Thursday, September 9, 2010

'Space' Warfare XII: Surface Warfare


Ask, and ye shall (sometimes) receive: A reader emailed asking me to discuss future ground war. This I will take a bit more broadly as warfare fought on habitable, shirtsleeves planets, including sea and air operations. Warfare on non-habitable planets is an ambiguous case, with features of boarding operations in space.

I intended to deal first with the space context. But y'all want grunts, preferably in power armor, supported by coolific armored vehicles and aircraft, with subs and trimaran assault cruisers out to sea. Which brings us to something that has not been tested yet. What happens when post industrial forces fight each other?

We don't know, but we have seen this movie before, in flickery black and white a hundred years ago. Industrial age Western armies had shown how well they could scythe down waves of natives, usually. The general prognosis was that 1900-modern weapons were so accurate and effective that when turned on each other they would pretty much wipe each other out, and quickly.

The Next War would be a come-as-you-are war, settled in months if not weeks by whoever ran out of arms and ammo first, if it weren't won a week earlier by strategy and tactical execution. 1870 was the prelude; 1861-65 merely an example of a semi-modern war fought entirely by blundering amateurs.

It did not work out that way in 1914, so I hesitate to say it would work out that way now, or in 2114. What might happen, in fact, is broadly what happened in 1914: Everyone goes to ground.

The general principle of future surface war, it seems to me, is that if you are caught out in the open you are headed for the celestial choir. This goes for guerillas, it goes for power armor troops, it goes for laser armed tanks, trimaran cruisers, aircraft, and spacecraft in low orbit. Give precision weapons a clear target and they will take it out.

Thirty meter mecha, sad to say, make for very clear targets.

Reconnaissance robotics, on the other hand, will be hard to take out. They can be very small and stealthy, making the Predator look like a B-36. So you should have plenty of scouts, including a robotic fly on the wall of the other side's headquarters. Your intel problem is noise - the more raw intel, the more noise. Any AI good enough to cut through it is an intelligence officer, not a piece of equipment.

A tank backed into the underbrush is still effective, because it is hard to find, and you may only find it when it opens up on you. A tank on the move has a target painted on it. This, I think, is the real advantage of power armor troops: Compared to tanks they are stealthy, and can slip through environments where a tank would draw attention and fire.

I expect power armor to be relatively light. At minimum you want enough to stop small arms fire, shrapnel, and the like. The maximum of useful armor is reached when a hit would kill you anyway, like getting hit by the equivalent of a truck. Against lasers this may mean the point at which you cook inside your armor, not good.

Future war may well be 'slow,' because the mobility of power armor troops is essentially foot mobility, with enhancements like powered roller skates. Mobility is limited behind the front as well, because truck convoys will be conspicuous targets even hundreds of km behind the lines. Logistics too will have to be stealthy.

It is easier to have a Ho Chi Minh Trail in the jungle, so one thing timeless will be the supreme importance of ground and the physical ecosystem. This of course gets interesting on habitable planets other than Earth.

Some kinds of fortifications might remain valid, basically because dirt absorbs a lot of damage points. Yes, there are bunker busters and Thor bolts, but the point is that such big powerful weapons are costly to deploy, carried by vulnerable platforms, and can be engaged by defensive fire. This could be the saving of large naval surface combatants, hard to sink except by massive attack that overwhelms their defenses.

The one way to achieve rapid, heavy movement, whether logistic or an actual assault, is to ramp up the noise level so high that the enemy's sensors are saturated, and nothing (you hope) is in 'plain sight.' If you are right you get blitzkrieg; if wrong you get the Somme.

Large scale surface war may thus have an alternating rhythm - weeks or months of stalking, skulking, and skirmishes along the front, interrupted by episodes of sheer rock & roll, perhaps to cover the fast movement of a truck convoy up to the front, where it will disperse itself and go to ground.

All of this takes place, or doesn't, against the background of nuclear weapons. The constraints on mobility in 'conventional' warfare could make it indecisive enough for the great powers to engage in it without risking a nuclear exchange. As in the 18th century they would be fighting for provinces, not national survival.


Now for the space context. If suitable planets are limited - say, Earth and terraformed Mars or Venus - politically balkanized planets are to be expected, unless you go mid 20th century retro and have the American Empire a Federation. Certainly on Earth itself you can plausibly expect Great Powers, with great power militaries.

In a few-worlds setting, space itself will be off in the background. India is not going to get in a major tussle with Olympus Mons; both have bigger problems much closer to home. And India and China are not going to take their arguments to the asteroid belt, at least not in a big way, because money spent on deep space forces comes out of much more critical surface, air, and Earth orbital forces.

This can have advantages for space-centric settings, because you can let the major Earth powers stalemate each other, keeping them off the deep space chessboard.

In the classic operatic setting of many colony worlds, it could be a different matter. Uniform planets are rightly bashed, and I've bashed them myself. But in such a setting I think politically unified planets will be common, perhaps the norm. In the colonization era everyone can have their own planet, and later on, even if local fissures develop - and they will - any planet that can present a united front enjoys a huge advantage in interstellar power politics.

Or putting it another way, any planet that cannot present a united front is at a huge disadvantage, drawing plot complications like flies. And here we are.


I could make the many and salient arguments for peace, but I know they would fall on deaf ears, so we'll go straight to comments.


The image comes from this futurist blog.

829 comments:

«Oldest   ‹Older   201 – 400 of 829   Newer›   Newest»
Milo said...

I think a good infantry-sized laser would have somewhere around:
- a battery power of several kilowatts
- a battery energy of up to a megajoule
- a capacitor energy of several kilojoules
- and optics capable of projecting this to a range of up to several kilometers

If the laser is highly inefficient, then these numbers need to be multiplied to compensate. Of course, there's a good amount of wiggle room in what "several" is.



Luke:

"room temperature superconductive"

Heh. Always a fun piece of unobtainium tech for sci-fi.

It's probably hard to justify us finding room-temperature superconductor materials that can be mined on some world but that can't be manufactured artificially, but it would certainly serve as a nice MacGuffinite if you could!

Even without that, having room-temperature superconductors everywhere is a nice hard-science way of reminding people that this is fuuuuuture tech.

Raymond said...

Only problem with that laser package, Milo, is the range. Kilometers aren't in the cards. Luke could get into more detail, I'm sure.

Room-temp superconductors are the Holy Grail, aren't they? Metallic hydrogen, if we ever figured out how to make it, would be. There's also a distinct possibility palladium hydride may be as well, at higher saturation rates. Hydrogen fits into the holes in the palladium lattice, apparently. And given the very limited palladium supplies on Earth, it would be a good reason to go to the asteroids.

Raymond said...

Albert:

Oh, believe me, trying to land advance units surreptitiously on an Earth-class homeworld would indeed be suicide. I think it would be a very different kettle of fish, however - the bigger the planet, the more likely it's balkanized to some extent. At which point you could get yourself a local ally or puppet state, and it's a whole different ball game.

Milo said...

As we've been discussing, one of the biggest advantages of lasers is accuracy, and as Byron pointed out, this means lasers will likely be used as sniper rifles before they become practicle as other kinds of personal arm. As I pointed out, another major advantage of lasers is flexibility, so I expect that even lasers designed for other roles should retain the ability to be used as sniper rifles in a pinch.

Sniper rifles can already reach over a kilometer today, so if lasers can't match that then that would seriously stymie their use.

For an assault rifle replacements, a more managable range of several hundred meters would suffice.

Rick said...

Unending chaos and violence ... my work here is done!

Luke said...

Raymond

Fixed laser installations are dead. Gone. If I'm invading your planet, I hit those from high orbit with kinetics launched when the site is facing away. Repeatedly. I don't come any closer until they are dealt with. I can spot them from geosynch, and they might even be worthy of nukes, not to mention the number and size of kinetics I can launch at nominal delta-v.

I can see fixed installations as playing a role. They might not be invulnerable, but the goal is to make the other guy hurt more than you will get hurt if your laser installation is taken out. A 10 meter mirror can hold a spot size of about 2 meters at geostationary orbit of earth with green light lasers. With a high power laser, this will enable the laser to attack geostationary spacecraft within view (with a 10 MW laser I calculate a drilling speed of not quite 0.1 mm/s in steel. A 100 MW laser would get you 2 mm/s in steel). Three such stations would allow full coverage of all distant orbits, and would allow attacking closer orbits as they come into view. Of course, you might not have conveniently placed sites commonly free of clouds, but if you do, you can use this as a first line of defense to burn those annoying attackers out of the sky. With wide enough coverage, they can't hide behind the planet and lob kinetics at you. Plus, your lasers can burn down the kinetics as they are in transit.

If these lasers can inflict high enough losses on the enemy, he might think twice about attacking, and if he attacks anyway he will lose a number of his assets before he finally takes out your laser stations.

As far as the kinetic strikes, I calculate a minimum delta-V (from Earth geostationary orbit to a grazing strike on Earth's surface) of 1.5 km/s (easily within the capabilities of solid rockets), and a transit time of 43000 seconds for the minimum delta-V trajectory. That will give the laser defense stations 12 hours to burn the kinetics.
(details:
initial semi-major axis = 4.2164e7 m
final semi-major axis = 2.42675e7 m (this gives an apogee at the geostationary orbit and a perigee at earth's radius of 6.371e6 m)
mu = 3.98e14 m^3 s^-2 (this is the product of earth's mass and the gravitational constant)
specific orbital energy = -mu/(2 * semi-major axis)
initial specific orbital energy = -4.72e6 J/kg
final specific orbital energy = -8.20e6 J/kg
specific potential energy at apogee = -mu/(radius of apogee) = -9.44e6 J/kg
specific kinetic energy = specific orbital energy - specific potential energy
initial specific kinetic energy = 4.72e6 J/kg
final specific kinetic energy = 1.24e6 J/kg
velocity = sqrt(2 * specific kinetic energy)
initial velocity = 3.07e3 m/s
final velocity = 1.57e3 m/s
delta-V = 1.50e3 m/s
)
This trajectory and very similar ones are those that will allow targeting of the back side of the planet. You can get strikes that take less time with more delta-V, but these attack the near side of the planet. The minimum delta-V strikes will be entering the atmosphere at 10.4 km/s. The faster your strikes reach the laser stations, the faster the re-entry (okay, technically there is no re in the entry, this is the first time the kinetic goes into the atmosphere, but re-entry is the common technical term so I will use it). 10.4 km/s through a dense atmosphere like that of earth is pretty harsh, and going faster makes it worse. There are probably ways to engineer your re-entry vehicle to take the heat, but you need to decide what the upper limit is for the tech in your story, which determines your minimum transit time (assuming you have unlimited delta-V).

Now once you have taken out all the defense stations on one side of the planet, your bombardment craft can hide on that side of the planet and target the stations on the other side with their grazing-strike kinetics. But while the stations have full coverage you have your work cut out for you.

Byron said...

I guess I didn't think of that about the sub mirrors. It seems like it would work, though probably more limited than a surface ship, as good submerged performance usually means poor surface stability.
Ferrell, that seems like it would work, except for the whole artillery spotter vs. strike team thing.
Milo, Albert seems to have solved the debate pretty well. I was assuming that there was rough parity between attacker and defender, and the attacker can't take too many losses.
The problem is that your method only works if you have a fleet a lot larger than theirs. I've been working from worst-case scenario. You have limited forces compared to theirs, and there's no cracks.
This might be a good time to explain my philosophy for these debates. I generally see us as some sort of general staff, and we're trying to work out (in this case) the general method to take an enemy-held planet. We do this starting at the hardest possible level, and assume that it can only get easier. In this case, I'm assuming the worst, IE strong defenses, and no gaps. If they're there, exploit them, but don't assume there will be.
On spacecraft vs. submarines, the 90 day limit might not apply. Of course, during the tour, the attackers ships can visit our giant mobile base (remember it from the last space warfare) or at least look out the window. Normal surface warship deployments are around 6 months. They can, however, get some fresh air. You can't do that in space, but you can see out. It's something we won't know until we get there.
The problem with balkanized = points of entry is the entry range issue. If you've opened hostilities, they might be able to shoot you down as you enter, even if you land in someone else's territory. Possibly even if you're over your ally's territory.
I mentioned sniper rifles simply because it seems ideally suited for that role. They can be expensive, with limited ammo and slow charge times, and it doesn't matter as much. Plus, pinpoint accuracy is most useful when you have someone with the time and training to use it.
Luke, the problem might be finding these kinetics. If the station can't move, there can be lots, and they can be chilled and launched from coilguns. They're thus hard to detect from the atmosphere. Radar stealth would work, and IR telescopes are somewhat ineffective from the planet's surface. You can't see it until entry, and then it's too late to get all of them.
This brings to mind that we should try some sort of wargame. The problem is that we'd rapidly fill 500 posts over tech assumptions.
Happy 200 posts everyone.

Luke said...

Raymond

Only problem with that laser package, Milo, is the range. Kilometers aren't in the cards. Luke could get into more detail, I'm sure.

The range at which a laser has full effectiveness depends on the material it is being used against. I'll just assume blaster style lasers here and neglect heat rays for now.

For a blaster, a well focused pulse will blow out a crater with a diameter that depends on the material strength. If you can focus your pulse inside this crater radius, your laser will be at full effectiveness.

I will consider a "battle laser" with a 5 kJ beam, firing 50 pulses of 100 J each, spaced 20 microseconds apart. This is a bit of overkill against unarmored infantry, but gives better hitting power against armor. Against ballistics gelatin, a 100 J pulse will blow out a hole with a temporary cavity of about 6 cm wide. The cavity will collapse on a time scale of a few milliseconds, but since our pulse is shorter than that, we don't need to worry about it. If we assume a 6 cm lens, diffraction-limited performance, and 1 micron laser light, the laser can focus for maximum damage out to 2.5 km. Of course, the human body is not ballistics gelatin. Ballistics gelatin is a reasonable approximation of muscle, but there is also skin, tendon, bone, and other stuff that is stronger than muscle. Against stuff held together by lots of collagen (like tendon and skin) expect full effectiveness out of 730 m. Against bone, expect full effectiveness out to 325 m.

Against armor steel (RHA), a 100 J pulse will blast out a crater of about 3.8 mm. That corresponds to a range of 160 m.

Against diamond-like carbon armor, a 100 J pulse will blast out a crater of 2 mm diameter. This gives a range of 83 m for full effectiveness.

Note that a laser can still cause damage at ranges greater than the range of maximum effectiveness. In particular, since most of what you blast through on a person is meat and viscera, the performance against bone and tendon is not as important. Especially since these lasers have more than enough penetration to go through several people (I predict about 1.44 m penetration through ballistics gelatin). Lethal ranges of more than two kilometer can be expected against unarmored troops. Against super-troopers in full armor, you will need to get a lot closer.

If you can switch to green-light beams, you can double your range. If you use a "sniper" lens with a 12 cm aperture, you again double your range.

I will note that at one point the military decided than most firefights took place within 300 meters, so they switched over to assault rifles rather than full powered battle rifles. If this holds in the future, it would argue that you only need to have your infantry laser perform at full effectiveness out to 300 m or so.

Luke said...

Byron

Luke, the problem might be finding these kinetics. If the station can't move, there can be lots, and they can be chilled and launched from coilguns. They're thus hard to detect from the atmosphere. Radar stealth would work, and IR telescopes are somewhat ineffective from the planet's surface. You can't see it until entry, and then it's too late to get all of them.

If you are illuminating the enemy spacecraft with your lasers, you will be able to see the kinetics via the reflected light from your laser. Some of the analyses I've seen are that multi-megawatt lasers are quite good for detecting cm-size scale objects in earth orbit.

Byron said...

How high of earth orbit? And what if I launch a bunch of balloons at the same time?

Raymond said...

Luke, thanks for the laser numbers. Numbers are awesome. Even when they support my worst fears while justifying the fact I was afraid in the first place. I was thinking the same way as Byron with regards to chilled, coilgun-launched projectiles in huge swarms. Also, if the spot size in the green range is 2m at geosynch (you said geostationary, but didn't specify an altitude, so I think you meant geosynch), it would be 4m in the micron range, right? Wouldn't that be too little resolution to pick up the IR signature of a 1m diameter projectile? Or am I missing something?

Also, for the infantry laser, I was thinking range against armored targets. I had no idea the range against meat would be so long.

Ferrell, that kind of landing was what I had in mind. And Byron, I was thinking of using it sparingly. And not against Earth-class planets. I do like the general staff bit, though.

What I wouldn't give for a video game that modeled half of what gets discussed on this blog. We have the CPU resources, we have the graphics engines, but somehow we get the same boring space marines.

Milo said...

Byron:

"The problem is that your method only works if you have a fleet a lot larger than theirs. I've been working from worst-case scenario. You have limited forces compared to theirs, and there's no cracks."

I see this as you trying to use a hundred knights to capture a castle defended by a hundred knights. You can, if you catch them offguard with an unexpected strategy or if one of their own betrays them or if they do something stupid or just if you get lucky, but your chances are pretty poor. I would avoid trying to capture a planet at those odds if I could help it.

We are talking about conquering Earth, here. That isn't something to be taken lightly.


"I mentioned sniper rifles simply because it seems ideally suited for that role. They can be expensive, with limited ammo and slow charge times, and it doesn't matter as much. Plus, pinpoint accuracy is most useful when you have someone with the time and training to use it."

Fully agreed. However, you also need good range.


"This brings to mind that we should try some sort of wargame. The problem is that we'd rapidly fill 500 posts over tech assumptions."

Solution: have evolving tech. If you think missiles are useless because laser point defenses are capable of easily shooting them down, then you can announce your side commences a research project to develop a laser that can effectively shoot down all missiles currently in use. Until this research project finishes, you do not yet have the laser and need to keep fighting with technology that was available when the war started, no matter how poorly designed you think it is.

However, we would still need someone to give a final ruling on what research projects work/fail/work partially/have horrendous cost overruns but eventually work. This person will probably not remain popular for long.

Milo said...

Luke:

"I'll just assume blaster style lasers here and neglect heat rays for now."

Good idea.


"This is a bit of overkill against unarmored infantry, but gives better hitting power against armor."

Well, powered armor might still be in the running, so it's good to be prepared.

Also, it would be desirable for infantry weapons to be somewhat capable against light vehicles, if at all affordable. Not tanks, of course, you need special weapons against those.


"Against stuff held together by lots of collagen (like tendon and skin) expect full effectiveness out of 730 m. Against bone, expect full effectiveness out to 325 m."

How do headshots work out? The first thing you hit, aside from an insignificant layer of skin, is the skull (a layer of bone), but what you really want to damage is the brain underneath.


"Against armor steel (RHA), a 100 J pulse will blast out a crater of about 3.8 mm. That corresponds to a range of 160 m.

Against diamond-like carbon armor, a 100 J pulse will blast out a crater of 2 mm diameter. This gives a range of 83 m for full effectiveness."


Those ranges are pretty poor compared to even modern assault rifles (around 300 meters), nevermind sniper rifles.


"Note that a laser can still cause damage at ranges greater than the range of maximum effectiveness. ... Lethal ranges of more than two kilometer can be expected against unarmored troops."

Ah. Much better.


"Against super-troopers in full armor, you will need to get a lot closer."

Cool. So that simultaneously justifies armored infantry and (relatively) close-range battles.


"If you can switch to green-light beams, you can double your range."

Light frequency will be based on what can penetrate the atmosphere well. Thus a compromise has to be struck between lower frequencies (which have longer ranges due to being scattered more slowly by the atmosphere) and higher frequencies (which have longer ranges due to suffering less diffraction).

Byron said...

It's because video games are commissioned by corporate executives, who's sense of awesome has rotted from years of striving for good hair. And they're advised by marketers. Don't even get me started about marketers. Still, who's to say that we need a video game. We have orbiter and graphing calculators. What more do you need?

Byron said...

Yes, sniper rifles will need good range. However, I can fit a lot bigger lens on a sniper rifle than a handheld one. Plus, you can target unarmored parts of the body.
Solution to tech:
We have Rick do it. We can't hate him, as he runs the site. Of course he might ban me for suggesting that.

Raymond said...

Still, who's to say that we need a video game. We have orbiter and graphing calculators. What more do you need?

Actually getting to see the virtual sky light up with falling kinetics? C'mon, some of us want the visuals. It would be spectacular to watch. And multiplayer between the bunch of us? Make the Starcraft slaves look like monkeys.

Byron said...

I said wargame, not RTS. That includes such things as paper games. Plus, there are entry halos in orbiter. I've gotten some at sea level, though on accident. I've even added a ship, though there were issues with that. (It was my Aurek)

Byron said...

This of course leaves the question of what any wargaming environment would look like. We'd probably have to create a fictional system with multiple habitable planets to make it work. Otherwise, we can't test enough stuff to really be feasible. I could do up the system in GURPS Space. Anyone interested?

