Planetary defensive deep meson sites

[Vladika]

Originally this was a response to another thread (The Operational Rules of Traveller by robject). I felt it would be a good thread by itself.

Nobody seems to have rules on planetary defenses, notably deep meson sites, how they're deployed, how they're targeted, how they're hardened.

I believe that Traveller does have a few things to say about planetary defense Deep Meson Sites, albeit indirectly.

Consider planetoids, armored or not. A planetary defense meson site (PDMS) is nothing more or less than the volume beneath the planet surface that would otherwise be available in planetoids as ships.

That same volume allows for costs, screen defensive power use, meson gun size etc. Call it a meson gun T, and a meson screen factor 9 and a "Bridge" for control rooms, a power plant, staterooms for crew, etc. just as if it were a ship, leaving out jump and maneuver drives of course.

Fuel could be continually supplied by underwater rivers, lakes or ocean access tubes and so forth. I would require a "holding tank" and fuel processors be included though.

With a deep site I would forgo nuclear dampers as unnecessary, or not, depending on "how deep is deep".

It's not complicated.

A few other rules are noted:

On the cheesy side TCS eliminates the need for ground assault by its rule on the victorious fleet having 100 offensive weapons points in orbit to control the planet. (I personally hate that rule). Also the long time between capture and use of shipyards is found in TCS.

 

[whartung]

Well, there's a little bit more to it than that.

Notably, a spinal mount in a ship (and we are talking spinal mount size guns, not bays weapons, I mean -- why not) has the entire ship as it's mechanism for turning and aiming the gun.

A deep site doesn't have that luxury unless there's hope that the planet will turn and aim the gun.

So, there's the mechanism to actually mount the gun, plus the volume to let it spin around and aim it.

I don't have my books handy, but swaging with a spinal mount for a 100K dTon planetoid, we get a vessel that's 100m in diameter, so we need to carve out a "room" that big to host the gun. Then we need to facilitate some kind of gun mount.

This is all doable, of course.

Finally, we need to resolve how/if a gun can be detected. How the gun is armored (there's armor factors for "packed dirt" of X dimension, so we can actually determine how much dirt can be used to armor it. Heck, they can add some superdense to it.

We could simply use a buried ship hull as "the room", say a spherical hull, with a diameter of the length of the gun + 10m for extra room. And then, as you said, add on a bridge, a power plant, some space for a computer and screen, some crew facilities. How much does it cost to dig a 100m diameter room?

But detecting, and countering -- that's a trick. There's a nice note in this ( http://grognard.com/info/brillanc.txt ) about essentially the folly of neutrino detection for fusion plants. I guess you can use densitometers to find "large, round holes" in the surface of the planet. None of the other mechanisms work as they look for shiny things against a dark sky.

And, what about a meson submarine? Why deep site it at all when you can sink it, and move it.

Can a deep meson site be impenetrable? By anything but another meson gun? That sure makes them pretty powerful.

Sticking 20 uncrackable T Meson guns makes a planet extremely hard to crack. You can saturate the guns with volume (they only fire so often), but even then you have to deal with them as emplaced artillery after the landing. And there's nothing to say you can't scatter smaller, Factor 9 guns all over the place -- building basements, parking garages, child day care center multi-purpose rooms, etc. Ship based weapons have pretty silly ranges when you consider how small planets actually are. A generic bay meson gun in Paris can make a solid mess out of Los Angeles, just aim it towards the floor.

Makes things messy for potential invaders. Invaders may simply deign to fall back to hurling rocks. Happy deep meson sites underneath a shiny, black, glassy surface that used to be called "Cleveland".

Perhaps there can be some rules on counter battery fire, but I don't know. Can a meson screen tell where the shot came from?

So, yea, at the base it seems straight forward, but there are definite issues around the emplacement, deployment, and countering of meson guns.

