Invading Star Systems/Defending Them

[RainOfSteel]

Originally posted by RainOfSteel:
</font><blockquote>quote:</font><hr />Originally posted by Tobias:


<snip>

D-50 days
The missile jumps, the exit point calculated in such a way that it will hit exactly when making a 168-hour jump.

I hope the robot brain doesn't roll a failure.

Originally posted by Tobias:

D-10 minutes
The missile exits jump space, about 120 Million kilometers from the target. Relying on its internal timekeeping, the missile begins last corrective maneuvers.
<snip>

This missile/robot is flying at 70% C. In only 10-minutes, can even a 6-G engine provide sufficient correction (assumning a less than accepable roll by the robot brain)?


Personally, I find the plan of action described completely reasonable in a Science Fiction setting. The trouble is, if it's really so easy, why isn't everyone doing it? Why aren't such weapons used all over the place to the point where published sources describe them?


I'd imagine that appearing in the correct position at the destination star would be just a tad more difficult while flying at 70% C; the total penalty DM would be at least, say, -1 per 10% of C, so at 70% C, that would be a -7 on the roll (although this varies greatly by mechanics system). The timing has to be vastly more precise, and so I feel ordinary computer Jump programs would not cover it. Only custom writen software would do (with tighter timing controls), and that only allows the attempt, it does not offset the penalty.

This huge penalty would explain why such tactics aren't used commonly (jumping in at an already built-up velocity).

Personally, though, jumping in outside the Oort Cloud and accelerating in, that would be pretty bad by itself. First, detecting a jump into this region would be very difficult, even from astronomical quality sensor arrays, assuming anyone is even looking. Second, the comment that even if the ultra-speed projectile/asteriod/what-have-you is hit by lots of defenses and broken up, the broken parts are still inbound at a speed that will get them from orbit to ground in only a few thousandths of a second. Whether any of it would get through the atmosphere or explode due to ram pressure, I don't know . . . but I can easily _imagine_ some getting through (it's just not that far a stretch to believe it). The main problem would be, I would _think_, is that once up to speed, there isn't going to be much in the way of chance to change course, so it's going to have to be on-target. </font>[/QUOTE]

 

[Ran Targas]

On the subject of hypervelocity kinetic warheads ...

Most high-pop worlds have these things called atmospheres that consume thousands of hypervelocity kinetic warheads daily. Only the big comets or meteors make it through.

In order to do any real planetary-scale damage, your warhead would have to be pretty large (say 50m in diameter). First you have to get roughly 550,000 metric tons of solid nickel-iron moving; can't use icy or rocky asteroids, they burn up to quick. How fast did you want to get this going again and how many ships are you going to cannabalize to do it?

The larger the mass, the easier it is for me to see it coming and target with multiple laser batteries, which also increases engagement window.

A couple things to remember;

1. planetary batteries across an entire hemisphere could be fire-linked to continously engage this cosmic bullet
2. all I need to do is vaporize just enough of your rock that the resulting exhaust jet deflects it into a less threatening or grazing orbit

 

[Tobias]

Originally posted by Ran Targas:
Most high-pop worlds have these things called atmospheres that consume thousands of hypervelocity kinetic warheads daily. Only the big comets or meteors make it through.

This not at all comparable. Not even close. Not even in the same league. Not even the same damn game.
The fastest meteor so far had a velocity of 42km/s. The ship I postulated has an impact velocity five thousand times that much. Which increases kinetic energy by twenty-five million times.
Ergo, a thousand-ton object at this velocity has the impact energy of a very fast asteroid of 25 billion tons of mass.
It's very simple. Energy is a function of two variables. Velocity and mass. Velocity is by far the more significant.
To stop the ISKKM, you would need to pump a significant faction of its own energy into it, which is nigh-impossible, and definitely impossible if you have an engagement window of ~5 seconds as you would have with any planet-based weapons.

Remember, the ship would impart energy equivalent to at least 5,000,000 Megatons of TNT. This is more than a thousand times the entire nuclear arsenal of the world, today.

Regards,

Tobias

 

[The Oz]

Tobias is quite right. It would be almost impossible to stop a weapon coming in at a signifigant fraction of lightspeed (for one thing, the weapon would be coming in right behind any light/radar/laser that bounced from it, cutting your available reaction time way down).

The only thing that makes his scenario difficult is the maximum speed of Traveller ships is limited by their impact with spacedust particles, and that can be worked around in various ways if you really want to.