Luke said...

Milo:

How do headshots work out? The first thing you hit, aside from an insignificant layer of skin, is the skull (a layer of bone), but what you really want to damage is the brain underneath.

My model is kinda iffy when the spot size is larger than the crater diameter from a well focused pulse. If I assume the volume excavated per pulse remains constant, then I expect that for the same laser as mentioned previously, at 2 km you will penetrate 7 mm of bone - which seems like it gives just enough left that it might go into the brain and cause a terminal headache. At 1 km, you are looking at about 3 cm of penetration through bone - quite lethal.

However, this model is on highly shaky grounds. I don't have anything better, though. I suppose it can be used as a first guess for fictional purposes.

If the model holds, at long ranges you may go for gut shots rather than head shots, because you won't need to go through bone that way, and a 6 cm hole through the abdomen is enough to ruin anyone's day.

Luke said...

Byron

How high of earth orbit? And what if I launch a bunch of balloons at the same time?

A document I have about a NASA study on removing orbital debris in the 2 to 10 cm size range from near earth orbit suggests that a 5 to 25 kW (time average) laser with a 5 to 10 m aperture lasing at 1 micron wavelength can be used for lidar targeting of debris out to at least 1500 km altitude (probably more, they only considered removing debrus at altitudes of less than 1500 km. For comparison, debris of this size can be seen from earth using reflected sunlight for about four hours out of each day according to the same report). For the 100 MW laser defense station using a 10 meter scope and emitting at 0.5 micron green light, and assuming the usual 1/r^4 scaling of active scanners, this suggests that you could lidar-target 2 to 10 cm objects out to about 70,000 km. Geostationary orbit is about 36,000 km altitude.

At the rates I calculated for the laser burning through armor steel, the balloons would last for only a fraction of a second under the beam. Anything that doesn't immediately incinerate is a threat.

Byron said...

I'm working up a random system in GUPRS Space. I plan for 6 habitable worlds: 2 planets and 4 gas giant moons. Before anyone starts screaming about astrophysics, this is mostly an attempt at polito-military simulation in a wide variety of environments. It's not an astrophysics simulator. As to how humans got there, I don't know. Generation ship? Technological crash? It's sort of irrelevant. The point is that we have a number of habitable worlds, and a number of domed ones.

Milo said...

Byron:

"I plan for 6 habitable worlds: 2 planets and 4 gas giant moons."

That's all? We can get that right here. Pick Earth, Mars, and... oh... Callisto, Mimas, Miranda, and Triton if you want to spread out your moon worlds. (Generally once a moon around a gas giant has been settled it will be easier for other people to continue building there rather than colonizing a new moon, unless space runs out - which will take a while - or someone wants to get away from others for social or military reasons, or you want both an open-air world and a domed world.) Neptune's system might be a good place to practice with hollow-asteroid habitats, given it only has one rounded moon. Then again, we might just not bother with Neptune anyway, it's no easier to mine from than Uranus and is annoyingly far away. Scientific research on Triton is probably the main reason to go there.

Balkanized?

The obsessed Scholar said...

Wow, 221 Comments. :D *Bookmark* *Suscribe*


Some thoughts on power armor.

In the middle ages, the Man-at-Arms AKA 'Knight' was the dominant arm on the field.

His plate armour weighed 45-60 pounds and it was proof to longbow shots, crossbows, impact weapons, cuts, thrusts and even early firearms.

The only way to kill one was to field another 'Knight' or swarm him and stick a dagger through his visor. His armour also permitted full movement and flexibility.


I don't see why you couldn't achieve this with PA. If the weight is around 800 Pounds (Which is much less than a modern riding horse) Why not design the armor with weight distribution tech? And if it's powered movement and flexibilty aren't going to be a problem. Neither is momentum if you have some kind of auto-breaking mechanism built in.

Finally, have the armor made from a high-strength nano-macguffiny carbon/metal alloy? Thus allowing more protection for less material and thinner/lighter armor. Also, what about adding a TROPHY type system on PA?


As for conventional battles. . .

Well as a writer, I confess that orbital defenses don't seem like the uber-weapons they're portrayed as. It was once thought air-power would make ground forces obsolete after all. Besides, as a writer I want and need large conventional slugfests.

I'm toying with the idea of Space-going equivalent of an Amphib Assault ship that's heavily armored and designed so it can enter and atmosphere and land.

And finally. Anyone know how to make sure things like Slag, Nukes and the whole MAD wouldn't be an issue anymore in a Space War setting?

Milo said...

Why do my posts keep getting deleted? I typed up a beautiful summary of colonizable worlds in our solar system. It went through, I know, I saw it!

Okay, retyping from memory. There are two classes of worlds: open-air and domed. I've argued before that a good system will have some of both, since there are economic and scientific advantages to not having an atmosphere in the way.

With generous terraforming technology, options for open-air worlds in our system are Tellus, Mars, and Venus. It's rather of a stretch to include Venus, since terraforming it is going to be very difficult and will require some pretty advanced technology, but then so would interstellar travel. Other options include Ganymede and other gas giant moons.

Domed worlds would include Luna, Callisto, Mimas, Miranda, whatever other gas giant moons you feel you need, and perhaps Mercury. Kuiper belt objects (Pluto and Eris) are unlikely settlement locations might be targetted if someone wants to get away from everyone else for some reason.

Phobos and Deimos are of little interest at first glance, but are important for one purpose: military. They could be good places to put orbital forts for defending Mars, and would also be places invaders would like to capture to use as a forward base.

While another system can have slightly more worlds than us, it would probably be in the same general order of magnitude. Having significantly more worlds would require travel between multiple systems, and then the nature of your FTL technology strongly influences strategy.

Milo said...

The obsessed Scholar:

"Anyone know how to make sure things like Slag, Nukes and the whole MAD wouldn't be an issue anymore in a Space War setting?"

ICBMs are deadly in large part because of their ability to hit anywhere in the world in minutes. Lack of stealth in space means that you would tend to have months to see an interplanetary weapon of mass destruction arriving, so you have plenty of time to scramble a defense to take down just one missile, no matter how big a boom it would make.

Weapons of mass destruction are much more of an issue if the enemy manages to get orbital bombardment ships into your orbit, or if your planet is Balkanized. This is why the future will likely see a trend toward reducing Balkanization. And why guarding your orbit is important.

Byron said...

I understand, but I was referring to open-air worlds. I'm going to have to play with the various numbers to make it work. There are a number of domed worlds as well. The moons are probably all around the same gas giant, to allow short-ranged battles. I'll describe the setting more as it develops.
Scholar, please read the back archives. I know it's a lot, but we've covered all of your ideas, and, no offense, but they don't work. The defenses are too deadly, and what's an 800 lb suit of armor to do? He can't do infantry ops. And you can't get rid of MAD. You just have to limit it's effects. I know you need your big ground battles as a writer, but as a strategist, I need realism. You see, this discussion is part of my plan to get a job in a think tank. (Just joking, but I take it seriously.)

Tony said...

Luke:

"The best modern Li:ion batteries can store nearly a MJ/kg. At one kJ per shot, a 10 kg battery pack would give you 10,000 shots."

First of all, the 5.56 mm NATO round has a muzzle energy of roughly 1,800 joules. Second, the actual expenditure of energy to get that into the projectile is much higher. In fact, the vast majority of the energy is lost in waste heat. Lasers will have similar limitations, without the heat rejection facilities of ejectable metallic cartridge cases.

"I can easily foresee an improvement of specific energy or specific power of batteries by an order of magnitude or more (maybe you will have a choice of one or the other, maybe you can do both at once. It is hard to say)."

"[S]pecific energy"? You mean energy density? The more energy you put in, the more energy is stored to be discharged, and the greater the hazard in case of damage or malfunction. Batteries aren't containers of chemical fuel. They're like pressurized gas tanks, which are more dangerous the higher the internal pressure. A charged battery is dangerous in proportion to its ability to push electrons down a "pipe" (electrical transmission medium). The more energy you put in a battery and the quicker you can get it out, the more hazardous it becomes.

"My favorite sci-fi super battery is a toroidal room temperature superconductive inductor supported by a carbon nanotube backing."

Magitech.

"...laser weapons...maybe...end up being better than projectile weapons in terms of lethality, cost, armor piercing, ruggedness, ammunition capacity, rate of fire, and accuracy."

But that's hardly the way to bet.

Milo said...

Uranus would be a good place for a multi-moon system. Titania, Oberon, Umbriel, and Ariel are all approximately the same size (the former two a little larger than the latter two) and so on comparable standing, with Miranda as the small but economically important extra (due to low gravity and proximity to Uranus making it ideal for the helium-3 mining industry).

You can have Miranda as a dome world and the other four as your open-air worlds, which would actually be a pretty sensible arrangement in real life if we can justify settling all four at all.

And that's before starting on what you can do around other gas giants.

Milo said...

^settling all five at all. Sorry.

Milo said...

Oh, and room-temperature superconductors aren't magitech, they're unobtainium. But so are weapons-grade lasers and fusion power, not to mention interplanetary spaceships and terraforming. All have a scientific basis.

Granted I'm not holding my breath for any of the above.

Thucydides said...

Retreating back to more "plausi-tech" for ground battles. The key for the mid future will be mobility, and I think air mobility will be the next step.

Helicopters and tilt rotors of today give you a hint of what may come, but a militarily useful vehicle needs to be rugged and soldier proof (not at all like an aircraft), and a military vehicle follows General Senger und Etterlin’s main battle air vehicle concept: The main battle air vehicle uses ground tactically without relying on it for mobility. Weird as it sounds, the idea of a morphing vehicle that can fly and fight in the air and on the ground (like some of these Japanese battle robots, but not transforming from a jet into a giant walking robot) makes a certain amount of sense.

Heavy lasers can be built and have their coverage extended through a series of relay mirrors, which can be virtually disposable by being mounted on drone aircraft, balloons or fired into space on cheap rockets. The laser itself can be carried aboard a 747 sized cargo craft (I have seen plausible programs based on a megawatt class FEL laser), allowing fire support to be on call without exposing the prime fire support weapon. Large aircraft carrying coil or rail guns can also provide fire support against ground, air or even low orbital space targets, once again changing the nature of air support back to a form of flying artillery.

Long range fire support will also be decoupled from the battlefield, "artillery" will be based on things like railguns mounted on ships (the proposed USN railgun program envisions firing at targets over 300km away), hypersonic cruise missiles launched from CONUS and appearing over Iran within two hours or even converted ICBMs raining programmable sub-munitions over the battlefield less than 30 minutes after launch (15 minutes for SLBMs).

Soldiers and equipment will be protected from this sort of mayhem by using techniques like metamaterial cloaks to become invisible at selected wavelengths or pulse generators to cancel out explosive overpressure waves. The lower tech enemy forces might resort to area weapons like napalm, thermobarics or even nuclear weapons to counter invisible, fast moving enemies.

Milo said...

Although... on second thought, that's assuming Uranus's moons can be terraformed. That might require an impractical amount of greenhouse gasses. Although I think their small size here actually helps - low gravity allows you to have a larger atmosphere for a given atmospheric density, so even if greenhouse density total is not too high you'll still have more greenhouse gasses just from the large amount of atmosphere between you and space.

Of course Saturn also has quite a few moons to play with, although it still needs a lot more greenhousing than Mars.

This is assuming terraforming is practical at all. Which it would need to be for us to have any habitable worlds except for Earth, even with FTL.



Thucydides:

"The lower tech enemy forces might resort to area weapons like napalm, thermobarics or even nuclear weapons to counter invisible, fast moving enemies."

Heh. Some day, nuclear weapons will be seen as puny low-tech stuff. A chilling thought.

Luke said...
This comment has been removed by the author.
Raymond said...

Thucydides:

Are you implying that helicopters and tilt-rotors are insufficiently militarily useful? I'd beg to differ, and so would the chopper pilots. As for fighting on the ground and in the air, why would you want to? I can't imagine any sort of hybrid which was armored enough to survive long on the ground yet light enough to have good performance in the air.

Teleros said...

Milo: "If your missiles can comfortably travel from water to air to vacuum blind and still kill their target spaceship, then counter-torpedos would probably also be able to comfortably travel from vacuum to air to water blind and still kill their target submarine."

My thinking was that all that water will make a submarine considerably harder to track than a starship (not to mention probably cheaper and so potentially more numerous). Admittedly, very large anti-sub torpedoes (fusion?) will work wonders at blowing up everything near where the missile launched from, but that's why I suggested one designed not to breach the surface of the ocean before the sub's clear (or nearly clear), although that'll depend on sub speed and how effective any counter-sub fire will be underwater (I've no idea how well a fusion bomb would work under a km or two of ocean etc, save that you can't use the usual above-ground calculators for it :P ).

Against such an attack, you either have to spam the area with a lot of anti-sub nukes, or design one that can track the sub down, which will be costly in terms of money and starship mass compared to regular missiles.


Raymond: "I'm actually with Byron on this one - APCs are large, and massive, and make for bigger targets on the way down. I have slightly more faith in an aircraft surviving a drop, since it actually has a chance to maneuver, but an APC is asking for trouble, at least until a large ASAT-free corridor is achieved."

Sure you're referring to the right person? I was addressing the point that for patrol purposes, small fighters / robots / infantry deployed from something bigger can cover a larger area than a single IFV, thus making them still useful. It's why we don't use tanks to patrol the streets & expect policemen to get out of their cars after all :P .


Byron: "Byron: Cut off enemy supplies, and then harass them until they run out of ammo."

Seems like the weakest plan: you've got to be damn certain you've cut off their supply lines for something like this to work, and then give them enough enticing targets that they spend what ammo they have left... presumably without losing too much of your own, much more limited, invasion force.


Milo: "Plasma weapons seem to be unphysical - you can't confine plasma from within, and if you shoot out plasma with enough energy to go boom, it will go boom as soon as it leaves the barrel of your gun. The exception is beams of relativistic plasma used in space warfare - essentially a particle beam of protons neutralized with electrons to avoid space-charge effects."

The best I've been able to come up for plasma weapons is, first, that they actually shoot particle beams rather than "plasma bullets" as in most sci-fi. Secondly, that they're used in a similar manner to squad automatic weapons today - ie big enough to hurt vehicles and do Very Bad Things to people - but because of this bulky & expensive (money, mass, power, etc etc) enough that outfitting an entire squad with them isn't practical. This last part is mostly due to some readings on Stardestroyer.net's page on the "plasma gun brainbug" - namely that if you have the technology to contain such a particle beam / blob of plasma, you can also protect against it the same way: thus your plasma gun needs to be more powerful... hence the equivalent of SAWs. A wide-beam setting might make for an impromptu (and short-ranged) flamethrower for clearing spaces, although I suspect grenades will still be a lot better for that job.

Teleros said...

Raymond: "I think guided personal-scale missile weaponry may have uses - think OICW rounds with rockets and seekers."

I've had the same idea - although aside from just damaging warheads, being able to shoot scanners, booby traps, beacons & such at the other guys could be quite useful. Are those civilians or soldiers in that house? Send a scan grenade in & find out. Enemy using heavy cloud cover to hide from orbital scans? Launch a few canisters of them over their lines... you get the idea I'm sure. Due to power requirements and accidental damage I can't see such things having a long service life once used, but if they're cheap enough they may find a use in giving you an edge.

Which reminds me that we shouldn't also forget the good old airborne micro-camera swarms.


Albert: "I find obvious that if you want to do the first against a planet with Earth's population and industrial capability, you need a few Star Destroyers to pull it off correctly."

I wouldn't go there :P . Aside from the magitech involved, Star Destroyers have the kind of "boil your oceans" firepower that opens up a whole new can of worms...

The second option is really the only way for anyone foolish enugh to try capturing a homeworld-class planet (like Earth).
Your constellation is going to be greatly outmatched by ground defences. Period.
So you camp in high orbit and act smart when you can.


I'd be camping well away from the planet and chucking rocks at them until they get the message (or there's nothing left...), but that sadly wouldn't involve much drama or ground combat :P .


Luke: "Wouldn't the same limitations apply to the spacecraft of the attacking forces? This would imply that unless they can rotate out their space crews, they will need to take the planet within 90 days."

Two points. First, I can imagine this being more of an issue for colony worlds than a planet like Earth, because if you're going for the latter you'll be sure to set up a hell of a supply base somewhere convenient anyway.

Second, given travel times, that 90 days limit may be different for starship crews, who'll have to be selected for not going nuts halfway through a months-long voyages. They may be nearing the end of the line or still fresh as a daisy. I can think of two ways to get around this - bringing extra crew along (stasis / cryo chambers at first?), and keeping up a constant flow of crews between your fleet and a suitably close R & R base, which brings me back to my first point.

Teleros said...

Typical, missed the second page of comments.

Raymond: "Actually getting to see the virtual sky light up with falling kinetics? C'mon, some of us want the visuals. It would be spectacular to watch. And multiplayer between the bunch of us? Make the Starcraft slaves look like monkeys."

Have you *tried* using that game's map editor? You could probably cook up our little game in it you know...

Byron said...

Teleros, you cut the supply lines by blowing up the factory. There's not a lot of wiggle room there. And they have to shoot. See my posts above.
I've gotten some work done on the setting, but sleep interrupted. I'll post the final specs when they get done. And the large number of habitable planets will remain a mystery. It's there for the purposes of allowing us to sim dealing with worlds with a reasonable atmosphere.

Albert said...

I wouldn't go there :P . Aside from the magitech involved, Star Destroyers have the kind of "boil your oceans" firepower that opens up a whole new can of worms...
I used Star Destroyers to symbolize "ludicrously unrealistic firepower".


I'd be camping well away from the planet and chucking rocks at them until they get the message (or there's nothing left...), but that sadly wouldn't involve much drama or ground combat :P .
Assuming you can redirect asteroids with decent time scales, AND that you can defend them from the stuff the people on the planet throw on them, like Orion-kinetic-impactors or nukes.

That would also be a war crime, because you are mudering civilians indiscriminately. You cannot claim you are "doing a war on terror" or "they have mass destruction weapons I want to take away" to shroud yourself as righteous if you start nuking planet surface at random.
(don't expect an asteroid to be more accurate than "huh, somewhere in this hemisphere")

Generally asteroid-killing is an option only for political entities ruled by Evil Emperors that don't want to look "Good" in the eyes of their population.

-Albert

Geoffrey S H said...

Having troops on the surface might distract the anti-orbital weapons, forcing them to fire on uyour ground forces (now engaging as closely as possible with their ground troops to avoid being fired upon).

Thererfore- either use the invading constellation as a distraction for the troops, or use the troops as a distraction for the constellation. In the (for you) most optimistic result, ground troops either reduce orbital defences, or you get to takle them out with your now (relatively ignored) space craft.
The most important part of orbital insertionbis the time it takes to reach the athmosphere- once there you should have a vastly reduced time to reach the surface and find cover.

Of course, the speed at whioch you would like to hit the surface woukld complicate matters... somewhat.

Milo said...

Teleros:

"My thinking was that all that water will make a submarine considerably harder to track than a starship (not to mention probably cheaper and so potentially more numerous)."

Yes, I agree, but this was in response to a hypothetical technology that would allow submarines to shoot spaceships from underwater without being fed telemetry from elsewhere. Under those circumstances, the sensor blindness works both ways, at least until the missile leaves the sea (but how does it know what to lock on?).

Anyway, the lack of visibility does hurt submarines in one way. Point defense doesn't work nearly as well for submarines as for spaceships.


"(I've no idea how well a fusion bomb would work under a km or two of ocean etc, save that you can't use the usual above-ground calculators for it :P )"

Explosions work pretty well underwater, since water is a noncompressible fluid. Projectile weapons (probably including explosion shrapnel), not so well. It's the overpressure that kills you.

Neutron bombs don't work underwater since water is such a good neutron shield. However, these neutron bombs will conveniently cause conventional explosions instead.

On a tangent: it's popular to see fusion bombs as "bigger than a fission bomb without that pesky fallout!", but it doesn't work out quite that nicely in real life, due to complicated technobabble. The short of it is that for any given technology that makes a big boom with pure a fusion explosion, I can quite easily use that technology to design a bomb that makes an even bigger boom with a mixed fusion-fission explosion, for nearly the same price and mass (but a lot more fallout).


"Are those civilians or soldiers in that house? Send a scan grenade in & find out."

Heh. Nice.


"I'd be camping well away from the planet and chucking rocks at them until they get the message (or there's nothing left...), but that sadly wouldn't involve much drama or ground combat :P ."

I'd be relatively easily deflecting those rocks given the amount of advance warning I have of their arrival (remember, if you can chuck them, I can stop them), while sending a sortie fleet to wipe out your poorly defended fleet of mostly tugboat-type ships out in the middle of nowhere.


