Reconciling Space Combat Detection

[Chronus]

I am trying to reconcile how the range of detection should be handled in space encounters in regard to space combat.

I tend to view space combat from a "submarine warfare" viewpoint. That is, spacecraft are difficult to detect each other in the vastness of space. To support this viewpoint, I point to the following in the rule-book:

- "many battles are slow, calculated affairs, with spears of brilliant light lancing out into the darkness aimed at where the enemy is predicted to be" (pg. 146, 1st paragraph). This is, perhaps, the cornerstone basis for this viewpoint.

- "Each turn in space combat lasts six minutes" (pg. 146, 2nd paragraph). This makes sense if most of that time is spent searching for the opposing ship.

- Stealth coating (pg. 106, 2nd column). Apparently, attempts at stealth are made as early as spacecraft construction.

- Encounter Distance (pg. 139 - 140). The range of the encounter is determined by how well the sensor check is performed. And, although, the rules do not explicitly state it, they seem to imply that one ship could possibly detect another ship much sooner with a more successful sensor check. Note, too, on page 139, that the DMs are modified by the other vessel's attempt at stealth.

The opposing viewpoint can point to these:

- "Stealth is virtually impossible in space" (pg. 147, bottom of 1st column). This is the opposing viewpoint's bedrock reference.

- Initiative (pg. 147). If the initiative went to the spacecraft that detected the other spacecraft first, then this point would easily fit under the "sub warfare" viewpoint. But it doesn't work that way. Rather, initiative is determined by the throw of the dice. Furthermore, and unlike ground combat, there is no bonus to the initiative for being combat ready.

- Enemy Vessel Locations (pg. 146, bottom of 1st column). The rule initially states that the encounter will begin at Very Long range. Near planets, the range is shortened.

The way I see it, the "sub viewpoint" has more going for it. Furthermore, the rules on Enemy Vessel Location don't appear to tell how the distance is determined, just that a wide range is possible. Still, the way initiative is determined seems to work strongly against the importance of stealth modeled in the "sub warfare" viewpoint.

Any suggestions? Am I missing a tidbit of information somewhere or mistranslating the rules somehow? Your advice is appreciated!

 

[dreamingbadger]

I don't think the sub anaology is right in MTU. As you can engage enemy vessel, albiet with difficulty at ranges in excess of 50000km and in the same "Surprise" text vessel detection is defined as "easy" or +4 to get the "blip on the screen".

Even today with relatively small numbers of earth based sensors we have a pretty good idea of how to find "passive" objects in space, frankly simple radar will do just fine fo quite a long ways.

We do seem to be missing a table that describes the "range" dm for sensors e.g. what range am I unable to detect anything...

I would suggest:

50,000+ Distant -6 Formidiable
25-50,000 Very Long -4 Very Difficult
10-25,000 Long -2 Difficult
1250-10,000 Medium 0 Average
10-1250 Short +2 Routine
1-10 Close +4 Easy
>1 Adjacent +6 Simple

But for a ship with Basic Military Sensors detection t 50,000 km becomes -4 for range, +4 (Easy to get the blip on the screen) or an average skill check on Sensors.

Then on page 140 we have the encounter table implying that the maximum effective range for an encounter is 120,000km (which would take a ship under thrust 6 about an hour to travel...) I suspect even the sleepiest crew would be able to come to battle stations in an hour, depends on your definition of surprise ?

Tactical or strategic surprise... "Strategically" I might be surprised to find the enemy in a place, however once he, she or it is there, it seems to be very difficult to achieve "tactical" surprise without the aid of a pop-up turret.

As for the Stealth coating being in cluded early in ship design, I can't say that it implies that spacecraft detection is difficult, today stealth is "designed" into aircraft or a sub and whilst the paint or hull coating maybe one factor in it's design there are many others, but they are most effective if they are designed in.

 

[Paladin]

How viable is the ability to accelerate to a high thrust and then "coast" closer to an enemy in an attempt to avoid detection?

Would that boost your ability to avoid detection or is the detection of "passive space junk" too effective to bother?

At what range are you no longer able to "fake" the appearence of a larger ship via a false transponder? Or use decoy drones to impersonate a small "fleet" of smaller ships?