 

[Hemdian]

IMTU, deep meson gun sites need surface-based sensor arrays (for targeting) and this is their Achilles Heel. That means that a planetary assault is not an impromptu affair, the first phase is espionage-based. Agents covertly make their way to the target world and secretly live among its people for up to a year (or more) before zero hour. They gather information about surface installations (and sensors). At zero hour those agents uplink the targeting data via tight-beam to waiting fleet.

The first wave is a combination of rapid fly-by and strike fighters to neutralise those sensors (and other planetary defenses). The second wave is the deployment of jump troops to secure landing zones. The third wave is the bulk of the ground troops.

The espionage phase is suitable for PCs in a military campaign. The PCs can be on either side: spies or counter-espionage.



A minor point: Spinal mount meson guns are linear accelerators but ‘bay’ meson guns are cyclotrons. Though we don’t have the stats for them, it is possible to have a large cyclotron that does the same damage as a spinal mount (you just wouldn’t mount one on a ship). These might be a better option for a deep meson gun site than the linear version … the size of your ‘room’ could be considerably smaller.

 

[Greylond]

One problem with ground based guns that aren't mobile is that they aren't mobile. Guns in static positions are easy targets for KEWs. At the level of tech in OTU, I'd think that ground targets that aren't buried deep would last only a few minutes after they were ID'ed and located.

 

[whartung]

IMTU, deep meson gun sites need surface-based sensor arrays (for targeting) and this is their Achilles Heel.

That's a good point. There would have to be surface and orbital sensor nodes in the defense web to help target incoming ships. This is manifested in the various rule sets through sensor hand offs and sensor lock mechanics. The foundation is that if one sensor can see you, every one can see you as the data is shared.

But that's fine, it works. You can see a concerted effort to try and blind the arrays on a particular side or quadrant of the planet, and park the fleet in that blind spot to continue operations.

However also consider, that apparently sensors don't have to be particularly large. If a 100dT Scout ship can mount suitable sensors, there may well be several redundant sensor sites placed around the world, some even possibly camouflaged. But it does bring up other issues, such as how well passive sensors work on the ground, how does the atmosphere impact them (if at all), etc.

So it's certainly a vulnerability, and a solid mitigation. Redundant sensors are far cheaper than multiple meson sites. But at the same time I can see it being quite difficult to locate a passive sensor if you don't know where it is. Or you can power up a random Scout ship in a down port and have it start uplinking data.

A minor point: Spinal mount meson guns are linear accelerators but ‘bay’ meson guns are cyclotrons. Though we don’t have the stats for them, it is possible to have a large cyclotron that does the same damage as a spinal mount (you just wouldn’t mount one on a ship). These might be a better option for a deep meson gun site than the linear version … the size of your ‘room’ could be considerably smaller.

in TNE, they're all tubes, or at least modeled and emplaced as tubes. Bay mesons are just shorter tubes than spinal ones. As I recall, length <-> power of the gun. Longer gun, more oomph, better range...I think. Anyway...

 

[sabredog]

Wouldn't close-enough be good enough for cracking deep meson sites? I would think that deep meson strikes would cause geological buckling and fracturing around the suspected site and effectively do the job on the site itself. Not to mention the damage bombing surface communications and tracking installations would have on fire control.

In any case, assaulting the sites would give the drop troops something to do if the surface sites can't be destroyed for some reason.

Or maybe deep penetrators built up from heavily armored, unmanned small craft of a couple of hundred tons accelerated at high-G towards the target and packed with nuclear explosives?

 

[Reban]

IMTU Deep Meson Site fill the same niche as 19th century coastal batteries and fortifications. Part of their role is to deny invading forces an easy approach to their targets, in most cases this means orbits that intersect with the starport, population centers and other targets of importance.

Meson guns have a virtually unrestricted field of fire, so they can be constructed on the opposite side of a world to the target it protects.

Meson gun sites will soak up a lot of an invading force's time, effort, manpower and logistics. Even if they can be bypassed they have to be dealt with at some point. They are a commanders headache. A defender with enough resources might build 2 or 3 deep meson sites just to distract an invading force from the hundreds of bunkers containing home guard commando forces ready to emerge and conduct a guerrilla war against the occupation force.

