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Old 11-23-2022, 05:00 PM   #1
seasalt
 
Join Date: May 2022
Default TL 9-10 air combat in the "Caliph" setting

Out of many of the settings in the old 3e 'Alternate Earths' supplement, the 'Caliph' setting seemed like an especially interesting one, especially in view of the real-world international culture war today. It's interesting because it is clearly "alternate history wank" for an ideology I strongly disagree with, yet it seems to have been intentionally set up in such a way that the "apostate" faction, the Jamahiriya, can easily be treated as the heroes.

But anyway - I dunno if I'd ever run it but it got me to thinking how an interesting military tech base for this setting could be fleshed out, especially if you want to go beyond the basics of "little squads in power armor running around trying to capture the robofacs". One of the illustrations shows a dogfight between a couple of futuristic jets and that captured my imagination while slacking off at work the other day.

First off I think a basic tweak to the setting is needed, of reining in the reactionless drive "thrusters" a bit. The problem is that if every civilian car has a high-thrust reactionless drive built into it, then literally EVERY vehicle in the setting, even individual suits of power armor, suddenly becomes a planet-killing WMD. Granted, the looming threat of WMD and global extinction is a major theme in the setting, but it shouldn't be quite THAT easy! At least make the warring nations need to build some antimatter nukes or killer nanite plagues or something!

I think the simplest solution is to say that the true "reactionless drives" are tachyon engines which have very low thrust and only work in space, meaning that launching one gives any spacecraft in the solar system plenty of time to intercept it and kill it before it reaches relativistic planet-cracking velocities. Wheres all of the flying cars and battlesuits and such are just using air-breathing fusion powered turbofans. If you have backpack-sized cold fusion power plants, you can build all the flying cars, flying tanks and power armor you want, no need for planet-killing high-acceleration reactionless drives inserted into every little jalopy. Honestly, I'm tempted to just say remove the reactionless drives altogether and say that the robotic probe ships carrying "stargates" to other solar systems are using highly efficient antimatter thrusters that still require reaction mass. That would be hideously expensive but the fact that there's a glut of resources is a major part of the setting already.

Anyway. The setting emphasizes that it's all about airpower and I think this kind of high-tech air combat could be really interesting. However the details are outdated and based on 3e, as it says everything uses "X-ray lasers", which don't work in atmosphere.

So what would these late TL 9/early TL 10 fighter jets look like? GURPS is... decent as a vehicle combat game if you want it to be, it handles it better than most other RPGs (which is damning it with faint praise, granted). The "Action 2" chase combat rules seem like they'd work ok. The setting writeup mentions that everyone is using neural interfaces to have sufficient "reaction time" so presumably everybody has got Enhanced Time Sense. It also says that combat robots aren't being used because they are too vulnerable to being hacked so all the vehicles will be piloted.

I imagine that fighter jets would be mainly armed with small semi-autonomous laser turrets for point defense, and maybe one big spinal laser to be used offensively. So, how can we make this both vaguely realistic and interesting so that it isn't just a contest of who has the bigger, longer-ranged gun?

I think the key is in heat-shielding. Basically, every fighter would have super-efficient cooling all over its body, which they'd need to anyway if they have a friggin' fusion reactor in there, that is gonna produce a lot of heat, not to mention lasers themselves are putting out crazy amounts of waste heat. So the same sytems keeping the planes from melting themselvees into slag would also be a powerful defense against lasers. A powerful enough laser could vaporize surfaces into plasma fast enough to breach through it, but it'd still be a potent defense.

In game terms, I'm thinking that each aircraft would have a "shield", except instead of a full on energy shield (which seems to be mostly limited to fixed locations or large spacecraft) it has the limitation that it only functions against lasers. And, firing the craft's own laser weapons or using the afterburners causes "damage" to the shield, which regenerates a certain amount of points each turn. And the one spot not covered by this "shield" would be the heat radiators, which I envison being on the back edge of the wings, which gives an excuse for old-school dogfighting to try and get behind the other guy and lase his radiators.