 

[dreamingbadger]

all possible you just need to convince the gm of the dm's and answer the question how long does it take to look like "not junk" and be a ship about to go into battle my guess is it's not just flip a switch. Visual and thermal would be the tough ones to get around, in that scenario.. which can resolve "hot" and "cold" spot's up to 25000km.

Maybe call it a stealth like dm on a non-stealth ship e.g. -4 but with a limit of no closer that 25k km ... and no active sensor's either so bear in mind if you will still need to fire them up and wepons and life support and... lets say to get back normal sensors and normal weapons back on line a difficult skill check for each one you want to bring back online (because they are "cold").

hopefully High Guard will answer some of these questions

 

[Rikki Tikki Traveller]

Trying to do something like thisi with a standard ship design is going to be tough, BUT, if you use a hollowed out planetoid, you might have a chance of fooling people for a while.

Hiding is space is actually very hard, even for a non-maneuvering ship. HEAT is a huge give away and the farther you are from the star, the easier it will be to detect you (since everything else will be so cold). Even the stealthiest ship will still have a heat signature...

 

[Mick]

You also going to have problems with anything over 10,000km with speed of light effects, you detect them there but they are no longer there.

Also when comes to heat energy weapons are going to put out a huge amount, if your laser cannon is 90% efficient (which is very good) there that 10% of out put in heat you have deal with (in my old Traveller game that was why space ships have wings they were heat sinks).

So a very stealthiest ship is going to use smart missiles (cold launched?) or mines?

 

[SSWarlock]

Even the stealthiest ship will still have a heat signature...

Pity a ship's excess energy can't be dumped into some kind of energy sink which is then bled off into jumpspace during a jump or fed into a spaceport's energy grid at the next landing. *muttermutter*

 

[GypsyComet]

The submarine analog works reasonably well for half-blind civvies, but falls apart once you start using the big stuff, or have access to fixed sensor platforms in the system.

For most ships being spotted isn't a matter of stealth so much as it is a matter of probability. "Is someone looking in the right direction?" No ship can look in every direction all the time, and smaller ships with "get you by" sensor packages have to constantly trade off between coverage and resolution.

There is also the question of processing what the sensors see. Raw signal processing of astronomic data takes a LOT of computing power. If your ship's computer is currently working on a Jump solution, scanning the heavens for anything beyond navigation fixes will be asking too much of a civilian comp. This can be where that skill level in Sensors comes in handy, as the operator may be able to beat the interpretation software to a conclusion, or nudge a second scan pattern towards a part of the sky that the first pass tells him is worth another look.

That said, once a ship is spotted, it will be hard-pressed to become "un-spotted". The heat signature of Traveller starships is significant, especially in systems with low-emission stars. It may even be possible to guess the TL, race, and/or shipyard that produced the target based on its IR signature, as this will be influenced by hull materials and engineering practices.

This isn't automatic doom, however, as IR does not provide a terribly tight "fix" when it comes to firing weapons at even one light-second of range. Getting a visible light or radar fix will usually be harder, and is the one area where passive stealth technology comes in handy, leaving the firer to dump a lot of fire down-range in the hopes that something will find the target.

There is also the movement of the firing ship to take into account. Not the big "3 gees of thrust" movement, but the little stuff. The vibrations of any vessel under power, the intricacies of tracking the weapon mount through tiny fractions of a second of arc, and similar. Some of this can be *mostly* dampered out, but you can't get rid of it completely. Getting everything to line up only to have a powered hatch open or a heat pump chose that second to shudder to a halt, altering the vibrations of the ship by a few hertz is all it takes, and its probably a lot less predictable than that. This also has the potential to affect a firing solution *twice*, since the pinpoint sensors are subject to the same external influences.

 

[Beastttt]

the duration of a beam laser can help as the longer the is on(figuring on a 1/100 of a second needed to cause damage you can cover alot of area with a 5 second long beam
same goes for a pulse laser as it may generate lots of 1/100 of a second pulses over a 5 second period


I figure other weapons such as meson,particle,fusion and plasma weapons are more akin to a shotgun effect
and lasers are more like machine guns where you can walk or fan in the direction needed