"Second, given travel times, that 90 days limit may be different for starship crews, who'll have to be selected for not going nuts halfway through a months-long voyages."

And submarine crews won't have been?

At least submarine crews can have realtime internet communication with home, if they aren't worried about complete communications stealth (which isn't really necessary if your enemies are up in orbit where they can't detect your communications anyway, or for that matter several weeks away from arriving at your planet). Interplanetary spaceships, by contrast, will be several lightminutes removed from home, at least.

Raymond said...

Teleros:

"Sure you're referring to the right person? I was addressing the point that for patrol purposes, small fighters / robots / infantry deployed from something bigger can cover a larger area than a single IFV, thus making them still useful. It's why we don't use tanks to patrol the streets & expect policemen to get out of their cars after all :P ."

Might have been you, might not. This thread has decided to sprawl, and it's hard to keep track of who said what a hundred posts ago. Sorry. In any case, despite to advantages of having some form of APC on the ground, I think it a) is more likely to get shredded on the way down, and b) isn't small or stealthy enough for the LRRP mission. Later in the process, if you can start landing heavier equipment, but not in the first stage.

"Have you *tried* using that game's map editor? You could probably cook up our little game in it you know..."

Don't have the game yet, actually. I really should. Out of curiosity, though, does it deal with low-thrust high-impulse engines and brachistochrone orbits? If not, does anything?

Milo said...

Geoffrey S H:

"Having troops on the surface might distract the anti-orbital weapons, forcing them to fire on uyour ground forces (now engaging as closely as possible with their ground troops to avoid being fired upon)."

Not really, since as I said, surface-to-surface forces and surface-to-orbit forces are going to be different branches of the military. The former largely twiddle their thumbs when there isn't something on the surface to shoot at, and the latter largely twiddly their thumbs when there isn't something in orbit to shoot at. Giving one of them something to shoot at won't much affect what the other is doing.

Also how did you land troops on my surface while I still have anti-orbital weapons?



Byron:

"And the large number of habitable planets will remain a mystery."

What do you mean by habitable planets? If they're terraformed and you give them a few centuries to develop, then there's not much remarkable about that - our own solar system has plenty of living space if you know how to use it, as I've been showing. (You said you only wanted two open-air planets and the rest are moons.) If they were naturally human-habitable when we got there, then yeah, that shatters suspension of disbelief.

The best reason I can think of for bothering with the dubious tech of going to another solar system without having FTL, is to get rid of Old Earth's political and cultural baggage, where our numerous Balkanized nations - even if they're whittled down over the centuries - seriously complicating politics. And also because even after centuries of terraforming, Earth will still be a rather Important Place and likely be ahead of the rest of the solar system.

...How large are your habitable worlds in your system? Is there much variation in size?

Byron said...

You are about to get Byron's Explanation of Why Ground Troops Won't Capture a Planet, Version 26.
This is meant to be a general response to everyone who is trying to justify landing troops and using them to take out the defenses. The following assumes a homogeneously defended and homogeneously hostile world. Do not attempt rebuttals that don't agree with those points.
The first major problem for any landing is the orbital defenses. These defenses include both ASAT and ABM-type defenses. The entry of a pod is very similar to a modern ballistic missile warhead. It is going faster, but that makes it easier to detect on entry. It also shortens response time, but that's counterbalanced by the fact that any military pod will be much bigger than a MIRV. This discussion ignores laser defenses, though those would be similarly lethal to these discussed.
So how effective would these defenses be? Most likely they would anti-decimate any attempted landing (leave 1/10th alive). The pods are on predictable trajectories, making them easy to hit. The objection is the failure rate of modern ABM systems. This is a red herring. Modern ABM systems are immature, and almost all of the failures are due to immature technology, not the difficulty of the task. Take the US Ground-based midcourse defense. Of it's 15 trials, 8 have been successful. Of the remaining 7, all have been due to something not working properly, such as failures to separate, and software bugs. These will not be in mature systems. This means that probably 90% of all missiles will hit.
Even if I'm very generous, and give the 50% figure for the system in the future (and I'm using up all of my generosity here) it still dooms any invasion. If the defender has as many missiles as you have pods, then the invasion is done. This is because modern units generally become combat-ineffective with 10 to 15% casualties. I can't see any way to stay effective with 50%.
Decoys could be used, but they'll take just as much mass as the pod they're decoying for, due to deceleration reasons.
(continued)

Byron said...

It is theoretically possible to overwhelm the defenses by dropping each person in his own pod, meaning that there are more pods than missiles. This solution isn't much better. The fact that they're entering the atmosphere means that pods will be destroyed if the heat shield takes damage. This allows shrapnel to be used to take them out.
Then there's the issue of once the pods reach the surface. "Landing ground troops" is not the objective here. Landing enough ground troops to be able to seize the planet is. This means that there is a large number of troops needed, and that they have to be combat-effective when they get there. Any sort of individual drop pods will suffer from scatter, which was a huge problem during the airborne assault in Normandy. This renders units ineffective, and leaves you with a bunch of men armed with infantry weapons wandering around mostly aimlessly. Powered armor might help some, but not enough to allow them to challenge ground forces that have tanks. And if you try to drop vehicles with these troops, those larger pods will be the first targets.
If the drop is composed entirely of these pods, then there is a higher chance some will slip through. Even then, there will still be heavy losses, and probably less men in total.
Once the troops are on the ground, what do they do? They have to be able to take out the enemy's defenses, which will be defended by his army. Yes, it might be possible to do this once when nobody expects it, but that's not a general principle. This requires being able to take out his military. If we use modern militaries for scale, this will probably be a Corps or two, which translates into around 20,000 combat troops.
So, to be able to take a planet with ground troops, you have to be able to land forces that can defeat 20,000 troops through the enemy's ASAT/ABM defenses. Even with a very generous 50% losses, and assuming that the formations only lose 50% effectiveness from that, and assuming troop parity, you need to launch 40,000 troops at the planet. Oh, and you have to ship those troops from your homeworld. And you need spaceships to provide cover for the formation, and suppress defenses. Ground invasions very rapidly turn into a superpower vs. minor power affair. You'd need more money to pull it off than it would take to use my or even Milo's approach.

Byron said...

And even then, that doesn't take care of all the problems. There are two other issues to be dealt with.
The most important is that at ground invasion, you get one shot. If they have stronger defenses then you expected, then you lose. Period. You can't haul two complete invasion forces across space. If you could, you'd commit them both at once. This is why landing forces to make a corridor makes no sense. The only way through the defenses is via numbers, so you'll commit them all at once. Plus, there's the fact you just told the enemy where you'll land. They'll move all their forces there.
Secondly, you need to have an occupation force at the end. If you seize the planet, but don't have enough men to hold it, then congratulations on the Pyrrhic victory. You've spent a bunch of lives and money and gained nothing.

Raymond said...

Raymond's Explanation of Why Some Ground Troops (But Mostly Aircraft) Might Be Useful To Capture a Planet, version 2.7 beta:

I think pretty well everyone here agrees on (or at least will concede) a few things:

- control of low orbit means you win, and get to land your occupation troops under threat of killing whatever you want on short notice.

- SOMs can be hidden, in bunkers or underwater or scattered on trucks.

- SOMs can kill things in low orbit with ease.

- the first stage of any invasion of a planet is a space fight, with lasers and/or missiles, with the invaders trying to kill off as many SOM sites and tracking stations and anti-orbital lasers as they can, and the defender trying to prevent it.

- while the defender still has missiles available to intercept incoming anything, the first stage is still in progress.

Now, if the attacker cannot finish the first stage convincingly, cannot destroy enough to get close to the planet in any way, then no invasion happens. Period. If, however, the defender's interception capability is more or less rubble, there will still be assets which can threaten craft in low orbit without necessarily intercepting everything sent to the surface.

This is the uneasy detente I'm interested in. This is where a concentrated landing to get forces more flexible than missiles from high orbit with a 12-hour flight time (thanks for the useful numbers, Luke). Contrary to the impression I gave earlier, I'd put more mass in aircraft than men, easy. Homogeneity of defending forces works against the defender in this case - I can land things faster than they can move a planet's worth of army. (Again, if I can't land with a reasonable chance of success, we're not at this point yet.) The primary purpose of these troops would be to give myself a platform to hunt down the type of weapon which I can't quite get a bead on from high orbit but still manages to wreck any chance of occupying low orbit.

Yes, I have a planetary army coming at me, but large formations are slow, and still vulnerable to the orbital weapons I have, even in high orbit. If I concentrate my forces, I land where I choose, and I can pick a good defensive position (planets are not homogenous). Depending on the exact nature of surface warfare, and given that their satellites are dead (if they're not, we're not at this stage), I might have a chance.

The reason I'd do this at all is to force the issue instead of an even longer siege, wherein hidden factories keep churning out missiles, I still can't get to low orbit, and their supply chain is short where mine is stupendously long. The better defended the planet, the longer the first stage lasts, and the further back my invasion force is. If, at any point, I cannot hit enough to secure landing, then this part does not happen.

Flame away.

Byron said...

Tony has a very good definition of a siege. The approaches seem to be that I'm laying siege, and Milo is trying to storm it.
The problem is with Tony's interpretation of siege tactics. There is no weak point like there is in a land fortress because orbits go all the way around. I suppose I could target a specific orbit, but any orbit worth owning will be heavily defended, and have vital targets. As I destroy stuff, they'll move it in.
This is also the flaw in Raymond's reasoning. According to Milo, ASATs will have a maximum range of about 1000 km. That means that your force has to land at least 1000 km from your target. It then has to cross that territory while the defender will do everything he can to thwart it. If you can land closer, then there's no reason you can't just bombard.
Plus, the only reason you've given to do ground assaults is targets too hard to take out from orbit. Anything like that will also be heavily defended on the ground. My proposal for use of ground troops (including aircraft) is as spotters to find any defenses that are hidden. If it's too heavy, just keep slamming it to make it impossible to get out.
Raymond, I do have to disagree with the "with ease" part. They can certainly force whatever's in low orbit to expend it's energy dealing with the attacks and shooting at defenses. This prevents it from shooting at ground targets. Plus, what's high orbit? Is it geosync, or is it just a couple thousand kilometers up? You seem to think that all ships have to be in one or the other, at least subconsciously. I see it as a gradual working-in. Plus, if you have lasers, than there's no time delay, even from geosync. There are other issues, though.
And Milo, all of the 6 planets are open-air. Most are about 75% of Earth's diameter and gravity.

Byron said...

And if it really can't be killed from orbit, like Luke's superlaser, then there's always this or this. It seems easier than a full-scale ground assault.

Tony said...

Byron:

"The problem is with Tony's interpretation of siege tactics. There is no weak point like there is in a land fortress because orbits go all the way around. I suppose I could target a specific orbit, but any orbit worth owning will be heavily defended, and have vital targets. As I destroy stuff, they'll move it in.
"


The various orbits are not analogous to the outer defenses of a fortified place. They are analogous to the hinterland, which must be cleared of the defender's mobile forces before a siege can begin. The defender's surface or subsurface deployed weapons with an ability to oppose enemies trying to land are the beginning of the planet's actual defenses against a siege, rather than a simple blockade.

Byron said...

Not that kind of orbit. I meant groundtracks. I can see how you got confused, but I was meaning that you can't just clear a specific point. Actually, now that I think about it, the groundtrack moves every orbit. That way, there isn't even a specific track you're clearing. It's the whole area.

Milo said...

Byron:

"According to Milo, ASATs will have a maximum range of about 1000 km."

Actually, I'm doubting my previous numbers here. This was based on the assumption that you're limited at shooting near low orbit (some 100 km). But if your weapons are that short in range, then that's going to be a more important limiter than the location of the horizon.

Basically the curvature of the planet doesn't really matter, since other concerns will be more important, so my numbers don't mean much.

The general idea still holds. Anything that can shoot into orbit is going to have pretty good range. (And really, 1000 km isn't that much to ask from an anti-orbit weapon. That's approximately the outer edge of "low orbit".)


"Plus, what's high orbit? Is it geosync, or is it just a couple thousand kilometers up?"

That depends on technology assumptions. From a military point of view, "low orbit" is anything within range of anti-orbit defenses, and "high orbit" is anything else. "Medium orbit" is anything just barely within range of defenses, or only within range of some very specific defenses (high-flying planes, mountain peak bunkers - yes, Mount Everest's height is only a small fraction of orbital altitude, but that's most of the atmosphere).

Nevermind how NASA currently defines those regions.


"Plus, if you have lasers, than there's no time delay, even from geosync. There are other issues, though."

Time delay from geosynch is about one tenth of a second - not much, although something moving just short of the speed of sound will travel 30 meters in that time.

The atmosphere is the main thing that makes it hard to shoot higher orbits. You have to use lower frequencies to not get scattered too much, but those diffract much faster than the Stupendous Range of orbit-to-orbit lasers. And missiles have to fight both atmosphere and gravity.

And yes, this means a Lunar fortress would be pretty handy... Unless the invader holds high orbit that's consistently in Earth's shadow from Luna.

We've largely been ignoring moonforts in our discussion of planetary invasion so far. (We've also been ignoring defending spaceships, but it can be assumed that those have already been shot down by the time anyone thinks of taking the planet itself. Although we're disagreeing on the timescale of orbit-to-surface warfare, I think we can still agree that whenever you have fleets from more than one hostile faction in orbit around the same planet, it will result in an awesome battle with lots of pretty explosions that quite swiftly lead to one or the other fleet not being there anymore. Days, tops, if you have trouble shifting around the orbits.)

Milo said...

"And Milo, all of the 6 planets are open-air. Most are about 75% of Earth's diameter and gravity."

You said "6 habitable [open-air] worlds: 2 planets and 4 gas giant moons". That's quite different from 6 planets.

You'll need a pretty huge gas giant to support four nearly-Earth-sized moons.

But go ahead, build your pretty little solar system. I'll shut up about it until you have something to show.



Tony:

"The various orbits are not analogous to the outer defenses of a fortified place. They are analogous to the hinterland, which must be cleared of the defender's mobile forces before a siege can begin."

The "mobile forces", in this case, being the defender's spaceships. Those have already been cleared before we started our discussion.



Byron:

"Actually, now that I think about it, the groundtrack moves every orbit. That way, there isn't even a specific track you're clearing. It's the whole area."

The main thing of note is equatorial orbits, whose ground track only ever circles over the equator. Every other orbit will also regularly cross the equator, although it won't spend all its time there. Naturally, the equator will be an important place to defend.

One idea is to use a highly elliptical orbit which passes close to Earth while near the place you want to bomb, then moves back out to higher altitude by the time you cross the equator or other heavily-defended areas.

Tony said...

Byron:

"Not that kind of orbit. I meant groundtracks. I can see how you got confused, but I was meaning that you can't just clear a specific point. Actually, now that I think about it, the groundtrack moves every orbit. That way, there isn't even a specific track you're clearing. It's the whole area."

I'm well aware of those problems, but that really is just an added complication, not a showstopper. You can't hover over a piece of planetary surface and blast away at it, but then again you wouldn't want to -- the longer you're above the enemy's horizon, the longer he has to shoot at you. And unlike Terrestrial sieges, you can't dig-in in the sky.

In practice one would probably establish bombardment forces in highly eccentric orbits that have periods equal to one sidereal day, and whose periapses place them over their target areas on closest approach. Then you just keep at it once a day until the defenders can't effectively defend the targeted region, and you can land your troops.

Tony said...

Milo:

"The "mobile forces", in this case, being the defender's spaceships. Those have already been cleared before we started our discussion."

The defender's defenses in orbit, to the degree that they exist, are part of his "spaceships". They're just unmaneuverable (or minimally maneuverable) ones, optimized for a certain mission.

Tony said...

I said:

"In practice one would probably establish bombardment forces in highly eccentric orbits that have periods equal to one sidereal day, and whose periapses place them over their target areas on closest approach. Then you just keep at it once a day until the defenders can't effectively defend the targeted region, and you can land your troops."

On further reflection, there's no reason all of the bombardment forces have to be in the same or even closely timed orbits. It should be possible to pick a class of orbits that have a bombardment platform coming over the horizon of the target area every few hours, giving forces there less time to recover and bring in reinforcements between attack passes.

Milo said...

Tony:

"And unlike Terrestrial sieges, you can't dig-in in the sky."

You could hide behind Luna, if Luna isn't fortified itself. OF course, that would be such a high orbit that you're probably beyond weapon range anyway.

High orbits in general can be thought of as fairly dug-in against surface-to-orbit defenses, which works well enough if what you're after is a blockade. But I'm skeptical of trying to actually take over a planet that way.


"The defender's defenses in orbit, to the degree that they exist, are part of his "spaceships". They're just unmaneuverable (or minimally maneuverable) ones, optimized for a certain mission."

Battlestations and sensor satellites and brown-water corvettes, yes, those count as part of his spaceships, and have already been blown up by the time anyone starts considering landing special forces.

However, a fortified moon would be significant enough to count for more than a mere spaceship, even if it's technically an "orbital fort".

Milo said...

Tony:

"It should be possible to pick a class of orbits that have a bombardment platform coming over the horizon of the target area every few hours, giving forces there less time to recover and bring in reinforcements between attack passes."

This is certainly possible, but it's less obvious if it's a good idea or not. Bunching up your bombardment ships would allow you to gain the benefit of Lanchester's law - they can still only fire the same number of shots in the time you spend within shooting range, even though they now have more targets they want to shoot at. By contrast, if you spread out, then they will be able to concentrate all fire on each ship as it comes.

Byron said...

While you could target a specific region, I'm pointing out that it will either be blindingly obvious or only once a day, with a bunch of time spent shooting at other stuff. Plus, the various ground plans seem to depend on a stupid defender. It's going to be pretty obvious that you're clearing a landing zone, and it has to be done ahead of time. He just moves some extra ASATs there and hides until the drop starts. Along with extra troops, of course.
Even if you pull off the landing, the troops have to go a couple hundred kilometers to the target. The Army says that typical speed for a unit road march is 25 kilometers per hour (ST 100-3). That means that you have to go at least 20 hours (I can't see any less than a 500 km range). When you get there, you still have to fight. Oh, and the numbers are for a road march, not a combat drive. That should slow things significantly.
And what do you do when you get there? I'm assuming it's fortified to prevent just such a stunt as you're attempting. It's impervious to any weapons you have, or it would be taken out from orbit. The only way to take it is via infantry. The rule of thumb is that you need a ratio of 3 to 1 to pull off a successful attack. I'm guessing it needs to be at least twice that here, when all you have are small arms, and they can use anything. If you can get the troops to pull this off, then why are you spending the money on them? Just buy more bombardment ships. Deep bunkers can't hold the entire world.
I guess I still don't see why a ground attack is a good idea. If stuff can be killed but not seen, either because of camouflage or laser dazzlers, it requires half a dozen man teams to deal with. It would have to be incredibly rugged to withstand bombardments from orbit. Mobility might be an issue if you have to go into a long-flight orbit and you don't have lasers. However, it can't defend you from anyone with lasers. While something might move 30m at Mach 1, it's going to be in a straight line. And trucks and submarines don't go that fast.

Milo said...

Byron:

"He just moves some extra ASATs there and hides until the drop starts."

That depends on how mobile his defenses are. Bunkers aren't, and subs can only cover area near the coast (assuming you're trying to land on, umm, land). Planes can go pretty much anywhere, and missile trucks can go anywhere the terrain isn't too hard (why would the attacker be trying to land in hard terrain?), and the latter are just generally suited for "move in quickly and hide until you can give a nasty surprise" type operations.

So it depends on tech assumptions regarding dominant defense types, to some degree.


"The Army says that typical speed for a unit road march is 25 kilometers per hour (ST 100-3)."

This is presumably with vehicles and good supplies. A ragtag bunch of troopers on foot, even with powered armor, will go slower. And what if there isn't a road handy?

Raymond said...

For the record, I'm arguing for six-man teams and supporting aircraft if there's a chance in hell of getting them down intact. Deep bunkers are a problem, but if you can get away with leaving them alone, then I wouldn't waste the men.

I think, Byron, that you believe I'm advocating landing troops while there are active SOM sites protecting the drop zone (I'm not), and I think you overestimate the amount of time the defenders would have to move forces (you've got 12 hours notice, if that, and the more forces you move to that drop zone, the more holes open up elsewhere). It's a question of initiative and force concentration, and the attacker is this case has the advantage in both.

Tony said...

Milo:

"However, a fortified moon would be significant enough to count for more than a mere spaceship, even if it's technically an "orbital fort"."

