Stealth in Space

[phavoc]

The SDB thread degenerated a bit, and I'm just as much to blame as anyone. I apologize to the group.

But my frustration at "It's impossible" is the driving reason behind this thread. I mentioned in one of my posts that our understanding of the physical univers is constantly changing as we learn more and more about it. I find it rather, ah, interesting (that should keep me out of trouble) that sometimes scientists forget that they actually don't know everything. Take the mass of the universe. That argument has been going on for decades and it's changed multiple times as old theories were tossed out as new information came to light. Traveller is a science-fiction game extrapolated from our technology in 1970. It, too, has undergone changes over time. I'm all for arguments, but the "it's impossible cause it's impossible today" doesn't fit within the genre. Besides, it's a bit of a copout.

In other threads in the past its been said that stealth in space is "impossible" because you "can't hide". That's a very broad assumption, and one that is unproven. But let's pick it apart.

The various detections schemes are - radar, IR, visual, & electronic. If you are using a fusion plant throw in neutrino detection too. I didn't break these down more as I'm trying to avoid writing a white paper here.

Radar - Energy is emitted by a transmitter and if it returns to the emitter the signal is analyzed. When radar first came out it was impossible to evade, but you could spoof it (tinfoil worked great). Over time we've figured out that you can bend the waves, absorb them, or overpower them. The latter lets the enemy know something is going on, but that's it. Technology has changed to allow for smaller waves to get better definition and make it harder to jam, but thus far history shows us it's a constant race between detection and evasion. Plus radar has a finite range as well. And space is VAST. Not to mention that active emissions make you a target.

Infrared - This seems to be the one where everyone says you can't hide heat in space. But that's not exactly the truth is it? A thermal detector is looking for heat that shouldn't be there. Today we have fighters that use their own fuel as a heat sink to help with lowering their IR signature. There's no reason why you a) could not do the same with LHyd or some other material - up to the point where it can no longer absorbe heat. We also know you can radiate heat, but obviously you can't radiate it towards the detector. IR is a passive sensor, so it's nearly impossible to jam. But it's possible that you might be able to spoof it. Much depends on how much heat you generate that you need to get rid of. The other issue is just how much heat can you absorb internally before it starts to 'leak'. We really don't know, especially since we don't have any of the materials used for hull plating in existence today. Plus we already know it takes some very delicate instruments to detect infrared targets. How much it would take to scan the entire sphere around your planet 24/7, to account for all inbound/outbound traffic, for all the junk that accumulates, etc, etc.. Granted computer power is nearly unlimited, it's still a potentially impossible project. But since we've never done it, we'll have to leave it at speculation.

Visual - Mark 1 eyeballs, telescopes, optical scanners, camera film. All can record visual imagery. And all have their limitations. We have some pretty new tech now that is the first generation visual cloaking device. It takes the image from one side and projects it on to the other. While it may not be perfect yet, it's still in it's infancy too. It's reasonable to assume that, like the constant battle with radar, there may be a battle too between visual detection and visual evasion.

Electronic - Another passive activity. Traveller already has rules for jump masking your signature to reduce your footprint. Today we have low-emission electronics, and senstive detectors to find them. And, like radar, this too is a constant battle between detection and evasion. And electronic signatures have a range as well. Space is full of background chatter and electronic noise. We've barely begun to scratch the surface here. This will probably be akin to the sonar battle, of trying to hide in the noise of the space "ocean".

Neutrino - This may be hard to get around. We know of neutrino's but that's about it. Building our own detectors is a bitch. Assuming we are able to build them in the future, it should be an easy way to spot somebody, since either you are a sun emitting them, or a fusion reactor. But we also don't know if you can somehow coax them onto a path of your choice (like through a magnetic field) and emit them away from your target. Then there is no stream of neutrino's to detect. Or maybe collapsed matter will slow them. Since we don't have any of that stuff, we haven't a clue. Still, there's no reason to think that some spiffy dude, dudette, droyne or some other race won't come up with a way to offset this in the future.

Thus far, from our own experience, just about every method of detection created has eventually been busted. That same thought process has been put into locks, encryption methods, currency and even mousetraps. I don't think it's a complete stretch to say that somebody, somewhere is gonna figure out a way to get around detection schema's. And, there's that other little point - we've yet to put a man beyond our own orbital area. We haven't fought any wars in space, and our history teaches us wars are when we quickly figure out ways to beat the other guy through a new idea, revising an older one, or new tech. We're pretty inventive when we are trying to kill each other.

