Very well, I stand corrected.
Sesitive enough to detect a starship at more than 600,000km, would you say?
Hans
Missing Tech in OTU
- Thread starter BardicHeart
- Start date
Sesitive enough to detect a starship at more than 600,000km, would you say?
Hans
a 2 mirror of 2m each interferometer is easily in our technical capability. It should be able to directly image worlds to 10pc. The Keck Telescope already has imaged an extrasolar planet. Actually, several. At 129LY. WIthout using the interferometer, and from planet's surface (thus dealing with haze and atmospheric losses), using a 2m scope.
http://www.sciencedaily.com/releases/2010/12/101208172320.htm
Heck, NASA's got a 4x2m interferometer on the schedule: The TPF.
So, cutting the haze, and using a pair of 2m reflectors (easily carried in 2 Td total, if you don't mind turning the ship to aim them), and quite possibly included in bridge tonnage in CT and MGT, and one should be able to point and shoot. And detect worlds in under a day.
Anyway, back to topic. I was referring to IR sensors. (unnamed sensors not withstanding). From what I remember, currently (as of ~80/TL 7) we could detect something with the thermal output of the shuttle boosting with its own engines out to ~ the distance of Pluto. From what I can recall, no version of Trav has IR sensors that are this good. MGT sensors are very low powered and just unbelievably low tech. I'd say that at ~4 TLs higher than now (TL 12) these sensors would be at least twice as good.
Xerxeskingofking
SOC-13
yes, but those a ground based IR scopes with massive, dedicated image processing software massaging the raw data to get the results out, with as long as they want to look and as long as they like to process the data.
thats different to what a starship sensor is doing, with signifcantly less processing power and a smaller window of obsovation and processing. the ships computer may be much more powerful, but it also has to run a starship, with multiple demands of it's runtime. Also, space is a much harsher enviroment than the one ground based telescopes work in. all starship electrionics have to be extensivily hardened agianst EMP, and that often means they are much less powerful than ground based systems of the same tech level (i think modern spacecraft run about 5-10 years behind the cutting edge when they were designed becuase of this.
let me ask you: have we sent a probe out with a IR sensor with enough resolution to discern useful infomation about a shuttle scale energy spike at the orbit of pluto? I'm pretty sure we havn't.
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The Earths atmosphere absorbs most IR from space. In addition, Earth based environment emits IR. Using a couple of 10" scopes in outer-space (your star ship) could easily surpass the capability of TL 7 ground based, HUGE equip. As for processing power, TL 7 computers are to TL 12-15 Ship computers as an abacus is to a current day mainframes.
Like I said, MGT sensor tech is ridiculously low tech.
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far-trader
SOC-14 10K
I think you are confusing capability with ability. And missing the entire game trope to boot. And ignoring any countermeasures what-so-ever.
Traveller presumes (if taking most of the sensor rolls as function) stealthy (1) ships. So we're not trying to detect the space shuttle with its engines flaming. Nor even the space shuttle with its engines dead (which is still a dead easy thing to pick out in space from very far away). We're talking about detecting a ship that has a very amazing hull capable of dealing with extreme heat easily (2), and using engines that don't produce exhaust output (3).
We're also talking about the game reality of not scanning the entire sky and identifying every object out there. In the game the concern is the immediate potential threats, so detection ranges are greatly reduced, to effective combat ranges. This permits nearly instant recognition of anything in that range. Otherwise you'd be spending an inordinate amount of time trying to catalog and id the thousands (10x, 100x, ...) of sensor hits.
So what about those non-starships? Are they easier to detect? One would presume so... IF the method of dealing with the heat issues is the jumpdrive. However even the non-starships in Traveller have the exact same "Oh my Emperor, I turned on the ship and it, it, it just melted into vapour! Does my insurance cover that?" heat issues. And they also can be carried externally through jumpspace by a starship. So, it can't be the jump drive itself but something else. Fans of the jump grid hull (not me, however see 4 below) IF it is included as part of all hulls (and since the hull price is identical whether starship or non) rejoice! Here is another argument for your side. The hull (all hulls) must have a "jump grid" that permits the diversion of heat from the ship into jumpspace. It's the simplest explanation within the rules of why Traveller ships don't instantly melt themselves and everything nearby to vapourized compounds.