Depends on where the moon is. If it's a large, distant satellite like Luna, then it's influence on the battle is not likely to be great. As Gneisenau at Waterloo pointed out, when asked for reinforcements for Wavre, if you win the main battle, it doesn't matter what happens in a separate economy of force action.

If it's a smaller moon, closer in, it could be a real problem, but in the long run its still just another thing to be planned for.

"This is certainly possible, but it's less obvious if it's a good idea or not. Bunching up your bombardment ships would allow you to gain the benefit of Lanchester's law - they can still only fire the same number of shots in the time you spend within shooting range, even though they now have more targets they want to shoot at. By contrast, if you spread out, then they will be able to concentrate all fire on each ship as it comes."

Pure attritional models seldom describe real world combat well, it at all. Aside from that, one has to balance the various positive and negative factors of the available courses of action. It may just be me, but I find that it's usually a mistake to make blanket statements about war.

I just mentioned a possibility. I didn't say it was necessarily the only approach.

Byron:

"I guess I still don't see why a ground attack is a good idea."

It may not be a "good" idea in the sense of being easy and obvious, but it does seem to follow that if you're trying to besiege a planet, your objective is to force capitulation sooner than a blockade would. Important in that calculation is that a planet can feed itself and maintain a certain level of industrial infrastructure on its own, rendering a blockade virtually useless unless losing contact with the outside universe is a bigger hardship on the defender than losing local autonomy.

So either contact with the outside world is not that big a deal, or the attacker is sufficiently mean, nasty, and/or ugly that accepting his sovereignty is out of the question for the defender. So what does the attacker do then? Bombard from orbit? Say he bombards all of the planetary industry, spaceports, airports, railroads, and, if he's a real bastard, little kids' baseball diamonds? What happens if the planet says, "Thanks, but no thanks?" Well, I guess the attacker will just have to conduct a siege and eventually take the planet by force.

Byron said...

I'm not saying your advocating landing in a zone you know has defenses. I'm saying that the process of stripping those defenses will give the defender notice of your plans, allowing him to move defenses you don't know about into the area. Plus, you still haven't solved the issue of movement. The 12 hours notice is far too little. If the defender is smart, or even average, he'll notice the defenses are being systematically stripped from a non-strategic area. This will be obvious unless you're lucky enough to have a target on the equator or only do one pass per day per ship, while spending most of the rest of the time over other defended parts. If you specifically target it, then it's even more obvious, such as 24 hour orbits. And by your own admission, you can't take them all out in a single pass. Plus, there's the 20 hours before they reach the target. And that's in perfect conditions. And why the supporting aircraft? How is a plane supposed to take out a bunker immune to orbital strikes? And how is it supposed to survive the defender hunting for it?
I agree that you can't really blockade a planet, but that doesn't mean you need ground troops. If all of the defenses are destroyed, then the war is won. And if the planet's industry is gone, then it can't build more defenses, which means that it will eventually run out. That means that it will be unable to resist your invasion. Eventually, they can't win. I'm saying that trying to force them to surrender with ground troops seems hideously expensive and complex compared to orbital warfare. Eventually, they'll run out of missiles, with help. Even if I can't find all of their factories, I can destroy certain sections of road and railroad, and keep throwing kinetics at them to keep them from being rebuilt. Plus, concentration of forces doesn't matter if they know where you're going to end up, and roughly how you get there.

Tony said...

Byron:

"I'm saying that trying to force them to surrender with ground troops seems hideously expensive and complex compared to orbital warfare. Eventually, they'll run out of missiles, with help. Even if I can't find all of their factories, I can destroy certain sections of road and railroad, and keep throwing kinetics at them to keep them from being rebuilt. Plus, concentration of forces doesn't matter if they know where you're going to end up, and roughly how you get there."

With all due respect, you're ignoring the reason the attacker is probably conducting a siege in the first place -- time is not on his side. He's mounting a military campaign over interplanetary or interstellar distances at great expense and risk. A planet, even one that has had a major portion of its industry and transportation infrastructure bombed out of existence, can wait him out, if the alternative is slavery or extinction. (One doesn't even have to imagine Bug Eyed Monsters in order to have such an implacable foe; humans seem to do just nicely in that respect.) Eventually, the job is just going to get to be too expensive and the attacker is going to have to go home.

Or he is going to have to invest the planet closely, clear a landing zone, make a landing, and win a ground campaign...all before his logistics run out. It's not a question of what would be convenient to do, imagining perfect logistics and all the time in the Universe. It's a question of what might need to be done in a real world, with real world limitations.

Raymond said...

I'm thinking the same orbits used to throw kinetics would be the same for the drop pods. Going by Luke's numbers earlier, that's a 12-hour flight time, with launch observed on the far side. The lack of a satellite network for the defender inhibits (but does not completely destroy) global communications. As for softening the drop zone, that's the province of intelligence and tactical feints (the stuff good war stories are made of). Defense-in-depth works against the defender, here. If I can manage to soften multiple sites at once, I will, and that gives me the initiative. If I can't, perhaps I didn't bring enough forces with me.

The aircraft are for mobility of the recon teams; here nuclear-powered aircraft come into their own. I'd really like to give my teams on the ground more than foot mobility if possible. Also, there's the issue of enemy aircraft. If lasers cannot reliably hit aircraft from beyond SOM range (medium orbit - Luke, any chance for some of your wonderous calculations?), you'll need air cover of your own. For recon closer than high orbit, for interfering with enemy movement, and for denying the defenders their air support. (Note I'm using Milo's high/medium/low orbit definitions here.)

Byron said...

Tony, slavery or death is not the only logical result of this sort of campaign. How many wars in recent history between powerful civilizations have ended with extinction for the losing side? Or slavery? There have been mass deaths, but only during the war. If I have to surrender and give up autonomy to preserve my life and the lives of my people, I will. The only time an order to fight to the death would be given is if the leaders are afraid of what would happen to them, like Hitler's last stand. (I know, but Germany surrendered after he shot himself.)
Why is it easier to win a ground campaign than to send some people in to provide targeting data? Troops will only put more burden on your logistics, so bringing people for a ground army exacerbates the problem you claim it solves.
The problem I have with ground assaults is this: If I have cleared a section of a planet's surface to the point at which I can safely land troops on it, then it is also clear to the point that I can kill anything on the ground in it. It is possible to clear a zone outside the main defenses, but the troops will be outnumbered and a long way from their target. Also, the only way to make a weapon reveal itself is to threaten something important in the area. If it doesn't shoot, you blow up this thing. If it does, then you should be too busy shooting at the missiles to harm the target. If the zone being threatened is has nothing important in it, then they won't fire, meaning you can't effectively clear it.
Raymond:
Haven't you heard of such novel concepts as ground vehicles and MANPADS SAMs? Dropping in half a dozen guys and a few Stinger equivalents, and having them steal a car or get one from your underground agents is a lot easier than half a dozen guys, a VTOL transport, and a fighter, and their crews. The aircraft will also be very vulnerable to enemy fighters and SAMs. Your plan only works if you have massive technological superiority. I could see one of your superfighters working on modern earth, but not against someone who has their own superfighters, or even regular fighters. In other words, how long would an F-15 last alone in the middle of the Soviet Union? It's better than what they have, but not that much better. Plus, the point of these teams is to find the enemy targets for the ships, not to fight the ships themselves. And the orbits depend upon the size of missiles. See Space Warfare I.

Byron said...

I finally finished my setting work. It's below.
(Part 1 of 3):
The "Rocketverse" is set in a star system that is similar to our own, except for the large number of habitable planets. All features are unnamed at the moment. If you claim control of one for the game, you also get to name it.
The system is home to a single star.
Class: K0
Age: 8.8 trillion years
Temperature: 5200 kelvin
Luminosity: .4428 solar luminosity
Radius: .00381 AU

The various major objects in the system are described below.
Summary
Object Orbital Radius
1. Asteroid Belt .082
2. Tiny Planet .229
3. Medium Planet .505
4. Medium Planet .662
5. Med. Gas Giant .927
6. Asteroid Belt 1.576
7. Sm. Gas Giant 2.837
8. Sm. Gas Giant 4.256
9. Sm. Gas Giant 7.235
10. Sm. Gas Giant 10.823
11. Large Gas Giant 17.317

Only planets 3 and 4, and four of the large moons of planet 5 have been detailed.
Planet 3:
Orbital Radius: .505 AU
Orbital Period: .4012 years
Orbital Eccentricity: 0
Moons: 2 moonlets
Blackbody Temperature: 319 K
Average Surface Temperature: 302 K
Hydrographic Cover: 95%
Density: .8 Earth
Diameter: .9485 Earth
Gravity: .7588 Earth
Mass: .6827 Earth
Atmospheric Pressure: .6070 atm
Axial Tilt: 20 degrees
Rotation Period: 18 hours
Volcanic Activity: Light
Tectonic Activity: None
Population: 420 million
World Unity: World Government
Government: Representative Democracy (unofficially Oligarchy)
Per Capita Income: @37318
Economic Volume: @15.7 trillion

Planet 4:
Orbital Radius: .662 AU
Orbital Period: .6022 years
Orbital Eccentricity: 0
Moons: 1 moonlet, 1 tiny moon
Blackbody Temperature: 279 K
Average Surface Temperature: 297 K
Hydrographic Cover: 70%
Density: 1 Earth
Diameter: .7934 Earth
Gravity: .7934 Earth
Mass: .4994 Earth
Atmospheric Pressure: 1.0314 atm
Axial Tilt: 17 degrees
Rotation Period: 20 hours
Volcanic Activity: Light
Tectonic Activity: Moderate
Population: 600 million
World Unity: World Government
Government: Representative Democracy
Per Capita Income: @47300
Economic Volume: @28.4 trillion

Byron said...

Setting, Part 2 of 3:
Planet 5:
Orbital Radius: .927 AU
Orbital Period: .9979 years
Orbital Eccentricity: .05
Moons: 10 inner moonlets, rings, 1 tiny moon, 1 small moon, 4 medium moons
Blackbody Temperature: 236 K
Density: .25 Earth
Diameter: 10.9027 Earth
Mass: 324 Earth

Moon 5-3:
Orbital Radius: 103.5757 earth diameters
Orbital Period: 3.4421 days
Orbital Eccentricity: 0
Blackbody Temperature: 236 K
Average Surface Temperature: 276 K
Hydrographic Cover: 45%
Density: 1 Earth
Diameter: .6222 Earth
Gravity: .6222 Earth
Mass: .2409 Earth
Atmospheric Pressure: .9333 atm
Axial Tilt: 27 degrees
Rotation Period: tidally locked
Volcanic Activity: Light
Tectonic Activity: None
Population: 10 million
World Unity: World Government
Government: Theocracy
Per Capita Income: @34400
Economic Volume: @344 billion

Moon 5-4:
Orbital Radius: 119.9297 earth diameters
Orbital Period: 4.2827 days
Orbital Eccentricity: 0
Blackbody Temperature: 236 K
Average Surface Temperature: 280 K
Hydrographic Cover: 70%
Density: 1 Earth
Diameter: .7297 Earth
Gravity: .7297 Earth
Mass: .3885 Earth
Atmospheric Pressure: 1.2405 atm
Axial Tilt: 24 degrees
Rotation Period: tidally locked
Volcanic Activity: Moderate
Tectonic Activity: None
Population: 1.5 billion
World Unity: Factictious (11 major powers)
Governments: Varies, usually Represenatative Democracy
Per Capita Income: @45150
Economic Volume: @67.7 trillion

Moon 5-5:
Orbital Radius: 136.2838 earth diameters
Orbital Period: 5.1948 days
Orbital Eccentricity: 0
Blackbody Temperature: 236 K
Average Surface Temperature: 278 K
Hydrographic Cover: 15%
Density: 1.1 Earth
Diameter: .6445 Earth
Gravity: .7090 Earth
Mass: .2945 Earth
Atmospheric Pressure: .8508 atm
Axial Tilt: 42 degrees
Rotation Period: 36 hours
Volcanic Activity: Light
Tectonic Activity: None
Population: 300 million
World Unity: Coalition (3 major powers)
Governments: Represenatative Democracy
Per Capita Income: @43000
Economic Volume: @12.9 trillion

Moon 5-6:
Orbital Radius: 152.6378 earth diameters
Orbital Period: 6.1547 days
Orbital Eccentricity: 0
Blackbody Temperature: 236 K
Average Surface Temperature: 284 K
Hydrographic Cover: 30%
Density: 1 Earth
Diameter: .8372 Earth
Gravity: .8372 Earth
Mass: .5868 Earth
Atmospheric Pressure: 1.1721 atm
Axial Tilt: 12 degrees
Rotation Period: 28 hours
Volcanic Activity: Moderate
Tectonic Activity: None
Population: 700 million
World Unity: Diffuse (97 governments, of which 32 have space forces)
Governments: Varies
Per Capita Income: @43000
Economic Volume: @30.1 trillion

Milo said...

Missiles have more or less unlimited range. A missile's effective range is defined by the distance where you can see it coming from so far away that you have all the time you need to effortlessly zap it with point defenses.

Unfortunately, determining how far away this is leads to spherical cows. Hence why I tend to think in terms of laser defenses rather than missile defenses. Which only requires spherical sheep.

Byron said...

Setting Notes:
I know that some of you may quibble with my abuse of astrophysics, or the lack of domed colonies. The domed colonies are coming. I just need to get them made, and it's been a long day. The planets presented above (except for 5-3) are the big players in this system.
The general scenario is a rivalry between planets 3 and 4 over control of commerce in the planet 5 system. While they are not the biggest economy, 5-4's governments can't get along. 3 is running short on resources, so it's trying to get more. And they don't go to the asteroid belts because one is hot enough to melt their ships and the other is past planet 5. Anyway, is anyone interested in controlling one of the powers (3, 4, one of 5-4's powers, or 5-5)?
Let me know.
Also, the @ sign represents the standard currency, which corresponds nicely with the GURPS, and thus modern, dollar.

Raymond said...

I did read through Space Warfare I, and it was just as vague about the particular altitudes as we have to be, dependent as they are upon the specifics of the missiles in question. That's why I'm going with Milo's high/medium/low orbit categories (or, we can even just say high/low).

The question of LRRP team mobility is on my mind. I'm thinking aircraft due to the speed and range (and extraction capability). Maybe local transport is preferable. In fact, giving the recon teams espionage and insurgency training is probably mandatory.

But I'm open to ideas, here. If local transport is unavailable for whatever reason, what kind of vehicle (if any) would you drop with them? ATVs? Small jeep-like things? Can we make power armor with wheels? Would Tachikoma-like things be feasible? Would anything with a motor be insufficiently stealthed?

And yes, if they have superfighters, then the fight is on. It probably would be anyways, unless I can get lasers in close enough to deprive the defenders of air support while leaving mine free to operate (barring MANPADS SAMs and smaller enemy laser sites). Enemy fighters can carry ASATs too, and hunting them down (or forcing them to ground) is a high priority.

Roger M. Wilcox said...

Luke wrote:

The best modern Li:ion batteries can store nearly a MJ/kg. At one kJ per shot, a 10 kg battery pack would give you 10,000 shots.

Is 1 kJ really that powerful of a laser shot?

I figure with 1% efficiency (typical of optically-pumped lasers last I heard), 1 kJ in means 10 J out. That's not a very potent zap.

Byron said...

Raymond, in Rick's initial post in Space Warfare I he outlines the types of boosters required to hit various targets. A V-2/SCUD (easily transported by truck and submarine) can hit a target up to a couple hundred kilometers. An ICBM class can hit something out to 6400 km. It takes a deep-space mission to hit anything farther out. This means that there is a direct constraint on how mobile long-range missiles can be. I can't think of any sort of mobile deep-space launcher. There have been mobile ICBMs, but they were large and easy to see. The trailer for the Midgetman is huge (I've seen it), and the missile itself is 40% longer than a SCUD, and has a third the warhead mass. This means that, as much as anything, low, medium, and high orbits will be defined by the types of weapons required to reach them. Anti-high orbit weapons sites will be fixed, and the weapons fired before the enemy arrives. Mid-orbit weapons will mostly be submarine-based. The Trident II has a longer range then the Peacekeeper does. The problem is the transit time of the weapons, which allows dodging and laser defense. Thus, they can't really deny the orbits to the attackers, just make it harder to use. Low orbit can be attacked by SCUD-class launchers. They're carried on a truck, and can go anywhere. Submarines might exchange several of them for one medium-orbit missile. These are the ones that can really deny you an orbit. They are hard to kill by virtue of low exposure time, and cheap to make. That's how I define the orbits, at least.
I would certainly pick an ATV-type thing, probably with an RTG. It wouldn't be that much bigger than a human, and certainly a lot smaller than a jet.
Roger, that's 1 KJ out. And Luke has pointed out that 65% efficiency looks achievable.

Raymond said...

Byron:

Those numbers (which somehow I missed on my quick refresher earlier today) sound about what I had in mind. I suspect the ICBM class weapons would be held in reserve in small numbers, because there isn't a lot the attacker would likely put in those orbits which would a) hang around long enough to be worth a shot, and b) not have sufficient laser defenses to survive. I suspect the missiles to stockpile will be the THAADs and SM-3s (well, their equivalents).

Luke: what kind of laser would we need to hit aircraft under cloud cover from a 6000-7000 km orbit?

ATVs sound good to me, but I'm not sure RTGs have nearly enough power. A couple kilowatts at best for the sizes we're talking about. (The advantage to nuclear-powered support aircraft - VTOL-capable charging stations.) They would be sufficiently quiet, though, and if the heat signatures could be well-masked, then they would be a net benefit. If we have ATVs, though, why not Tachikomas, which would be better armored, and more capable in really rough terrain? (For those who aren't familiar with Ghost in the Shell, see here.)

Raymond said...

Also, why such a high population and so many governments on 5-6? Is that the origin world, or is 3?

Milo said...

Raymond:

"I'm thinking aircraft due to the speed and range (and extraction capability)."

While we're dreaming about imaginary technology anyway, have you considered jetpacks?

Or small lightweight one-person planes, effectively just a couple of wings and a simple propellor?

You're not going to fight in those, obviously, but they could help in getting from point A to point B.



Roger M. Wilcox:

"Is 1 kJ really that powerful of a laser shot?"

I tend to estimate that a good small arm, based on current rifles, would have an energy of "several kilojoules" of actual shot energy (after reducing for inefficiency, so you may actually pay more).

A more accurate estimate is hard to give due to the different damage mechanisms of lasers and rifles.


"I figure with 1% efficiency"

1% efficiency? I doubt anyone is going to use a laser with 1% efficiency. Try 30%, 65%, 80%...

Milo said...

"Planet 3 (and others):
Volcanic Activity: Light
Tectonic Activity: None"


Huh? I thought those would go hand-in-hand.


"Planet 5:
Mass: 324 Earth"


That's 1.02 Jupiters.

Ganymede is only 0.025 Earth masses. I have serious doubts whether a Jupiter-sized gas giant could support so many moons that size.


"Moon 5-3:
Average Surface Temperature: 276 K"


Chilly.

Pressure, gravity, and temperature differences are all things marines will need to be trained to cope with to be able to occupy other planets.



Other numbers look sensible as far as I bothered to check.

Milo said...

"Planet 3:
Average Surface Temperature: 302 K"


Toasty.


"Planet 3:
Atmospheric Pressure: .6070 atm"


This is within the tolerance range for what humans can acclimatize to, although it's equivalent to several several kilometers up on Earth. Like living on a planet-wide superheated Tibet. (That may actually be good - sweat evaporates more easily in low pressure.) Non-genetically-engineered humans from places with thicker atmospheres will almost certainly need time training for operations in this atmosphere.

Wikipedia cites 0.475 atmospheres as the approximate limit of human tolerance. (Okay, so that was bars, not atms. Close enough.) The upper limit is when you start getting nitrogen narcosis, which starts setting in lightly around 2 atmospheres - possibly more with acclimatization, but no-one's ever tried.



I think that's everything.

Byron said...

Raymond:
That's better than I put it about the ICBMs. I didn't know what a Tachikoma was, and I'm not sure if it's practical, but it seems to be in the same category. I don't know about the origin world. The population is based on tables in GURPS space, and the world's characteristics.
Milo:
My bad. It should be 8.8 billion years. I guess it was a typo.
The thin atmosphere helps bring the temperature down. Plus, I checked, and it seemed survivable, if unpleasant to me. Volcanic and tectonic are not linked according to my tables. I don't make them, I just give the results.
It's entirely possible that the entire system is the result of ancient terraforming. It's not relevant, as I was focusing on making a setting for a wargame.
And the outer planets would be below the freezing point if I hadn't messed with the tables. But yes, there will need to be environment training. Just one more thing we don't usually think about.

Byron said...

Milo, blogger's acting up again. If it says too long, then back up and see if it posted. I've seen that one three times.

