Armies of the Fifth Frontier War, Impressions Not Errata

[Anstett]

For a fictional description of how devastating orbital bombardment might be, refer to Neal Stephenson's Seveneves. The Moon gets broken up and its shards come tumbling into the Earth's atmosphere. I'm not sure how if that's exactly how it would play out, but knowing what I know of Stephenson, I'm sure he did due diligence in his research.

It is a very good book... until the last third and the twists at the end.
I do believe that the first third of the book is solid science used for fiction, the middle part is good solid theory.

 

[MasterGwydion]

My guess is that it would depend on the size rocks used.

 

[MonsterX]

For a fictional description of how devastating orbital bombardment might be, refer to Neal Stephenson's Seveneves. The Moon gets broken up and its shards come tumbling into the Earth's atmosphere. I'm not sure how if that's exactly how it would play out, but knowing what I know of Stephenson, I'm sure he did due diligence in his research.

Obviously, you can totally turn a planet into lava, or even break it to bits, if you've got Traveller level TL, lots of ships and the time to do it. Under a certain set of assumptions, this becomes the standard operating procedure. You can even do it from another star system: just accelerate an object for months or years until it is near light speed and then smash it into an enemy planet.

However, that does not make a fun space opera. You want the Space Patrol boarding enemy blockade runners and gunfighting through the ship corridors. Battledressed space marines fighting their way across the icy surface of Jovian moons to destroy the enemy missile base so that your battlecruisers can refuel, while long-range fighters patrol deepspace ensuring that your fleet is not caught by surprise, occasionally getting in dogfights with enemy patrols. You want marines in drop pods securing landing zones so that your troop shuttles can land safely. These tropes are fun, and have lots of opportunities for PCs to do heroic, or villainous, stuff. Getting smashed to death by an asteroid doesn't really do that very much. Maybe once.

Since this is all make-believe and we don't really know how all this tech will play out in practice - which also requires thinking through how the TL matches with the societies, and military doctrines - we can make a set of assumptions that give us "Hammers Slammers", rather than "The Dark Forest". (Dark Forest is a much better book, but Hammers Slammers would make for a better game). So let's do that instead. It is not necessarily unrealistic or at least more unrealistic than the rest of this.

It is ok to assume that many smart people in Charted Space have been thinking about how to asteroid bombard each other, and also how to stop from getting bombarded, and the bombardment stoppers have won this round, so here we are with armies and navies invading planets, and bombardment that is militarily useful but dangerous to do and expensive and limited in effect .

 

[MasterGwydion]

The more I learn about Charted Space, the more I think that the only viable settlements are those 10s of kilometers below the planetary surface. Deep enough that rocks and other orbital bombardment won't work without cracking the planet in half. (and tons of meson screens because meson guns are a threat no matter where you are. )

Edit - Settlement-scale Grav Screens as well, including deploying these grav screens as decoys where there are no unground settlements to protect.

 

[paltrysum]

Getting smashed to death by an asteroid doesn't really do that very much. Maybe once.

True, but escape from a place that's about to get smashed might make for an exciting scenario.

 

[MasterGwydion]

Chewie died getting a moon dropped on him while the Falcon barely got away. So, yeah, that tracks.

 

[Condottiere]

Or, he's Bigfoot, guarding the Millenium Falcon's crash site, and Han's grave.

 

[Vormaerin]

True, but escape from a place that's about to get smashed might make for an exciting scenario.

Oh, definitely. But you probably don't want to make that scenario a feature of your main conflict between two recurring foes.

 

[actionman]

For a fictional description of how devastating orbital bombardment might be, refer to Neal Stephenson's Seveneves. The Moon gets broken up and its shards come tumbling into the Earth's atmosphere. I'm not sure how if that's exactly how it would play out, but knowing what I know of Stephenson, I'm sure he did due diligence in his research.

Or Larry Niven's Footfall or Lucifer's Hammer.

Footfall was a good book. Thank you for reminding me of it.

 

[tomfreshwater]

You don’t even need to drop rocks. Drop enough sand and the atmosphere will heat up due to friction killing anything on the surface.
The real use of sand casters finally realised. Sand would also be much harder to shoot down. Maybe easier to repulse? Depends if they apply to a single point or a wide area.

 

[actionman]

View attachment 5866

Here is your Canon source. Rebellion Sourcebook page 43

Am I reading this right? Did they use bludgeons as asteroids? What did they do, get a bunch of bludgeons and sprinkle them throughout asteroid belts?