And I haven't even touched on the countermeasures such an ability would permit. Nor the applications for vehicles.
In short, yes, in Traveller stealth in space is not just possible, but the norm. And the ramifications of this are huge. The least of which is that detection of space craft is difficult and very limited in range. That's what the rules say. Reality can take a long walk out of a short airlock...
(1) Yes, there is no stealth in space, in reality... this is a game with technology only dreamed of though.
(2) About the only thing I've ever seen that has a hope of making it work is that it is connected to jumpspace somehow and all the waste heat is dumped there. Given that every starship has to have a jump drive I can live with that as a hand wave. So Traveller starships are by default, externally at least, space background level temperature for purposes of detection.
(3) Post HG2 revision anyway, prior to that there was the high fuel (reaction mass/coolant/burned) maneuver drive - aka fusion torch drive. Also excusing muttering in some side products (iirc not in the main rules) about the reactionless drives producing great heat, heat which is somehow magically all radiated out very tiny ports from the maneuver drives, when such heat would melt anything, but the ship is ok and operating them in atmo is ok and does no damage to the downport, city and countryside as you fly over or land and take-off. Again the only thing that makes any sense is that it is handled by the jump drive and dumped into jumpspace.
(4) I may have to accept some kind of "jump grid" hulled universe
Not at all. The game trope means it's fine to pretend that you can't spot other ships at long distances for when you game (as long as you can manage to suspend any game-ruining disbelief). But it's not fine to carry those unbelievable game rules over into setting development. As for countermeasures, you can reduce your EM emissions, but there are no countermeasures for heat emissions. Short of subspace heat sinks or stealth fields, that is, and there is no mention of any such thing in any of the ship construction rules. There is ONE mention of a stealth field in an early Amber Zone. But until the Traveller rules writers add stealth fields as a common (albeit expensive
) option for ship-building, stealth fields is rank science fantasy.Well, there's also heat transfer from one side of the vessel and emitting it all in the opposite direction, but to accept that, I'd want a) rules for installing such a system and b) rules for employing it.
Too bad there isn't a way to tell the system to ignore known sources of sensor hits. Some sort of electronic device with discriminatory powers. Maybe even programmable in some way. We could call it something like an Electronic Data Processor or Programmable Electronic Device...
Indeed. They're also ignored. Not mentioned at all.
Hans
Andrew Boulton
The Adminator
NOTE: This is very interesting, but some of the comments have been a touch rude. You've all settled down now, but make sure you keep it that way.
There aren't ANY real CMs for IR sensors in deep space.
Processing/scanning time is non-issue for advanced computers/DSP.
Meaning: If you're within Ort cloud range and not masked by a body, you're seen and tracked by any ship absent some fantasy item of course. BUT, that doesn't yet exist in Official TU.
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its not about whether or not something is able to be detected....
its all about whether something can be identified.
consider if you were to stand in the middle of a football field in a filled stadium.
you'd be able to see every one of the 60,000+ people in the stands
some of them might have guns
one of them wants to shoot you...find that one before he can pull the trigger
not so easy despite the fact they you've already detected him with a quick glance around the stadium.
you just haven't identified him yet.
and if you act before having a positive ID on him, you better hope that you're lucky.
or consider the old "Where's Waldo" books
Waldo is in plain sight, yet in some pages, he's a challenge to find.
countermeasures, even today's ecm for planes and tanks, don't try to make the plane/tank totally invisible...they try to make the plane/tank hard to identify separate from any background noise or other sensor hits ( perhaps simply by creating many many false sensor hits as the countermeasure ), even if only to defeat smart weapons* or to gain enough time for it to shoot first.