Then of course, there's missiles. The TL9 "Genius Missile" from high tech is probably ubiquitous and could be launched at almost infinite ranges, since it's smart enough to perform its own target identification and try to evade point defenses. I envision that a basic tactic might involve hitting an enemy with lasers first, to overheat him and force him to turn away and flee (angling his most powerful fixed-forward weapon away) and them fire a missile or two to finish him off. Rapid-firing gyrojet "guns" would be the secondary weapons.

I think that conventional guns would probably not see much use, because even if they're electrothermal, the range will be way too short compared to lasers, and a big enough shell to do much damage will get shot out of the air before it can hit. Since calculating the penalties each and every time a projectile is incoming would be ridiculous amounts of bookkeeping I'd just look at what attack bonus a particular weapon gets with a -20 "shooting the projectile" penalty as per the basic rules, and assign it an impromptu "block" based on that to use against micro-missile swarms, with each laser turret allowing another block per turn. And as for bigger genius missiles, which would be armored and have countermeasures of their own, do attacks against them the old fashioned way. This creates a tactical decision as the pilot has to choose between shooting at the enemy aircraft while trying to dodge missiles, versus focusing on shooting the missiles down and letting the opponent rake him with lasers.

What are your thoughts on what air combat in a setting like this might look like? I think thematically, it fits the cultural aesthetic, since nimble fighters are a bit like medieval horsemen - closing in to threaten the enemy, then backing off, even using turreted lasers and mini-missiles to do a bit of a "parthian shot".

Last edited by seasalt; 11-23-2022 at 05:14 PM.
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Old 11-23-2022, 07:04 PM   #2
mlangsdorf
 
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Default Re: TL 9-10 air combat in the "Caliph" setting

I'm not sure that putting the radiators on the rear of the wings is a good idea. It makes it dangerous for a fighter aircraft to attempt to retreat, because that exposes the most vulnerable surfaces to the enemy. It might make more sense to put them on the upper surfaces of the wing. You still have aircraft jockeying for position, but now they're jockeying for vertical position while trying to stay out of their opponent's front arc. Vertical position also gives an interesting set of trade-offs, because as the aircraft climb into thinner atmosphere, their radiators become less efficient. If an aircraft climbs too high, it may not be able to fire fast enough to burn through the target's heat shield.

I think railguns firing saboted, stealth projectiles (to minimize intercept from point defense) might see some use. They'd be short-ranged and inaccurate, but kinetic impacts would break the heat shielding very well, leaving the target vulnerable to laser attacks - assuming that the impacts didn't cause catastrophic airflow issues. It might be something that some air forces are experimenting with - railguns aren't consistent weapons, but they may have some high profile victories that make people think they're better than they are.

Stealth aircraft might also exist. These would be relatively low performance, turbojets, turbo-scramjets, or hyperfans with a heavy emphasis on thermal stealth. They can't intercept (or run from) a fusion air-ram fighter, but may be able to ambush them. The threat of stealth aircraft firing close-in railguns into a squadron pursuing a fleeing enemies might limit the decisiveness of air engagements. Again, this may be a more theoretical threat than something that actual happens, but the history of war is full of military forces that let their tactics be dictated by a potential threat that never materialized in practice.

Brilliant missiles are robotic missiles, so if robotic aircraft aren't used because of the threat of hacking, you need to explain why brilliant missiles aren't vulnerable. It might simply be a time question - the missiles' robo-brains aren't active enough long enough to be hacked - but I would probably limit the endurance of brilliant missiles to around 20-30 seconds. That also limits their potential range, which encourages everyone to engage at closer ranges.
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Old 11-23-2022, 09:34 PM   #3
Fred Brackin
 
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Default Re: TL 9-10 air combat in the "Caliph" setting

The missing element for Caliph is the contragravity generator (which I had assumed was standard anyway). "Aircars" using thrust alone for vertical lift but getting lift from a lifting body shape in horizontal flight could hit Mach 3 if it has the right streamlining and could handle the skin temperature problems.

