Invading Star Systems/Defending Them

[Ran Targas]

Tobias - I'll agree with some of the above

So let's develop standard Imperial doctrine for planetary assault; here's my take:

D-30days
- Plan, plan, plan ...
- Recon, recon, recon

D-25days
- Force tactical recon element enters target system

D-20days
- Task Force forms
- TF and escorts conduct mock assaults away from prying eyes; plan is approved

D-15days
- Force tactical recon makes report to TF

D-14days
- TF and any additional escorts begin transit to target system

D-7days
- Force tactical recon makes report to TF
- Final assault plan promulgated
- Force tactical recon begins covert operations against planetary defense and communications systems

D-day
- Escort groups enter system to secure J-point at target and local gas giant (if applicable)
- Assault group enters system and deploys in max defensive formation, engaging any hostiles
- Electronic warfare assets deploy to jam all planetary communications
- As system defense forces are eliminated or rendered inoperative, transit to target planet
- Escorts re-deploy to blockade positions
- Orbital defenses eliminated
- Orbital habitats occupied or destroyed
- Supplimental covert operations teams deployed to eliminate special threats
- Assault Group takes position outside planetary battery range and demands made

Then comes the stand off ... unless you can land your walkers and destroy the main power generator!

 

[Tobias]

Originally posted by Ran Targas:
So let's develop standard Imperial doctrine for planetary assault; here's my take:

You might want to go to www.freelancetraveller.com and look up the White Paper by Rick Stump. It's found under "Doing it my way".
The MegaTraveller Supplement COACC also deals with the procedures of invading a world.

I largely agree with your time table. However, I would not formalize the recon and planning phase. Depending on the situation, it might take months or hours.

I am also somewhat unclear about what you mean by escort and assault forces. I would classify the assets in the invading force this way:
- Assault Group: Landing Ships and support craft for making the actual planetfall.
- Assault Support Group: Combat Ships for bombardment, as well as Gunboats and Fighters, with their carriers, to close in on the planet and elimate defenses.
- Battle Group: Battleships and Cruisers to eliminate enemy spacecraft presence in the system. Secondary task is wide blockade of the target world.
The groups would operate in close cooperation and have additional escorts, tankers and other auxiliary craft assigned to them.

Regards,

Tobias

 

[RainOfSteel]

Originally posted by Tobias:
@ RainofSteel

Btw, sorry if my last response to you seemed a little snappy, but I was just in a hurry when I posted it.

Regards,

Tobias

No worries, you didn't attack me, as far as I could see. Ideas are open to as much ripping as necessary.

I've done some writing and submitted it to criticism before others (where you are not allowed to even say as much as a word in your own defense). That thickens the skin.

 

[RainOfSteel]

Originally posted by Ran Targas:


<snip>

Well, the heart of this discussion is how do you conquer a TL15 high-pop planet with elaborate planetary defenses without destroying the ecosphere; IMHO you can't. With TL15 defenses, limited planetary bombardment with kinetic or fission/fusion warheads would ineffective. So you're left with complete sterilization or siege. If you want the planet, you would have to encourage the planet's leadership to concede.

<snip>

My thoughts about entrenched defenses at high TL numbers were leading me to the same conclusion (it would be difficult/near-impossible to capture a High-Pop High-Tech world with massive defenses) It just seemed that certain possibilities of interstellar/interplanetary warfare didn't seem realized by anything discussed in canon.

Now, let me repeat something I vaguley referred to originally. I really only envision a handful of worlds in the entire Imperium receiving this sort of treatment. I don't think even all Depot systems would receive this sort of build up, not fully, anyway. Because many are viewed as "far in the rear", the budgetary will, would, I think, not be present to pay for full maintenence of defenses. In some, antiquated systems at TL-14, plus a maximum array of much smaller size, would be present due to the passage of centuries. I can see some Depots where empty racks of abandoned weapons emplacements dot the world (and possibly some really interesting mine systems scattered here and there, ala the mines discussion going on over on the TML).

However, there is one obvious spot, Depot/Corridor, that shines out. As a single star systems, it can be viewed as the lynchpin on which the path the spinward sectors hang.

