'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.
828 comments:
«Oldest ‹Older 401 – 600 of 828 Newer› Newest»Byron:
I've been saying from the very beginning it was a spec ops job start to finish. To continue our metaphor, that entire company I have at my disposal would be SEALs or Force Recon. Why wouldn't spec ops work, again?
Luke:
Cosmic rays are sufficiently energetic (over and above solar proton flux) to result in radioactive isotope production. List shamelessly stolen from Wikipedia:
Tritium (12.3 a): 14N(n, 3H)12C (Spallation)
Beryllium-7 (53.3 d)
Beryllium-10 (1.6E6 a): 14N(n,p α)10Be (Spallation)
Carbon-14 (5730 a): 14N(n, p)14C (Neutron activation)
Sodium-22 (2.6 a)
Sodium-24 (15 h)
Magnesium-28 (20.9 h)
Silicon-31 (2.6 h)
Silicon-32 (101 a)
Phosphorus-32 (14.3 d)
Sulfur-35 (87.5 d)
Sulfur-38 (2.8 h)
Chlorine-34 m (32 min)
Chlorine-36 (3E5 a)
Chlorine-38 (37.2 min)
Chlorine-39 (56 min)
Argon-39 (269 a)
Krypton-85 (10.7 a)
Hydrogenated plastics are mostly to put as much hydrogen in the way as possible. Lower-Z elements produce fewer harmful isotopes.
The energetic protons of the storms in question aren't in nearly the same range, but the overall flux is many orders of magnitude higher. And yes, it's still ionizing radiation, but ionizing inside you instead of showering you in reaction products.
And where did you get the 10 tons/m^2 figure? The (conservative) NASA estimate is more like 20 gm/cm^2, or 200 kg/m^2. (Ref: NASA paper 20040010797_2004001506, pp 90-92)
Milo:
I call them C3 craft, after the usual shortening of characteristic energy. Decent magnetospheres? Try Earth. Jupiter has too strong of one, and Saturn and Uranus aren't bad.
You can still run a craft from a storm shelter - you just can't go outside and do maintenance until afterwards. Also, normal solar wind isn't as worrisome as background cosmic rays (some of which are the highest-energy particles from the sun), so anything which will protect you from the latter will do the same for the former (except, of course, the storms).
Armor will, for the most part, be a waste of mass. If you do have any, make it a faceplate in the front covering a narrow angle, since the ranges will be long enough you won't have much parallax between enemies.
The craft themselves will (most likely, based on current proposed designs) be reactor and engines on one end, long truss in the middle with the radiators on each side, and the payload (crew hab, sensors, weapons, fuzzy dice) at the front. Not much machinery to bury the crew inside; you're thinking too naval again ;)
Byron again:
I'm obviously more cynical than you, because smart generals with stupid politicians is sort of the usual state of affairs, isn't it?
Oh, yeah, and go go 400+ posts!
[I may be in bed soon, so try not to leave too much for me to catch up on tomorrow.]
Milo:
I don't see any need to keep the command craft back at interplanetary distances. A light minute or so should work fine since a planet with an atmosphere cannot zap you with x-ray lasers. Unless they have very powerful visible light lasers, I suppose. This will give a short enough time to control kinetic strikes (which, as mentioned, take somewhere around half an hour to an hour). As I mentioned, the big question will be laser targeting. Can you let on-board automated targeting routines decide what is and is not a hostile submarine, aircraft, or troop formation? Or do you need to bring your command craft closer, to within a few light seconds?
I'm beginning to think it likely spacecraft will not have mass-based proton shielding at all. An artificial magnetosphere can deal with solar storm protons and ions, and the dose from galactic cosmic rays can be treated medically. Mass based neutron shielding to protect your from your reactor will still be necessary.
You can make your mirrors more robust - but if you do so, for the same mass budget you will not be able to zap from as far away. That means the guy with the flimsier mirror will disable your mirror before you can use your mirror at all.