I got pissed in the last thread, I'm hoping I won't do so again here. Looking forward to hearing rebuttals, but if all you are going to say is the equivalent of 'nyaaah!', please find another thread.

 

[Lemnoc]

Having lurked on those various threads, it seems the baseline objection starts with the assumption that “against a dark, featureless background under optimal conditions X can be detected from Y distance.” It grates against those of us who understand that conditions are rarely optimal or ideal, and that new dark objects are being discovered all the time; IRW, stealth technology—like codebreaking—seems very call-&-response, every new advance spawns new countermeasures.

The argument that Voyager’s 300-watts can be detected at Kuiper distances, while instructive and cautionary, breaks down somewhat once you recognize that its position and signature are already well understood. Folks know exactly where to look for it before the search even begins. That's hardly the start point for most covert operations.

I’d say that every takeaway from the “dark, featureless background under optimal conditions” improves at least the conceptual possibility of plausible stealth in space. Given that, anyone who would throw an arrogant tantrum about that in your game probably doesn't really belong in your game.

 

[darue]

thermoelectrics should be able to convert excess heat, where it could be stored in the 'jump capacitors' and/or emitted as a tight beam laser (could cause detectable backscatter with local dust).

The most detectable thing on the traveller ship designed for stealth might be the gravitics Mdrive. but I don't know that we have any rules for gravity wave detectors.

the thing is, any highly sensitive sensor is not going to be looking out on a black void, it's going to detect the universe screaming at it in all frequencies, while it tries to pick out a whisper.

 

[phavoc]

thermoelectrics should be able to convert excess heat, where it could be stored in the 'jump capacitors' and/or emitted as a tight beam laser (could cause detectable backscatter with local dust).

The most detectable thing on the traveller ship designed for stealth might be the gravitics Mdrive. but I don't know that we have any rules for gravity wave detectors.

the thing is, any highly sensitive sensor is not going to be looking out on a black void, it's going to detect the universe screaming at it in all frequencies, while it tries to pick out a whisper.

Ooh. The thermoelectric issue might solve a LOT of the IR problems. I was unaware of that. Great idea!

 

[Old timer]

After reading the other post, one thing that seemed to be forgotten, is that in MGT you can have as an option, a stealth hull, which imposes a penalty on sensors roll and lock ons. High guard also has stealth jump drive as an option. I do like the discussions here about potential ideas for stealth, they are interesting reads, but i dont need a real world justification when i am playing a science fiction (bold for emphasis, i am not shouting ) role playing game, after all we have jump drives, manoeuvre drives (not clearly defined) artificial gravity, plasma, fusion, meson weapons and so on in the game, and i dont see many real world physics arguments for those.

 

[Galadrion]

The argument that Voyager’s 300-watts can be detected at Kuiper distances, while instructive and cautionary, breaks down somewhat once you recognize that its position and signature are already well understood.

In addition, while Voyager's transmissions are fairly small (half an order of magnitude under a kilowatt? Negligible.), they are intended to be received. These are deliberate signals, not emissions. They're also focused in our direction, which means that (a) they are quite a bit more detectable to us, and (b) they are quite probably considerably less detectable to anyone who doesn't happen to be inside the transmission path.

People who use Voyager as an argument in this debate need to understand something: there is a considerable difference between a transmitter and a stealth installation. Using one as data to argue about the other is (at the very least) risky. Most likely, all they're going to do is display their ignorance of both subjects to all and sundry.

 

[High Orbit Drifter]

I too get frustrated with the attitude that we know everything today. As you point out, its unrealistic at best and the march of progress often stomps on such ideas.

I do like to have at least a minimal mechanic in place for something as important as stealth, however. Players are either going to have to use it, and so rig up something, or they will come up against it, and will have to deal with it somehow. In either case it can be abstracted to dice rolls well enough ("you roll a 14? You detect a Zhodani cruiser in the upper atmosphere!"), but it more interesting if you give some detail.

Of course that detail can degenerate into technobabble - or bovine postconsumer extrusion mass.

