Interface engagements

[whartung]

Perhaps this is a better thread than the Composite Marine Vehicle thread.

One of the key aspects regarding the vehicle troop capacity is the cost of casualties should the vehicle be destroyed during interface.

This is kind of what prompted my other question regarding Fusion Gun ballistics.

Orbial superiority will, most likely LEAD to aerospace superiority, but if it GUARANTEED it, then this issue on vehicle size would simply not be an issue. You could assume that transit was always safe, so do what you want.

The two major threats are fixed installations (missile, gun, laser, meson batteries) and mobile, aerospace forces. Anyone using actual airframe vehicles against oribtal forces deserve getting blown out of the sky. I would think that there would be special Interface gun ships with as many MFDs as the sensor suite would allow to handle multiple targeting, and just lay in to the flying vehicles with lasers.

Airframe vehicles would be spectacularly vulnerable, due to their lack of armor. Their speed is meaningless, light speed weapons simply don't care. Once they rise above the ground clutter, laser batteries will just eat them up. This is particularly poignant with even "heavy armor". Orbital weapon platforms most like won't play along with the AFV designers and shoot at them from the front.

See, that's the thing -- barring the "getting snuffed out of the sky like bugs in a zapper" detail, why should grav powered armor not fly up and engage shuttles on their way in? Grav MBT with high powered fusion gun vs Ships Boat -- ouchies.

But, the low orbit support ships should really prevent that, depending on volume of the response force. Why should anything live above 5000 feet?

Which basically leaves ground facilities, and we all know the issues with ground facilities against orbital superioriy. But even then I would think that lasers would be a popular mechanism for blotting out invading landing craft.

Of course, all of this supposes that the forces land in a dangerous area at all, and not on the opposite side of planet, in perhaps some safe locale (like the middle of the main ocean), and then NOE in lost in wave and ground clutter towards a beachhead being pasted with kinetic energy deadfall from orbit.

What kind of scenarios do you folks see playing out?

 

[sablewyvern]

There's a whole range of variables at play here that are going to influence any answer:

What capacity do the transports have to add directly to the conflict (ie, as weapon platforms)?

What is an acceptable number of losses in both vehicles and troops?

What are the vulnerabilities of dismounted troops, and how does this compare to mounted troops?

How likely are carried troops to survive any given mission kill on their carrier? (A high survival rate makes close deployments more attractive.)

How adversely is an offensive going to be affected by a longer deployment time?

At what range do dismounted troops become effective, and at what range do they become vulnerable to anti-personnel weapons?

Is a longer exposure in NOE flight more or less dangerous than a brief exposure in a direct deployment from orbit to the combat zone?



I'm not conversant enough in the specifics of the OTU to give answers to these questions, but I would suggest deployments would be as close as possible to the mission objective as those answers will allow.

 

[jec10]

In the set of OTU rules I am familiar with that best deals with interface combat (MT) it is by no means easy to 'pick off' moving targets from orbit. Look at the difficulties for the tasks on the range table. In MT at least those orbital fire support ships might not be particularly effective against fast moving grav defenders down below.

 

[Major B]

Another consideration that adds complications to the problem will come up when you start to consider logistics.

How fast will those troops and vehicles exhaust their expendable resources once they get on the ground and how will you get them more?

I think this is another critical role for the supporting craft. Deadfall drops to preplanned drop zones may be a solution too but I see limits on that tactic. For example, those drop zones would be ideal targets for the defenders (using deep meson guns or surface weapons).

Unfortunately I don't have much in the way of answers, just more questions. That is why these discussion threads have been very interesting to me.

 

[whartung]

Frankly, I can't see anyone landing anything until the meson sites are disabled. I mean, seriously, imagine a small nuclear blast going off every minute along your line or in your rear. At least until the battalion meson screens start getting deployed, but that's not going to cover much I fear.

With meson guns you have no real front line. At least aircraft and missiles have to travel across a front line and potential defenders before they get to the soft chewy center. MGs don't have that limitation, so that makes them particularly disruptive.

 

[whartung]

In the set of OTU rules I am familiar with that best deals with interface combat (MT) it is by no means easy to 'pick off' moving targets from orbit. Look at the difficulties for the tasks on the range table. In MT at least those orbital fire support ships might not be particularly effective against fast moving grav defenders down below.