Milo, Byron:
3. You are defending a planet. All your space assets and most of your surface-to-orbit defenses have been blown to smithereens, and the enemy
has undisputed space superiority. They have likely landed advance recon teams on three continents, but you can't be sure, because your global communications are in chaos and your last long-range observatory just got knocked out. Before it was lost, you detected a large number of engine signatures from the enemy planet - likely troopships carrying occupation forces. You still have plenty of surface-to-surface forces,
including heavy vehicles, hidden in nondescript-looking warehouses to
avoid orbital bombardment. Most of the enemy's fleet is in high orbit out of range from your few remaining surface-to-orbit weapons (unless you're willing to gamble away a missile on a shot that has a poor chance of making it). Otherwise, they too are in hiding. Unfortunately, for whatever reason,
surrender is simply not an option. You have to fight to the bitter end.
What do you do?
4. You are defending a planet. All your space assets and most of your surface-to-orbit defenses have been blown to smithereens, and the enemy
has undisputed space superiority. They have landed troops on your southern continent and have begun constructing a forward base. Your heavy unit in the area was forced to retreat with heavy casualties from its attempt at a counterattack, due to heavy orbital bombardment and transatmospheric air assets. Your last long-range observatory just got knocked out. Before it was lost, you watched the second wave of enemy craft arriving in high orbit, likely troopships carrying occupation forces and heavy units. You still have plenty of surface-to-surface forces,
including heavy vehicles, hidden in nondescript-looking warehouses to
avoid orbital bombardment. Most of the enemy's fleet is in high orbit out of range from your few remaining surface-to-orbit weapons (unless you're willing to gamble away a missile on a shot that has a poor chance of making it). Otherwise, they too are in hiding. Your southern continent, however, has no surface-to-orbit assets left; that was where they concentrated their attack after the initial bombardment, and they're too far inland for your submarines to provide effective coverage. Unfortunately, for whatever reason,
surrender is simply not an option. You have to fight to the bitter end.
What do you do?
Raymond:
"The craft themselves will (most likely, based on current proposed designs) be reactor and engines on one end, long truss in the middle with the radiators on each side, and the payload (crew hab, sensors, weapons, fuzzy dice) at the front."
A vertical design puts a lot of stresses on your hull (like a skyscraper), and has trouble dodging since it accelerates along its own length.
Hardly the only reasonable design.
Luke:
"Mass based neutron shielding to protect your from your reactor will still be necessary."
If your reactor produces neutrons. Fission reactors and deuterium-tritium fusion reactors will. Deuterium-helium reactors will, but only in small amounts that don't require that much shielding. Helium-helium and proton-boron produce practically none, although those are less efficient.
Anyway, this shielding will be around your reactor, not you crew compartment. (Oh, and don't start on shadow shields. I want a design that actually makes it possible to dock with other spaceships. That means my ship shouldn't be lethal to everything that comes near it.)
"You can make your mirrors more robust - but if you do so, for the same mass budget you will not be able to zap from as far away. That means the guy with the flimsier mirror will disable your mirror before you can use your mirror at all."
Yeah, except that given equal zaps, the flimsier mirror can be effectively damaged from a longer range than the robust one. So it balances out.
Raymond
Cosmic rays certainly can result is radioisotope production. It is just not a very important source of radiation from a health hazard point of view. Note that meteorites are not dangerously radioactive.
Also, solar storm protons can range up to 100 MeV or so in energy. This is much more energy than is needed to activate atoms (a typical activation threshold is 10 MeV). With particles in the 10 to 100 MeV range, the solar storms will be producing radiation showers you will need to worry about.
Ten tons per square meter comes from two sources. First, the mass of our Earth's atmosphere above our heads is 10 tons per square meter. This isn't a perfect comparison, because the cosmic rays that interact in the upper atmosphere produce muons (in the first ton/m^2 or so), and the muons have time to mostly decay by the time they reach ground level. This is not true of radiation shielding made of condensed matter, so at 10 tons per square meter you would get more radiation than on earth. It would probably not have dangerous chronic radiation exposure, though.
Second, you can look at the behavior of radiation showers produced by cosmic rays. This page gives a good overview of radiation shower physics http://www.cosmic-ray.org/reading/detect.html. When I worked the numbers, I got something close to 10 tons per square meter for reasonable protection. Feel free to work the numbers yourself, though.
Raymond:
Scenario 3
Wow. They took out the internet? Harsh.
I think the enemy is acting oddly here - if they took out most of my surface-to-orbit defenses, their ships should be moving into low orbit to put the heat on me.
But, we're supposed to look at this from the defender's side. So okay.