Given the threat posed by the Vargr, and the obvious possibility that fleet elements there might have to be moved elsewhere to deflect threats, it then becomes apparent that the Depot, at least, needs some heavy fixed defenses to deter any force silly enough to come in its direction.

Of course, this is me believing that rational thinking is going on at the highest levels of the Imperium. I could be fooling myself. But given the pork-barrel possibilities of deploying such huge numbers of weapons systems, I can see impressive lobbying efforts in the old-boys network fuedal halls of court at Capital in favor of it, such lobbying would be backed with considerable money. If it ever succeeded (and, I think, IMTU, it would), other interests from other ends of the Imperium would wake up and see that they would want/need something similar in their areas, which would lead to a few other worlds with similar build-ups. The Navy wouldn't, I think, want to spend _that_ much on it, because they think mobile, but a few worlds, maybe 2-10, throughout the Imperium, would receive such treatment.

The wealthiest high-pop worlds (if they're near a threat, of course) would also look seriously at heavy defenses. The world and its population cannot conveniently move around like the Imperial Fleets. These governments would try to deploy some kind of defenses, and probably a lot of them, because their ongoing power depends on it.

 

[RainOfSteel]

Originally posted by Tobias:


<snip>

</font><blockquote>quote:</font><hr />Originally posted by Ran Targas:
With TL15 defenses, limited planetary bombardment with kinetic or fission/fusion warheads would ineffective.

I might disagree, depending on what you mean by "limited". There is no conceivable practical means to defend against well-planned kinetic bombardment.


<snip>

Regards,

Tobias </font>[/QUOTE]Jump space defenses? Okay, this is clearly beyond any TL system described in any source. But I can see where it might be possible to deploy Jump Fields in the path of incoming objects, which would "dump" such objects directly into Jumpspace in an uncontrolled manner, where they would be lost/destroyed without their own jump field.

Something a little more reasonable would be Gravitics based defenses, although they, too, would probably need to be higher than TL-15. Repulsor Tech and point defenses could deal with ordinary missiles, but against objects moving at very high velocities, I don't think any non-quantum computer system could produce an intercept.

However, there are no weapons systems in the TU that can launch objects at these high velocities. (Which is not to say that such things aren't reasonable, just not in the game as described.) There are also no quantum computers, even though there probably should be. If we introduce the quite-reasonable very high velocity kinetic weapons into the game, we can also easily introduce sophisticated quantum computers, which, I believe, would be able to produce intercept solutions. Very high power repulsor systems controlled by quantum computers might well do the job. Of course, it might take an array of repulsors to put up a significant enough barrier to stop such enormous kinetic energy. Say, 100 100-dTon Repulsor Bays?

Well, I'm not sure I'd deploy either ultra-velocity weapons, quantum computing to mTU. Some of this discussion makes me wonder if I should even bother trying to include heavily defended worlds in mTU, either. I'll have to think about it more.

 

[RainOfSteel]

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


<snip>

</font><blockquote>quote:</font><hr />Originally posted by Ran Targas:
With TL15 defenses, limited planetary bombardment with kinetic or fission/fusion warheads would ineffective.

I might disagree, depending on what you mean by "limited". There is no conceivable practical means to defend against well-planned kinetic bombardment.


<snip>

Regards,

Tobias </font>[/QUOTE]Jump space defenses? Okay, this is clearly beyond any TL system described in any source. But I can see where it might be possible to deploy Jump Fields in the path of incoming objects, which would "dump" such objects directly into Jumpspace in an uncontrolled manner, where they would be lost/destroyed without their own jump field.

Something a little more reasonable would be Gravitics based defenses, although they, too, would probably need to be higher than TL-15. Repulsor Tech and point defenses could deal with ordinary missiles, but against objects moving at very high velocities, I don't think any non-quantum computer system could produce an intercept.

However, there are no weapons systems in the TU that can launch objects at these high velocities. (Which is not to say that such things aren't reasonable, just not in the game as described.) There are also no quantum computers, even though there probably should be. If we introduce the quite-reasonable very high velocity kinetic weapons into the game, we can also easily introduce sophisticated quantum computers, which, I believe, would be able to produce intercept solutions. Very high power repulsor systems controlled by quantum computers might well do the job. Of course, it might take an array of repulsors to put up a significant enough barrier to stop such enormous kinetic energy. Say, 100 100-dTon Repulsor Bays?