I love those ideas on IR. The backscatter on the dust gives the person doing the searching a chance to figure it out, but doesn't make it an automatic "there he is".

I've wondered about superconducting thread to dissipate ship heat. As long as you're not near a significant body can a ship trail out such a thread, the heat radiating along the length? If the thread is long enough, and thin enough, it would be difficult to pick out any one point. And the ship can reel it in when done.

Neutrino production is a problem I've recently been thinking over. That is an automatic production of fusion, difficult to stop without too many game side effects. So what if different types of energy production were used? Maybe solar panels or a fission reactor that emits harder to detect low energy antineutrinos (starting to sound a little technobabbly). These alternate energy sources would be used only when the ship is stealthed - they probably don't produce enough power to run drives, weapons and such, but enought to keep the ship going until the right moment.

 

[Wil Mireu]

I too get frustrated with the attitude that we know everything today. As you point out, its unrealistic at best and the march of progress often stomps on such ideas.

There's a difference between "thinking we know everything" and "knowing more than someone else" though - what's important is to provide the evidence to back up one's statements so that readers can look at the source material themselves.

And the march of progress only goes so far. Maybe 'extreme physics' like FTL, relativity, quantum physics and so on could change in the future, but the basic stuff is going to stay the same. Heat transfer, radiation, the principles of sensor technology etc are not going to change - and answering questions like that of 'stealth in space' require an understanding of all those things.

What frustrates me is when some people that brush realism concerns with excuses like "the story's more important". For them perhaps it is, but one should assume that whoever is asking the question already understands that they can just make anything that they like up "for the sake of the story" and are asking their questions because they want to know how it really works since they're interested in putting THAT in their stories. So an answer like "meh, armwave it away and put the story first" is actually really unhelpful.

I've wondered about superconducting thread to dissipate ship heat. As long as you're not near a significant body can a ship trail out such a thread, the heat radiating along the length? If the thread is long enough, and thin enough, it would be difficult to pick out any one point. And the ship can reel it in when done.

That would just make your ship even more obvious though. Instead of being a point source, now it's a linear one. And I don't think it would really help that much to radiate the heat, because it's pretty much a one-dimensional line - you need a large surface area to help with that.

Neutrino production is a problem I've recently been thinking over. That is an automatic production of fusion, difficult to stop without too many game side effects.

Neutrinos are actually only a side effect of proton-proton fusion, which is what happens in the core of stars. Other forms of fusion (e.g. D-D or D-T fusion, which are more likely to be used in power generation in reactors) produce far less neutrinos, if they even produce any at all - see e.g. http://www.visionofearth.org/industry/fusion/fusion-fuel-cycles-what-they-are-and-how-they-work/ .

 

[CosmicGamer]

My English isn't the best and I often find that a lot of the debates that occur are over differences in interpretation of words vs differences in interpretation of theories.

Here are just a few definitions for stealth I got from different online dictionaries:
1. cautious and surreptitious action or movement
2. the state of being furtive or unobtrusive
3. secret, clandestine, or surreptitious procedure.
4. done or happening in a secret or quiet way that does not attract attention
5. Not disclosing one's true ideology, affiliations, or positions
6. Having or providing the ability to prevent detection by radar
7. an aircraft-design characteristic consisting of oblique angular construction and avoidance of vertical surfaces that is intended to produce a very weak radar return
8. used to describe military aircraft that are designed so that they cannot be easily seen by radar

If the discussion is about general stealth and not being invisible, or undetectable to radar, or other specific detection methods, then I'd say

of course there is stealth
of course there is stealth detection
The success of stealth needs to consider both
A. the specific technologies and methods for detecting stealth
and
B. the specific technologies and methods for creating stealth

Stealth might simply be trying to pass oneself off as a trade ship in a convoy instead of a mercenary escort hire to protect them.

Something as low tech and simple as a ship traveling in the wake/shadow of a large freighter could perhaps work against some very high tech visual and radar detection while the highest tech radar, neutrino and other electronics stealth technologies might not prevent visual detection.

The variables of A and B can be extensive as heat, visual, radar, neutrino and all the possible stealth technologies and methods are evaluated (even those that are futuristic and we haven't come up with yet) then compared to all the different stealth detection technologies and methods.