Milo said...

"1. Asteroid Belt .082"

An asteroid belt that far in sounds a little odd to me, but then we only have one solar system to base on. I'm probably just biased. Not that I know what creates asteroid belts, anyway.


"4. Medium Planet .662"

This is at near the optimal habitable zone for an Earthlike planet around a K0 star.



There. That has got to be broken up enough to work. Maybe.

Milo said...

"But yes, there will need to be environment training. Just one more thing we don't usually think about."

This, of course, requires simulating the environment of your target world (and planetary area... the Sahara isn't the same temperature as the Antarctic), presumably without your enemies being polite enough to lend you a piece of their planet to train on.

Temperature and air pressure can be regulated pretty nicely in a sealed dome, along with simply finding an appropiate place on your own world in some cases. Gravity is harder - to simulate a significant change in gravity without having a suitable allied world on hand you would have to train on a space station with spin gravity, which is nicely variable.

Raymond said...

Milo:

US nuclear aircraft programs were stalled and cancelled by the advent of ICBMs, but the logistics question (who wants to run jet fuel across interplanetary distances?) would at least restart research in it. And no, I wasn't thinking personal aircraft, but now that you mention it...

Going by some of the up-and-coming compact reactor designs (eg the Hyperion Power Module, 20 tons, 70MWth) and some of the current research on superconducting generators and motors, I can get an airframe roughly the size of the SR-71 with a cruising speed just under Mach 2 and VTOL capability from lift fans, along with 4-8 tons of payload. Add in a laser or two for point defense, use Super Nano Carbon Stuff for the skin (bonus: reentry capability), and you've got a pretty nice platform to support recon teams.

WRT environment training: I'd say that would be a key intelligence element. Enemy space stations rotating at your planet's gravity? Domes appearing on the surface held at your planet's average temp? Start stockpiling SOMs...

Milo said...

You would need some sort of spies to tell what rate a space station is rotating at, nevermind parameters on anything down on the surface. That's not something you can just easily tell with interplanetary sensors.

Also, armies would regularly train for the gravities of all inhabited worlds in the system, just in case. Even if you're not at war with them now, you might be later.

Byron said...

You just set up a spinhab. And I was thinking of asking Rick to host the game and running it long-term. You know, play by mail.

Milo said...

A forum of some sort would be convenient. Particularly one that allows some editing of posts.

Byron said...

No, I am not ignoring the cleaning-up part. I'm merely pointing out that, when low orbit is secured, there is no possibility of conventional resistance. Any conventional force will be destroyed before it can engage. That doesn't make unconventional opposition impossible. However, that's what the occupation troops are there for. They're there to deal with that. And yes, we could have a discussion of counterinsurgency, but that would be better left to another venue.
And yes, a forum would be convenient. I can set up an invisionfree.

Raymond said...

Albert:

Bah. GitS is harder SF than half the works mentioned in this blog (+ comments). If we ban manga references as impure and insufficiently hard, then can we ban FTL, nanotech and the Singularity? Pretty please? >8P

Also for the record: a) a couple hundred men and a dozen aircraft sounds just about right, and b) I don't say skip the Siege or the Vauban Fort battle, I'm just saying my little guts-and-glory storytime comes between Siege and Occupation (where the real counterinsurgency starts).

Byron, if you get a forum up, do post the link (if you haven't tired of my blathering yet).

Albert said...

I'm just saying my little guts-and-glory storytime comes between Siege and Occupation (where the real counterinsurgency starts).
Nope. What your ground units will do is Occupation. Simply because what they were supposed to destroy in your concept is the same stuff that prevents them from being deployed in the first place. (anti-low-orbit-missiles)

But being in numerical inferiority for any standard, it's gonna be harder than piercing the defenses.

Btw, you seem to see my comment, but I don't. What is happening here?

-Albert

Byron said...

Completely out of the blue, but on nuclear depth charges: a 200 kiloton nuclear warhead would have a lethal radius of about 10 kilometers against 1980s submarines.

Raymond said...

Albert:

Occupation is where the enemy has officially surrendered, and your troops are there to keep order. Counterinsurgency is the occupation troops try to prevent the population screwing that up. Guts-and-glory is just behind-the-lines warfare - everything's shooting at you.

Byron:

Cool number. Not very useful with the 12-hour lead time from geosynch, but useful if you have aircraft available and something to tempt the sub to take a shot.

Milo said...

For comparison: 10 km is approximately the distance of the horizon at eye level, the depth of the deepest parts of the ocean, or the altitude of an average jet liner.



Raymond:

"Occupation is where the enemy has officially surrendered, and your troops are there to keep order."

Or when the enemy asserts that they're still in control of their territory, but are plainly lying through their teeth.

Or when you've already blown up the enemy's centers of government and so there's nobody to authorize a surrender.

Raymond said...

10 km indeed makes for a hell of a depth charge, but oceans are huge. 25 knots, I think Byron mentioned as a baseline, and that means what, 20 minutes to get out of range?

Albert said...

Occupation is where the enemy has officially surrendered, and your troops are there to keep order.
Wouldn't be a proper occupation, but wouldn't be really different from it.

To land troops you need to have cleared orbital defences, and that means that to fight you they cannot use very big stuff or they get spotted and bombed from your fire support ships in orbit.

It will be a low-power but very bloody warfare in areas where enemy soldiers can disappear into the ground clutter very easily and vehicles are pointless anyway.
But you still have civilians around, because noone evacuates a city because a few hundred marines "invaded" it.

Think of the battle of Stalingrad, but add civilians to the city.

This kind of warfare would be generally suicidal for very small forces like you have.

-Albert

Milo said...

Stalingrad is lots more fun than Iraq.

For fictional values of "fun".

Rick said...

Low orbits up to a couple of hundred km are by far the most dangerous facing missile defense, because a surface launched kinetic does not need a big booster, and warning time after launch is down to a couple of minutes.

Even to reach 1000 km requires 4.5 km/s of net delta v (after launch losses), compared to 2 km/s net for 200 km. You'll probably need another boost stage, and warning time approaches 10 minutes.

So the advantage of surface missile defense falls off quickly as orbital periapsis increases.

BUT - if you're gonna land on the planet, you have to pass through that low zone. Like coast artillery, you have to pass through its kill zone to get to the beach.


Invading a major planet with a billion plus people is basically an Empire-sized job, not something peer planets can expect to do to each other, unless someone's defenses are horribly deficient.

Putting it another way, France got sucker punched in 1940, and you can never rule that out.

On the third hand, friction in the military sense will likely not go away, and making all this stuff HAPPEN will be exceedingly difficult.

Raymond said...

Rick:

I know you're not much of a fan of constantly blowing stuff up, so thanks for letting this thread go on for so long.

I also think you're right about needed overwhelming military superiority - if it's a peer planet, how do you possibly overwhelm them so completely? I'm tempted to say the better method of getting a peer out of the way, at least, is to skip the invasion altogether and Kessler their low orbits. That would keep them from being much of a spacefaring power for a while...

Byron said...

First of all, I've set up a board for the Rocketverse (I couldn't think up a better name) simulation. It's here. If you're interested, sign up. I'm still getting the bugs out.
And I don't really see insurgency as being such a huge problem. Those sort of things occur when they are either supported from the outside, or there is a long-term power vacuum. There wasn't an insurgency in Germany or Japan after World War II. It could be an issue, but I'm not certain of it. Also, that's not really relevant to the current discussion. Counterinsurgency is difficult, but it's not a space warfare problem.
And, though you can't take a peer planet, you won't send more forces than are required to do the job. It just costs too much.

Luke said...

Roger M. Wilcox:

I figure with 1% efficiency (typical of optically-pumped lasers last I heard), 1 kJ in means 10 J out. That's not a very potent zap.

1% efficiency was typical of old flash-lamp pumped solid state lasers. Modern diode pumped solid state lasers regularly get to around 30% efficiency. This may go up with the advent of higher efficiency diode lasers for pumping. My models predict that a 500 J "blaster" style laser pulse could drill a hole through a person, so for 1 kJ in and 500 J out with a 50% efficient laser, you could have an antipersonnel laser. Of course, modern 500 J pulse lasers are much larger than what would be considered reasonably man portable, so we will need a fair amount of advancement in this field before we can get laser rifles.

Anonymous said...

OMG,(as my daughter would say) 50 posts in 24 hours? Wow.

Anyway, I think that some of you misunderstand what the commandos are for: they aren't there to fight the regular forces or as artilliry spoters (they'd be shooting exactly the smane weapons at the targets that those targets were designed to defend against); no, these commandos (and only about half these six man teams might make in to the surface) are there to blow up submarine communications, satillite sensor downlinks, mobile ASAT launchers, other command & control, as well as any other millitary targets. Their job is to disrupt the defenders' ability to coordanate a defence against that mass troop landing just outside the defender's territory. The attacker is going to take losses, and the longer the war lasts, the more he takes and the less likely it is that he'll be able to achieve his objectives. The defender also takes losses, but it's a race to see who winds up with whose gun is pointed at whom...

Byron: your No-Name System is cool...way complicated, but cool!

Ferrell

Byron said...

And how, exactly, do they get to those targets to blow them up? Because any high-value targets will be defended, to prevent what you want to happen from happening. I'm not trying to be a spoilsport, but the defender's job is to frustrate you. I don't see how half a dozen men will sneak in and blow up one launcher, much less the dozen it will take to make a difference. I can see a very few commando teams that are to take out crucial targets, such as any superhard bunkers (if such things exist). They do it with Davy Crockets when the bunkers are open. (I almost wrote Davy Jones. Would that be the naval version?)
And thanks. It has to be complicated, or we could only do one or two wars.
Happy 300 posts in 4 days, everyone. I know this is a record.

Luke said...

Raymond:

If lasers cannot reliably hit aircraft from beyond SOM range (medium orbit - Luke, any chance for some of your wonderous calculations?), you'll need air cover of your own.

What is SOM range?

I presume you are talking about lasers on the invading spacecraft burning defending aircraft out of the skies. In this case, there are a number of questions that need to be answered. First, are we assuming aircraft flying above the cloud layer? Does the attacker need to be able to detect the enemy aircraft? Can it resolve the aircraft from high orbit? How powerful are the attacker's lasers? What size of mirrors is the attacker using to focus its lasers?

If I presume a laser-armed planetary bombardment craft has a 100 MW laser and a 10 meter mirror, and that the lasers put out 0.5 micron green light, then at 36,000 km (geostationary orbit) an attacker can put its beam into a 2 meter wide spot. Since this works both ways, the attacking spacecraft can resolve objects as small as two meters, so most aircraft will be visible (fuzzy, but visible) if the attacker knows where to look.

At that spot size, an aluminum alloy airframe would be eroded at a rate of a bit under 2 mm/s. That's going to cause a lot of problems real fast. At higher altitudes, aluminum alloy is removed faster - if the external pressure is 0.1 atmospheres the airframe will be burned away at a rate of about 3.5 mm/s. This hits around 5 mm/s at 0.01 atmospheres pressure. The maximum rate of removal is about 6 mm/s in vacuum.

If the aircraft are made out of super-high-tech-nano-carbon-stuff, the rate of erosion is a bit under 0.2 mm/s, which is still not very healthy. At low pressures, this maxes out at about 0.25 mm/s.

Of course, this works both ways - a 100 MW, 10 m laser station groundside can put the heat on the spacecraft at this altitude. Presumably, the first battle is between the laser spacecraft and the laser ground stations. Only if the spacecraft win do we advance to targeting defending aircraft.

Luke said...

Raymond:

Luke: what kind of laser would we need to hit aircraft under cloud cover from a 6000-7000 km orbit?

I estimate the difficulty of shooting lasers through clouds here:
http://games.groups.yahoo.com/group/sfconsim-l/message/66173

We will need to use near infrared light - a visible light laser would just scatter off the cloud droplets without evaporating them.

The next question is what kind of cloud layer? Nimbostratus clouds average around 2 to 3 km thick, and using my estimate of 5.5 MJ to evaporate a one square meter hole through a kilometer of cloud, it will take about 15 MJ to burn a one square meter hole.

So lets give our laser armed attackers a 10 meter mirror and a 100 MW laser emitting 1 micron light. Our laser can evaporate 6.67 square meters of cloud cover per second. At 6000 km altitude, the laser can be focused to a spot size of about 80 cm. That lets it cut through cloud at a bit over 8 m/s. Since aircraft tend to fly at speeds in excess of 150 m/s, this means that this laser is going to be hopeless at targeting aircraft flying under 2.5 km thick nimbostratus clouds. You would need a laser some 20 times as powerful for this application, or a mirror 20 times as wide.

Anonymous said...

Byron:"And how, exactly, do they get to those targets to blow them up? Because any high-value targets will be defended, to prevent what you want to happen from happening. I'm not trying to be a spoilsport, but the defender's job is to frustrate you. I don't see how half a dozen men will sneak in and blow up one launcher, much less the dozen it will take to make a difference. I can see a very few commando teams that are to take out crucial targets, such as any superhard bunkers (if such things exist). "
Ok, they get there by the old fashioned way; subtifugue. The point of the commandos isn't to take out the super harded bunker, but to isolate it; also, as to commandos not being able to make a difference during a war; from the way it sounds, you've never had the "privilage" of being aggressed by a real commando team, like the Rangers, SEALs, or the SAS...their job is to slip in, blow stuff up, and/or kill vital personnel, and slip out before you even know that they're there...they are very good at this job and have been at it for quite some time...
I do not see the need for them going away as long as humans fight each other in an organized way.
If you are fighting against a world that is unified, then you might not ever be able to conqure it one-on-one, but if you're attacking just one contry on a planet, then maybe...

Ok, rant over...Your "Rocketverse" is, as I've said before, way cool! And, for the record, I like complexity!

Ferrell

Byron said...

I understand that it's their job, and that they may be very good at it, but that doesn't mean that they will always do it. Plus, why should they take the risk of blowing it up if they can just call an orbital strike? Nobody's explained this to me. The closest I've gotten is Raymond on long lag times, which shrink significantly when you realize you can park yourself 6400 km overhead relatively safely.

Milo said...

Ferrell:

"50 posts in 24 hours? Wow."

Is that all? It felt like more.



Luke:

"Does the attacker need to be able to detect the enemy aircraft?"

Duh.

Exception is if you try to take it out with homing missiles, in which case they only need to detect the aircraft once they're in the atmosphere. You still have to guess its position approximately right.


"Can it resolve the aircraft from high orbit?"

I am assuming that sensor resolution will be pretty good, provided there are no clouds in the way (and radio might be able to deal with that?), but the sensor software won't always be able to tell a plane from other clutter.


"Presumably, the first battle is between the laser spacecraft and the laser ground stations. Only if the spacecraft win do we advance to targeting defending aircraft."

Hmm. Interesting. Which of various surface-to-orbit defenses you would prioritize killing first. I hadn't put much thought to that.

Byron said...

It was more for the email feed. The problem is blogger.
I would have to say the laser stations would be my first targets. Missiles are not terribly effective beyond a few hundred kilometers altitude, and that leaves lasers as the prime means of targeting ships at long range. Even if we don't have Luke's superlasers, they could easily be deadly in medium orbits.

Milo said...

Ferrell:

"And, for the record, I like complexity!"

Ah, definitely. But more specifically, I like complex patterns. Neither complete order nor complete randomness constitute true complexity.

Thucydides said...

Are you implying that helicopters and tilt-rotors are insufficiently militarily useful? I'd beg to differ, and so would the chopper pilots.

Not at all. A Main Battle Air Vehicle would be more useful than current aircraft because it would be rugged and (because of the ability to fight and move on the ground) less limited by weather effects. Comparing a current helicopter to a MBAV would be like comparing a steam traction engine to a 2010 Toyota Tacoma.

As for fighting on the ground and in the air, why would you want to?

The ultimate goal of ground combat is to seize and hold ground. You can pound a place to rubble, but unless you occupy it, the enemy can simply regroup and move back in (or just hide in the rubble). MBAV's need the ability to shoot their way into a landing zone, fend off enemy aircraft, UAVs or hostile MBAV's (hence the air combat requirement), as well as supporting dismounted troops on the ground. A MBAV might be able to scoot across the ground in the manner of a hovercraft and technically fight in the air (popping up from behind a building or terrain feature to fire its weapons) rather than drive around on tracks or wheels, but that is mostly details.

I can't imagine any sort of hybrid which was armored enough to survive long on the ground yet light enough to have good performance in the air.

Super nano carbon stuff is pretty versatile, and the sort of high energy systems which are being postulated for spacecraft drives and laser weapons would be equally useful for lightweight vehicles. Given the dramatic improvements of weapons technology, I would suggest the best way to avoid being destroyed is to move fast, not be seen (metamaterial cloaks) and have some sort of active countermeasure rather than passive physical armour as your only protection.

Milo said...

Thucydides:

"the sort of high energy systems which are being postulated for spacecraft drives and laser weapons would be equally useful for lightweight vehicles"

Assuming that you have the energy for them. A tank can't mount the same reactor as a battleship.

Speaking of which, I'm figuring a destroyer-sized interplanetary spaceship would already be putting out 100 GW or so just to power its engines, which means you have quite a lot of power to play with for your laser when the engine is off... if your optics can handle it.

Raymond said...

Luke:

Forget the orbit-to-air lasers, then. They might make defenders' air operations interesting, but cannot be counted on as a blanket defense. (Also, I'm thinking more of the 10MW range, not the 100MW.) This class of orbital laser should be relatively invulnerable to kinetics at that altitude, though, right? If they are, then I can put my kinetic ortillery alongside, which gets the orbital strike times down substantially (closer to what Byron has in mind). Better for the spotter teams to work with, certainly.

Thucydides:

Sounds a lot like my nuke-powered superfighters, but skewed more towards ground combat. Hovertanks? Hovertanks are always fun. Dunno if they're as Hard as we seem to expect around here, but they're fun.

Speaking of armored things:

To the various people in this thread pooh-poohing powered armor because it masses a mere 400 kg? Bah. Seriously, bah. You ever consider the contact patch of the average car? Less than a square foot per tire, at 750-1000 lbs per tire. Bicycles? Your body weight on a few square inches. Anyone ever heard of snowshoes? Maybe that's just me, being from the Frozen North. (Seriously, I grew up in Edmonton, which is the same latitude and general geography as Siberia. We learned how to walk in snowshoes in grade school.) Totally a worthy tradeoff to be protected from random shrapnel and peasants with AKs when there's only a few of you and you're a long way from home.

Milo:

Try maybe 10GW for the largest craft. Bigger than that, and your radiators will be too spectacularly huge to be feasible. (For all the discussion in the Spherical War Cows threads, the concerns about radiators and heat sinks apply more directly to waste heat from your propulsion system than your weapons.) Kilometer-long spacecraft start running into problematic torsion stresses, and if you start building your warships with naval-like hulls instead of trusses to deal with that, the mass requirement goes up so high you lose the advantage of that kind of power. 10GW thrust power for a 2000-ton dry mass craft is quite sufficient to achieve a one-way Juptier trip in four months or so (using an exhaust velocity between 300-400 km/s and propellant roughly equal to dry mass). If you need more mass than that, it's more practical to build more ships. Of course, that's assuming D-He3 fusion or equivalent, and to extract electrical power of any substantial fraction would require yet another massive radiator. Let's say max 100MW available on-board power. See the NASA paper here for an excellent Plausible Midfuture baseline interplanetary craft. (Bonus: this allows us to set some limits on laser tech, so as not to make everything happen at Stupendous Range and invalidate everything we've been arguing here.)

Milo said...

Raymond:

"Hovertanks? Hovertanks are always fun. Dunno if they're as Hard as we seem to expect around here, but they're fun."

Hovercraft are good at traversing terrains such as water, beaches, swamps, and snowfields. Less good at rugged terrain and dense forests, but then no ground vehicle does very well there. Their easy transition across beaches makes them best put to use as amphibious landing craft, which is indeed the one thing that hovercraft have been used for so far.

However, this requires you to justify fighting across surface terrain in the first place. No point in amphibious beach landings if you can just land your troops from space outside cities, and this only takes place once most of the battle is over.


"10GW thrust power for a 2000-ton dry"

My "destroyer-sized ship" was 10000 tons (maybe not the best approach to building spaceships, since they might not be as heavy as nautical ships even in the midfuture, but it's a convenient number), so adjusting for that, you number is only half mine. Not far off.

Geoffrey S H said...

The hardest part of orbital insertion would be getting into the athmosphere (when going up against orbital defences). Once you are there going through the athmosphere would take less time.
The speed at which you want to hit the surface would affect your plans... somewhat.

Albert said...