Well, I'm not sure I'd deploy either ultra-velocity weapons, quantum computing to mTU. Some of this discussion makes me wonder if I should even bother trying to include heavily defended worlds in mTU, either. I'll have to think about it more. </font>[/QUOTE]Oh, and it just occured to me, that a planet can use ultra-velocity kinetic weapons as well. While probably useless against normal starships, the invading force using them will have to mount them on something. Probably something big and, in my limited imagination, not too agile (if it's using it's agility, anything it fires isn't going to hit the target, something fired at this speed is going to have to be aimed very precisely, I would think by aligning the entire platform).

The trouble is, since ultra-velocity weapons (defined as capable of accelerating a mass to significant fractions of C and actually expecting them to arrive at a target) aren't defined in any design sequence, it's difficult to know exactly how they would be deployed and used, but anything you can stick on a ship can be stuck on a planet or in orbit of it. Even if an invading fleet attacking with such weapons _could not_ be attacked with similar weapons from a planet, the planet can mass far, far, far more conventional missile launchers, firing way to many missiles for any fleet's point defenses or ECM to have a hope of warding off.

Cost of 1 Tigress Battleship (in qty) = 362+ billion credits.
Mounts 430 50-ton Missile Bays

362BCr/12MCr cost of 50-ton Missile Bay = 30,166 Missile Bays (roughly, of course, does not account for base costs, C3, personnel, etc.).

 

[RainOfSteel]

Also, looking at the huge number of missile bays I'd have available for just the price of one top of the line battleship, and tossing 2/3 of them to account for costs of support, leaves me with 10,000 missile bays.

Even if a whole fleet shows up with a lot of ECM jamming to defeat planet based meson fire, I can envision loading up some of my missile bays with ECCM missiles that fly out with regular missile volleys and work to defeat the jamming (by projecting counter-jamming and by providing extra sensor systems capable of providing better targeting information at closer range via synthetic apertures generated across the ECCM missile volley via data linking). The missiles themselves wouldn't be enough to destroy capital ships with enough armor, but smaller vessels, especially ECM drones and fighters . . . I think they'd be dead.

The planet, too, may send out it's own ECM/ECCM drones to supplement ground-based systems.


I'd also like to further my original post. If I look through HG, it's readily apparent that meson guns rule the battlefield. Once you get your armor up high enough, other weapons systems can pretty much strip a target of it's turrets, etc., but they can't inflict the real damage necessary to blow up such a heavily armored ship. I extend this to apply to ground bases as well.

I also read articles about HG combat in the JTAS reprints.

None of these seem to mention ECM/ECCM in any way, and there is no discussion of it in HG. I haven't checked out my TNE copy of 1st Ed FF&S, and I never had the MT design sequence; and I've never read either of their combat systems and don't know the effect of ECM/ECCM and jamming in general in those systems. My ideas didn't really cover anything available from MT or TNE (or even GT or T4 or T20), only CT (where there is also no discussion of ultra-velocity weapons). Maybe being stuck 20 years in the past in the CT universe is a bit odd, but from what I read on various web-sites, I'm not too isolated.

 

[Tobias]

Originally posted by RainOfSteel:
Jump space defenses? Okay, this is clearly beyond any TL system described in any source.

Actually, these are described in MT. They are TL 20 or 21 IIRC. So they are quite out of reach for any forces in OTU.

Something a little more reasonable would be Gravitics based defenses, although they, too, would probably need to be higher than TL-15. Repulsor Tech and point defenses could deal with ordinary missiles, but against objects moving at very high velocities, I don't think any non-quantum computer system could produce an intercept.

The problem is not computing the intercept, it's that a conventional weapon might destroy the KE weapon, but it will not keep the remaining pieces from hitting the planet.

However, there are no weapons systems in the TU that can launch objects at these high velocities.