In a extremely strategic space combat simulation game each category of stealth ability and detection might be given ratings (tech level might be a factor) which go towards determining if a ship is detected. A simpler strategic space combat simulation game might simply use a generic ECM vs Sensors.

My observation is that for game purposes and in real life it's usually not a matter of X will always make one stealthy against everything or Y will always detect everything.

There is no reason a GM can't come up with DMs for a Traveller detection or stealth roll based on the numerous variables specific to the situation. I do believe sensors and specialized stealth items do describe the DMs, ranges and so on. If you wish to add additional stealth and detection to your games, you'd just need to come up with the details, and DMs, specific to it.

EDIT: Often these discussions go into the probably costlier, higher tech, and harder to achieve "being undetectable". It is still quite valuable to stealthy alter ones heat, electronics emissions, and so on with no intention of being undetected but instead, trying to make your ship harder to "lock on", target or hit by making your ships exact speed, direction, and other characteristics harder to determine... Stealth in Space

 

[High Orbit Drifter]

That would just make your ship even more obvious though. Instead of being a point source, now it's a linear one. And I don't think it would really help that much to radiate the heat, because it's pretty much a one-dimensional line - you need a large surface area to help with that.

Wouldn't a one-dimensional line be harder to detect than a three dimensional point source? Well, 2 dimensional to most sensors I'd guess. If the superconducting thread was wound with a strand of stealth/black thread it would appear, from a distance, as a series of slightly curving dashes - imagine a white thread wound with a black thread against a black background that itself is peppered with white spots (stars, planets, dectectable ships, etc.).

And remember the thread can be thousands of miles long, as long as the ship isn't near a significant body it probably has only a minimal chance of fouling.

If this cannot totally hide a ship, I wonder if it can alter its profile? That is, make it appear smaller, maybe much smaller, than it actually is? This could work for any number of other stealthing techniques - a ship alters its heat signature/power output profile to look like a communications relay satillite, for example. Or a warship makes itself look like a Scout with several remote drones around it?

 

[Wil Mireu]

If this cannot totally hide a ship, I wonder if it can alter its profile? That is, make it appear smaller, maybe much smaller, than it actually is? This could work for any number of other stealthing techniques - a ship alters its heat signature/power output profile to look like a communications relay satillite, for example. Or a warship makes itself look like a Scout with several remote drones around it?

It doesn't really work like that. A ship emitting heat with a wire trailing behind it is still emitting the same amount of heat as one that doesn't - the wire won't do anything to reduce that because it has minimal surface area (being superconducting also won't help).

If you have something attached with a large surface area then you can use that as a radiator - you pump hot stuff through pipes in the radiator fin and it radiates into space much more efficiently. That would serve to keep the ship cool (which would really be the primary reason to have them) but would also increase its IR profile since it's now larger and still emitting a lot more heat than the background.

But that said, Traveller doesn't seem to care about heat in the first place, or its ships would all have huge radiator fins - so for the purposes of the OTU and default ship rules, heat isn't the issue, it's other stuff like neutrinos - though if Traveller fusion reactors don't use p-p fusion then they won't generate neutrinos... and also if heat magically disappears in the OTU then maybe neutrinos and any other radiation does as well.

 

[Sigtrygg]

Here is a little experiment.

On a really dark, cloudless winter night you and a friend go out to a field a few miles from the nearest street light.

Your friend walks into the field in a random direction while you face the other way so you have no idea where they are.

After 10 minutes they have to strike a match and you have to find them.

There is no stealth in space for a multi-gigawatt fusion reactor maintaining a room temperature environment - basic thermodynamics and black body radiation physics. If you do not understand this either take a course or just admit you haven't a clue about real science.

or read this:

http://www.projectrho.com/public_html/rocket/spacewardetect.php

by the way this is supposed to be an attempt at humour so don't take it personally - I use a version of Star Cruiser adapted to CT for handling stealth.

 

[Bardicheart]

I would say based on what we do know of current real world physics and technology is that hiding in space is less about concealment and more about the ability or inability of the sensor to look in the right place at the right time. Obviously a system that had more sensors is going to have better odds of spotting a ship than a system with a lone array at the planets only downport. I think that's an important consideration in any of these discussions. Space is vast and trying to scan an entire system takes a lot of sensors and processing power, not impossible but also not something every system would have. Economics and tech development / availability will be factors.