Surfaces sensors for DMS don't have to be fixed. I put mine on submarines, trucks in the wilderness, aerial platforms, satellites and looking back from moons.

Add to the deep meson sites other defenses in depth, don't discuss them in isolation.

I recently came across the US Midgetman program. Russia are increasing the rail based ballistic missile forces, all possible models for missile, laser and kinetic defense platforms for YTU. Flood the skies with drones and orbit with kill sats and mines, then broadcast "Come and get me! "

 

[McPerth]

From the other thread the OP quotes:

I'm not sure where did I read it, but IIRC planetary defense MG are deeper than what a densiometer can detect, and so, unless you have a map telling you their exact positions (quite possible in the Rebellion, as the same fleet attacking the planet is the one expected to defend it, but depending on espionage for other settings), cannot be targeted by attacking fleet and the only way to stop them is by destroying their sensors arrays, so blinding them too.

As for MT sensors (the only ones I know well enough), if your deep meson guns are more than a kilometer deep into earth, they are undetectable to densiomentes. I'm not sure Neutrino detection could be used with interferring mater, but your power source could as well be not in the same place, and have several alternative places.

So, as Hemdian told, you must pinpoint their sensors and knock them off, either by the straffing runs he told about or by commando actions.

But sure there are alternate sensors ready, and some of them even mobile (submarines come to my mind). even with passive sensors such as neutrinos or densiometers, they will have it easier than the attackers (IMHO) and can direct the deep MG sites, so avoiding to expose themselves.

 

[Vladika]

Surfaces sensors for DMS don't have to be fixed

I'd say this is true but calibration would be a nightmare! This would be especially bad opening up at long range against a maneuvering fleet while your plant rotates (in most all cases 3 dimensionally, unless the attacking fleet has the decency to come in on the planetary equator). Even then, unless the mason site was also on the equator...

Add communications lag and a moving sensor platform. No wonder computers are huge!

 

[Reban]

I'd say this is true but calibration would be a nightmare! This would be especially bad opening up at long range against a maneuvering fleet while your plant rotates (in most all cases 3 dimensionally, unless the attacking fleet has the decency to come in on the planetary equator). Even then, unless the mason site was also on the equator...

Add communications lag and a moving sensor platform. No wonder computers are huge!

These are good points. Taking more inspiration from my 19th century coastal fortifications I'd suggest a possible solution is registered fire or registered targets. Your deep meson sites and sensor infrastructure isn't going anywhere during peace time so most of their time is spent training and practicing hitting targets in the volume of space around a planet.

Space is huge, but the volume of space around your defended planet within range of the meson gun is smaller. You can divide it up into grids, boxes, hexes or whatever works best for you. So your search sensor tells you the targets vector will take it into box AA, YZ and hands off to a sensor calibrated for that volume of space. That sensor is responsible for pin pointing the target. Target information is passed to single meson guns or better still batteries of deep meson gun sites which fire along the expected vector of the vessel.

Granted there are lots of holes in this suggestion, but I'm drawing on real world systems and procedures to imagine solutions for future technology.

The greater the communications lag the harder my solution is but closer in, say 1ls lag it will possibly give an attacker pause for thought.

The important point about deep meson sites and all planetary defenses is this: You're not going to stop and invading force dead. What you can do is degrade, delay and disrupt the attacking force and make it difficult for him to execute his plans. If the invader comes he is lightly to push all the way in until he can achieve orbital superiority and put troops on the ground. Use deep meson sites to reduce the forces available to him when he finally achieves that and make it possible for your own COACC and Ground Forces to fight back.

 

[Reban]

PDMS and surface targets

I think we can get sucked into always imagining the use of deep meson sites at maximum range. Now I know what the counter argument is: anything that gets inside a deep meson sites maximum range can inflict awesome damage on the surface of a world. So why would you ever have reason to use deep meson sites at less than maximum range?