Actually, there are. You just need a Spacecraft with 6Gs acceleration and a Robot. It will take a while (several weeks) to accelerate to the desired velocities (say 80% C), though.

Very high power repulsor systems controlled by quantum computers might well do the job.

To be able to stop even a small ship zooming in at 80% lightspeed is a task equivalent to lifting a small moon out of its orbit. Gravitics aren't up to it.
Note that you need nothing non-canonical for such a kinetic kill weapon. A 6G-spaceship with two months' worth of fuel and a robot as crew is absolutely sufficient.

The only problem is with the "limited" part. A ship of 1000 tons mass at ~250,000 km/s will impart the equivalent of 7,800,000 Megatons of TNT. This will probably effect the entire planet.

Regards,

Tobias

 

[Tobias]

Originally posted by RainOfSteel:
I'd also like to further my original post. If I look through HG, it's readily apparent that meson guns rule the battlefield. Once you get your armor up high enough, other weapons systems can pretty much strip a target of it's turrets, etc., but they can't inflict the real damage necessary to blow up such a heavily armored ship. I extend this to apply to ground bases as well.

Yes, they do, but there are disadvantages, too. They are not useful anti-fighter weapons, and all non-spinal meson guns can be easily defeated by screens.

None of these seem to mention ECM/ECCM in any way, and there is no discussion of it in HG.

ECM/ECCM is probably what the computer to-hit modifiers are all about.
ECM isn't really detailed in any CT publication, but I felt the use of ECM drones would be SOP for an invading force. I didn't envision it to totally shut down the defenders.

One remark though: In anything the planetary forces do against the invading fleet, remember that the fleet is mobile, while the planet is not. There's the rub.

Regards,

Tobias

 

[BrennanHawkwood]

Originally posted by Tobias:

</font><blockquote>quote:</font><hr />
Something a little more reasonable would be Gravitics based defenses, although they, too, would probably need to be higher than TL-15. Repulsor Tech and point defenses could deal with ordinary missiles, but against objects moving at very high velocities, I don't think any non-quantum computer system could produce an intercept.

The problem is not computing the intercept, it's that a conventional weapon might destroy the KE weapon, but it will not keep the remaining pieces from hitting the planet.
</font>[/QUOTE]Especially if the defenders are unable to engage the object until it is relatively near its target. If the attackers are using your idea (as mentioned below) of strapping a ship to a large rock and letting it go, the ideal time to attack it would be in the outer system while it was still operating at reasonable speeds...though if the invading force has pretty much thrashed the defender's ships this probably isn't an option.

</font><blockquote>quote:</font><hr />
Very high power repulsor systems controlled by quantum computers might well do the job.

To be able to stop even a small ship zooming in at 80% lightspeed is a task equivalent to lifting a small moon out of its orbit. Gravitics aren't up to it.
Note that you need nothing non-canonical for such a kinetic kill weapon. A 6G-spaceship with two months' worth of fuel and a robot as crew is absolutely sufficient.

The only problem is with the "limited" part. A ship of 1000 tons mass at ~250,000 km/s will impart the equivalent of 7,800,000 Megatons of TNT. This will probably effect the entire planet.
</font>[/QUOTE]Something like this most definately would not be 'limited'. A neat example of this sort of attack on a world can be found in David Weber and Steve White's novel The Shiva Option.

Going after one of the Arachnid hivewords the Alliance fleet jumps into the system and heads out into the the outer system rather than going after the mainworld. Once there, "they set up camp" in a large asteroid field and selected a handful of asteroids to turn into kinetic weapons. They built drives, robotic control systems and defenses onto them and then sent them in-system aimed at the mainworld. The Alliance fleet followed them in to help protect them from being blown apart too soon for them to achieve the impact that was desired.

Once they got to the planet IIRC only 1 large asteroid and 1 or 2 of the smaller ones were left, but all it really took was the large one. The damage it did pretty much wiped out the planet.

Certainly not a weapon of precision or 'limited' effect!...

Another disadvantage of this scenario was that it took the Alliance fleet something like two or three years from arrival to hitting the planet to carry this campaign out.