But here's the thing, you need to consider this a tracking issue. If we have systems capable of tracking objects the size of Rampart Fighters (Which are, what, 10 Td?) and engaging them, at a range of 100,000 Km, how much of a problem do you think they should have at, say, 300 Km?

If they're laying low, hidden in ground scatter etc, then sure, but only because the sensors can't see them very well. But if they get on open ground, or climb up in to the air to any reasonable altitude (1000-1500m), well, they're in for a whole lot of love from ship-to-ship lasers, IMHO.

The interface engagment should be treated much like a deep space boarding operation. With the planet having potentially lots of anti-shipping capability, but once attacking combat ships are safely in orbit, that's where things get interesting.

At that juncture I just don't know if there's much the defenders can do but simply wait for the invaders. The real goal is to keep them out of the inner system and out of orbit, once that's done and the attackers have achieved that, I don't know what's left.

Which puts the question of combat capable orbital landing craft in a whole new like. Why not just start bringing troops down in 5000 Td, streamlined transports.

 

[Major B]

Whartung, you've just admirably illustrated why these discussions are so difficult (and I guess why the number of threads grappling with it keep growing).

None of us has a common visualization of what a planetary assault will look like. Questions like how much preparatory bombardment and what type / how many troops and how to insert them / when is the transition from prep fire to assault / what role will fighters and support craft play - these are all insufficiently answered the same way.

It depends.

Every assault operation will have different composition for defenders and attackers so while tactics may apply to some situations they will not apply to others. And the tactics used will (or should) drive the number and type of troops and the equipment they carry/ride/use.

And even then, both sides retain the options to innovate - change the way they employ their weapons and people in an attempt to gain an advantage. Its not beyond reason to postulate a defender directing his deep meson guns (just one example) to hold fire until after the landing starts, then target the assault force in the hope of causing enough damage that the fleet no longer has confidence in success on the ground. That tactic could gain them a temporary advantage, buying time perhaps for reinforcements to arrive from another system.

 

[Hemdian]

Looking at the "Invasion Earth" boradgame there is another logistical issue: when a world invasion is part of a wider war then some key assets may not be available or only be available for a fixed window of time. If I remember IE correctly (its been a few years), the invading side had to dump as many troops as possible on the target planet before loosing their big transports. Ideally you tried to win orbital superiority in parallel to this.

Even if I've misremembered IE, these mission constraints could apply (to lesser or greater degree).

 

[Hemdian]

Deadfall drops to preplanned drop zones may be a solution too but I see limits on that tactic. For example, those drop zones would be ideal targets for the defenders (using deep meson guns or surface weapons).

If your drop zones are in major population centers then the defender's own civilian population becomes an 'inadvertant' human shield.

 

[Foxroe]

Seeing as such a scenario has never occurred (to our knowledge at least ), this is strictly an enjoyable exercise in speculation. So I offer my MCr0.02.

Interface battles would be greatly influenced by the disparity in TL. Superior TL's would have the advantage (more so when the difference in TL is substantial). The best a lower TL dirt-side force could hope for is a protracted guerilla war after the fact, or to hire off-world mercenaries equipped to handle the invaders. A higher TL force defending against a lower TL invading force, as you pointed out, would be like shooting fish in a barrel.

When opposing sides have equivalent equipment TL, then victory becomes a function of advantage, whether strategically created or "built-in". As previously pointed out, there would be a lot of variables for admirals and battlefield commanders to mull over. Advantage could be in the form of greater numbers of troops/vehicles, terrain type in ground engagements, skill/experience level of the troops, weather (or similar local environmental phenomena), mines/traps, looking for sensor "holes", troop deployment intelligence, orbital approach plan, etc.

It might be fun to test out the combinations of forces and all of the variables. Gather together a few people, decide on a rule set (Striker or whatever), design a few scenarios, and play each out a few times. See what works and what doesn't. Only then would you have a better understanding of what is appropriate to the scenario when it arises in your Traveller game.

As far as orbit-to-ground deployment of high-TL forces goes, IMO the best tactic would be to send in your initial troops diluted to the squad/platoon level in armed grav APC's (lots of them ) and/or in jump capsules. Once the "beach-head" is established, bring down the larger bulk-transports. And for extra spice, pre-invasion commando raids on key military assets might make enjoyable Traveller adventures for your players.