My few remaining surface-to-orbit defenses are insufficient to defeat the enemy in orbit, so an eventual occupation is inevitable and I have to prepare for it (using strategies similar to scenario 2). The question is how to put my few remaining defenses to their best use before I lose them. Obviously I have to keep them hidden as best as possible until I have targets in low orbit. So the real question is, do I prefer to use them to take out some of your orbital bombardment ships or to take out some of your troopships, knowing that I can't get all of either one, let alone both?
I think the bombardment ships are a bigger threat, since they can only be taken down with surface-to-orbit defenses, while troops can be engaged with surface-to-surface forces after they land (and are harmless if they don't land). Blowing up a lot of your troops would make my surface forces' job a lot easier, but my shorter supply lines mean my troops can probably take on whatever troops you're capable of shipping, if not for their space support looming overhead. I'll take my chances attriting your troops the hard way - my surface-to-orbit defenses lie in wait until your bombardment ships move into range. If they never move them into range, then their loss - my defenses seem to be working well enough as a "fleet in being", no need to squander that advantage. I might gamble a shot at a low-orbiting troopship with a lasersub, if I think it can safely duck and run before you can pinpoint it accurately enough to retaliate (quite likely if your bombardment ships are in high orbit), but bunkers and missile trucks are out.
But wait! Why am I keeping them hidden? Your ships are up in high orbit where they aren't much of a threat. If you move them into low orbit, then I'll have the targets I want. Bunkers are at risk to kinetics launched on multi-hour trajectories from high orbit, but subs/planes/trucks are not. I'll still hide them when feasible, but your recon team doesn't pose much of a threat without low-orbiting fire support to take out what they find.
What I do want is to try to ensure that when you move your bombardment ships into low orbit, I get a Lanchesterian advantage (or rather, the minimum possible disadvantage). How hard this is depends on my weapon ranges, and on whether you will keep your ships in low orbit or only make elliptical passes. If you make elliptical passes, though, then that gives me a hint of where you're focussing on.
The defenses I have left are probably mostly laser-based. Missile-based ones would have expended their ammunition in the last battle (the one where you blew up most of my defenses in the first place), and the remaining launch platforms are of little use unless I can dig some extra missiles out of the warehouses (those would probably already have been loaded onto trucks when I detected the incoming invasion last month) or my factories are able to manufacture more while the siege lasts (hard to do, even if I have time).
Okay, okay. So I have a few lasersubs, laserplanes, and laserbunkers. The bunkers, obviously, stay where they are, and don't fire until they have a bombship in range (they do not risk revealing themselves to hit troopships unless I have evidence that you've already detected their location). Supersonic laserplanes could provide surprisingly good coverage - I may well be able to keep up with the ground tracks of bombships coming in on an elliptical pass from high orbit, unless you catch me off-guard by suddenly burning into a steep approach (which will cost a lot of propellant to perform, and is only good for one pass). Barring those steep approaches, even if a few of my laserplanes are out of range to intercept your bombship's periapsis, I can still call up a significant number even if I had them spread thinly across the planet. I can't keep up with the ground tracks of stuff in circular low orbit, of course, but I hardly need to - as long as you stay in low orbit, I can prepare an intercept at any point along the orbit, with both laserplanes and lasersubs (although I might do it with only lasersubs, despite the Lanchesterian disadvantage of keeping the laserplanes away, since those are more vulnerable against low-orbital bombship lasers, are useful for other missions re: elliptical passes, and are less hidden so might give away the location of my ambush).
I can't do much to catch those recon teams if all I've been able to narrow their position down to "somewhere on this continent". However since your recon team is only useful with aid of orbital fire support, I will assume that they will probably go near the ground tracks of your low-orbiting bombships (once you have low-orbiting bombships, which you said you currently don't). This gives me an idea where to start searching, using my own special forces (including surface-to-surface patrol subs in the aquatic portion of the track). These patrols will be spread equally along the ground track in question, regardless of where my actual important stuff is. It also means that anything along those ground tracks needs to be well-hidden from both space and ground observers. This is another reason to not use laserplanes around permanently-low-orbiting bombships until I run out of lasersubs, since while they can fly above clouds (and thus be hidden from the ground) or fly below clouds (and thus be hidden from space), they would have a very hard time flying through clouds. My lasersubs, for their part, are safe unless your recon team brought their own minisub or other sub-hunting equipment. I'll have them do silent running just to be safe.