 

[Ran Targas]

^But Tobias, the real rub is the planet is not just an isolated island fortress like Iwo Jima, it's a self sufficient, planet-sized battle station with comparitively unlimited power, resources to replace lost forces, armor in the form of planetary crust, etc.

Sure a BB has 30k missiles to fire, but what would a planet have? And a BB can't build more!

Remember D-Day? The Germans would have easily repelled the largest invasion force ever if they had to only protect Normandy. A well defended and prepared planet should be able to repel almost any assault unless to total sterilization is an option for the attacker. And even then, mounting thrusters on asteroids or nuking the planet from orbit wouldn't cut it. Anti-missile systems and surface-to-space beam weapons (firing near continuously) would cut an asteroid into enough parts to produce only light damage or deflect it into a less threatening orbit.

Again, think about the defender having everything the attacker has (and in much greater numbers) except he doesn't have to lug it around a solar system to use it.

All you really can do is hope the local population really hates its government and is willing to move against them. If the people love their leader, for every nuke you fire, they'll build 100 to fire back at you.

Another thought! What if you ignore the planetary defenses and just pump mesons and nukes into the planet's atmosphere or geologically unstable regions or shallow seas? How much energy would be necessary to cause ecological catastrophe?

 

[BrennanHawkwood]

Originally posted by Ran Targas:
^But Tobias, the real rub is the planet is not just an isolated island fortress like Iwo Jima, it's a self sufficient, planet-sized battle station with comparitively unlimited power, resources to replace lost forces, armor in the form of planetary crust, etc.

Sure a BB has 30k missiles to fire, but what would a planet have? And a BB can't build more!

Remember D-Day? The Germans would have easily repelled the largest invasion force ever if they had to only protect Normandy. A well defended and prepared planet should be able to repel almost any assault unless to total sterilization is an option for the attacker. And even then, mounting thrusters on asteroids or nuking the planet from orbit wouldn't cut it. Anti-missile systems and surface-to-space beam weapons (firing near continuously) would cut an asteroid into enough parts to produce only light damage or deflect it into a less threatening orbit.

Again, think about the defender having everything the attacker has (and in much greater numbers) except he doesn't have to lug it around a solar system to use it.

All you really can do is hope the local population really hates its government and is willing to move against them. If the people love their leader, for every nuke you fire, they'll build 100 to fire back at you.

Dependant on the local resources, yes. If it is a HiPop industrial world that has had that status for several hundred years (or longer) it will be a major pill for an invading force to handle, but its local resources available for long term rebuilding may be limited, possibly severly if it is a world that relyies on technology simply to survive its environment. (It likely has the machinery and knowledge to build a seemingly infinite stream of weapons, but does it have a large enough supply of plutonium or steel or water or any other raw materials that they would normally import to maintain that sort of production?)

This effect is also a good reason for laying seige and waiting for time, attrition and diplomacy to resolve the situation. If it does come to an assault it would be important to pick your target carefully because you are going to have to deny the world access to its key command/communication and industrial assets as quickly as possible because you are right about the how worthless it would likely be to just grab some random patches of ground.

Another thought! What if you ignore the planetary defenses and just pump mesons and nukes into the planet's atmosphere or geologically unstable regions or shallow seas? How much energy would be necessary to cause ecological catastrophe?

Ah...but that hardly falls under the label of 'limited' does it? Of course, there are likely to be grades of limited...popping a couple of less important domes on a vacuum world or dropping some 'clean' nukes on a couple of smaller cities/installations to prove that you are willing to use such tactics might convince the locals to give up.

I would imagine the problem with doing this with ecological catastrophe's like you comment on is the long term effects can be rather unpredictable and if the long term intent is to make use of the world's resources yourself it may not be of a sufficiently limited impact to be acceptable. All of which is somewhat dependant on the planet's defenses being light enough to get that close to the world...which depending on your take on how heavily and in which manner a world is protected may be in question.

