
From my perspective, space is a VERY big place and if you have a small ship and don't want to be found, just turn everything off will make it really hard for someone to find you. It's like trying to pick out a single, tiny, asteroid within an entire solar system. Not easy to do.
So, if your ship is mostly or completely powered down and drifting, it's going to be damn hard to find.
So, if your ship is mostly or completely powered down and drifting, it's going to be damn hard to find.
Marcatlas
SOC-12
Wrong. Your ship with everything turned off is a bright light (in the IR band) against a pitch black IR background. How exactly is that hard to pick out?
Another concept to explore is using sand like canisters, but launching chaff instead.
Relatively inexpensive if just blocking against one spectra, more and more expensive if more or all, with little grav spoofers thrown in.
They should make your ship easier to initially detect with a larger reflective bloom, but tougher to lock onto and get effective hits.
Relatively inexpensive if just blocking against one spectra, more and more expensive if more or all, with little grav spoofers thrown in.
They should make your ship easier to initially detect with a larger reflective bloom, but tougher to lock onto and get effective hits.
Enoki
SOC-14 1K
Why would it be? If the hull were the same as ambient temperature, it's invisible in IR. What makes you easy to find is you "rotate and radiate" sending out things like sensor signals and such. Then you become a lighthouse.