So a Caliph civilian aircar gets lift from contragravity and doesn't need thrusters with output equal to loaded mass or more. One quarter to one sixth that still gives it a jetliner like thrust-to-weight ratio and it doesn't need to go supersonic for the trip lengths it's practical for.

The interstellar probes with antimatter engines would be a bigger deal than you might think. especially making enough antimatter. That's a job for one of those second level "K" civilizations. You can do it in Spaceships but you probably need something like 4000 miles per second of Delta-V..

Without easy cheap reactionless thrusters Caliph is too young a civilization to have built up to that level of space activity.

The laser defense tech you need is what 3e called thermal superconductivity and it did indeed cut laser damage by half. Firing lasers into the cool end of a heat engine just makes the engine shut down because there's no longer a cooler place to pump the waste heat to. You have to _protect_ the radiators from laser attack.
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Old 11-24-2022, 02:17 PM   #4
Anaraxes
 
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Default Re: TL 9-10 air combat in the "Caliph" setting

Quote:
Originally Posted by mlangsdorf View Post
I'm not sure that putting the radiators on the rear of the wings is a good idea. It makes it dangerous for a fighter aircraft to attempt to retreat, because that exposes the most vulnerable surfaces to the enemy. It might make more sense to put them on the upper surfaces of the wing.
If the aircraft use lift to maneuver, then this might not work well. Fighters generally roll their lift vector toward their target and pull into it; lift, pointed correctly, is what makes planes turn. So, pilots with radiators on the upper wing surface would constantly be rolling them toward the enemy. Hopefully they're not in a position to shoot at you -- perhaps with turreted weapons -- but still, it seems to me that the bottom of the wings might be a better choice for air superiority aircraft. Ground support aircraft may not want them on the bottom for fear of ground fire, of course. I think there are also aerodynamic reasons to avoid disturbing the upper wing surface more than the lower one. Spoiling the airflow over the top tends to make wings not work, or at least work less well.

If the aircraft don't use lift to maneuver, then they could put their radiators almost anywhere.

While we're on the topic, it's probably worth mentioning the "Meredith effect". Discovered by a British engineer right before WW II, it's a means of using a radiator also to produce thrust by taking advantage of the energy added to the airflow by the heat exchanger, meaning it has more energy. It's sort of a ramjet, if a weak one. It was used in the Spitfire, Hurricane, and P-51 Mustang, among other aircraft, just to get a little more oomph out of the engine. If the Caliph aircraft are radiating a lot of heat and flying in atmospheres, they might do the same thing. In that case, the radiators are going to be in a place where they can exhaust generally in line with the main aircraft thrust, while facing to the airflow. That leaves a lot of possibilities, but the historical examples tended to favor the bottom. It's also possible that high-tech aircraft simply have so much thrust that it's not worth bothering with the little bit extra.
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Old 11-24-2022, 03:36 PM   #5
mlangsdorf
 
Join Date: Aug 2004
Location: Austin, TX
Default Re: TL 9-10 air combat in the "Caliph" setting

The mechanics of Caliph's fusion air-rams are 90% technobabble and game mechanics. Almost anything is justifiable, and it's mostly a question of what mechanics and play experience is desirable. I was mostly offering some reasons why vulnerable radiators at the back of the plane might not be desirable.