Byron said...
And I don't really see insurgency as being such a huge problem.... There wasn't an insurgency in Germany or Japan after World War II.
As I said, this isn't exactly insurgency, but very close to it. Since you like WWII references, go look at how fun was the Italina campaign.
The Good Guys had sky superiority (somewhat equivalent to orbiting spacecraft), but the terrain was (an is still) exceptionally rugged. "No campaign in Western Europe cost more than the Italian Campaign in terms of lives lost and wounds suffered by infantry forces."

Now try to do something like that again with space paratroopers. Even with Star Wars tech and Jedi powers your paratroopers get owned.

Raymond said...
You ever consider the contact patch of the average car?
the reason why most cars routinely get stuck in mud or sand. There are off-road cars that have bigger tires just for that reason. And even then, sometimes they get stuck anyway.
Heck, sometimes tanks get stuck too.(the reason for having a strong winch on most serious off-road cars)
Bicycles? Your body weight on a few square inches. The same as cars. Ever tried going on gravel? If it is deep enough you'll likely fall.

Anyone ever heard of snowshoes? Ever tried to use snowshoes in a house? They are kinda annoying to use when doing stairs.

To sum it up, If the point of powered armor is protect infantry, it fails, because it adds too much weight to let infantry do what is supposed to do (storm buildings and other smaller places).
If its point is to enhance infantry, then it may be good. But that would be an exoskeleton that grants limited protection, not an Iron Man suit.

Hovertanks? Hovertanks are always fun. Dunno if they're as Hard as we seem to expect around here, but they're fun.
Some fiction I read calls the category Skytanks.
"Due to increasing lethality of directed energy weapons, the only way was design something fast as an aircraft able to fly as low as an helicopter with full VTOL capability"

I'm going to ignore the part where they say Skytanks are also as sturdy as a tank. It's soft sci-fi, you know.

-Albert

Albert said...

stupid typo. <.<

"italian campaign"

-Albert

Raymond said...

Albert:

Oy vey, with the stairs! If you're sending your highly-trained commandos on houseclearing duties, you've got a problem with mission profiles. Commandos aren't really infantry, in mission or in deployment, and powered armor should be considered a very light armored vehicle. Which happens to have some of the same mobility characteristics as infantry. It doesn't rely on rolling friction (the real reason wheeled vehicles get stuck in most cases), and it can change its profile to take better advantage of terrain (ie it can duck).

And infantry are barely suited to storming buildings outside of a counterinsurgency context. They're squishy and vulnerable, easily ambushed, overly reliant on cover, and have a hard time carrying heavy weapons. Houseclearing is for drones and thermobarics. (Which, by the way, can be carried individually by powered armor!)

Besides, if they really need to do an op without the armor, they can. But then it's their call in the field, not some General Staff REMF like us.

Hovertanks:

I imagine them as Strykers with ducted fans instead of wheels (no low-clearance skirts here), capable of low-altitude flight (eat that, Apaches) and preferably mounting railguns (hooray for fire support). If using chemfuel, they'd make the Abrams look like a teetotaler, but if we're tossing around nuclear power sources, then maybe they'd even be feasible.

Raymond said...

Milo:

Unless we're considering the kilometer-long club, we should probably start dividing naval masses by ten to find their spaceborne equivalents. I think a destroyer of 1000 tons and 5GW is plenty big.

Byron said...

If the vehicle depends on mobility to keep it safe, then it's not much use for occupation. It works for semi-guerrilla warfare, but that only lasts so long if you win. And Super Nano Carbon may be versatile, but future weapons will keep pace with it.
Raymond, I'm not saying that armor that weights 400 kg. is useless for all missions. I'm meerly saying that it can't do a lot of modern infantry missions. Even with "snowshoes" it is still to heavy to do stairs, or upper floors in Iraq. All the snowshoes do is make it harder to move inside. Plus, I've admitted that it would be useful for pacification duties. It's just not a good idea for direct combat.
Geoffrey, how is going through the atmosphere fast? It's when you're most vulnerable. One minor hit before you stop making plasma and it's all over.
The Italian campaign was not an insurgency. Air superiority is not the same as space superiority, either. If I have a ship with lasers overhead, I can zap anything I can find. That puts strict limits on how powerful opposition can be. Plus, that sort of stuff is what happens after the invasion, not during it. It's a legitimate point, but we're discussing how to invade a world, not what happens after it.
Also, it's eating your posts, but not on email. This is getting really annoying, because for a long time I thought that if I got the email, then it was good.
Raymond (again, I'm working through the backlog):
I agree that powered armor becomes practical when it's no longer infantry. However, then it isn't infantry, it's a vehicle. Still, I question the wisdom of sending in commandoes in powered armor. I can see using exoskeletons to carry stuff, but I don't think that they should be engaging in combat at all. Plus, you yourself have several times referred to powered armor replacing infantry. It leads to confusion.

Raymond said...

Geoffrey:

I'm getting your posts by email, too. Want me to throw a copy up for you?

Byron:

As this thread has evolved, so has my thinking on power armor. I think the current infantry mission is too broad to be replaced by any one system, but squishy, loudly-complaining grunts a long way from home should be used as sparingly as possible, especially for missions like clearing buildings which are bloody at the best of times. I think power armor supported by smaller drones (air and ground) would be more effective as a whole. Drones could (and probably will) prove even more mobile than grunts in a lot of indoor areas, and you don't care so much when they trip a claymore or walk into a shooting gallery. Power armor can afford the mass to carry a drone with them, as well as a thermobaric missile for turning the building to rubble if that doesn't work.

For the recon teams we keep going back and forth about, I wouldn't give them power armor for direct combat, I'd give it to them for survivability and carrying capacity. Getting pinned down by the crudest of projectile weaponry sucks when you're several hundred million klicks from home. Likewise not being able to carry that antitank missile you could really use right now...

Tony said...

Byron:

"Tony, slavery or death is not the only logical result..."

We're talking about (or at least I thought we were talking about) a situation in which a planet fails to capitulate upon loss of its space forces. Okay, what are the logical motivations? Sheer stubbornness? A Divine decree that resistance must continue in order to provide plot progression?

I don't think so. The alternative to resistance has to be sufficiently unacceptable that resistance will be maintained even after isolation from the rest of the Universe, and even if the only hope is that the attacker will eventually tire (or run out of money) and go home. The alternative may not be actualy slavery or extinction, but if it isn't, it at least has to be perceived to be about that bad.

"Why is it easier to win a ground campaign than to send some people in to provide targeting data..."

The attacker has a complementary dilemma. If the defender does resist occupation, what can the attacker do? A planet can eat longer than blockading forces out in space could practically be supplied over great distances. So a simple blockade is out.

So what happens if the attacker tries strategic bombardment? Even if all of the defender's industrial infrastructure is smashed, he's still on a planet and he can still eat. Eventually the attacker will have to go away.

If the attacker therefore mounts a siege, it will be logistically stressful and economically expensive. And the planet can still eat longer than forces in space can maintain themselves. So the attacker has to get down on the ground and win a campaign there relatively quickly, before his logistic capabilities give out. Or the defender will again just wait him out.

At no point did I say that it would be "easier". But it might be the only alternative for the attacker, if he wishes to capture the planet.

Citizen Joe said...

With orbital lasers, things could turn back to the days of trench warfare. While the LaserSat is in its firing arc, you stay inside. When it passes, you have some time to scramble to the next position. I would hazard a guess that you'd be in the firing arc 20% of the time. If you put up multiple LaserSats you can improve your coverage. But you're looking at the same sort of tactics as the Normandy Invasion with its machine gun nests and mine fields.

Luke said...

Raymond:

If they are, then I can put my kinetic ortillery alongside, which gets the orbital strike times down substantially

For a 6000 km altitude orbit, if a kinetic launched on an orbit that just grazes the Earth's surface (a perigee at Earth's radius) the kinetic will arrive in one hour, 15 minutes after launch. This will take a delta-V of 980 m/s. The kinetic will arrive with a specific kinetic energy of 41.3 MJ/kg and a velocity of 9.09 km/s. Note that this will hit a point on the opposite side of the planet from which it was launched (although because the attacker is orbiting in the same direction, he might be able to see the strike - at 6000 km altitude, the orbital period is 3.8 hours, so in the time it will take for the kinetic to hit home, the attacker will have moved 1/3 of the way along its orbit. A quick sketch of the geometry indicates the attacker will see the strike just below the limb of the planet.)

If you have more delta-V to impart to your kinetics, they can arrive sooner. 980 m/s is not a lot of delta-V. Solid rockets can usually get you 2 to 3 km/s of delta-V. With 3 km/s, you can put a kinetic on an orbit that will reach perigee in 48 minutes. Of course, perigee is inside the planet, so it will strike somewhat earlier than that. The actual time to impact involves more sophisticated calculations than I feel like doing with pencil and paper, but since it is going fastest near perigee it will probably not take all that much less than 48 minutes - somewhere in the 35 to 45 minute range. The kinetic will strike with 33.9 MJ/kg of specific kinetic energy, and be moving at a speed of 8.23 km/s.

All of this neglects aerobraking. Punching through a thick atmosphere is likely to slow the projectile down to some degree and erode the front portion (thus reducing the kinetic energy of the strike).

It also assumes Earth. For other planets, you will need to redo the calculations.

Byron said...

While drones are a partial solution, there's a difference between clearing a building that you know has hostiles in it (thermobarics) and clearing one that might have hostiles in it, but also has civilians in it. Those civilians will probably be less responsive to drones than to humans.
On carrying: exoskeletons, again.
Tony:
Not really. If you think you might be able to win, then you will hold out until they have killed enough defenses that you think you can't. And if the defender's industry is smashed, they can't resist you much longer. Once they can't, you land troops. These troops are there to control the planet, not seize it. In some ways, we're looking at it from different angles. Under your plan, if the defenders don't surrender, you land troops to take the planet. Under mine, when their defenses have been smashed enough, they have no choice but to surrender. You can't resist someone who you have no means of fighting against. Once the defender is deprived of the means of fighting back, you land troops. The surrender is irrelevant. They can't resist, so even if they don't surrender, they just increase their casualties.
Joe, Normandy was World War II. But otherwise, yes. Still, why wouldn't you bring enough laserstars to keep constant surveillance? Also, laser dazzlers might be useful for the defender to prevent the all-seeing eye. It also has the side effect of requiring ground spotter teams, which make for good stories.

Raymond said...

Luke:

That kind of time-to-target warms the cockles of my bloodthirsty heart. Lovely. Ground targets beware.

CitizenJoe:

If I can't bring enough lasers to form continuous coverage, I shouldn't be invading. However, going by Luke's Awesome Numbers earlier, cloud cover will be a Major Problem. Look for defensive cloud-seeding just before the invasion.

Byron:

How we dance around the same thing with different names. Yes, exoskeletons, with just enough armor to keep out the shrapnel and peasant bullets (which as we've seen further up, actually turns out pretty light). Just don't leave them soft & squishy if you don't have to.

Tony said...

Byron:

"Not really. If you think you might be able to win, then you will hold out until they have killed enough defenses that you think you can't. And if the defender's industry is smashed, they can't resist you much longer. Once they can't, you land troops."

Nice in theory. But it presumes that the attacker can destroy defending industry quicker than it can be rebuilt, and within his own logistics window. Let's not forget that, in principle, sieges take place because an attacker cannot afford to wait around, yet he cannot force a quick capitulation either. As I see it, you're arguing that a quick capitulation can always be forced, but not considering what happens if a siege operation has to be mounted.

Thucydides said...

Remember the purpose of the Main Battle Air Vehicle is to "use ground tactically without relying on it for mobility."

Current technology would indeed be something like a Stryker with ducted fans, or a Moller "Skycar" with a chin mounted machinegun. If the size factor is similar to current vehicles, then getting down to the ground to support dismounted troops is possible even in cities and complex terrain (with the added bonus of being able to insert troops at rooftop level or simply bypass strongpoints depending on the commander's intent).

Forces armed and equipped with MBAV's would resemble Cavalry or "Mounted Rifles" more than Marines or line Infantry, which implies different organizations and tasks for these units. Sweeping around flanks or making rapid insertions to displace the enemy (and get inside the enemy commander's OODA loop) would probably be the doctrine they use rather than stand up fights. When they do "uncloak" they can deliver a vicious "combat pulse" then vanish before a retaliatory strike on the area (using thermobaric or nuclear weapons) takes place.

MBAV's will require a powerful and compact power source, perhaps an order of magnitude greater than available today (tanks have 1500hp engines, the MBAV will need something like 15,000hp on tap. The V-22 has 2 X 5,000 hp turbines powering the rotors, so this isn't a wild guess.). Don't forget armoured vehicles were envisioned as far back as the 1500's (Leonardo Da Vinci made workable plans) but AFV's had to wait until the arrival of internal combustion engines in the real world (Steampunk is a different story [heh])

Byron said...

Then explain how the defender is supposed to build missiles with me throwing kinetics at anything that looks even remotely like a missile factory. The siege is to run out his stocks of missiles that have already been built.

Geoffrey S H said...

Yes please Raymond- I'm not planning on posting again, but I wanted to explain why I kept posting the same thing twice. I've got the point and I'll leave it.
Haven't had this problem with eaten posts for a long time.

Tony said...

Byron:

"Then explain how the defender is supposed to build missiles with me throwing kinetics at anything that looks even remotely like a missile factory. The siege is to run out his stocks of missiles that have already been built."

Why does the defender's stock of already existant defensive means (not just missiles, but rail guns, laser batteries, whatever) necessarily have to be 100% vulnerable to the attacker's ability to attack surface targets? Part of defense planning is to program, manufacture, and stockpile sufficient means to resist an attack.

See, you're assuming that the attacker can bring, over long distances, any means necessary to force relatively quick capitulation. In some situation that might be possible, but not in all situations, certainly, and probably not in most. What happens then?

That is the question I am trying to address.

Raymond said...

Geoffrey, I don't know why the internet gods hate your post, but I tried to repost it, and while it got through on the email I don't see it here. Something you said?

Geoffrey S H said...

Perhaps they despise weakness, and admitting I'm wrong makes them furious...

Basically I apologised for arrogantly ignoring the arguments of everyone here and continually asserting my views, not helping at all with the discussion. Especially with Byron AND Milo.

I shall not post anymore.

There. Done.

Raymond said...

Geoffrey, if the denizens of this thread haven't told me to get bent yet, I think you're quite safe.

Geoffrey S H said...

ps: "and" was supposed to be lower case

Milo said...

Raymond:

"And infantry are barely suited to storming buildings outside of a counterinsurgency context."

Which is the context that many of us are saying will be infantry's primary role will be, so...?


"Unless we're considering the kilometer-long club,"

Are nautical ships a kilometer long?

Yeah, I know mass is more of an issue in space than on the sea - the sea is pretty good at supporting heavy masses, and has the largest vehicles (and the largest animals) of today. But it's hard to put a specific number on things. Anyway, I figure at least passenger liners will need about the same amount of space to carry the same amount of passengers... although that raises the question of just how many interplanetary passengers you're going to have. (And before you bring up jetliners: those can do many more roundtrips in the time it takes a nautical ship or space ship to reach its destination, so they can afford to carry less people per trip given equal total traffic volume.)



Tony:

"So the attacker has to get down on the ground and win a campaign there relatively quickly, before his logistic capabilities give out. Or the defender will again just wait him out.

At no point did I say that it would be "easier". But it might be the only alternative for the attacker, if he wishes to capture the planet."


Yes, but this gets done after the anti-orbit defenses are smashed.

Milo said...

Citizen Joe:

"With orbital lasers, things could turn back to the days of trench warfare. While the LaserSat is in its firing arc, you stay inside. When it passes, you have some time to scramble to the next position."

I would rely on camouflage to sneak by without getting noticed by the LaserSat. It has an entire planet to watch, after all.



Luke:

"All of this neglects aerobraking. Punching through a thick atmosphere is likely to slow the projectile down to some degree and erode the front portion (thus reducing the kinetic energy of the strike)."

Projectiles would, of course, be designed to minimize aerobraking. A dense and heat-resistant material like tungsten would work well. Projectile shape would likely be streamlined, no matter how cool the visuals of chucking chunks of crude rock at someone.



Byron:

"And if the defender's industry is smashed, they can't resist you much longer."

I still don't see why you're bothering with the industry. Industry takes time to churn out new equipment. Time take they would have during a protracted insurgency (so at that point you need to start targetting the factories, yes), but during the space stage it still strikes me as easier to just not give them the time. I'll need to fight their anti-orbit defenses at some point anyway... and unless you can propose some way to skirmish with soft targets while staying clear of hard targets (which would require a way to divide the "terrain" into more than just "low orbit" and "high orbit"), I'd rather get it over with as soon as possible. Their side has better endurance than mine, even if I do smash the factories, so waiting games don't pay.


"The siege is to run out his stocks of missiles that have already been built."

And how do you plan do defend against the enemy launching every single missile he has on the planet? Any strategy that involves parrying bullets with your face reeks of desparation. Especially if, as you've been saying, you don't have numerical superiority.

Milo said...

Speaking of Byron AND Milo, we seem to be mostly on the same side but there's still one issue we haven't managed to see eye-to-eye on. We are, apparantly, not infallible authorities.

Raymond said...

Milo:

Counterinsurgency is a mission for occupying troops. Exoskeleton-equipped recon teams landed by drop pod at potentially high casualties shouldn't be considered standard infantry and shouldn't be anywhere near COIN work. Whether the occupying forces have power armor or not is a matter to be settled in another thread, dealing with asymmetric warfare IN SPAAACE!

For the spacecraft size issue (I hate calling them ships! Rick, we need a new short term...), at 100GW thrust power you're going to need to get rid of at least 50GW of waste heat, in which case your radiators have to take up a tenth of a square kilometer (@250 kW/m^2 per side). That's the kind of size I mean by the kilometer club.

Byron said...

How are these defenses supposed to resist orbital attack? What methods do we have to attack forces in orbit?
Missiles on trucks/submarines: Stealth, but can be forced to fire.
Laser sites:
Can be bombarded until they crack.
Fixed missile sites:
Can be bombarded.
These all seem to be able to be dealt with from orbit.
Resistance to the last is mostly an issue of how the attacker behaves. Imagine the following scenario:
Tony's World is under attack by the Empire of Byron. Emperor Byron is known to be fair and honest with his conquests so long as they surrender before he lands ground troops. Tony's World has had it's defense pretty much destroyed. Emperor Byron transmits the following message:
"Prime Minister Tony of Tony's World, you have fought bravely and well. However, you have lost. Your defenses are smashed, and I can land troops whenever I wish. I will give you 24 hours to surrender peacefully to me. If you do, then I will allow your government to remain intact, subject to control by my appointed governor. There will be no reparations, and you will be taxed at the Empire's normal rate. The current senior members of government will have to go into exile, but there will be no prosecutions.
If you refuse my offer, none of the above conditions will stand."
What would you do? You have to go into exile, but the empire isn't evil. Surrendering minimizes damage to your people, because yes, orbital bombardment can't stop you from eating, but it can return you to the 1800s.
On the attacker's side, it makes sense to gain a reputation for being magnanimous. You have to give up some prerogatives, but you don't have to send large armies over interplanetary distances, and you skip the economic damage a protracted campaign would cause.

Geoffrey, thanks for the apology. I must admit that I got rather frustrated at times, when it seemed you were ignoring me, and probably went too far. Still, you've learned something, and who knows what else you'd learn if you stay.
Milo, that's what the wargame is meant to settle.

Milo said...

Grr. Radiators.

We really need some way to improve on those. We can have fusion reactors, lasers, room-temperature superconductors, carbon nanostuff... but we're still stuck with plain old radiators? Anyone have an idea how to make radiators that aren't absurdly huge and vulnerable?

Byron said...

Droplet radiators might work.

Milo said...

Byron:

"On the attacker's side, it makes sense to gain a reputation for being magnanimous."

Well, yes. Having a reputation of being fair to those who surrender encourages others to do so. Having a reputation of inflicting slavery or extinction on anyone under your control encourages others to fight to the bitter end. Of course, if you're ruthless enough, there's always the Mongol approach - make it clear that you will be fair to those who surrender, but really, really harsh to anyone who doesn't accept your terms of surrender the first time you offer them.

Tony said...

Milo:

"Yes, but this gets done after the anti-orbit defenses are smashed."

"[S]mashed"? Isn't that a rather hyperbolic adjective? Why can't we be a bit more professional and say "neutralized", or maybe "sufficiently degraded"? Just a thought...

Anywho, it would probably be impossible to neutralize or suffciently degrade all of the anti-orbit defenses that a planetary economy could build. But like in any siege operation, the attacker has the advantage of concentrating against a specific point, while the defender must be strong everywhere. The attacker must fully engage only the anti-orbit defenses that can interdict attempts to land in the target zone. Most of the planetary anti-orbit weapons can be left alone, just as most of the artillery and defenses of a XVIIth century fortress were left alone by a besieger.