-Fox

 

[Merxiless]

Sounds like Invasion: Earth.

 

[jec10]

I think that in a high threat environment you'd use jump troops (i.e. troops landing in individual armoured drop capsules spewing out decoys as they come in) as the first wave. They'd be battle dress/grav belt/FGMP-14/tac missile equipped and call in ortillery for heavy fire support.

On the targeting from orbit point, the difficulty profiles chart on page 72 of the Megatraveller Players Manual is the source. It is quite clear that the base difficulty to hit at that range is Formidable (or Impossible for TL11 and below), even assuming you have detected the target.

 

[Golan2072]

Orbial superiority will, most likely LEAD to aerospace superiority, but if it GUARANTEED it, then this issue on vehicle size would simply not be an issue. You could assume that transit was always safe, so do what you want.

This raises a question: would the majority of planetary-surface invasions be conducted after total orbital superiority has been achieved by the invader, or would, in many cases, an invasion will be launched while an orbital battle is in progress in order to tip the scales in that battle (e.g. knock off SDB hideouts/fueling-posts, missile batteries and deep meson sites)? And is it possible for the orbital zone of a planet to be contested (i.e. no side having total control) for a prolonged time all while planetary forces are clashing as well?

 

[R_Chance]

This raises a question: would the majority of planetary-surface invasions be conducted after total orbital superiority has been achieved by the invader, or would, in many cases, an invasion will be launched while an orbital battle is in progress in order to tip the scales in that battle (e.g. knock off SDB hideouts/fueling-posts, missile batteries and deep meson sites)? And is it possible for the orbital zone of a planet to be contested (i.e. no side having total control) for a prolonged time all while planetary forces are clashing as well?

I'd think full scale invasions would wait until orbital superiority was gained. Too much to lose if you were moving troops and equipment in large numbers against orbital capable weapons. However, I'd bet on raids to eliminate targets like SDB bases, meson guns etc. Gives those commando units something useful to do with their drop capsules and fancy ECM. I have always figured on seiges to take most planetary targets (at least those with large spread out populations and resources). The fleet moves in takes the high ground, reduces the planets ability to interdict orbit to ground movement and then invades. It runs roughly like a WW II Pacific invasion... and of course the island hopping strategy is perfect for interstellar warfare too. No need to take most planetary surfaces. Just eliminate their ability to interfere in space travel and move on. Keep the expensive, time consuming seige warfare for important targets that you're navy needs to fight / win the war. You can always clean up the planetary targets later.

 

[mbrinkhues]

Some questions:

+ Does every planet have deep meson sites?
s
From the TNE material this seems to be a relatively rare case, reserved for high tech planets. Most systems make do with SDB's and planetary based Anti-Spacecraft missiles

+ Does one have to take every system?

Island hopping has already been suggested. But where in WWII the US took the major islands and ignored the minor ones, a space-based invader might do it the other way round. Take minor systems as refueling stops and bombard/suppress the major systems. Using ships like the "Nemesis" Intruder one can quickly attack orbital yards etc., reducing the enemies major assets.

+ Wings can be useful

Depending on the system a winged craft actualy take on interface crafts. Athmospheric top speed is limited for the landers and high fuel consumtion limit deployment.

+ Fluuuuten

The seas of a world can provide a lot of cover. One Challenge has an article about a deep diving sub using detached laser and sensor platforms

 

[Golan2072]

I'd think full scale invasions would wait until orbital superiority was gained. Too much to lose if you were moving troops and equipment in large numbers against orbital capable weapons.

Of course, this doesn't count counter-attacks by the enemy after the orbital zone has been cleared of the initial enemy presence. These, in turn, depend on the availability of enemy naval forces, how important the system is, and how far is it from the front lines (i.e. how easy is it to get to from the enemy's territory. An important system near the front line would experience several counter-attacks; for the ground-troops these would mean, at best, periods without (or with reduced) ortillery support as the battleships would move to fend off the counter attack, or at worst, the loss of orbital control to the enemy which would turn the table on the invaders.

Less important systems, on the other hand, would experience less (if any) counter-attacks, but those would be the systems less attractive to the prospective invader in the first place...