It is true that if an enemy craft is approaching from the flank, an aircraft would need to expose the upper surface radiators to roll into a reciprocal course - though turning away is safer since the radiators roll away from the flanker. I think that becomes part of the tactical maneuvering: if an enemy gets within effective laser range and bearing while flanking an aircraft, the flanked aircraft has to turn away (possibly into a twisting climb if it wants to re-engage) or accept that its vulnerable if it turns to engage. But I think that it is better if turning to disengage is generally safer, since that means that outmatched or losing fighters have a low risk retreat.
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Old 11-24-2022, 03:42 PM   #6
Anthony
 
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Default Re: TL 9-10 air combat in the "Caliph" setting

Aircraft really aren't going to use radiators; they'll rely on conductive cooling across large amounts of area exposed to a high velocity air stream. They have more heat problems than ships (which can use water), but less than ground vehicles and way less than spacecraft.
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Old 11-25-2022, 05:17 PM   #7
seasalt
 
Join Date: May 2022
Default Re: TL 9-10 air combat in the "Caliph" setting

Quote:
Originally Posted by mlangsdorf View Post
...

I think railguns firing saboted, stealth projectiles (to minimize intercept from point defense) might see some use. They'd be short-ranged and inaccurate, but kinetic impacts would break the heat shielding very well, leaving the target vulnerable to laser attacks - assuming that the impacts didn't cause catastrophic airflow issues. It might be something that some air forces are experimenting with - railguns aren't consistent weapons, but they may have some high profile victories that make people think they're better than they are.

Stealth aircraft might also exist. These would be relatively low performance, turbojets, turbo-scramjets, or hyperfans with a heavy emphasis on thermal stealth. They can't intercept (or run from) a fusion air-ram fighter, but may be able to ambush them. The threat of stealth aircraft firing close-in railguns into a squadron pursuing a fleeing enemies might limit the decisiveness of air engagements. Again, this may be a more theoretical threat than something that actual happens, but the history of war is full of military forces that let their tactics be dictated by a potential threat that never materialized in practice.

Brilliant missiles are robotic missiles, so if robotic aircraft aren't used because of the threat of hacking, you need to explain why brilliant missiles aren't vulnerable. It might simply be a time question - the missiles' robo-brains aren't active enough long enough to be hacked - but I would probably limit the endurance of brilliant missiles to around 20-30 seconds. That also limits their potential range, which encourages everyone to engage at closer ranges.
I love these ideas! This is exactly the kind of conversation I was hoping to have! So yeah, you make a good point about robotic missiles. My thought as to why they'd be usable while combat robots wouldn't be, is that brilliant missiles don't need to have an external command input after they launch, to tell them to return and shut themselves down for repairs. Once launched, they just need to recognize an enemy vehicle and dive on it. Of course, that raises the possibility of them getting confused and attacking friendlies, but I think some friendly fire is a worthwhile risk for beyond-visual-range weapons. Though their practical range might be somewhat limited since fusion-powered aircraft are going to inevitably outrun a misisle too small to carry a reactor.

I like your idea about railguns, as a sort of "more advanced" weapon which only starts appearing later in the campaign as it gets miniaturized enough that a plane can fire one and handle the recoil. I imagine they'd shoot bursts of flechettes which rip up the skin of the enemy aircraft and ruin their heat-sinking capability. Thematically, this is also a sort of weapon that would be more likely employed on an aircraft that isn't really expected to come back, as it's too slow to run away after making its surprise attack... and thus shows the increasing desperation of whoever starts using these stealthy sniper planes first.

Quote:
Originally Posted by Fred Brackin View Post
The missing element for Caliph is the contragravity generator...

Without easy cheap reactionless thrusters Caliph is too young a civilization to have built up to that level of space activity.
Ack... this is what I was afraid of. After re-reading the writeup in alternate earths, I have to agree that the contragravity can't be excised from the setting.

Which brings me back to the original problem. How do you avoid the fact that every battlesuit and civilian aircar is suddenly a planet-killing superweapon capable of blowing the earth apart like a shotgun to a canteloupe? A global war is the central premise of the setting! Are we assuming that nobody considered building kinetic kill vehicles? The real problem is it doesn't NEED to be planet-killing - kinetic projectiles with high-acceleration reactionless drives can be scaled to any power you need, from taking out a single city on downwards, and even with lasers there is NO POSSIBLE WAY to defend against them.