If you have bombships in multiple low orbits, then I have a harder time figuring out where to patrol, but I also have an easier time setting ambushes since you don't know which orbit I'll hit (and since your bombships are spread out).
I also have to keep my surface-to-surface forces hidden from your recon teams, of course, but that's something I would have already had to do anyway once you landed occupation forces (which would surely have a few recon teams of their own), so it's nothing new. Details for how to do this should go under scenario 2.
Proceed as with scenario 2. I'm not ready to try answering my own scenarios.
But wait. On the other hand, in an extended counterinsurgency operation, you'll probably only be using bombships sporadically, when a target presents itself. As long as I keep down like a good guerilla, you can probably provide all necessary fire support with only a few bombships, and any more is overkill. In this case all my speculation on thinning out your bombships is pointless, and I should have been thinning out your troopships instead. I simply wait and keep everything hidden until the troopships arrive. Subs are submerged, planes are under clouds or in hangars. If you bring bombships into low orbit, I will move important stuff away from the ground track to keep it safe, if feasible. Once the troopships arrive, I calculate their approach vector and use those supersonic laserplanes to intercept their landing, with the added complication that I now have to do so while dodging bombships that are also in low orbit. I'll stay under clouds when possible, but you may well pick cloud-free places as your landing spots to prevent that. If you're smart, you would land your troopships, one at a time, while escorted by many bombships at once. That way I can't reasonably pick them off.
*yawn* It's getting late. Maybe I'll have something later.
Remember, this is still all just discussing how to put my remaining defenses to their best use. The rest is identical to scenario 2.
Milo:
Almost everything boils down to scenario 2, because scenario 1 is a crude parody of what I've been suggesting. I'm almost hurt you think I'm that suicidal or cavalier. I don't intend to land anything but missiles until you can't effectively stop a drop pod. Seriously, man, I thought I'd made myself clearer than that. And land when enemy tanks can still operate in the open? Do you think I'm crazy? (Actually, it turns out I am a little bitter.)
Clarifications on scenarios 3 and 4:
- the internet isn't down, it's just in chaos; full of forum-dwellers like us :) spreading misinformation, crippled by power outages and line breaks, subject to constant DoS attacks and intrusion attempts.
- bombships are in medium 6000 km orbits, with a 45-75 minute time-to-target at ten Ricks (coilgun-launched; Ricks aren't free, but they are cheap), and the lasers are in similar orbits to a) defend the bombships and b) shoot anything that flies on a clear day. Coverage is pretty much global, with as many different inclinations as required. They're out of range of THAAD-class weapons, and just barely in range of ICBM-class.
- an assumption which I thought was obvious (but very well may not be) is that landing a company or three of men by drop pod from medium orbit is doable, but landing a division's worth is not. To actually land tens of thousands of infantry, plus supporting equipment and vehicles, requires uncontested control of low orbit and at least one established landing site. It will require a modicum of surface-to-orbit spacecraft support structure, at least a fueling depot (details vary greatly upon specifics of STO transport).
- given the above, it may be feasible to only control low orbit over a smaller piece of the ground track, and move troops down using more elliptical orbits. Maybe.
(little typo, "Soopy" above was supposed to be Snoopy, the shultz's cartoon charachter)
Now, even assuming Emperor Byron (from your scenario posted above) manages to destroy all my anti-orbit defences, I'll still laugh at his ultimatum. My ground forces can deny the land to his occupation troops for years without even moving. They'll just camp into the (still inhabited) cities and wait for him to come root them out.
Any competent nation will have its leaders in ultra-safe bunkers. Orbital strikes on them are not an option. Trying to find them with SAS is very hard (spies would be a much better bet) while killing them probably isn't an option (again, if you use spies you have better chances).
Also, ground troops have the benefit of terrain where they can hide into, and your lasestars cannot see them.
They can move under the clouds, and use them as a shield against your lasers.
And anti-orbit defences still working but hidden (I find ludicrously unrealistic the assumption that you blast away ANY AND ALL my anti-orbit defences), can surge up a few missiles to keep the laserstars busy (or force them to flee) while my ground units are in the open.
Ok, RocketPunks!
What you wanna throw at me now?