 

[Sigtrygg]

I think it is an example of sloppy writing and editing, possibly transcription error as well.

It was likely meant to be written as "the budgeons used were small asteroids."

 

[MonsterX]

True, but escape from a place that's about to get smashed might make for an exciting scenario.

one exciting scenario, maybe. Unless it is a relativistic smash, in which case its more like: "you're all having a pleasant dinner at the starport when suddenly you all die."

 

[actionman]

You can even do it from another star system: just accelerate an object for months or years until it is near light speed and then smash it into an enemy planet.

That's why friends don't let friends use reactionless drives, but Traveller is Traveller. Launch the weapon, and it hits the target 50 years later when the war has been over for decades. The target system is going to see it years out because it will occlude the stars behind it. It could be equipped with a stealth system that bends light around it, etc., but whatever.

Thoughts on rock-ery.

Attackers would have to spend a long time gathering and preparing the hundreds of rocks, and the attacking fleet would be unavailable for other operations while it sits there doing that. It would probably take weeks at least (microjump out to the asteroid belt, finding suitable rocks, maneuvering them onto the correct trajectory, etc.). If there isn't a suitable asteroid belt in the target system, then hundreds of rocks would have to be brought in from other systems. That would mean hundreds of ships occupied for at least 2 weeks longer.

Defenders, however, would have years to secretly prepare rock weapons. The local asteroid belt could be seeded with concealed automated defense systems. Any source of rocks could be. An attacker mining operation on a moon or asteroid to secure rocks would be vulnerable to rocks itself. Meson emplacements, monitors, robot SDB's, kinetic kill weapons, etc. With enough time and money, the systems gas giant could have a defense network of heavy asteroid monitors bristling with heavy long range meson guns, in addition to possibly thousands of cheap rock-based kinetic kill vehicles hidden in the rings surrounding the gas giant (if there are rings. If not, monitors it is, or even thousands of asteroids set in orbit around the gas giant). The attacking fleet can jump in all it wants, but it's going to suffer grievously if it attempts to refuel at that gas giant.

Tactic:

Position hundreds of guided rock weapons in a meson-dense staging area. When the attacking fleet tries to assert orbital dominance, rock munitions are launched. At the appropriate distance, the rock munitions split into hundreds of kinetic kill projectiles like a giant shotgun. The attacking fleet can easily scatter and reform, but that's the point. If they concentrate to conduct orbital supremacy operations, they deal with rocks. If they attack the rock munitions staging area, they have to deal with heavy monitors. Either way, it takes time, consumes supplies, and probably results in ships rendered non-mission-capable.

Consider:

An attacking fleet enters the system and moves to secure orbital supremacy above the mainworld. In orbit, they face meson fire from hundreds of deep emplacements, monitors, and thousands of surface-to-space missiles (grav propulsion, not hard to do. Thousands of them could be scattered all over the planet). Add to that blizzards of rock-based kinetic kill projectiles whenever the attacking fleet wants to form up and do something. When they disperse to avoid the projectiles, SDB wolfpacks attack isolated enemy ships. SDB's would maneuver under cover of planetary meson emplacements. Defender calculations would probably go something like, what size rocks can an attacking fleet maneuver onto an attacking trajectory, how many ships do they need per rock, and how much meson, kinetic kill, or nuclear firepower do we need to destroy rocks of that size, per rock?

The system would be a bonded superdense meson-spined porcupine, and the attackers would have to decide how many ships they are willing to lose to take it. This question becomes more important if the attacking fleet will need to take multiple such systems on its route of advance, and then face counterattack from fresh defending fleets.

"Come, Joe-Danny, try us if ye be men."

 

[actionman]

I think it is an example of sloppy writing and editing, possibly transcription error as well.

It was likely meant to be written as "the budgeons used were small asteroids."

Of course, but it was goofy enough for me to want to comment on it.

 

[MonsterX]

Or Larry Niven's Footfall or Lucifer's Hammer.

Footfall was a good book. Thank you for reminding me o

That's why friends don't let friends use reactionless drives, but Traveller is Traveller. Launch the weapon, and it hits the target 50 years later when the war has been over for decades. The target system is going to see it years out because it will occlude the stars behind it. It could be equipped with a stealth system that bends light around it, etc., but whatever.