I want to offer some ideas but first want to set out some assumptions about meson guns. First the meson gun effect as I understand it creates particle decay inside the target. Matter is converted to energy and the resulting explosion annihilates matter releasing gamma rays (perhaps not the total annihilation of a matter/anti-matter weapon but close). The effect is similar to a clean nuclear device. Second the meson beam is not stopped by intervening matter or armour only field effects. So you can fire through the planet.

Suppose as well as the long range deep meson sites you seed your defended planet with shorter range, say out to far orbit, range meson weapons. For want of a better name let’s call them; Deep Meson Posts. Place them so as to cover whatever surface targets you think might be the target of invading ground forces, for example site the weapons so that their sphere of range intersects with the Starport.

Now if the invading force get past your deep meson sites. The deep meson posts can target enemy landers as they drop from orbit towards ground targets. Correct me if I’m wrong but even if a meson gun in atmosphere misses it will still interact with matter (the atmospheric gases) and so the landers will be subject to secondary effects such as blast and an intense gamma ray burst.

Equally these deep meson posts can be employed against enemy troop concentrations on the ground. As an example a Starport has been taken by a Division of Imperial Marines. The supporting Battle and Assault Squadrons overhead have already spotted and neutralized the planets deep meson sites on the way in. The situation is grave. Imperial invaders stand on the soil of the Mother-planet. The High Command issue the order and a network of deep meson posts power up their previously stealthed systems and conduct what might be a one off fire mission against a pre-registered target, the Starport.

I’d suggest half the battery aim to detonated perhaps 10m below the reinforced concrete landing pads, while the other half conduct an airburst above the pad. When the dust clears you should be left with a chasm filled with the Emperor’s Finest. Now if you’ve destroyed the ground element should the Naval forces in orbit above withdraw or press on with a scorched earth attack from orbit?

In orbit above the soon to be Imperial world, INS Space Gator hangs in orbit. A sensor tech turns away from his holotank and calls the attention of his admiral.

Tech: Admiral Sir! The 5th Marine Division Orbithead at the Spaceport….it’s not there anymore!

Admiral: The Marine Division or the Spaceport?

Tech: Both Sir!

This mode of use for deep meson sites poses a lot of questions for Traveller universes. On balkanized worlds, is the construction of deep meson sites the equivalent of a secret nuclear arms program? Do authoritarian rulers use deep meson sites to control the population? i.e. toe the line or I wipe out your island/city/region.

Apologies if I’m getting off topic.

 

[shield]

There are rules for building deep meson sites in the TNE Fusion Fire and Steel book including access shafts and garv assisted gun cradles.

Vulnerable areas include sensors, power and access shafts.

The access shafts could be hidden anywhere, they are only liftshafts. You would only find these by spying or extremely lucky breaks.

Power - a dedicated fusion PP is ideal but is detectable via neutrino sensors. If I was designing a site, I would hook it up to the planetarypower grid with possible backups from tidal generators on the sea floor.

Sensors. Just sheer redundancy here- hide sensors on orbiting sats, moons, small ships, submarines. The weak link is the data transfer route. Civilian sensors can be dropped out of the net by jamming, others will have to be jammed or destroyed individually.

One of the easiest ways to spot a deep meson site would be during its construction. They are digging out a considerable sub-surface installation and linking it to the power grid etc. and then installing delicate and expensive electronics. A good spy might be able to spot this activity.

Just had an evil thought, you could hide the meson site on the planet's moon (especially easy if there is a colony there. Any invaders will tend to be looking at the planet in front of them not the moon they have just gone past.

 

[McPerth]

Power - a dedicated fusion PP is ideal but is detectable via neutrino sensors. If I was designing a site, I would hook it up to the planetarypower grid with possible backups from tidal generators on the sea floor.

I thought more than tidal PP about a geothermic one (after all you must already dig it a kilometer deep if you want to avoid densiometers), but would it be powerful enough to power a large Meson Gun? Frnkly, I don't know, but I have serious doubts about it.

