Large Scale Fleet Combat

[phavoc]

The concept of MAD works with nukes as it does wth planet killers. Just as your planets are going to be vulnerable to kinetic energy bombardments, so is your opponents. And you don't even have to pop in close. build up your speed, jump a few billion kilometers out from your target, release your whatevers travelling at near C, and let their trajectory do the work for you.

No, I think planet busting is a cardinal sin for any star empire with planets to lose in a similar fashion.

 

[DFW]

Friends don't let friends drink and command the fleet.

Wish you had been around saying that before Pearl.

 

[DFW]

No, I think planet busting is a cardinal sin for any star empire with planets to lose in a similar fashion.

What's all this planet bustin' about? Fleets aren't depoted(sp?) in orbit around heavily populated civvie worlds.

 

[Treebore]

No, I think planet busting is a cardinal sin for any star empire with planets to lose in a similar fashion.

What's all this planet bustin' about? Fleets aren't depoted(sp?) in orbit around heavily populated civvie worlds.

True, space fleets are at space stations outside of atmospheres. Now they may turn vacuum worlds into space stations. I can see that working.

 

[steelbrok]

One partial solution is to decide that:

Objects with near c/relatavistic velocities are far more likeley to misjump or have problems entering jump space at all. Handwave around increased mass as c is approached and or the high velocity destabilising the jump singularity.

This means rocks have to build up their near c velocity at the target system, thus allowing sensor networks and conventional defences a chance (if its going that fast then pretty much anything shoved in its way is going to collide with enough energy to destroy/divert or smash up your rock)

 

[Rikki Tikki Traveller]

I have used the idea that when you emerge from Jump your velocity is ZERO relative to the nearest large mass (planet or star). Basically, if you emerge at the Jump Boundary of 100D, you are at rest relative to whatever created that boundary. It doesn't stop the Near-C Rock problem, but it does make it a lot harder to use. Now you have to do everything within the target system (like Steelbrok said).

 

[Egil Skallagrimsson]

Certainly in terms of MgT, it seems an open question whether a ship retains it's velocity when in jump.

You can handwave either way.

Egil

 

[phavoc]

I don't recall which book I read it in (perhaps the core?) but I think that a ship leaving jump space retains the heading and velocity it had when it jumped.

 

[Egil Skallagrimsson]

Can't find that the likely sections in my copy of MgT core. That is not to say that it isn't tucked away somewhere, or in another MgT book! (And another thread established that I have an early print of the core book)

Always assumed that a ship would leave jump with the same heading and velocity, but this is no more likely than a ship losing all normal space velocity in jump and exiting on a random bearing, or that a ship has to reduce its velocity to 0g to safely jump.

Doesn't really matter unless your campaign revolves around jumping huge kinetic planet killers into enemy systems! Under other circumstances the ship can quickly manourve and alter speed.

Egil

 

[steelbrok]

One partial solution is to decide that:

Objects with near c/relatavistic velocities are far more likeley to misjump or have problems entering jump space at all. Handwave around increased mass as c is approached and or the high velocity destabilising the jump singularity.

This means rocks have to build up their near c velocity at the target system, thus allowing sensor networks and conventional defences a chance (if its going that fast then pretty much anything shoved in its way is going to collide with enough energy to destroy/divert or smash up your rock)

I had another thought about this.

In MGT jump works by creating an artificial singularity and inflating the mini universe thus formed with hydrogen

This universe must be tiny compared to the real space distance of a jump
So unless you reduce your velocity as much as possible it would be like trying to drive through your garage at 70 mph.
At the very least a hefty misjump penalty should be applied for entering jump at high speed

 

[Rikki Tikki Traveller]

TNE used the idea of Conservation of Momentum through Jump. CT never specifically mentioned it either way, but from what I have read, it was assumed by the authors.

 

[phavoc]

Perusing through the JTAS CD-ROM last night I came across an article on jump travel. In it it stated that a ship retains its heading and velocity that it had when it entered jump space. Civilian ships typically reduce their momentum to about zero and align themselves in the direction they want to be travelling before jumping. Military ships and couriers typically will be at their maximum velocity before jumping.

 

[DFW]

TNE used the idea of Conservation of Momentum through Jump. CT never specifically mentioned it either way, but from what I have read, it was assumed by the authors.

So did MT & GT...

 

[steelbrok]

How do you decide what the heading is relative to in the new system though?

Given that emergence is somewhat random you could as easily be moving away from your destination at high speed as towards it

 

[DFW]

How do you decide what the heading is relative to in the new system though?

Given that emergence is somewhat random you could as easily be moving away from your destination at high speed as towards it

Simple, you determine your intended vector at the new system. Let's say the target is Earth and you want to have this heading:

(*) (e) <------------ <>
sun earth ship

If you're jump is accurate (see MGT rules) you get it. If you miss, the GM determines where you emerge in the inner system. Wherever that is you have that vector. If you came out on the opposite side of Earth's orbit, you would be moving away from the sun (and the Earth).

 

[kristof65]

Assuming that you can fairly accurately calculate your ships relative headings and velocities upon exiting the target system, you still have a lot of variables to contend with. Variables that can make where a surprise attack will come from predictable.

If heading upon entering j-space determines the heading upon exiting j-space, then thanks to orbital positions and the 100d limits of both the departing and recieving systems stars and planets, surprise attacks of the type mentioned will tend to have both corridors and time frames of success. Places to watch more thoroughly, and areas to place picket and patrol vessels to get rear or flank attacks on arriving vessels.