Maybe it could be assumed that they are, in fact, contra-gravity, and can't produce 1G worth of thrust constantly once they're outside Earth's gravity well. Maybe the amount of acceleration they provide drops dramatically as it gets into space, since it is "pushing" against the gravitational field of earth or another planet... which means that once it's in space the acceleration drops to a few thousandths of a G. That, at least, means they would take several years to build up planet-killing velocity and ships with conventional fusion thrusters could catch up to them before they get very far.

Quote:
Originally Posted by mlangsdorf View Post
The mechanics of Caliph's fusion air-rams are 90% technobabble and game mechanics. Almost anything is justifiable, and it's mostly a question of what mechanics and play experience is desirable. I was mostly offering some reasons why vulnerable radiators at the back of the plane might not be desirable.

It is true that if an enemy craft is approaching from the flank, an aircraft would need to expose the upper surface radiators to roll into a reciprocal course - though turning away is safer since the radiators roll away from the flanker. I think that becomes part of the tactical maneuvering: if an enemy gets within effective laser range and bearing while flanking an aircraft, the flanked aircraft has to turn away (possibly into a twisting climb if it wants to re-engage) or accept that its vulnerable if it turns to engage. But I think that it is better if turning to disengage is generally safer, since that means that outmatched or losing fighters have a low risk retreat.
I actually really like this. It means that tactically, it is one's flanks that need to be guarded even more than one's tail, and the most risky thing to do (yet ultimately necessary) is to turn towards a enemy incoming from the flank. So, there's a balance between pulling a potentially fatal amount of Gs by turning hard towards the enemy (plus bleeding off a lot of your airspeed due to the inefficiency of making sharp turns), versus turning too slowly and giving the other guy a chance to vaporize your radiator surfaces and leave you crippled.

This also plays into the psychological element of fear/courage, which I think should always be a big part of any war-oriented RPG game. In the context of this specific setting it would be one of the major disadvantages of the Jamahiriya and Caliphate of Hind, since their warriors are are less likely to have the kind of suicidal bravery that "mujahedeen" do, helping to counterbalance the advantages they (particularly the Jamahiriya) get from embracing a more scientific, data-driven approach to warfare.

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Originally Posted by Anthony View Post
Aircraft really aren't going to use radiators; they'll rely on conductive cooling across large amounts of area exposed to a high velocity air stream. They have more heat problems than ships (which can use water), but less than ground vehicles and way less than spacecraft.
If it was just engines, sure. But when you're talking about mounting laser weapons with an output of several megawatts or more, conductive cooling across the surface isn't going to cut it, not on top of a fusion engine. If your laser weapon can melt another aircraft to death in spite of the cooling effects from airflow, that means it's putting out enough thermal energy into your plane to melt YOU to death as well.

And, more importantly, if lasers are the main weapons (which they absolutely will be, since even railguns can't come close in terms of range and accuracy) then you need to defend against them, and reactive exploding armor works a lot less well for an aircraft than a tank... not least because one of the biggest dangers of getting hit with a laser pulse in an aircraft is that the plasma explosion might make your plane lose control and start tumbling, so ERA defeats the whole purpose.

So, I think that if you're needing to radiate the heat of multiple laser hits as well as your own weapons, you want a super-cooling skin all over the surface of your fighter jet, and use radiators to shed the heat. From a gameplay perspective I think this works well since it gives a "weak point" that your wingmates need to protect, and creates the issue that SOMEBODY in every formation has to draw the short straw, of being the first into the breach who is unavoidably going to catch hell at the start of any engagement.

Morale is the most compelling part of combat in a game like this, even moreso than clever tactics or feats of skill. When troops are fighting on the ground, even with a jump pack or whatever, they realize that they are pretty much stuck in it once a firefight starts and that if they try to run away they'll just get mowed down. But fighter pilots don't have that certainty to lean on. They always have the option to break formation and abandon the rest of their wing in a dogfight.