And the defender can only reposition some of the defenses. If he thins them out too much, the attacker will just change his focus and come down against the weakened point(s).

Raymond said...

Until we learn to sidestep the laws of thermodynamics, we're stuck with radiators. Maybe if we get some cool metamaterials which work in the infrared range, then at least we can shove the heat out the rear end where it belongs. Droplet systems always struck me as much more inherently lossy than advertised, and you still need a great deal of real estate to disperse massive amounts of heat. Less than an order of magnitude improvement, at best.

Tony:

We're talking insane concentration of firepower, unheard of outside nuclear weapons, and military campaigns conducted over astronomical units. Smashed, annihilated, demolished, eviscerated - this bit of hyperbolic poetry is all we have to contextualize the scale.

Besides, I hate the clinical vocabulary of the modern military. Everyone here familiar with the Culture series? Warships classes were named Torturer, Gangster, Psychopath, and other names which better reflected the reality of what they inflicted.

Mangaka2170 said...

What about, instead of building absurdly huge radiators that can get shot off easily, using smaller radiators for normal ship's operations and carrying (possibly) internal radiators composed of a material with a high heat tolerance (like tungsten) for when the shooting starts? That way, you can retract your operation radiators when the shooting starts, and after combat you can cool down the combat radiators with the operation radiators?

Since we're already assuming fairly large ships with powerful drives, the mass cost shouldn't necessarily be that much of a problem, especially if we decrease the size of the ship to compensate for the heavier radiators.

Byron said...

Tony, you seem to be trying to force a space assault into an 18th century siege. It isn't. And yes, smashed is the right word. Actually, it's destroy. To quote FM 1-02 (Operational Terms and Graphics):
To damage a combat system so badly that it cannot perform any
function or be restored to a usable condition without being entirely rebuilt.

However, I like smash better.
Mangaka, what you're describing sounds like a heat sink. There's no such thing as an "internal radiator"

Mangaka2170 said...

Okay, so use a tungsten-based heat sink or radiator system. Another advantage tungsten has as a radiator material is its high strength, meaning that you can actually armor your radiators and still have them work.

Raymond said...

Mangaka:

It's an issue of radiator area, not so much of mass (but that is an issue), and the temperature is determined by the required heat rejection temperature of the cold end of your power cycle and the condensation point of your working fluid. The numbers I gave were generously assuming a rad temp in the 1500-1600 Kelvin range, which is a couple thousand degrees below the sublimation point of carbon. Your radiator material will most likely be a carbon-carbon composite, which is quite similar to the Super Nano Carbon Stuff we're using for armor anyways.

Raymond said...

Also re: radiators - the issue isn't even their vulnerability in combat (all spacecraft are delicate butterflies in the face of Plausible Midfuture weaponry) but the size required for normal operation and the torsional stresses one encounters when that size gets too big. Kilometer-long behemoths with a hundred gigawatts thrust power will snap like twigs unless you massively increase the structural mass, and that eats into payload fraction. Make ten smaller craft instead, and enjoy your more flexible constellations. When you build a Ravening Death Beam that requires all hundred gigawatts, then we'll talk.

Tony said...

Byron:

"How are these defenses supposed to resist orbital attack? What methods do we have to attack forces in orbit?
Missiles on trucks/submarines: Stealth, but can be forced to fire.
Laser sites:
Can be bombarded until they crack.
Fixed missile sites:
Can be bombarded.
These all seem to be able to be dealt with from orbit."


They wouldn't be defenses if they couldn't fire effectively on spacecraft in at least low orbit.

Aside from that, you're still ignoring the factor of time and the limits of logistics. What one theoretically could do, given unlimited resources and time, is generally not what one can do, given the practical limits of the real world. If we can't agree on that, we're just talking past each other.

"Resistance to the last is mostly an issue of how the attacker behaves. Imagine the following scenario..."

Historically, the tipping point in a siege run by a set of formal rules was usually where the attacker made a lodgment in the defenses, at which point he declared the place "indefensible", and invited the governor of the defenders to capitulate with honor. If the governor chose to fight on -- for any number of reasons: maybe relief was coming, maybe he thought he could still outlast the besieger's logistics resources, etc. -- then if the attacker made a full and final breach, the defenders could generally expect a murderous sack. The analogous event in a planetary siege would be where an attacker had made a landing, established a sufficiently large lodgement area, and had resisted at least one serious counterattack.

As for the magnanimity of Emperor Byron, I never doubted it. But not all potential enemies are Byrons.

Milo said...

Tony:

""[S]mashed"? Isn't that a rather hyperbolic adjective? Why can't we be a bit more professional and say "neutralized", or maybe "sufficiently degraded"? Just a thought..."

Don't try to pretty up war. It isn't.

I like to call a fusion-powered laser spade a fusion-powered laser spade.

Also, I like smashing stuff.


"Anywho, it would probably be impossible to neutralize or suffciently degrade all of the anti-orbit defenses that a planetary economy could build."

Sure can, if you bring all the warships that several planetary economies could build.

Conquering big targets requires big forces.

I again urge everyone to remember that we are talking about conquering Earth. That is not something to be taken lightly.


"But like in any siege operation, the attacker has the advantage of concentrating against a specific point, while the defender must be strong everywhere."

Yes, but anti-orbit defenses likely have ranges so good (at least a few hundred km, quite possibly a few thousand km) that being everywhere is, while not trivial, easier than it sounds. And some defenses, like submarines and planes, can move to keep up with the enemy. They're probably too slow to keep up with a low-orbital ground track as it circles the planet every few hours, but they can at least cluster their firepower around the track's circle.


"If he thins them out too much, the attacker will just change his focus and come down against the weakened point(s)."

If spaceships have better mobility than ground subs/planes.

Milo said...

Raymond:

"Until we learn to sidestep the laws of thermodynamics, we're stuck with radiators."

You can reduce the amount you need by decreasing your systems' inefficiencies to reduce waste heat, but unfortunately, while the laws of thermodynamics don't forbid you to have 99.9% efficiency on everything, the laws of Murphy do. Still, anything that reduces the reactor and engine's waste heat would be seriously useful.


"Droplet systems always struck me as much more inherently lossy than advertised,"

I never quite understood how they work, so I'll reserve judgement.


"Smashed, annihilated, demolished, eviscerated - this bit of hyperbolic poetry is all we have to contextualize the scale."

Oh, there will be no eviscerating. That only happens with sharp weapons. There is no melee combat in space, and hypervelocity projectiles don't benefit from having a pointy edge.



Mangaka2170:

"What about, instead of building absurdly huge radiators that can get shot off easily, using smaller radiators for normal ship's operations"

I am now talking about just the radiators that will be needed for the engines, which need to run for weeks at a time. I doubt you can find an internal heat sink that will last that long... although if you can, it would solve a lot of problems.

You could retract those big radiators when the shooting is about to start and use smaller radiators or heat sinks for your lasers (which would justify having less laser power than engine power), although lasers are still going to be producing a pretty high amount of waste heat.

Byron said...

Tony, by dealt with from orbit, I meant without a landing.
I still think that a few troops and a lot of ships (my way) is preferable logistically to a few ships and a lot of troops (yours).
And yes, the same thing happens, but you continue to misinterpret the situation. The lodgement is when the defenses are destroyed, before the troops land.
And the example was to show what a smart attacker would do. Not all attackers are smart, but those that aren't generally don't last long.

Milo said...

Of course, there is the question of what your objective is. If the objective is to capture the planet and capitulate its government, then this requires "storming the castle", and I would refuse to attempt it without sufficient forces. If, however, your objective is merely to extract some trade concessions, then you might be able to accomplish that with just a blockade in high orbit and/or general harassment of enemy ships in space, without engaging the ground defenses. If you're a colony declaring independence and your objective is just to get the imperialists to leave you alone, then you can pull everything back to your own planet and go on a full defensive - although you would need warships to maintain your ability to engage in space trade against possible enemy blockades. Unless controlling the planet is the objective, I would not ship over my marines at all and the battle would be entirely space-naval in scope.

When multi-planet empires fight each other, then you might be able to achieve local superiority of numbers by calling in forces from other fronts. If the I can concentrate attacking fleets from multiple different planets faster than you can concentrate defending fleets from multiple different planets, then that gives me an opportunity to beat you (on this front) even if my numbers aren't superior to yours overall.

There is also always the option of espionage. Many medieval sieges ended when someone inside the castle was bribed to throw open the gates. This would be a good way to win wars that otherwise appear unwinnable... if you have something to offer (or can pretend you do).

Raymond said...

Byron:

Ha! I've at least partly convinced you to go from "no troops" to "a few troops". Victory. We shall sign the peace treaty at once. Let us quibble no more over the details of the Exoskeletal Powered Armor of Great Strength.

Tony:

You'd better bury those factories deep, because an hour's time-to-target with 10-Rick kinetics will pulverize (quite literally) anything as big as a truck as quickly as I can call down the fire missions. Your deep bunkers may take some work, but I have lasers in orbit, and clear days end badly for you.

Milo:

That was my callback to the very old "swords and spaceships" post. Also, shrapnel eviscerates spacecraft in orbit (and flesh on the surface), and there will be much shrapnel.

And would you really furl your sails in the middle of a fight? They can still operate with a few holes in them. Same with radiators. It just puts some efficiency limits on spacecraft size for a given propulsion tech.

To everyone, in regards to comparative industrial output:

Ricks are not a measure of damage, but a measure of the damage efficiency of mass. A ton of mass in orbit at ten Ricks is worth ten tons of mass on the surface in explosives. If I show up to this fight with a planetary economy behind me, I can bring a lot of missiles.

Byron said...

Raymond:
Ha! I've at least partly convinced you to go from "no troops" to "a few troops". Victory. We shall sign the peace treaty at once. Let us quibble no more over the details of the Exoskeletal Powered Armor of Great Strength.
Sorry to burst your bubble, but those are my occupation troops. You know, the ones that I send down after I convince the enemy to surrender through my overwhelming orbital bombardment. I suppose that if I expect them to fight to the bitter end, I might bring some combat troops. It won't be SOP, though.
If they're really die-hard, there's always option two. After you smash the orbital defenses, destroy the rest of their industry. Wait for either a revolt or a few years. When they can't support a modern force, land troops.
Also, the radiators will have fluid flowing through them. A hole will take a whole section down. You can compartmentalize, but that will probably reduce efficiency and add mass.

Tony said...

Byron:

"Tony, you seem to be trying to force a space assault into an 18th century siege. It isn't. And yes, smashed is the right word. Actually, it's destroy. To quote FM 1-02 (Operational Terms and Graphics)..."

Deuling authorities? Oh, goodie! From JP 1-02 Department of Defense Dictionary of Military and Associated Terms:

neutralize — 1. As pertains to military operations, to render ineffective or unusable. 2. To render enemy personnel or material incapable of interfering with a particular operation. 3. To render safe mines, bombs, missiles, and booby traps. 4. To make harmless anything contaminated with a chemical agent.

And I'm not trying to force anything into anything else. My examples are used to illustrate fundamental principles. If I wanted, for example, to illustrate the principle that an attacker has the advantage of concentration, while the defender has the burden of dispersal, I could have used almost any siege or campaign against a fortified position. Here are just a few:

332 BC :: Tyre
70 AD :: Jerusalem
1453 AD :: Constantinople
1683 AD :: Vienna
1864 AD :: Petersburg
1944 AD :: "Fortress Europe"

Raymond said...

Byron:

Treachery! We are at war again!

I like me some orbital bombardment, but I keep hearing those refrains about "overwhelming air superiority" and "shock and awe" running through my head, and then I groan and cross myself and drop some actual people on the ground to exorcise the ghosts of the Kosovo campaign (among others).

The carbon-carbon heat-pipe radiators NASA (and others) are currently researching actually use a narrow coolant channel in between much wider solid plates of graphite. The idea is to make the radiator more resistant to damage from micrometeorites. If the channel is damaged, yes, that (small) section of radiator is compromised, but some holes in the graphite plate have hardly any effect. And there are a lot of independent sections.

Byron said...

Yes, but in this case, neutralize includes destroy. They're both doctrinally correct. What will we do?
And concentration works, but it's effects are reduced when you have to attack certain targets (the ones that will force capitulation) and you have to ship your forces a couple thousand times farther. The problem is that you seem to consider "all wars are decided by ground forces" a fundamental principle. While most are, I think we can make an exception.

Luke, can you give me some numbers for "Plausible Midfuture" lasers for Rocketverse?

Tony said...

Milo:

"Don't try to pretty up war. It isn't.

I like to call a fusion-powered laser spade a fusion-powered laser spade."


I'm really not the person you want to be lecturing on how pretty war is or isn't, k?

I'm not trying to bite your head head off, so please take this as a simple statement of fact, which I can verify to any extend you may think you require verification.

Professionals use the terms they use because those terms remove the emotion from the discussion. It's not about prettying things up, it's about getting on with business. Of course nobody can insist on that here, but you should take it as a bit of friendly advice that if you want to be taken seriously, you should try to present your thoughts professionally.

"Sure can, if you bring all the warships that several planetary economies could build."

All of the warships that several planetary enconomies can build are not likely to be able to carry the weapons to neutralize all of the defenses that a single planetary economy can build and deploy locally. That's why the attacker will likely be forced to concentrate his attack and take chunks of the planetary surface.

Byron said...

No, just a misunderstanding on your part.
I understand your reluctance to embrace orbital bombardment, but I'm trying to come up with an analogy for what I see that taking a planet is like in modern terms. Please don't dig too deeply.
Imagine an island twenty kilometers across. The sea surrounding it is full of mines, so you can't cross it. It's defended by a bunch of SAMs and AAA sites, and garrisoned by a mechanized infantry division. You have a bunch of fighter-bombers and a YAL-1 modified to shoot at ground targets. For ground troops, you have a company of paratroopers that must be dropped by a standard mass drop (no HALO). If you get rid of all the SAM sites, the YAL-1 can kill anything that tries to mess with your troops. If you don't, it's spending most of it's time fending off SAMs. So tell me, how good of an idea is it to punch a hole in the defenses and drop your troops to take out the rest?

I have to agree with Tony on jargon, but the forces of several planetary economies can neutralize all of a single planet's defenses eventually. If they can't, then they lose. Logistical concerns mean that any army from space will be minuscule compared to a surface army.

Raymond said...

Sorry, Tony, but I disagree with you on jargon.

We will neutralize hostile surface-to-orbit weapons systems by repeatedly smashing guided projectiles from orbit into launch mechanisms and observation sites and pulverizing them into itty bitty pieces. In our inital operations planning, we must be cognizant of the mass requirements of the initial bombardment phase. While the boom-efficiency of orbital weaponry is higher than the opposing surface systems, the estimated requirement for guided orbital missiles is well into the metric shit-ton range.

Byron:

I'm only reluctant to embrace the absolute supremacy of orbital bombardment over everything else. And if we're going to work with the island metaphor, it better be a couple hundred kilometers across, mostly jungle, and the SAMs restricted to Stingers, because I can take out all the SAMs on one side of the island and land my troops hours before the other side of the island comes into play.

Byron said...

What do you mean by "it'd better be?" The force concentration is, I believe, approximately reasonable. You can only move a few people across space, while I can recruit a lot at home far more cheaply. And yes, the island is full of jungle, and a lot of the SAMs are Stingers.

Raymond said...

Twenty km across is small enough that SAM coverage is nearly complete with only a site at each end, which isn't reflective of the proportional dispersion required to cover an Earth-sized planet, and the island must be big enough that even mechanized infantry will find it nearly impossible to shift forces from one side of the island to the other in something less than days.

Milo said...

Raymond:

"Also, shrapnel eviscerates spacecraft in orbit (and flesh on the surface), and there will be much shrapnel."

Oh right. I forgot about that. Thank you. There will be evisceration. Good.


"And would you really furl your sails in the middle of a fight? They can still operate with a few holes in them."

Sails are quite durable. Radiators are likely to be more brittle, so a small projectile can still tear off a big piece rather than just punching out a small hole and going out the other end.

Also, sailing ships had crew who knew how to sew, with ample supplies of spare cloth and rope.


"Ricks are not a measure of damage, but a measure of the damage efficiency of mass. A ton of mass in orbit at ten Ricks is worth ten tons of mass on the surface in explosives."

Yes, but a ton of mass in orbit needs a fair amount of delta-vee to get sent into the thing you want to hit. You don't get your Ricks for free. At least not all of them.

And Ricks also work for surface-to-orbit missiles. It's relative velocity that determines damage, so a slow missile hitting a fast ship still has the almighty Rick on its side. Generally, any two objects colliding in space will constitute a victory for whichever of those two was more expendable.



Byron:

"Yes, but in this case, neutralize includes destroy. They're both doctrinally correct. What will we do?"

Obviously, we need to use real military protocol.

What this means is that if we don't like each others' vocabulary, we can try and change it at gunpoint. Have fun.



Raymond:

"We will neutralize hostile surface-to-orbit weapons systems by repeatedly smashing guided projectiles from orbit into launch mechanisms and observation sites and pulverizing them into itty bitty pieces."

Woo!

Byron said...

Sure. Maybe it's bigger, and all the forces are proportionately larger. It doesn't really matter.
Still, let me get your plan straight. You'll take out all the SAMs on one end of the island, then land your troops. It will be a while before the other guy can repel them. But what are they doing? They can't win a mass ground battle. You said yourself all the SAMs are dead. The enemy can move forces several times as fast as you can. (A reasonable estimate. They are doing road marches. You're in combat.) So what do they do? And keep in mind that anything besides simple SAM sites that's worth taking out will be guarded by at least a company. And you usually can't win attacking a fortified position at even odds. And you never can do it more than once. One other scenario perimeter. You have to have at least 2/3 of ground troops alive at the end.

Tony said...

Byron:

"The problem is that you seem to consider "all wars are decided by ground forces" a fundamental principle. While most are, I think we can make an exception."

Ummm...no. I'm just not convinced that bombardment alone would be decisive against an entire planet, if the consequences of capitulation were perceived to be a worse alternative. And you haven't said anything to convince me. If you've said all you can say, then we'll have to let it go at that.

Byron said...

Then the attacker has to make it so that capitulation is not a worse alternative. I'm going at this as the attacker, so that's my job. I've already told you how I'll do it. If you look at it differently, then so be it, but we've reached the point of different premises=different results.

Milo said...

By the way, Tony, you were the first person in this thread to use the word "smashed" to refer to orbital bombardment. (Byron used "smash" once before, referring to ground battles, and that was hundreds of posts ago. It didn't really take off until after you used it.)

"So what happens if the attacker tries strategic bombardment? Even if all of the defender's industrial infrastructure is smashed, he's still on a planet and he can still eat. Eventually the attacker will have to go away."

Milo said...

Sigh. Disappearing posts again. It was there, I saw it! I think links are making it mess up or something...

So anyway.



Tony:

"Ummm...no. I'm just not convinced that bombardment alone would be decisive against an entire planet, if the consequences of capitulation were perceived to be a worse alternative."

I agree. If they decide to resist you hard enough, then you need to do an Iraq-style occupation. But that is something to do after their orbital defenses have been, pardon me, smashed. You don't land ground forces to help you take out orbital defenses, you land them after the orbital defenses have been taken out. Yes, it would be cool to have hunter-killers helping you win the battle from down on the surface of the planet - as Raymond put it, "you (and maybe a few friendlies) against the world (literally), concentrating on specific, focused objectives, always on the run, always outnumbered". But I can't see it working.



Byron:

"Then the attacker has to make it so that capitulation is not a worse alternative."

This is not always possible. Politicians decide objectives and generals figure out how to accomplish those objectives. If the politicians say "bring me some slaves!", then how will the generals go about pulling this off without offending anyone?

Raymond said...

I've got fighter-bombers, they're in jungle. I can take out whatever I can see from high altitude, get a little lower, take out the stuff I couldn't see before. I can't really take a YAL-1 to just above treetop level, especially considering they've got enough stingers left to really ruin my day if I give them that tempting of a big, slow target. I'm still stuck guessing where the rest of them are, with no way to know for sure without carpet-bombing the whole island. So yeah, I carpet-bomb a couple beaches, then I drop empty crates with parachutes at one and my commandos at the other. The commandos then stalk around the jungle, kill small outlying stinger teams not worth a whole bomb, and start calling in fire missions on bigger stuff (especially those pesky well-camouflaged fuel depots that mechanized infantry division holds so dear). Once enough of the division's hidden supply chain is neutralized that it's no longer mechanized (and it'll take a week to march from one side to the other), then we're in business. If I can secure a nice big LZ, I can even bring in some heavier stuff. (That part's a maybe.)