The reason we haven't seen such things in Traveller is that war just isn't practiced that way in the time of the Imperium. All the wars of the Imperium have been limited wars, fought for limited aims. You don't destroy the planets you want to conquer.

There's also the deterrent effect: it's too easy for =both= sides to do this in a war. If one side starts wiping out planets, the other has no reason not to return the favor. Look at how the threat of nuclear retaliation kept nukes from being used here for over 50 years during the Cold War.

Also, the Third Imperium and its rivals are all too big to be wiped out with one massive strike, so this kind of war would just invite similar retaliation without having much hope of seriously crippling your target.

When smaller empires go to war this might be a viable strategy. Build enough of Tobias' Jump Missiles to hit every enemy planet, position them so they can all strike every planet at once, and WHAMMO!!! No more enemy, just some isolated and unsupplied ships. What probably keeps this from happening is that these pocket empires don't live in a vacuum (a political vacuum, that is). A small empire doing this to a rival would probably have an Imperial (or Soloman, or Zhodani, or Aslan, or Hiver, or K'kree, or even Vargr) battlefleet drop by soon afterwards inquiring as to just why it was necessary to do that. A small empire using such weapons on one enemy might just use them on another, perhaps on an Imperial planet. And the Imperium would be very worried about that and would probably take steps to see that it didn't happen. This threat of Imperial intervention would keep most pocket empires from contemplating this kind of war.

Now, the Virus of TNE might have behaved differently. I'm not familiar with TNE so I can't say, but did TNE backgound mention any "planet-killer" strikes by Vampire fleets?

 

[Tobias]

I agree with the Oz's analysis overall. FWIW, the armor on my sample ship was indeed intended to protect against micro-particle impact.

When you think of it, there have been very few major wars involving the Imperium. The Frontier Wars, for all their media importance, are rather small in scale, and clearly are no all-out wars. Their purpose seems to let the Imperium know that it cannot expand further without the wars turning ugly.
The Solomani Rim war was a slightly different affair, but it was both sides' goal to conquer, not to destroy.
The Civil war was IMHO almost purely a naval affair, that didn't involve planetary surfaces much.
And that's about it, isn't it? All the other wars were assimilation and pacification campaigns against much smaller enemies.

Regards,

Tobias

 

[Tobias]

One possibility that just occurred to me, however, is the use of near-c accelerated starships as terrorist weapons. I hope it isn't too tasteless to draw this parallel to September 11th, but terrorists could easily turn captured civilian spacecraft into weapons this way.

Regards,

Tobias

 

[BrennanHawkwood]

Originally posted by The Oz:
When smaller empires go to war this might be a viable strategy. Build enough of Tobias' Jump Missiles to hit every enemy planet, position them so they can all strike every planet at once, and WHAMMO!!! No more enemy, just some isolated and unsupplied ships. What probably keeps this from happening is that these pocket empires don't live in a vacuum (a political vacuum, that is). A small empire doing this to a rival would probably have an Imperial (or Soloman, or Zhodani, or Aslan, or Hiver, or K'kree, or even Vargr) battlefleet drop by soon afterwards inquiring as to just why it was necessary to do that. A small empire using such weapons on one enemy might just use them on another, perhaps on an Imperial planet. And the Imperium would be very worried about that and would probably take steps to see that it didn't happen. This threat of Imperial intervention would keep most pocket empires from contemplating this kind of war.

Yeah...I would imagine that wiping out worlds (especially big industrial ones) tends to have a negative impact on interstellar trade. The 3I tends to have issues with worlds/factions which do that sort of thing near or within its borders.

Could make an scenario for a mercenary or Imperial military/scout campaign though...have a small world capable of building Tobias's ISKKMs have them go wacko religious or something and start popping these suckers off at the 'Unbelievers'. The GM would want to be careful not to let things escalate too far though or it could out of hand if the PCs can't handle the situation.

Now, the Virus of TNE might have behaved differently. I'm not familiar with TNE so I can't say, but did TNE backgound mention any "planet-killer" strikes by Vampire fleets?

I can't remember any specific references to Virus doing such a thing, but it has been a while since I've read any of the TNE background material. From what I do remember there were a couple of strains of Virus that would probably would have had no problems carrying out such a masively destructive attack. Perhaps it didn't tend to happen because the purely suicidal strains (IIRC) also tended to be fairly stupid and tended to lash out at whatever they could reach first...like their own fusion plant...