Likewise, all the systems within 6 parsecs can be watched with small patrol vessels looking specifically for signs of fleets manuevering on suspicious vectors and velocities - once these are spotted and identified as potential sources of trouble, the patrol ship can jump to warn the depot of possible trouble. As long as they jump before the fleet does, they'll likely arrive in system with enough time to get the defenses moving. And even if their information turns out to be inaccurate, it acts as a readiness drill.

So a true surprise attack would work best by either jumping a fleet to empty space a parsec or three away from the target system, and manuever in from there, or attempting the near impossible task of coordinating multiple fleets converging in from multiple systems.

The one thing that all of the prior posts and points here tell me is that the most valuable aspect of interstellar warfare, like all other warfare before it, is intelligence. Even with the delays of interstellar communication, the side that can predict their enemy's movements better is going to have the upper hand.

 

[DFW]

Assuming that you can fairly accurately calculate your ships relative headings and velocities upon exiting the target system, you still have a lot of variables to contend with. Variables that can make where a surprise attack will come from predictable.

Not a problem. There are a very small amount of variables.

If heading upon entering j-space determines the heading upon exiting j-space, then thanks to orbital positions and the 100d limits of both the departing and recieving systems stars and planets, surprise attacks of the type mentioned will tend to have both corridors and time frames of success. Places to watch more thoroughly, and areas to place picket and patrol vessels to get rear or flank attacks on arriving vessels.

Departing position is infinite. (cut down if the planets orbit is within the stars j-shadow). Approach to a planet can be from any direction (spherical) and thus is an IMMENSE amount of space. You'd have to have thousands of picket ships to guard against high velocity approaches to even a large planet like Earth. Do the math on what the velocity of a ship after only 6 hours of 6G accel (~1300km/sec) and how fast it traverses the 100D limit of a size 8 world. (~16 minutes)

Likewise, all the systems within 6 parsecs can be watched with small patrol vessels ...

Only if you control those systems.

or attempting the near impossible task of coordinating multiple fleets converging in from multiple systems.

Only if a commander is stupid enough to have them leave from different hexes as opposed to the same hex.

 

[kristof65]

Not a problem. There are a very small amount of variables.

My point was that the defending fleet can make every calculation that any attacking fleet can make, and maximize it's own forces to watch the most likely paths.

And utilize the three most important things about real estate - Location, Location, Location.

That will apply to selecting depot locations as well - not only in what star systems are selected, but where within those star systems those bases are located. For example, putting an orbital base just outside the stars 100d limit effectively "blocks" half the space you have to watch. Systems that happen to have gas giants sitting just outside the star's 100d limits would be particularly attractive, as you can place your base within or between the shadow of both, and have much narrow corridors to watch.

It is, in fact, the existance of the jump shadows that provides "terrain" - not the planets, moons and stars themselves, because the jump shadow multiplies their effective volumes.

Departing position is infinite. (cut down if the planets orbit is within the stars j-shadow). Approach to a planet can be from any direction (spherical) and thus is an IMMENSE amount of space. You'd have to have thousands of picket ships to guard against high velocity approaches to even a large planet like Earth. Do the math on what the velocity of a ship after only 6 hours of 6G accel (~1300km/sec) and how fast it traverses the 100D limit of a size 8 world. (~16 minutes)

Sure, if you're talking strictly trying to use picket ships as a defense within the defended system, and you're not taking into account that a base will likely use both planetary and stellar jump shadows to create corridors.

Furthermore "spy" vessel in a system 4 parsecs away, upon seeing a fleet accelerating at 6G for 4 hours along a certain vector can jump to the depot system and warn them an attack may be on it's way, and transmit fleet composition, last known speed and vector. Based on that info, the most likely incoming vecotrs can be calculated, and ships and defenses can begin manuevering into position. The advance warning may be only minutes, or it could be hours. Sure, it may turn out to be nothing, but the occassional false alarm is not only better than the alternative, it works as training, too.

Likewise, all the systems within 6 parsecs can be watched with small patrol vessels ...

Only if you control those systems.

So you're saying that a couple of 100 to 400 ton ships sitting well above the orbital plane using passive sensors will always be detected and run out of the system? You said it yourself - space is big. A couple of small, non-manuevering patrol vessels are much, much less likely to be detected than a manuevering fleet.

 

[DFW]

Furthermore "spy" vessel in a system 4 parsecs away, upon seeing a fleet accelerating at 6G

There won't be any spy vessels to warn anyone as they'd be blown away. Also, you are unclear on a planets jump shadow. It creates no "corridors" only a spherical volume. (I listed Earth which is a large planet and how fast you can traverse its shadow at relatively low velocities.)

Bottom line, the defenders won't know when. They will just know that they are subject to, at anytime. Like I posted earlier, a few planetoids accelerated to intra-system travel speeds (which are higher than I listed) and bye, bye parked ships. Unless you have something specific that you have not yet posted, you have no credible defense.

 

[steelbrok]

How do you decide what the heading is relative to in the new system though?

Given that emergence is somewhat random you could as easily be moving away from your destination at high speed as towards it

Simple, you determine your intended vector at the new system. Let's say the target is Earth and you want to have this heading:

(*) (e) <------------ <>
sun earth ship

If you're jump is accurate (see MGT rules) you get it. If you miss, the GM determines where you emerge in the inner system. Wherever that is you have that vector. If you came out on the opposite side of Earth's orbit, you would be moving away from the sun (and the Earth).

Well, yes, the GM can determine as he/she wishes but if we're looking seriously at maintained vectors then you have:
One vector from the two stars relative movment one to the other
One based on the different movements of the two planets
and the last one as a result of the ship's acceleration