*smart weapons don't yet have the processing power to identify targets. They have to rely on the launcher to tell them which target they should hit.
its all about whether something can be identified.
consider if you were to stand in the middle of a football field in a filled stadium.
you'd be able to see every one of the 60,000+ people in the stands
some of them might have guns
one of them wants to shoot you...find that one before he can pull the trigger
not so easy despite the fact they you've already detected him with a quick glance around the stadium.
you just haven't identified him yet.
and if you act before having a positive ID on him, you better hope that you're lucky.
or consider the old "Where's Waldo" books
Waldo is in plain sight, yet in some pages, he's a challenge to find.
countermeasures, even today's ecm for planes and tanks, don't try to make the plane/tank totally invisible...they try to make the plane/tank hard to identify separate from any background noise or other sensor hits ( perhaps simply by creating many many false sensor hits as the countermeasure ), even if only to defeat smart weapons* or to gain enough time for it to shoot first.
*smart weapons don't yet have the processing power to identify targets. They have to rely on the launcher to tell them which target they should hit.
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far-trader
SOC-14 10K
Quite to the contrary. In the Official TU (the rules, not the Imperium et al per se) ships (at least functioning ships that don't want to be found) clearly have very effective CMs for all manner of available detection the way the rules for detecting and tracking them work. That it is not described exactly how that works is very true. As true as the fact that it must be there.
Meaning: In Traveller (picking CT because I know it best, others are similar iirc) if you're NOT within 0.5 light seconds of most ships, or up to 2 light seconds of the best equipped ships, your ship is not detectable. Period.
And that is if you're not trying to hide. Cut those ranges in half if you are purposefully operating without active emissions. Using natural bodies as cover cuts that down even more.
And further, after you are detected if you manage to slip beyond just 3 light seconds you are lost to all sensors. Invisible. Gone. At least until again within detection range.
A paltry 3 light seconds. Far far short of the Ort cloud.
I don't know about you but the only answer (that makes sense) to that I can see is there must be some standard (magic tech) applied to all ships. It must be included in the hull because there is no difference in detecting applied to starships vs non-starships (so it can't be the jump drive).
Now, detecting other bodies, natural bodies and non-(magic tech) built ships, yes I agree completely, it's dead easy because that is what reality is.
The other reality (in the game) is that ships are not so easily detected. The mechanics of it are not explained. Not even mentioned (except as a consequence of the rules for detection) as Hans noted. Still, it exists.
Based on temp difference a ship can be ID's as a ship, very easily.
In deep space there is no 'noise' to blend into when talking IR. False hits would involve launching decoys. Not effective for the durations needed to confuse.
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Actually, the absence of scientifically correct data isn't = to countermeasures. It just equals writers who have no understanding of basic physics and thus couldn't write a correct rule set. The point of this thread is stating what is too low of a tech not, what can we justify based on the writers not understanding tech/science.
far-trader
SOC-14 10K
That's funny, I thought the point of this thread was to fill in the "Missing Tech in (the) OTU". Seems to me the (magic tech) that is so much in the background and common as to be invisible and not even worth a mention, this (magic tech) which makes ships extremely difficult to detect (even impossible at not very long ranges), fits the point of the thread perfectly.
I personally don't think it is "writers who have no understanding of basic physics and thus couldn't write a correct rule set" which I find insulting. I think it is game designers who wanted to make a playable sci-fi game. They couldn't possibly explain every little item. They probably didn't want ships instantly detectable no matter how far away they were (and I'm sure they knew the science well enough to know the fact) for the simple fact that it makes the game more fun. They made a choice that in this sci-fi universe stealth in space was a given. Rather than make up a reason (which would only be shot down) they ignored it. It's not really important how it works. The point is it does.