Likewise, the amount of system traffic would play a role. If the system has hundreds of intersystem ships moving about (mining asteroids, shuttling cargo from the up port to planet side, moving between in system colonies, etc.) as well as significant interstellar trade traffic going in and out, its not so much that you aren't seen as simply getting lost in all that clutter. Or literally hiding in plain sight.

There's also considering how much you could use asteroid belts, dust clouds, gas giants, etc. to mask your ship and allow you to hide. Something hinted at in various books, but I don't recall it being give a serious treatment.

To my mind, if I were going to write up house rules for it, I'd come up with three things.
A system sensor rating that indicated its general ability to detect objects
A system traffic rating, which indicates how much traffic there is and affect the chance of getting "lost" in the clutter
And finally DMs for various objects that might provide "cover"

So far as defeating sensors, I think a good argument can be made (and seems to be the assumption in the rules) that any sensor devised will also eventually have means devised to counter it, and probably counter counter measures as well. That's been the history thus far and I can think of no good reason to believe it won't continue in that direction. At TL 12 (a solid four TL above our own) who knows what new materials might have been developed. Traveller seems to assume this will be the case and I'm fine with going along with that. Some others aren't.

Frankly I think some of the argument comes down to this. There are those of us who can accept (i.e. suspend disbelief) that advanced technology can allows ships that are specially designed for it to be difficult or impossible to detect in space, especially at long distance. Others of us cannot accept (suspend disbelief) that premise. Each side has their reasons but I somehow doubt most will change their mind. That said, it only seems constructive that for those who want such possibility to then focus on developing any house rules that are may be helpful in that regard and leave it at that. For those that don't want such in their games, well, just ignore it.

 

[Ishmael]

Traveller Universe != Real Universe

The same laws of nature may or may not apply to each other.

Trav ships appear to have no heat issues and do not have anything related to thermal management ( no radiators yet without roasting the crew )
F=ma doesn't seem to apply either.

If you're going to enforce a known law of nature in the game, you should probably enforce as many of them as possible to keep things honest.

For decent sensor rules though, try these.
http://traveller.mu.org/house/sensor.rules.html
http://traveller.mu.org/house/sensoraddenda.html
http://traveller.mu.org/house/sciencesensors.html

 

[phavoc]

There is no stealth in space for a multi-gigawatt fusion reactor maintaining a room temperature environment - basic thermodynamics and black body radiation physics. If you do not understand this either take a course or just admit you haven't a clue about real science.

or read this:

http://www.projectrho.com/public_html/rocket/spacewardetect.php

by the way this is supposed to be an attempt at humour so don't take it personally - I use a version of Star Cruiser adapted to CT for handling stealth.

Interesting website, though I'm not sure where's they are getting some of their data, considering we can't get out INTO space to make some of those readings possible. Saying you could observe an event from Proxima Centauri is a little bit ballsy. Could be true, but I don't have the science background to fully dispute it.

One thing is we don't have fusion reactors yet, nor do we have gravitic drives. Hell, we have no idea how a gravitic drive / thruster plates might work as far as tracking goes. So I'd say stealth wins on that argument, since there is no data to say otherwise.

The heat/IR argument is interesting, but I noticed that the site author never goes into any explanation of what it would take to dump your internal heat into an onboard heat-sink (such as your fuel). That's something we do with stealth fighters today to reduce heat signatures.

Their decoy argument is interesting, but has a few holes in it. Mainly the idea that we don't have any experience or data to know what might happen if you tried to build a decoy platform. We already know today you can electronically spoof sensors, and you can spoof IR sensors as well (flares are active/passive defenses that are in use by aircraft). Who's to say you would not be able to in the future replicate the exposure of data being emitted by your spacecraft.

And let's face it, the speculation of it can / it can't will remain speculation until we get out in space and start building warships to fight with each other. History has shown us we usually are able to build a defense against most things. And with tech for detection, so comes tech for evasion. The website had some interesting theories to it, but there was that normal tinge of "you can't do it because x-y-z"... of which a lot of that is based on incomplete data (i.e. we ain't tried to do it yet).

I would say based on what we do know of current real world physics and technology is that hiding in space is less about concealment and more about the ability or inability of the sensor to look in the right place at the right time. Obviously a system that had more sensors is going to have better odds of spotting a ship than a system with a lone array at the planets only downport. I think that's an important consideration in any of these discussions.