General Albert, over and out. :)
Trying again from IE. Blogger 7 me 0 for now.
I really think you all are grossly understimating the defender.
Sure, it saves a lot of pains, but if you assume you go to fight Snoopy on a Sopwith Camel with an ace on a F-22 you don't get a good approximation of what a true opponent will be.
So, being a faithful upholder of defensive tactics (in pc games) myself, I'll explore the behaviour of a Smart Defender .
I'm assuming an attacker nation that attacks a devender nation that have the same resources available on their home planets, and more or less the same wealth and tech. But most tricks work even for beggar nations.
First, industrial capability is pretty much irrelevant in the first few months of war. That's the reason why most militaries stockpile stuff like crazed squirrels. And being that they saw you coming months or years away, they will have built more than enough stockpiles for decades.
Second, you can shoot and kill with your laser ships, but I doubt must military personnell and equipment will sit in the open with a HIT ME sign that could be read from orbit. They will stay hidden in ground clutter, better if into cities, where there are civilians you don't want to kill (Bad PR).
And please note: they will realize that moving in battle formations is a stupid idea much before you start shooting on them.
(continued)
awesome. continuing the post.
Third, I also dubt that they will keep firing defences until the last missile like your convenient attacker-friendly assumption.
They will let *you* think you have destroyed all the defenses in some area and when you place enough craft over there, or even your constellation to begin an orbital bombardment, they PWN you.
Yeah, this way they allow you to kill some juicy target to feel safe, but usually it is worth it because your resources are much more limited.
After one trick like this you will NEVER know if a patch you have just cleared is in fact cleared or a trap. Be afraid, be VERY afraid.
Another similar trick is to accept the surrender (or let you think you have cleared a patch from defences) and let you drop your troops. Then PWN them with their ground numerical superiority shortly after drop. You have powered armors, but I have snipers with anti-vehicle rifles (the .50 or his future offspring). And tactical nukes like Davy Crocket (with better guidance) too. Or just buckets of chimps with a gun to swarm you blind. You wanna play with me?
I can also use anti-air defences during drop to kill the landing crafts. What you do if your occupation army is gone? Be afraid, be VERY afraid.
Fourth, being the enemy at the same general level of wealth and techlevel, SEALS or SAS won't have a so devastating effect, because they will face enemy SAS tasked to protect the VIPs/equipment. (they can easily break some havoc on low-priority targets, big deal...).
Also, their operation won't be as easy as Raymond suggests if
A)their entry point is obvious (drop pods) And any half-brained defender will tactical-nuke the area where they just dropped "just to be sure" or anyway encircle them and gun them down.
B)there is no extraction point, this means that after they attacked a place, the defenders will have good chances to catch them, due to way better knowledge of the area, and much more resources available to track them down (the whole ground army).
Imho, this is a good scenario for a book where you have heroes, but a stupid tactic to do in reality with trained men.
-General Albert, Ground Defence Command.
awesome. continuing the post.
Third, I also dubt that they will keep firing defences until the last missile like your convenient attacker-friendly assumption.
They will let *you* think you have destroyed all the defenses in some area and when you place enough craft over there, or even your constellation to begin an orbital bombardment, they PWN you.
Yeah, this way they allow you to kill some juicy target to feel safe, but usually it is worth it because your resources are much more limited.
After one trick like this you will NEVER know if a patch you have just cleared is in fact cleared or a trap. Be afraid, be VERY afraid.
Another similar trick is to accept the surrender (or let you think you have cleared a patch from defences) and let you drop your troops. Then PWN them with their ground numerical superiority shortly after drop. You have powered armors, but I have snipers with anti-vehicle rifles (the .50 or his future offspring). And tactical nukes like Davy Crocket (with better guidance) too. Or just buckets of chimps with a gun to swarm you blind. You wanna play with me?
I can also use anti-air defences during drop to kill the landing crafts. What you do if your occupation army is gone? Be afraid, be VERY afraid.
Fourth, being the enemy at the same general level of wealth and techlevel, SEALS or SAS won't have a so devastating effect, because they will face enemy SAS tasked to protect the VIPs/equipment. (they can easily break some havoc on low-priority targets, big deal...).
Also, their operation won't be as easy as Raymond suggests if
A)their entry point is obvious (drop pods) And any half-brained defender will tactical-nuke the area where they just dropped "just to be sure" or anyway encircle them and gun them down.