My advantage is that you never know just how many troops I put down, which were crates instead, and how many more I have. I can hit anywhere on the island basically whenever I want, and I can drop more troops into your rear if you decide to gamble that I landed my entire force in one spot.

Your advantage is that despite the pretty beaches and nice roads cutting across the island, you don't have to stay out in the open. You'll be slower, and your mechanized infantry won't be very mechanized (or they'll be bombed quickly), but you can still do something, and you've got enough stingers left to take a potshot at my lovely laser plane (if I fly it too low) or the choppers I'd need to march through and teach the civilians the new language. My YAL-1 will run out of fuel eventually, and obviously I don't want to resort to saturation bombing. You expect me to sit in the air and wait?

Raymond said...

Sorry, "...enough choppers to fly in all the personnel I'd need to march through..."

Milo said...

The pertinent question is, given available weapon ranges, can you effectively clear a safe zone for landing in while staying safely out of reach of the majority of the enemy's forces?

Tony said...

Milo:

"By the way, Tony, you were the first person in this thread to use the word "smashed" to refer to orbital bombardment. (Byron used "smash" once before, referring to ground battles, and that was hundreds of posts ago. It didn't really take off until after you used it.)"

I look at it this way: using "smashed" in the context of physical and economic damage to an infrastructure is simply descriptive. Using it in the context of military operations is somehow gratuitous. Maybe because it reminds me of too many internet discussion with .mil porn fanboys who are all excited about the destructive power of weapons, but don't have a clue about the effects on the receiving end. Maybe it just seems more personal to me, as a veteran, when it involves military targets. Your milage may vary.

Milo said...

I mostly used a harsh word to reflect the amount of effort that goes into it. "Neutralize" makes it sound easy. Like it's just a routine procedure.

Raymond said...

Tony:

I can't speak for everyone here, but I'm not trying to piss off anyone too badly. And I'm most assuredly not a .mil-porn fanboy (any squeeing coming from me is mostly ironic). I do have reservations about the clinical (and overly acronymized) vocabulary currently in vogue in the military establishment, but I don't think for a second that the people instructed to carry it out have any illusions.

"Smash", though, is pretty much descriptive in the context of big chunks of whatever coming down from the sky and landing on stuff with a big boom.

Raymond said...

[Note: damn internet not picking up tone of voice. "Can't speak for everyone here" wasn't aimed at anybody as some sort of passive-aggressive bitchery.]

Milo said...

Excuse me, I need to go engage in some passive-aggressive bitchery at other people for engaging in passive-aggressive bitchery and/or being insufficiently clear about that they're not engaging passive-aggressive bitchery.

Figuring out the tone of voice is left as an exercise for the reader.

Tony said...

Milo:

"I mostly used a harsh word to reflect the amount of effort that goes into it. "Neutralize" makes it sound easy. Like it's just a routine procedure."

Well, at some level of abstraction it is a routine procedure. And it's not a very high level at that. "Target neutralized" is the term used whether you're a grunt in a hole with a radio or a staff officer in a tent sending and email (or a teletype, back in the day).

A little bit more friendly advice: using harsh words for impact comes across as a pose to people who know what the words are really trying to describe. Remember what i said, professional language isn't meant to hide the reality, but facilitate rational thought by removing the emotion from it. It's no different than an ER doctor using medical jargon to describe an accident victims wounds rather than exclaiming, 'Holy crap, this dude is f*cked up!"

Raymond said...

ER doctors (I was raised by one) have a strange blend of technical jargon and obscenity. Usually so they can concisely confer exactly what part of the dude was f*cked up. Same for the soldiers I've known. Restricting the vocabulary to the technical terminology is saved for official reports and court testimony.

Tony said...

Raymond:

"I can't speak for everyone here, but I'm not trying to piss off anyone too badly. And I'm most assuredly not a .mil-porn fanboy (any squeeing coming from me is mostly ironic)."

I didn't take it that way. I took it as a bit of good-natured sarcasm to remind me not to take myself too seriously.

"I do have reservations about the clinical (and overly acronymized) vocabulary currently in vogue in the military establishment, but I don't think for a second that the people instructed to carry it out have any illusions."

I have reservations when such language is used in a deliberate attempt to obfuscate reality. When used as intended, to communicate information in a precise and professional manner, it is what it is, and I wouldn't change it.

"'Smash', though, is pretty much descriptive in the context of big chunks of whatever coming down from the sky and landing on stuff with a big boom."

If we're going to use such terms, I think "blown to smithereens" is more accurate. Above a certain gigajoulage, the immediate effects of KE weapons are pretty much indistinguishable from nuclear weapons.

Tony said...

Raymond:

"ER doctors (I was raised by one) have a strange blend of technical jargon and obscenity. Usually so they can concisely confer exactly what part of the dude was f*cked up. Same for the soldiers I've known. Restricting the vocabulary to the technical terminology is saved for official reports and court testimony."

I was both in the service and worked in accute care hospitals, so I know what you mean. But you did miss a category of communication in which technical jargon is almost always used -- discussions of a theoretical nature. One can sit and watch an artillery bombardment and say, "Somebody over there is getting blowed the f*ck up!" But when planning for the artillery mission, the discussion is about how many volleys from how many battereis to achieve target neutralization. I'm sure you can think of a parallel example from the world of medicine.

Raymond said...

Most medical discussions of a theoretical nature (that I was privy to) were peppered with exclamations of "No, if you do that, you'll f*ck him right up. His esophagus will constrict, and then you're up shit creek. You have to do this...". YMMV.

Citizen Joe said...

RE: Radiators. Anything made by man will break down eventually. Radiators will need to be compartmentalized so that you can repair them while in use. The fact that they'll need to be retractable in the first place already takes up the added mass, shut off valves aren't going to be significant compared to that.

Raymond said...

Citizen Joe:

Heat-pipe radiators are actually fairly new, but they're extremely compartmentalized. That's one of their biggest strengths (well, that and the substantial reduction in mass). One section has its central channel punctured, and other sections are unaffected. Plus, the working fluid for the rad is self-contained and never comes into direct contact with the heat transfer fluid from the heat source. If you set up the heat exchanger properly, you can just swap them, no valve required.

Luke said...

Byron

Luke, can you give me some numbers for "Plausible Midfuture" lasers for Rocketverse?

A reasonable guess would be specific powers of around 1 kJ/kg. This is about two orders of magnitude better than current high powered lasers, and puts the output of lasers in the same ballpark as modern engines, motors, and generators. This could let you, for example, field a 100 MJ laser with a 100 ton mass for your laser equipment. This doesn't count the focal assembly - mirrors will mass extra.

Milo said...

So speaking of space-to-space lasers and laser armor...

All spaceships that intend to stay in transit for extended periods need to be pretty well-shielded against cosmic rays like the solar wind (i.e., protons). Since we're going to need a pretty thick (and massive) amount of this shielding anyway, it would be nice if the shielding could also double as armor rather than needing separate layers of armor for everything you might have thrown at you.

Apparantly the best proton shielding materials are ones that contain lots of hydrogen. So among those materials that give mass-efficient proton shielding, which has the best anti-laser and anti-kinetic properties? From what I've seen plastics in general seem to have pretty low melting points, which isn't so hot when you need to resist lasers. (Pun intended.)

Civilian ships can use tricks like using their water tanks as proton shielding material, but that's way too fragile for a warship.

Raymond said...

Cosmic rays and solar proton storms are actually two somewhat different threats. Cosmic rays are mostly dangerous because they are ionizing radiation - this is where the hydrogenated plastics come in, because low-Z materials will produce less harmful spallation of radioactive material.

Proton storms, on the other hand, are the ones which require storm shelters with fairly massive water shielding. But these are sporadic, and are fundamentally temporary. Get the warning, get in the shelter, wait for a few hours, get back out and carry on. Also, they're more of a concern in interplanetary space - a planet with a decent magnetosphere will give some protection.

Luke, Byron, can we have the lasers at only one order of mag above present tech (say, 10 kg/kJ)? Mounting gigawatt lasers on destroyer-class craft (~2000 tons) is a little much, doncha think?

Byron said...

Raymond, you don't have anything heavier. Plus, you're pushing the analogy again. What you're having your people do sounds like special forces stuff, not conventional ground troops. I already went over why that's not a good idea. You say "not worth an airstrike" for some of the stinger teams (trucks). If you average one casualty per truck, then each truck will take at least two tons of launch mass to remove between food, pod, guy, and gear. If you use a 20 kilogram kinetic, it's 20 kg. If you use a laser, it's practically free.
Plus, the point of the entire exercise is to force the enemy to reveal all of their missiles and take them out, allowing you the pinpoint fire support from the orbiting spaceships. That allows you to defeat any conventional opposition. Haven't you read Footfall?
As to empires and politics, smart generals with stupid politicians usually don't last very long. Take a look at Nazi Germany. Still, if I want slaves, I'm not going to go to a planet that is of the same technology and economic level. I'll find a primitive backwater to invade, instead. Actually, I have the evil but smart empire's solution to planets surrendering. All planets are in four classes:
A. A full member of the empire. Light taxes. A high degree of autonomy. No repercussions. I offer this to high-tech, high-economy worlds when I first show up.
B. Higher taxes. Limited autonomy. Possible exile for current leaders. This goes to worlds that are less important, or more important worlds after I've stripped the defenses but before the troops go in.
C. The worlds that shoulder the real burden. High taxes, run by the empire. No slavery, but limited personal freedoms. Probable prosecutions of resistance leaders. Less-important worlds that resist, or important worlds with ground fighting.
D. Worlds taken over by the empire. The inhabitants are taken into slavery and forced to work for me. This is for worlds that I'm mad at.

Byron said...

Luke, what about efficiency, and jitter and such? And how much will the mirror mass? I just need rough numbers.
Raymond, efficiency might mess with that. Too much heat out means that it can't fire for very long.

Luke said...

Milo:

You only need extensive shielding if you are protecting us radio-sensitive humans (or other biological material). These can remain some distance from the fighting, and radiation-hardened combat craft can be directed via remote control. This reduces the need for armor. There remains the question of how far away the decision makers can be and still direct the laser fire control in an acceptably short time (since kinetics take a good fraction of an hour to arrive, their effectiveness will not be hurt by an extra minute or so light speed delay).

Hydrogen is the most effective material for stopping energetic protons and nuclei. However, it is not all that much better than other elements. About 10 tons of carbon shielding per square meter will reduce the radiation level to something reasonably safe. If using hydrogen-rich materials such as HDPE or water, this might go down to 7 or 8 tons per square meter for the same level of protection. Since ten tons per square meter is massive overkill for armor, particularly when the rest of the spacecraft will not be so armored, you can just use however much armor you think you need on the habitat section of the transport spacecraft, and the rest can be borated polyethylene with a back layer of lead to stop the gamma rays.

Raymond

Both cosmic rays and solar storms are ionizing radiation. In fact, both are energetic protons and nuclei. The cosmic ray spectrum tends to have higher energies than the solar storm spectrum, so you need a bit thicker armor to protect against galactic cosmic rays. The galactic cosmic rays come in a steady drizzle. It may be possible for medical science to treat the chronic radiation exposure of galactic cosmic rays. As you note, however, solar storms deliver acute doses well beyond the lethal limit, so some form of shielding is needed against these. Fortunately, solar storm protons and nuclei have a low enough energy that various electromagnetic methods seem promising for stopping them. These would not work against galactic cosmic rays.

Hydrogenous plastics don't really do much to prevent "harmful spallation of radioactive material." You still get hadronic showers (the production of pions, hadrons, anti-hadrons, and nuclear fragments) and electromagnetic cascades (high energy bremsstrahlung photons and high energy electrons and positrons).

I have no problem with assuming lasers of 0.1 kW/kg specific power. We won't be getting man-portable laser rifles, but if that's what we want for our tech assumptions, that's what we have.

Luke said...

Byron

A near term efficiency of 50% is likely. Plausible mid-future lasers could easily be in the 60% to 80% efficiency range.

Jitter is pretty much solved. You can get near diffraction-limited spots that can be held steady on their targets.

Mirror mass will probably vary depending on whether you are in space or on the ground. In space, you can use a lot flimsier structures because the mirror does not have to support its own weight. I'm a bit busy right at this moment, but as a guess you could look into the folding mirror of the James Webb space telescope for estimates of what a large space-based mirror might mass.

Thucydides said...

For fairly advanced planetary economies, I suspect that orbital bombardment will not have the effect of throttling their supply chains. This argument sounds suspiciously like the bomber arguments that raged before and during the Second World War.

While allied "round the clock" bomber offensives smashed anything that looked like infrastructure in Germany, the military dispersed production and were producing more military equipment and upgrading to new generations of kit as the war dragged on.

On the allied side, places like the huge Willow Park factory were churning out B-24 bombers at a fantastic rate, while shipyards were cranking out supply ships and warships at rates that far outstripped the Axis powers. In terms of logistics, the Allies had the ability to overmatch the Axis powers either individually or separately (the British Empire had a globe spanning resource, manpower and production base; without the United States the Empire would still have won the war in 1948 or thereabouts. The Soviet Union would probably have been able to win the war in Europe in 1946 or early 1947 without outside intervention).

21rst century techniques will make the balance even more lopsided as far as small to medium pieces of equipment are concerned, think of dispersing 3D printers everywhere and seeding the Internet with the plans and recipes for military equipment and supplies. I suspect the true limiting factor will be manpower; the fabulous "Luft '46" aircraft would be produced in large numbers but there would not be enough trained pilots to fly them. In the near future, trained soldiers will be in short supply after the smoke clears from the initial clashes, especially the technical troops that keep everything running and the staff which oversees the operations. (Depending on how cold blooded you are, getting more "grunt" infantry can be pretty simple).

Unmanned equipment pretty much begs to be robotized, clouds of missiles following simple swarm algorithms to overwhelm any enemy who shows himself would be a logical response to lots of kit but few shooters. This would be true for ground combat, sweeping the sky of enemy combatants and clearing low orbital space as well.

Byron said...

And how, exactly, is this dispersed production supposed to produce ASAT missiles? They're quite a bit bigger than rifles, which means bigger stuff is required to make them. Plus, dispersed production isn't as efficient as mass production. Economies of scale will still work in the future. Plus, if the invader is cold-blooded enough, he can just destroy all modern stuff. I'm not saying it's ideal, but it would work.

Milo said...

Raymond:

"Proton storms, on the other hand, are the ones which require storm shelters with fairly massive water shielding. But these are sporadic, and are fundamentally temporary. Get the warning, get in the shelter, wait for a few hours, get back out and carry on."

Having to regularly scramble for a special shelter for several hours and die if you don't strikes me as rather inconvenient. I guess I can see the necessity, since having the majority of your shielding only covering a small shelter would save significantly on mass, but I would rather give my ships all-weather capability if at all possible.

Anyway, the sun still casts some solar wind the rest of the time. Solar storms are just when the wind is unusually intense for a while. You need to have at least enough shielding to cope with normal solar wind.


"Also, they're more of a concern in interplanetary space - a planet with a decent magnetosphere will give some protection."

And how many planets with decent magnetospheres do you see in the solar system, hmm?

Anyway, even if they all had magnetospheres, interplanetary voyages are long. You will spend the majority of your trip there, unless you're laying siege to an enemy planet. Orbit-only ships (I'm tired of calling them "brown-water" since there's no water... have ideas for a better name?) can be designed to take advantage of the particularities of their home planet and so may sometimes be able to skimp on shielding, but any interplanetary attack ship needs good shielding, period.



Byron:

"As to empires and politics, smart generals with stupid politicians usually don't last very long."

No, but they make for enticing stories.

Milo said...

Luke:

"You only need extensive shielding if you are protecting us radio-sensitive humans (or other biological material). These can remain some distance from the fighting, and radiation-hardened combat craft can be directed via remote control."

Interplanetary distances are too large for remote control from home - lightspeed lag, you know. Also, Burnside's Zeroth Law.

Warships need to have crew onboard. If you have the humans remote-controlling drones, then the base they're remote-controlling from needs to be onboard a ship that travelled through interplanetary space with the drones.

However, you are correct that only the habitation module strictly needs proton shielding. If your ship has a significant amount of mass in reactors, engines, weapons, etc., and a comparatively small amount of crew that does not usually need to visit most of the craft's machinery, then you can save a fair amount of mass by shielding only the crew compartment. You can also bury the crew compartment deep inside the ship (a good idea in any case) so the ship's machinery doubles as an implicit shield.


My problem is I'm trying to figure out how much armor spaceships will be carrying. I get that with their stringent mass limitations they will often go for as little as possible, but "eggshells armed with sledgehammers" doesn't make for the most exciting battles. So I figured that proton shielding is something that everyone in space has to have, no ifs or buts about it. So I hoped to use that to guess some sort of minimum for how tough spaceships will be against other stuff.


"(since kinetics take a good fraction of an hour to arrive, their effectiveness will not be hurt by an extra minute or so light speed delay)"

The outer solar system can have a lightspeed delay of hours. Also, kinetic orbit-to-surface bombardment is hardly all a ship will be doing. People have been saying how any enemy that shows itself for even a few seconds (a lasersub that surfaces to fire, etc.) can be instantly lasered into oblivion, and that requires someone to hit the fire button in a timely fashion. Space-to-space combat (whether orbit-to-orbit or deep space) also isn't going to be waiting the better part of an hour for its shots to land. Even kinetic orbital bombardment can be faster if you have good enough guns.


"Mirror mass will probably vary depending on whether you are in space or on the ground. In space, you can use a lot flimsier structures because the mirror does not have to support its own weight."

Yeah, but flimsy structures are... flimsy. And can get shot. If your weapon is significantly easier to destroy than the rest of your spaceship, everyone will be aiming for that.

Byron said...

But everyone will likely push the upper end of technology with regards to wavelengths, so they will all be in the same range. That means lasering the other guy's mirror is not going to destroy it.
Also, I've got the laser data up at rocketverse. Why do I have only three members, and nobody signed up for powers?

Milo said...

Thucydides:

"(Depending on how cold blooded you are, getting more "grunt" infantry can be pretty simple)"

I'm going to repeat an observation I made in another thread - equipment has costs too. If I'm going to equip my soldiers with expensive gear, then I'm going to try to spend an amount in the same order of magnitude to the gear's cost in training them to use it properly - because why not? It's not significantly increasing my costs, and it's a serious force multiplier.

Of course, if the bottleneck in training your troops is time rather than money, then you may be in more difficult straits.



Byron:

"And how, exactly, is this dispersed production supposed to produce ASAT missiles? They're quite a bit bigger than rifles, which means bigger stuff is required to make them."

They can be made in parts and assembled. However, making parts one-by-one with equipment designed for manufacturing smaller stuff will take a while to produce all the parts for a missile. Also, you still need the resources to feed into your machine.

Milo said...

Byron:

"But everyone will likely push the upper end of technology with regards to wavelengths, so they will all be in the same range. That means lasering the other guy's mirror is not going to destroy it."

Remember, even your own laser would fry your mirror on a direct hit. Your mirror survives because the laser focussed so it's spread across a larger area on your mirror than it will be on your target.

Byron said...

Which is why you can't keep full industrial capacity under bombardment. Some stuff would get through, but I don't think there would be enough to matter. Plus, if I want as much intact as possible, just blast the rail lines near the mines. I can fix them when I land, and keep blasting them to stop them from being repaired.
Oh, and I agree with you on the grunts thing. A good military takes years to make.

Milo said...

Okay, here's another angle.

We keep thinking in terms of "If I were trying to take over a planet, what would I do?".

Let's try looking at things from the other side - the side that doesn't have the convenience of getting to call down death from above.

Consider the following two scenarios:

1. You are defending a planet. All your in-space assets have already been either blown up or have disgracefully retreated. However, you still have fairly solid surface-to-orbit defenses of all types, and most of the enemy's fleet is in high orbit out of range from your weapons (unless you're willing to gamble away a missile on a shot that has a poor chance of making it). Meanwhile, however, you detect a company of marines that somehow slips through your defenses (don't ask how) and lands on your planet. You are not 100% certain, but you believe the enemy spaceships are just making some final preparations and plan to storm you soon, with the marines assisting them from the ground. What do you do?

2. You are defending a planet. All your space assets and surface-to-orbit defenses have been blown to smithereens and the enemy has undisputed space superiority. They are now beginning to land troops in large numbers. You still have plenty surface-to-surface forces, including heavy vehicles, hidden in nondescript-looking warehouses to avoid orbital bombardment. Unfortunately, for whatever reason, surrender is simply not an option. You have to fight to the bitter end. What do you do?



Also, happy 400th post! Third page coming soon!

«Oldest ‹Older   201 – 400 of 829   Newer› Newest»