Actually, that brings another facet of world defense to mind...in some cases a world might surrender or accept a seperate cease-fire with an invader sooner than expected if it was deemed that the damage a successful defense would do to the world would reach unacceptable levels. Remember that in the case of the Imperium, member worlds do still have their own local government calling the shots. If a world has ended up with significant defenses (which could well include large quantities of nuclear armed missiles either on the planet or in orbit) and finds itself faced with an enemy who is prepared to assault or engage in an 'aggressive' siege the leaders of that world could well decide that their freedom is not worth the damage to their environment, infrastructure or their population.

Of course, coming to this decision could earn them some stiff penalties from the Imperium (or whichever empire they were a part of) if they are reclaimed.

 

[Tobias]

Okay, first I have to say that I made a slight miscalculation because I didn't figure in the increase in mass as you accelerate to near-c velocities. An object at 80% c will have its mass increased by ~35%, which also has an effect on kinetic energy.
Let's postulate a desirable speed of 70% c, which is manageable and will result in a 25% mass increase. Accelerating the ship below to this kind of speed will take ~45-50 days.

The procedure is as follows:

D-57 days
In an empty hex, the interstellar missile begins accelerating. Its vector is set in the same direction as the target planet's orbital plane*.

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.

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.

D-24 seconds
Missile is 5 million kilometers from target and points nose towards planet.

D
Kaboom!

* I hope anybody understands this. These technical terms are difficult for me to express in English.

My calculation were based on a target planet orbiting a G2V star at one AU.
Also, I assumed you want to hit a specific target area, with a variance of about a few kilometers. If you just want to hit the planet, you can set the jump exit point much closer to the planet. This would limit the time between jump exit and impact to less than a minute for the missile and a few seconds for the planet.

Regards,

Tobias

Appendix A:

Ship: ISKKM
Class: ISKKM
Type: Jump Missile
Architect: Tobias
Tech Level: 14

USP
MX-1216841-C00000-00000-0 MCr 125.750 100 Tons
Bat Bear Crew: 1
Bat TL: 14

Cargo: 0.000 Fuel: 26.000 EP: 8.000 Agility: 6

Architects Fee: MCr 1.258 Cost in Quantity: MCr 100.600

HULL: 100.000 tons standard, 1,400.000 cubic meters, Cone Configuration

CREW: Pilot

ENGINEERING: Jump-1, 6G Manuever, Power plant-8, 8.000 EP, Agility 6

AVIONICS: Bridge, Model/4 Computer

HARDPOINTS: None

ARMAMENT: None

DEFENCES: Armoured Hull (Factor-12)

FUEL: 26.000 Tons Fuel (1 parsecs jump and 56 days endurance)
No Fuel Scoops, No Fuel Purification Plant

MISCELLANEOUS: 0.5 Stateroom, 0.000 Ton Cargo

COST: MCr 127.008 Singly (incl. Architects fees of MCr 1.258), MCr 100.600 in Quantity

CONSTRUCTION TIME: 38 Weeks Singly, 30 Weeks in Quantity

 

[Tobias]

Originally posted by Ran Targas:
But Tobias, the real rub is the planet is not just an isolated island fortress like Iwo Jima, it's a self sufficient, planet-sized battle station with comparitively unlimited power, resources to replace lost forces, armor in the form of planetary crust, etc.

Not to be misunderstood: It would definitely take tremendous resources to conquer a well-defended planet in a condition worth having.

Anti-missile systems and surface-to-space beam weapons (firing near continuously) would cut an asteroid into enough parts to produce only light damage or deflect it into a less threatening orbit.

Against the hypervelocity kinetic weapons I suggested this would be entirely useless.

Again, think about the defender having everything the attacker has (and in much greater numbers) except he doesn't have to lug it around a solar system to use it.

Actually, being mobile is an advantage. The attackers can concentrate the offensive resources of several systems, in some cases of huge interstellar empires, against one system.
When you have equal forces, and invasion attempt will probably fail miserably. The key is building up a local superiority to overwhelm the defenders.
Or blast them into oblivion.

If the people love their leader, for every nuke you fire, they'll build 100 to fire back at you.

Nuclear weapons are not all that effective against high-tech space craft, and it's tremendously easier to shoot down at a planet than vice versa.
As soon as enemy space forces in the system are eliminated, there is no threat to the invading fleet if they keep a safe distance.