B)there is no extraction point, this means that after they attacked a place, the defenders will have good chances to catch them, due to way better knowledge of the area, and much more resources available to track them down (the whole ground army).
Imho, this is a good scenario for a book where you have heroes, but a stupid tactic to do in reality with trained men.
-General Albert, Ground Defence Command.
awesome. continuing the post.
Third, I also dubt that they will keep firing defences until the last missile like your convenient attacker-friendly assumption.
They will let *you* think you have destroyed all the defenses in some area and when you place enough craft over there, or even your constellation to begin an orbital bombardment, they PWN you.
Yeah, this way they allow you to kill some juicy target to feel safe, but usually it is worth it because your resources are much more limited.
After one trick like this you will NEVER know if a patch you have just cleared is in fact cleared or a trap. Be afraid, be VERY afraid.
Another similar trick is to accept the surrender (or let you think you have cleared a patch from defences) and let you drop your troops. Then PWN them with their ground numerical superiority shortly after drop. You have powered armors, but I have snipers with anti-vehicle rifles (the .50 or his future offspring). And tactical nukes like Davy Crocket (with better guidance) too. Or just buckets of chimps with a gun to swarm you blind. You wanna play with me?
I can also use anti-air defences during drop to kill the landing crafts. What you do if your occupation army is gone? Be afraid, be VERY afraid.
Fourth, being the enemy at the same general level of wealth and techlevel, SEALS or SAS won't have a so devastating effect, because they will face enemy SAS tasked to protect the VIPs/equipment. (they can easily break some havoc on low-priority targets, big deal...).
Also, their operation won't be as easy as Raymond suggests if
A)their entry point is obvious (drop pods) And any half-brained defender will tactical-nuke the area where they just dropped "just to be sure" or anyway encircle them and gun them down.
B)there is no extraction point, this means that after they attacked a place, the defenders will have good chances to catch them, due to way better knowledge of the area, and much more resources available to track them down (the whole ground army).
Imho, this is a good scenario for a book where you have heroes, but a stupid tactic to do in reality with trained men.
-General Albert, Ground Defence Command.
Nice. I posted the above once and Blogger placed three posts. Better than nothing anyway.
-Albert
Raymond, no the entire company is from the 82nd Airborne. They're your conventional troops. You also have, say, a SEAL platoon.
However, I have yet to hear a reasonable plan to use a reasonable number of troops for a reasonable mission, except for artillery spotting. I've already covered why raids on trucks are less efficient.
And, when the politicians are stupid enough to demand slaves from a comparable world, then you're going to lose. Period. Unless you have much better technology or a much, much higher industrial base, you can't win that sort of fight.
3 and 4. I stage a coup, then sue for terms. If I absolutely can't do that, then pull a Stalingrad. Fight as much as possible, and deny them what they came for, if possible. Otherwise I agree with Milo's analysis. However, I will add one thing. If you are using raiders, then I send my special forces teams to hunt them down, because they conveniently pinpoint themselves for me every time they attack.
Milo, I have to disagree on "much shielding" Compared to fission or D-T fusion designs, yes, but that's only if you don't want more power, and everyone wants more power.
On conventional surface forces, Milo says it best:
but my shorter supply lines mean my troops can probably take on whatever troops you're capable of shipping, if not for their space support looming overhead.
This is my motto for ground battles.
However, or my factories are able to manufacture more while the siege lasts is wrong. Those factories were the first things to go up.
Raymond, what is this company supposed to do? It can't take out any reasonable concentration of my forces, and it's too large to go unnoticed. Plus, it's leg/light vehicle mobile, and moving tactically. The defender doesn't have those disadvantages.
General Albert, for the sake of argument (no hiding behind strategic privilege, here), where is the point where you stop trying to intercept what's coming down, and start hiding and waiting with your surface-to-orbit weapons?
There are also some technical questions we haven't really answered:
- on a clear day, can 10 or 100 MW lasers at 500nm and in a 6000 km orbit kill SAMs fired from the surface? Luke?
- how easy is it to differentiate a missile from a drop pod during the plasma sheath phase of reentry? Citations preferred.
- how much cross-range can we get from our orbital missiles? Can we hit a tank on the move, or do we have to wait until it stops?