 

[Tobias]

I think what it boils down to is:
- Successfully invading and conquering a major world is possible, but consumes tremendous amounts of resources.
This is well supported by canon, by the way. Consider how the Invasion of Terra consumed enough resources to turn the war from certain Imperial victory to stalemate.
- Destroying an enemy world is comparably easy if you have no second thoughts about the population.
Canonical example: Lucan's Black War.
- All-out wars between major interstellar powers are essentially unwageable.

Regards,

Tobias

 

[Ran Targas]

Tobias, after further analysis of your missile and actually reading it, I eat my words and concede you the victory, Sir! My focus was on utilizing in-system stellar debris vice building a cruise missile; excellent idea BTW. But if these exist in sufficient quantities, someone has figured out a way to defeat them! In your opinion, what is it? At 0.7C, a well place sandcaster round might just do it.

 

[Tobias]

One possible solution, if you don't want ISKKMs IYTU (and I can understand perfectly why you wouldn't) is to handwave that the relativistic effects of high velocities screw up jump fields. That would still leave the basic idea possible by making the whole run in normal space, but the craft would be open to premature detection and destruction for quite a long time.

Regards,

Tobias

 

[Tobias]

Originally posted by RainOfSteel:
I hope the robot brain doesn't roll a failure.

I think this is unlikely. It's not all that difficult a maneuver.

This missile/robot is flying at 70% C. In only 10-minutes, can even a 6-G engine provide sufficient correction (assumning a less than accepable roll by the robot brain)?

Yes, unless I made a major mistake. I did the calculations for this twice, and I allowed for a generous margin of error.
The instructions to be followed by the robot brain would be very simple (turn to X and accelerate for Y minutes at Z Gs). I see no problem here.

Regards,

Tobias

 

[Tobias]

Originally posted by Zutroi:
Debris hit by a relativistic ship will do ENORMOUS damage, up to and including vaporizing the offending weapon. Of course, the ball of plasma that USED to be a ship is still going to hit your atmosphere at a shade under the agreed upon .7c.

That's the problem. The thermal energy alone will be enough to cause a catastrophe of untold proportions.
Also, how dense is the debris field going to be? To provide reliable protection it would probably have to be so dense as to block out the sun.
Placing a large object in the missile's way might work well enough if it is still far away from the planet, though.

Regards,

Tobias

 

[Ran Targas]

All in all, Tobias, your weapon will/would turn the course of OTU history. Imagine devastation across entire sectors as whole planets are rendered lifeless. Imagine driving your creation into a star, the resulting flare could wipe out whole inner systems!

Expect the secret Time Cops to be materializing in your bedroom tonight! They will be taking you for a short ride to visit some dinosaurs, where you and your missile will be safe(?).

 

[Tobias]

Well, it is a classic example of a typical "Star Trek problem". Traveller has done its best to avoid the worst of these by excluding "beaming" and "replicators", but they still pop up.

In a movie or TV series, people never seem to recognize clever, devious, innovative applications of given technology. In Star Trek, this borders on the ridiculous. Has anybody not asked himself: "Why don't they replicate some old-fashioned assault rifles to use against the Borg?" or "Why didn't they beam a nuke right into the Borg ship?" or something like that?

In an RPG, especially an SF RPG, you can't stop the protagonists from thinking of such applications. Thus RPG universes, and SF universes especially, have to be better thought out than TV universes. Traveller does a good job, generally speaking, and this is just one loophole.

As has already been said, the easiest solution would be to postulate that strong relativistic effects make jumping difficult, unstable or even impossible. This would not make much of a change to anything else in Traveller, so it can be implemented into Traveller universes without problem.

Regards,

Tobias

 

[Tobias]

Yes this would be the optimal way but very few empires have the time or will to do this to other empires.
Can you name a country that has alowed a part of itself to leave and join another country willingly. the population got a say in it.
Wars have been fought to stop this from happening (i can think of one civil war that you may remember.

This is a good point, but the situation would depend on the empires and worlds involved.

The Imperium and the Solomani Confederation, for example, are both fairly loose associations of member worlds with distinct governments and cultures. In this case, it is possible that a world might join one side or the other, provided its internal affairs are largely left alone. If sufficient economic pressure is applied, the world government might be convinced to join the "enemy" in this case.

OTOH, the situation is entirely different with monolithic cultures like the Zhodani or the K'Kree, which have a strong feeling of cultural loyality, and a fair deal of xenophobia on top of that. Subverting or assilimating a Zhodani world, for example, is probably impossible, or would take generations and a very large contingent of occupation troops.

Regards,

Tobias

 

[Jame]

Well, so far you've all discussed getting the ships in-system and what to do with them in orbit, but aside from Tobias I don't think anyone's mentioned having troops on the ground.
So I'll bite.