Regards,

Tobias

 

[Zutroi]

Regarding relativistic weaponry, I just realized that I and many others of us MAY have been wrong. They can be defended against. All your planet needs to do is orbit a collection of debris. 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. And you'll produce a lot of radiation when pebble hits ship (hard x and gamma rays are NOT your friends), a mixed blessing since it may or may not scour the life off of the surface of your world (air is a pretty good defense against short wavelengths), it will make the space around the target world very uninhabitable!!

 

[RainOfSteel]

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 (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.

 

[vegascat]

TIME TO GET BACK TO THE BASICS!!!!!

The chances of taking a planet by force has little to do with the weapons and defenses involved. the most important point is the "Will of the Defenders".
The point of any attack is to attack an objective in a way that will bring about the result you want.
Aim your power (weapons, special forces, espionage) at a specisic point in overwhelming force. To do anything else is waste.
Avoid collateral damage. It is a waste that will royally piss off the locals, and in the long run cost you heavily.
If your goal is to annex a planet, your target is the loyalty of the population. Your effective weapons are infiltration and subversion. This will take much longer than attcking with massed meson guns, but is cheaper, more certain, longer lasting, and requires much less in the way of occupation troops.

 

[Richard Saunders]

Originally posted by Zutroi:
Regarding relativistic weaponry, I just realized that I and many others of us MAY have been wrong. They can be defended against. All your planet needs to do is orbit a collection of debris. 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. And you'll produce a lot of radiation when pebble hits ship (hard x and gamma rays are NOT your friends), a mixed blessing since it may or may not scour the life off of the surface of your world (air is a pretty good defense against short wavelengths), it will make the space around the target world very uninhabitable!!

Hello.
If you place a debre field around a planet you make the planet more likle to fall.
The invading fleet needs to only fire small (relativly) kinetics missiles at the planet because the radiation from the impacts with the debry will EMP the planet (no planet will wast the money sheilding all possible electronics on planet) yes the military will but if you destroy the planets infrustructor the people are going to go hungry (imagine if you will the US with no electronics (no comunications, no car, no trucks, no trains, no hospitals, no electricity to factories or homes).
You also have the radiation hitting the planet (yes with warning the people can be moved underground (airraid shelters) but how do you move crops and other plant life underground.
How long is a Hipop planet going to hold out if there is no food (most modern citys have about two yes 2 days food in hand, after the power goes so does any fresh food, its pointless having 20000000tons of grain in Kansas if you cant get it to New York.
You can probably imagine the destruction and chaos after a week and this would be world wide.
All you would need would be 3 or 4 missiles every day for a week then 1 missile every 3 days (stop the ground forces from repairing the network with protected spares).
After about a fortnight you would be down to a midpop world, after a month probably 100's of millions dead and rising fast.
If the planet doesnt have an orbiting debry field you could do the same by firing small high C missiles into the atmosphere yes they may not hit the surpace but think of the radiation, a couple of nucs into uperatmosphere and see EMP above.
I hope someone can find the hole in this, I dont feel safe anymore.
For rocks from space try Robert Heinlein's "the moon is a harsh mistress" or Nivens "Footfall" or was it Pournelle.
BYE.

 

[Richard Saunders]

Hello sorry.
As an asside any weapon moving faster than .5c will be undetectable because of the frequency shift of the returned signal, the speed is probably lower a lot lower.
BYE.

 

[Richard Saunders]

Originally posted by vegascat:
TIME TO GET BACK TO THE BASICS!!!!!

The chances of taking a planet by force has little to do with the weapons and defenses involved. the most important point is the "Will of the Defenders".
The point of any attack is to attack an objective in a way that will bring about the result you want.
Aim your power (weapons, special forces, espionage) at a specisic point in overwhelming force. To do anything else is waste.
Avoid collateral damage. It is a waste that will royally piss off the locals, and in the long run cost you heavily.
If your goal is to annex a planet, your target is the loyalty of the population. Your effective weapons are infiltration and subversion. This will take much longer than attcking with massed meson guns, but is cheaper, more certain, longer lasting, and requires much less in the way of occupation troops.

Hello.
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.
BYE