My emperor waves a decadent hand at me, and says "I want this world." I'm not willing to commit seppuku. My emperor is not as...merciful as Emperor Byron. If we're back at a stalemate, or a siege, now what?
And a philosophical question:
When do we break out the bioweapons?
Albert, I've been trying to assume a reasonably smart defender, who won't do things like ignore raiding teams. Still, here's my response:
First, industrial capability is pretty much irrelevant in the first few months of war. That's the reason why most militaries stockpile stuff like crazed squirrels. And being that they saw you coming months or years away, they will have built more than enough stockpiles for decades.
Yes, but they will have to replenish the stockpile, unless you destroy the factories. And industrial capacity will dictate how big of a stockpile they have.
Third, I also dubt that they will keep firing defences until the last missile like your convenient attacker-friendly assumption.
They will let *you* think you have destroyed all the defenses in some area and when you place enough craft over there, or even your constellation to begin an orbital bombardment, they PWN you.
Yeah, this way they allow you to kill some juicy target to feel safe, but usually it is worth it because your resources are much more limited.
After one trick like this you will NEVER know if a patch you have just cleared is in fact cleared or a trap. Be afraid, be VERY afraid.
But if you say "Surrender or I kill all of your leaders with my laser" they have three and a half options:
1. Surrender
2. Let you kill the leaders (not practical)
3. Shoot missiles at you to distract the laserstar
3.5. Have the "leaders" be a decoy
Another similar trick is to accept the surrender (or let you think you have cleared a patch from defences) and let you drop your troops. Then PWN them with their ground numerical superiority shortly after drop. You have powered armors, but I have snipers with anti-vehicle rifles (the .50 or his future offspring). And tactical nukes like Davy Crocket (with better guidance) too. Or just buckets of chimps with a gun to swarm you blind. You wanna play with me?
I can also use anti-air defences during drop to kill the landing crafts. What you do if your occupation army is gone? Be afraid, be VERY afraid.
Two words: Orbital bombardment.
Also, that just makes the attacker mad. He won't land until he has orbital superiority, and he'll probably BDZ your planet then, or at least nuke a couple of cities.
And Emperor Byron will say "Very Well. We'll begin the bombardment." Then order all of the factories on your planet destroyed. Distributed production or not, you can't maintain an army very long that way.
I'm going to guess that missiles and drop pods can be told apart. I have no proof, but here's my logic:
The point of a drop pod is to stop before it hits the surface. The point of a missile is to go through the atmosphere as fast as it can. Thus, as far as I can tell, we can tell the mass and acceleration of anything coming out of orbit. This is for the same reasons we can tell the mass and acceleration of anything that burns an engine in space. The plasma trail shows the power usage, and Doppler shows acceleration. A missile will have low acceleration, while a pod will have high acceleration.
I don't think we can hit moving targets, simply because the missile will be in a plasma sheath the whole way down. Even if it could steer, it can't see the target. It might be inertially guided, but I don't know how it could be told the target had moved.
When do we break out the bioweapons?
It depends what we want the world for. Are we after the population, or after the industry or resources?
Byron:
"Yes, but they will have to replenish the stockpile, unless you destroy the factories. And industrial capacity will dictate how big of a stockpile they have."
There would be some economic limitations to this, but in principle the stockpile of planetary defense munitions, and the size/organization of the defensive force, would be designed to outlast an attacker's likely logistics capabilities.
Yes, but an attacker won't attack unless he thinks he can win, by beating that stockpile. Planets are hard to take, but it is possible. I've been focusing on what happens when you have enough of an edge to possibly do so.
Byron:
Sigh. I think this metaphor's stretched well past breaking point. But if we're continuing with it:
- there is no way I bring a company to take the whole island. In addition to the platoon of SEALs and the company of paratroopers, I've got a battalion's worth of Marine Expeditionary Force in their transport craft just on or over the horizon, complete with helicopters. What's the modern strategy for that? Bomb the LZ heavily, drop the paratroopers, secure the LZ, move in marines by chopper? (Honest question about current SOP for such operations.)
- before you object to the battalion, what do you think the occupation force would be? Fluffy bunnies?
- when did I ever say the initial teams would have a primary mission other than LRRP? I make an offhand comment about targets of opportunity...