Of course, if you can't swallow that nothing is stopping you from changing it for your game. Not now, or ever in the past, and never in the far future
I personally don't think it is "writers who have no understanding of basic physics and thus couldn't write a correct rule set" which I find insulting. I think it is game designers who wanted to make a playable sci-fi game. They couldn't possibly explain every little item. They probably didn't want ships instantly detectable no matter how far away they were (and I'm sure they knew the science well enough to know the fact) for the simple fact that it makes the game more fun. They made a choice that in this sci-fi universe stealth in space was a given. Rather than make up a reason (which would only be shot down) they ignored it. It's not really important how it works. The point is it does.
Of course, if you can't swallow that nothing is stopping you from changing it for your game. Not now, or ever in the past, and never in the far future
Missing tech. NOT missing fantasy items. Wrong genre. Try the FRPG boards.
I would have put it a little more diplomatically, but I agree with the essence of it.
Traveller is reasonably hard SF, in such as it keeps the "fantasy items" to the necessary minimum.
Jump technology is necessary.
Gravity control (inertial compensation, artificial gravity) in necessary.
Magic devices that nullify a ship´s IR signature or make it indistinguishable from other IR sources are NOT necessary.
Personally, I´d include at least Black Globes among the unnecessary fantasy items as well, but that´s another discussion.
far-trader
SOC-14 10K
Missing tech. NOT missing fantasy items. Wrong genre. Try the FRPG boards.
No worries, the wink makes all the difference. We're both opinionated, as long as that's the extent of it I'm good
That said however (and yep, opinion again) I think I'm well within the sci-fi genre for stealth in space.
Stealth may not be necessary (and imo the effect is not limited to just IR spectrum), to some, obviously the game designers disagreed. Heck I don't even find it so much necessary as fun and the way the game was designed.
And really jump tech is not even necessary. Certainly not gravity control. One could have a rousing good game with nothing but solid proven science... but we're talking about Traveller (as designed), which does have jump tech, grav tech, and yes even stealth tech as I've pointed out.
Oh yeah, Black Globes are another discussion entirely, though related
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The problem is that it does not make sense that it would be applied to all ships. Let's postulate our magic tech "Subspace Heat Sink". It's a device that you can feed heat into and it disappears from the ship (into subspace, natch (subspace is the medium that thrusters thrust against[*])). Since thrusters and jump drives apparently generate oodles[**] of waste heat, SHSses are included in all ships with thrusters, which is all ships above TL8 (7?). So thanks to the ship's SHS, it's possible to maintain a pleasant shirtsleeves environment suitable for humans to survive in.
[*] Let's assume, for purpose of this argument, that there are no ways to use these SHSses for unintended purposes like power generation.
[**] 1 oodle = 10 buttloads.
[**] 1 oodle = 10 buttloads.
But objects that radiate at 22 degrees Celcius can be detected at what range by present-day sensors, let alone TL15 sensors? Far more than 900,000 km, I believe. (Please correct me if I'm wrong).
To ensure that a ship can't be detected by its IR radiation, it is necessary to reduce its emissions to somewhere aroun 4 degrees Kelvin. In other words, to maintain a heat difference between the outside and the inside of the hull of around 285 degrees.[***]
[***] Please don't digress into discussing how low IR emissions you might be able to get away with. Even if it's 10 or 20 or 40 Kelvins, my main point stands.
Doable? Given an SHS, yes.
Doable with a heat exchange system that takes up no space and costs no money? >>SPUNNGGGG!<< -- There went my belief suspenders.
It's easy to understand why a military ship would want the ability to lower its IR signature to undetectability[****]. It's a lot less understandable that a civilian ship would bother. Even if such a system cost nothing and took up no space (>>SPUNNGGGG!<<), it would still be an unneccesary complication and thus an unneccessary source of breakdowns. If it costs anything at all...
[****] Though if it takes up ANY space, the ship design system ought to provide the option to leave it out in favor of something else.
Hans
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I agree. I just like for Traveller, that real science (or plausible extensions) be used unless it is really necessary to handwave. IE: We need FLT travel & a power source than enables it. Stealth from IR isn't required to play the game as is.
That was my basic thrust anyway.