Space is vast and trying to scan an entire system tat advanced technology can allows ships that are specially designed for it to be difficult or impossible to detect in space, especially at long distance. Others of us cannot accept (suspend disbelief) that premise. Each side has their reasons but I somehow doubt most will change their mind. That said, it only seems constructive that for those who want such possibility to then focus on developing any house rules that are may be helpful in that regard and leave it at that. For those that don't want such in their games, well, just ignore it.

Very well said.

 

[Wil Mireu]

I would say based on what we do know of current real world physics and technology is that hiding in space is less about concealment and more about the ability or inability of the sensor to look in the right place at the right time.

That is exactly the problem here. Nobody is arguing that ships can be 'invisible' in space - ships will be emitting radiation like crazy, and while that could be mitigated somewhat by some stealth technologies it won't ever be reduced to zero.

The issue here is another ship or station's ability to detect those ships - and I have never seen a convincing argument - not even on Winchell's site - that states that all ships will be detected all (or even most of, or part of) the time. Maybe orbital telescopes can scan the whole sky in 6 hours (I don't know), but they're more specialised and powerful than ship-borne sensor suites, and they're mostly looking at things that are lightyears away, not moving at a rapid clip at a distance of a few AU. And I really doubt that ships or stations will be processing Tera- or Petabytes of high resolution skymap data in realtime just to find ships that might or might not be out there. You may be able to detect a radiation blip on the sensor, but by the time you slew the sensor back maybe it'll be gone, and by the time you get out there to investigate it'll definitely be long gone.

So yeah, the radiation may be there to detect - so in that sense "there's no stealth in space", but there is absolutely no guarantee that the sensors are going to be able to detect that radiation and identify what is producing it.

 

[darue]

well, this is remarkable...

(I long ago got sick of the every-six-months "invisibility invented" stories, that always turned out to be a letdown on reading. but this one may be significant...)

Invisibility cloaking is no longer the stuff of science fiction: two researchers in The Edward S. Rogers Sr. Department of Electrical & Computer Engineering have demonstrated an effective invisibility cloak that is thin, scalable and adaptive to different types and sizes of objects.

Professor George Eleftheriades and PhD student Michael Selvanayagam have designed and tested a new approach to cloaking—by surrounding an object with small antennas that collectively radiate an electromagnetic field. The radiated field cancels out any waves scattering off the cloaked object. Their paper 'Experimental demonstration of active electromagnetic cloaking' appears today in the journal Physical Review X.
http://phys.org/news/2013-11-thin-invisibility-cloak.html

The system can also alter the signature of a cloaked object, making it appear bigger, smaller, or even shifting it in space. And though their tests showed the cloaking system works with radio waves, re-tuning it to work with Terahertz (T-rays) or light waves could use the same principle as the necessary antenna technology matures.

Eleftheriades and Selvanayagam? Are those Vilani names? :lol:

 

[Wil Mireu]

Eleftheriades and Selvanayagam? Are those Vilani names? :lol:

First one is Greek, definitely. Second one probably is... Malaysian? Indian? South Asian anyway...

And its sounds like their tech works on radiation reflected by the object, not emitted by it (e.g. from an onboard reactor...).

 

[darue]

Eleftheriades and Selvanayagam? Are those Vilani names? :lol:

First one is Greek, definitely. Second one probably is... Malaysian? Indian? South Asian anyway...

And its sounds like their tech works on radiation reflected by the object, not emitted by it (e.g. from an onboard reactor...).

one layer facing out another facing in. Still, it would seem to require a purpose built hull, or the deployment of a "shell" somehow around the craft. Maybe at TL14+ the antenna arrays can be integrated into the hull material. I would think by TL12 such a technique would be very well developed. Now the question is, why so LITTLE stealth or even 'cloaking' in OTU? Imperial tech-suppression? but none of the other powers use it either apparently. Maybe LIDAR is too concentrated to cloak effectively? Maybe the radar frequency spectrum is modulated and changes too rapidly for the 'cloak' to adapt perfectly. rendering the whole thing moot. Still would be effective as heck against passive sensors.

 

[phavoc]

Similar to the CV90 tank cloaking they've developed.

http://www.photonics.com/Article.aspx?AID=48282