Last edited by seasalt; 11-25-2022 at 05:20 PM.
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Old 11-25-2022, 05:56 PM   #8
mlangsdorf
 
Join Date: Aug 2004
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Default Re: TL 9-10 air combat in the "Caliph" setting

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Originally Posted by seasalt View Post
This also plays into the psychological element of fear/courage, which I think should always be a big part of any war-oriented RPG game.
I think you can do a lot of emphasize psychology with upper surface radiators - turning toward or away from a flanking attacker; playing chicken on reciprocal courses with the additional question of who is willing to overheat their fighter more to dump more heat on the other guy; who climbs higher as their cooling efficiency drops; and whether to risk going into a dive for better cooling at the cost of possibly exposing your radiators. And this is definitely something that different air forces, depending on training and doctrine, might have different answers on.

Intriguingly, the first person to fire possibly has a defensive advantage, if his attacks dump enough heat into the enemy that the enemy can't respond with the same intensity. Obviously, ideally fighters attack each other with high rear passes, but if a fighter ends up in a scissors, firing first can be an advantage. Or not - if the firing starts from too far away, the firer builds up all the heat but doesn't deliver much. Another psychological question, actually - wait for your fire to be as decisive as possible at the risk of waiting too long and being on the wrong side of the heat transfer issue.
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Old 11-25-2022, 07:58 PM   #9
Anthony
 
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Default Re: TL 9-10 air combat in the "Caliph" setting

Quote:
Originally Posted by seasalt View Post
If it was just engines, sure. But when you're talking about mounting laser weapons with an output of several megawatts or more, conductive cooling across the surface isn't going to cut it, not on top of a fusion engine.
Actually, it pretty much will. A couple megawatts isn't much. If necessary, use expendable coolants.
Quote:
Originally Posted by seasalt View Post
And, more importantly, if lasers are the main weapons (which they absolutely will be, since even railguns can't come close in terms of range and accuracy) then you need to defend against them, and reactive exploding armor works a lot less well for an aircraft than a tank... not least because one of the biggest dangers of getting hit with a laser pulse in an aircraft is that the plasma explosion might make your plane lose control and start tumbling, so ERA defeats the whole purpose.

So, I think that if you're needing to radiate the heat of multiple laser hits as well as your own weapons
If the laser doesn't successfully penetrate, the heating is pretty much irrelevant.
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Old 11-25-2022, 09:20 PM   #10
Fred Brackin
 
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Default Re: TL 9-10 air combat in the "Caliph" setting

Quote:
Originally Posted by seasalt View Post
Ack... this is what I was afraid of. After re-reading the writeup in alternate earths, I have to agree that the contragravity can't be excised from the setting.

Which brings me back to the original problem. How do you avoid the fact that every battlesuit and civilian aircar is suddenly a planet-killing superweapon capable of blowing the earth apart like a shotgun to a canteloupe? t.
Actually no. Use talk about blowing planets apart around here and you'll run into the factoid that to actually blow an earth-sized planet apart efficiently you'd need to replace a sphere at its' core 7 miles in diameter with pure antimatter.

To accumulate that much KE you need an asteroid at least as big as the dinosaur killer travelling at very near lightspeed. You'd need to accelerate it at 1 G for a whole year to get near C.

A 1 ton (metric) aircar with thrust only equal to 1/6th G with lift provided by contragravity needs 6 years and "only" delivers 43 gigatons. It won't hit the surface of Earth either. It'll go FLASH! as soon as it hits the upper atmosphere which will be very bad for living beings of that hemisphere and probably mess up the atmosphere as a whole but it won't treat the planet as a shotgun does a cantaloupe.

Also, even for the 1 G acceleration you have to go a half a light-year out to get to your starting place which will take you more than a year because you have to come to a stop before you launch your projectile.

Reactionless thrusters do create the possibility of very powerful KE weapons but actually blowing up Earth will be orders of magnitude more difficult than you thought.
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