Thoughts on rock-ery.

Attackers would have to spend a long time gathering and preparing the hundreds of rocks, and the attacking fleet would be unavailable for other operations while it sits there doing that. It would probably take weeks at least (microjump out to the asteroid belt, finding suitable rocks, maneuvering them onto the correct trajectory, etc.). If there isn't a suitable asteroid belt in the target system, then hundreds of rocks would have to be brought in from other systems. That would mean hundreds of ships occupied for at least 2 weeks longer.

Defenders, however, would have years to secretly prepare rock weapons. The local asteroid belt could be seeded with concealed automated defense systems. Any source of rocks could be. An attacker mining operation on a moon or asteroid to secure rocks would be vulnerable to rocks itself. Meson emplacements, monitors, robot SDB's, kinetic kill weapons, etc. With enough time and money, the systems gas giant could have a defense network of heavy asteroid monitors bristling with heavy long range meson guns, in addition to possibly thousands of cheap rock-based kinetic kill vehicles hidden in the rings surrounding the gas giant (if there are rings. If not, monitors it is, or even thousands of asteroids set in orbit around the gas giant). The attacking fleet can jump in all it wants, but it's going to suffer grievously if it attempts to refuel at that gas giant.

Tactic:

Position hundreds of guided rock weapons in a meson-dense staging area. When the attacking fleet tries to assert orbital dominance, rock munitions are launched. At the appropriate distance, the rock munitions split into hundreds of kinetic kill projectiles like a giant shotgun. The attacking fleet can easily scatter and reform, but that's the point. If they concentrate to conduct orbital supremacy operations, they deal with rocks. If they attack the rock munitions staging area, they have to deal with heavy monitors. Either way, it takes time, consumes supplies, and probably results in ships rendered non-mission-capable.
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Consider:

An attacking fleet enters the system and moves to secure orbital supremacy above the mainworld. In orbit, they face meson fire from hundreds of deep emplacements, monitors, and thousands of surface-to-space missiles (grav propulsion, not hard to do. Thousands of them could be scattered all over the planet). Add to that blizzards of rock-based kinetic kill projectiles whenever the attacking fleet wants to form up and do something. When they disperse to avoid the projectiles, SDB wolfpacks attack isolated enemy ships. SDB's would maneuver under cover of planetary meson emplacements. Defender calculations would probably go something like, what size rocks can an attacking fleet maneuver onto an attacking trajectory, how many ships do they need per rock, and how much meson, kinetic kill, or nuclear firepower do we need to destroy rocks of that size, per rock?

The system would be a bonded superdense meson-spined porcupine, and the attackers would have to decide how many ships they are willing to lose to take it. This question becomes more important if the attacking fleet will need to take multiple such systems on its route of advance, and then face counterattack from fresh defending fleets.

"Come, Joe-Danny, try us if ye be men."

I don't think an inbound asteroid from another system would be easy to detect. It likely won't occlude anything because it would not need to be big - and even a big planet would not occlude anything on this scale. It would'nt take THAT long to get there, depending on the size of the M drive, but if you manage 1G, then it would take about 1 year to accelerate to just below light speed and 1 year per light year - 3,26 years per parsec. So, not decades but long enough that the war will likely be over, but we are just doing this for spite. In the final approach, it would start occluding stuff, but by then it would be coming in so fast, it would be barely behind the light waves you detect it with - you'd have maybe seconds to detect, target and decide to shoot it, most likely just enough time to say "oh fuck!". Accelerating all the way or at more than 1G would only make it arrive marginally faster, but would give it more and more potential energy, and also reduce reaction times on the planet. And when it hit, it would shatter the planet. This is the Dark Forest weapon.

The ONLY counter I can think of would be if it passed a ship enroute and that ship jumped to warn the target planet, basically 0 chance, since the ship would have to be sitting well out in the Kuiper Belt, in the right position to see it go by. The other possibility is to get lucky and see it leave from its origin system, in which case just jump out and put something - anything - in its path and boom!

But as to your thoughts on rock dropping, I agree this could be the calculus. It seems like it would differ based on local conditions - how many rocks? where are they? have the defenders prepared them with defenses or not? Likely in lots of cases, dropping rocks wouldn't really be a factor for a variety of reasons, but in some cases it might be important. This is interesting because it makes the whole star system into a theater of combat with need for lots of different kinds of ships, and maybe even marines and other capabilities.