Okay, if you get the fleet in orbit and bombard your target for a couple of months, you've done a lot of damage, killed a few million people and still don't have control of the planet. So how do you get it? Send in! The TROOPS! (Sung to the tune of "Send in the Clowns.") Now, how many troops of what type do you need, and what do you do not only to get them to the ground, but with them on the ground?

 

[Tobias]

Originally posted by Jame:
Okay, if you get the fleet in orbit and bombard your target for a couple of months, you've done a lot of damage, killed a few million people and still don't have control of the planet. So how do you get it? Send in! The TROOPS! (Sung to the tune of "Send in the Clowns.") Now, how many troops of what type do you need, and what do you do not only to get them to the ground, but with them on the ground?

For invading a high population world, you would definitely need very many troops. A population 9 world of TL 13, for example, has about five million combat troops available. As an invader, you would probably need numerical and/or technological superiority.
So you have the task of transporting a total of, say, 10 million troops to the target world, get them there safely, and supply them for a month, possibly longer.
High technology armies being very "vehicle heavy", I assume the following tonnages for transport. All are in displacement tons (~14m^3):
- Accomodations, per man: 3 tons (half a stateroom, plus training facilities etc.)
- Equipment, per man: 10 tons (this is about half the transport displacement of a High TL grav vehicle. While the actual ration will be more like 4 soldiers per vehicle, you also have to take into account spare parts, drone vehicles, hand weapons, miscellaneous equipment etc.)
- Supplies: 1 ton per two weeks. This is somewhat more than current combat units need, but its reasonable IMHO at higher TLs.

So, per man, your invasion force will need 15 tons, carrying supplies for one month of heavy fighting. For a force of 10 million, this amounts to 150 million tons. You would need approximately 300 large transports of 100,000 tons each for this. These would cost about as much as 50 battleships of ~200 ktons.

Add to this: Gunboats and fighters and their carriers. You would probably want several thousand SDB-like gunboats, and several tens of thousands of fighters.
You want a total of ~50 fleet carriers of about 200 ktons, each carries either a hundred gunboats or a thousand fighters. Cost, with craft, is about equivalent to that of a battleship for each.

Such a large collection of giant eggshells would naturally have to be escorted by several cruiser squadrons and myriads of destroyers.
Then, you naturally also need a battlefleet of several squadrons, to destroy enemy fleet elements and to deter them from attacking your transport craft.

This is what you need to get your invasion fleet to the planet. More on what you do when you're finally there will come later.

Regards,

Tobias

 

[BMonnery]

Originally posted by Tobias:

High technology armies being very "vehicle heavy", I assume the following tonnages for transport. All are in displacement tons (~14m^3):
- Accomodations, per man: 3 tons (half a stateroom, plus training facilities etc.)
- Equipment, per man: 10 tons (this is about half the transport displacement of a High TL grav vehicle. While the actual ration will be more like 4 soldiers per vehicle, you also have to take into account spare parts, drone vehicles, hand weapons, miscellaneous equipment etc.)
- Supplies: 1 ton per two weeks. This is somewhat more than current combat units need, but its reasonable IMHO at higher TLs.

So, per man, your invasion force will need 15 tons, carrying supplies for one month of heavy fighting. For a force of 10 million, this amounts to 150 million tons. You would need approximately 300 large transports of 100,000 tons each for this. These would cost about as much as 50 battleships of ~200 ktons.

Currently ~75% of C-Sups are artillery rounds and a lot of the remainder is fuel. With battlefield meson sleds and fusion reactors this can be cut down a lot.

Bryn

 

[mad13142000]

Not so fast...If I control the orbitals, I control the world. Go ahead and muster up a division of homeguard. I see it from space, and one kinetic strike later, no more homeguard division. I imagine that I'll only have to make a few demontsrations before the planet submits.
Could there be guerillas in the hills? Yes, but they'll be in really small bands, and I'm sure that I could convince the population as a whole to not take potshots at my occupation force...
Any defender HAS to come out in the far system to meet my fleet...If he doesn't, I simply kill him with repeated missle and fractional C weapons passes where he sits. He's dead meat. Only by closing range can he keep the options open, and the odds even...If he really wants to give up initiative, I could always put orion drives onto some large asteroids and REALLY clean house...

-MADDog

 

[Jame]

Well, Maddog, you still need to get to the government buildings, and that requires you put troops on the ground. And you don't know that they'll automatically submit, and since you shouldn't bombard populated areas that you might want, you'll still likely want to put troops on the ground...