 

[R_Chance]

Some questions:

+ Does every planet have deep meson sites?
s
From the TNE material this seems to be a relatively rare case, reserved for high tech planets. Most systems make do with SDB's and planetary based Anti-Spacecraft missiles

+ Does one have to take every system?

Island hopping has already been suggested. But where in WWII the US took the major islands and ignored the minor ones, a space-based invader might do it the other way round. Take minor systems as refueling stops and bombard/suppress the major systems. Using ships like the "Nemesis" Intruder one can quickly attack orbital yards etc., reducing the enemies major assets.

+ Wings can be useful

Depending on the system a winged craft actualy take on interface crafts. Athmospheric top speed is limited for the landers and high fuel consumtion limit deployment.

+ Fluuuuten

The seas of a world can provide a lot of cover. One Challenge has an article about a deep diving sub using detached laser and sensor platforms

I'd think only high tech / high pop targets and important naval bases would have deep meson sites. SDBs and missiles would be much more common. As for taking planets, the key judgment would be on utility for your own war plan. The US skipped major islands after neutralizing their air and naval assets in the Pacific (i.e. the japanese base at Rabaul).

Wings have their utility in atmosphere, but I suspect a lot of orbital craft would use speed and the high ground to shoot down aircraft (fish in a barrel time). SDBs were always supposed to make use of seas and the atmospheres of gas giants for cover. Finding them would be the trick. The cat and mouse aspect of that always brought AS warfare to mind for me.

 

[R_Chance]

Of course, this doesn't count counter-attacks by the enemy after the orbital zone has been cleared of the initial enemy presence. These, in turn, depend on the availability of enemy naval forces, how important the system is, and how far is it from the front lines (i.e. how easy is it to get to from the enemy's territory. An important system near the front line would experience several counter-attacks; for the ground-troops these would mean, at best, periods without (or with reduced) ortillery support as the battleships would move to fend off the counter attack, or at worst, the loss of orbital control to the enemy which would turn the table on the invaders.

Less important systems, on the other hand, would experience less (if any) counter-attacks, but those would be the systems less attractive to the prospective invader in the first place...

That's why planetary seiges would be prolonged and difficult. I'd think they would want to push the front significantly beyond a system before engaging in a seige and degrade the enemies interstellar capability in the area. If your forces are deep in a gravity well focused on planetary ops you wouldn't want any surprise visitors...

 

[Icosahedron]

+ Does every planet have deep meson sites?

From the TNE material this seems to be a relatively rare case, reserved for high tech planets. Most systems make do with SDB's and planetary based Anti-Spacecraft missiles

I'd think only high tech / high pop targets and important naval bases would have deep meson sites. SDBs and missiles would be much more common.

Another aspect is fealty to the Imperium. The big boys are not going to allow someone to build a deep meson defence if there's a chance they might need to 'show the flag' there in a decade or two. Only the most loyal and stable worlds will be sanctioned to build them.

What was that? Sovereignty issues? You don't need to get Imperial sanction?
Say hello to our new taskforce. We've decided to build a military base by the starport on that plot of land you're going to sell us...

 

[mbrinkhues]

I'd think only high tech / high pop targets and important naval bases would have deep meson sites. SDBs and missiles would be much more common. As for taking planets, the key judgment would be on utility for your own war plan. The US skipped major islands after neutralizing their air and naval assets in the Pacific (i.e. the japanese base at Rabaul).

Wings have their utility in atmosphere, but I suspect a lot of orbital craft would use speed and the high ground to shoot down aircraft (fish in a barrel time). SDBs were always supposed to make use of seas and the atmospheres of gas giants for cover. Finding them would be the trick. The cat and mouse aspect of that always brought AS warfare to mind for me.

Actually the example was a deep diving sub that used tethered and/or com-laser linked sensor plattforms disguised as floating rubbish. When the enemy fleet crossed the horizon missile and/or laser plattforms where released, fed datat from the passiv buyos and attacked en mass. DP9 used something similar for the Atlanteans counter-measures against CEF fleet assets in "Heavy Gear"

As for wings vs. ships it works best in the "Gravdrive" universe (MT, GT) and has problems in the "Heplar" universe (TNE) Ships with DirectEnergy Drives can constantly maneuver to keep position over the battlefield. Ships with fuel drives get into the same problem as the cruiser in the Arthur C. Clark Short-Story (or it's relative in one of the Venus Prime books)