 

[shield]

It obviously depends on the size of the meson gun. You could couple tidal generators with geothermal supplies and a damn big TL15 battery pack. You would use the planet's power grid for main power - available unless the invader knocks out the power grid, and the rest as back-up. Even if it took 24hrs to build up power for a single shot, it would still be devestating - each 24 hrs a chunk of the highport or the new govt office explodes. It would seriously put a kink in any occupation. Obviously less useful in th heat of battle, but very useful for any resistance.

 

[Hemdian]

There would be a lot of variation on a case by case basis:

Not all worlds will have the option of tidal power. Apart from the obvious need for a large enough sea or ocean, you also need a large moon (or be a moon) ... my understanding is that in most locations on Earth lunar tides are stronger than solar tides.

Not all worlds will have the option of geothermal power. On older worlds the core will have solidified and cooled.

 

[atpollard]

I think the same gravitational forces that create tides also create the stress to keep the core liquid (which also generates the magnetic field that protects the atmosphere from solar winds) ... so a world will have an atmosphere, tide and geothermal energy - or none of them. Ironic, is it not?

 

[Hal]

Also? Do not forget "bore sighting" when it comes to meson guns.

All that is needed to nail enemy troops on the planetary surface, is to aim at a pre-aimed location and use a forward observer to call in fire - one who has access to a meson communicator. Of course, such a radio communicator needs to know precisely where the meson comunicator post is - but a rational military mind would build repeaters under ground where one aims their commo at the repeaters, and they in turn send the signal to the real command post.

Ask yourself the following:

Even if a world government's fleet has been defeated, the primary government may not have surrendered to the invaders. Are you willing to take the chance that 10 meson sites armed with only BAY weapons, haven't already bore sighted the likely locations for an occupying force, and be ready to use their weapons in support of the resisting military against the invaders? Just look at the STRIKER rules to see just how nasty Meson gun strikes are for battles, and then ask yourself "How would YOU avoid this kind of mess?"

The answer is relatively simple:

The conventions of war are such that failure to surrender to a clearly superior force negates the convention of blowing the world back into the stone age or engaging in the destruction of the world's ecosystem - as any other approach would result in unacceptable losses to the occupying troops.

World sterilizations would occur more often than not with the introduction of Meson weaponry in my opinion. Frankly, I'd rather see Traveller do away with it entirely.

Think about it. Electromagnetic weapons such as lasers have a hard time hitting a target at a given distance, yet there is a weapon so accurate, that it can aim not one, but TWO particle streams at a given target - and have them hit a target that a laser can not? Hmmmm.

That's my 2 credits worth at least.

 

[Vladika]

Think about it. Electromagnetic weapons such as lasers have a hard time hitting a target at a given distance, yet there is a weapon so accurate, that it can aim not one, but TWO particle streams at a given target - and have them hit a target that a laser can not? Hmmmm.

I think Hal makes an incredibly good point here, at least in regards to hitting a ship at a distance. As far as hitting your own planet's surface, or any other point inside of or on, I would think that child's play.

His point on Laser weapons though is very on target. A laser can be visually (any sensor devise) "tracked onto" a target, moving or not. The only thing might be "time on target" to damage sufficiently.

Are you willing to take the chance that 10 meson sites armed with only BAY weapons...

You would definitely need to destroy or neutralize these weapons quickly or risk serious losses to an invading force.

 

[rancke]

One thing to keep in mind is that the evidence of the Fifth Frontier War[*] shows that planetary sieges are long drawn out affairs that take months or even years to complete. Apparently planetary defenses enjoy some significant advantage over attackers. Is it that deep meson sites are very difficult to locate or that they are difficult to destroy? Or something else?

[*] The setting material, not the boardgame; I don't know how long planetary sieges last in the boardgame.​

Hans

 

[HG_B]

One thing to keep in mind is that the evidence of the Fifth Frontier War[*] shows that planetary sieges are long drawn out affairs that take months or even years to complete. Apparently planetary defenses enjoy some significant advantage over attackers. Is it that deep meson sites are very difficult to locate or that they are difficult to destroy? Or something else?
Hans

A fictitious outcome that has no known or logical reason can be thrown out as incorrect unless it can be duplicated using a known rule-set...