Targets of opportunity are just things that need a kinetic that you didn't expect to find. And while the force ratios might be dissimilar, even your MEU can't take on a mechanized infantry division. Still, we've agreed that the only ground troops are scouts, at least at first. Progress.
Raymond:
on a clear day, can 10 or 100 MW lasers at 500nm and in a 6000 km orbit kill SAMs fired from the surface? Luke?
Assuming the missile airframe is made of ultrananocompositestuff, and assuming the attackers have ten meter focusing mirrors, then for a 100 MW laser I find that the SAM will lose around 7 to 8 mm/s from its exposed regions. If it can somehow keep a highly armored nosecone pointed at the attacker at all times, it might survive for a minute or two (assuming a meter or so of nose armor), but if unarmored bits are exposed they will be removed in seconds.
At 10 MW, it is probably not much of a surprise that the drilling speed is reduced by about a factor of 10 (a bit more, actually, but not enough to matter). So multiply all times above by about ten.
how easy is it to differentiate a missile from a drop pod during the plasma sheath phase of reentry?
If you wanted to, you could probably make a missile look like a drop pod, if the missile is using nukes. For kinetics, you need a high impact velocity at the ground, which you can't do if you are slowing down enough that your troops will survive landing. Making a drop pod look like a missile is probably impossible - to large of a frontal area, and it would be going too fast for a soft landing.
Byron:
"Yes, but an attacker won't attack unless he thinks he can win, by beating that stockpile. Planets are hard to take, but it is possible. I've been focusing on what happens when you have enough of an edge to possibly do so."
There's more than one way to skin a cat. You've been focussing on overwhelming force. One can also outmatch the defense at a point, get on the ground, and attack defensive forces from the surface.
Oh, My Eyes Have Been Opened!!!!!
Yes, that's how to take a planet. You punch a hole, land ground troops, and send them against an enemy that outnumbers them probably ten to one. At the end of long supply lines, with little heavy equipment, and without orbital fire support. This sounds like a great idea.
Luke:
Yay numbers. From the sounds of things, THAAD-class SOMs and smaller don't really stand much of a chance of intercepting a drop (assuming, of course, a decent laser constellation with overlapping coverage). The kind of armor required to survive until intercept more closely belongs in the ICBM class, which I believe we've already determined will no longer be present in any great numbers (due to usage, destruction, or being forced into hiding).
So let's say we can drop on a clear day and make it all the way down intact, but the enemy will know where you are without a lot of misdirection.
Another, somewhat different tack (note that it's an idea, not a position, so don't try to hold me to it later):
Drop minisubs? Not for hunter-killer duties. Just to give the landed scouts the cover of ocean, wider deployment areas, less certainty about their current location. And, of course, to be able to pick a stretch of ocean without heavy SOM defenses.
Raymond, the laserstar can be overwhelmed if you shoot enough missiles. Particularly at it. These minisubs are more plausible, but I'm still not sure how good of an idea they are, as they'd be a lot bigger than a man, and you run the problem of them hunting you down.
Tony,
When I get back, I'll show exactly why logistics don't favor ground forces.
Byron:
"Oh, My Eyes Have Been Opened!!!!!
Yes, that's how to take a planet. You punch a hole, land ground troops, and send them against an enemy that outnumbers them probably ten to one. At the end of long supply lines, with little heavy equipment, and without orbital fire support. This sounds like a great idea."
You seem to have a facility for reading manuals. Perhaps you could look up the subjects of Mass and Maneuver and get back to us.
Yes, the laserstar can be overwhelmed, but it turns an intractable problem into a Lanchesterian one. It's something.
I don't have enough data on minisubs to properly evaluate their plausibility. Any naval experts around? Rick?
Also, at what kind of altitude would the plasma sheath of a missile disperse, and allow the missile to be guided?
Just to point out that in our real history, V-2 rockets were built in dispersed factories and launched at a high rate at London in the closing phase of the European phase of WW II. Rick has pointed out a V-2 is about the minimum acceptable weapon for ASAT duties, so we have a historic baseline of over 3000 missiles built and 2000 fired.
Even with state of the art sensors and weapons, and total air and space domination, the United States was unable to find and destroy the mobile SCUD missile launchers during the first Persian Gulf War (and sending SOF teams in the desert didn't help matters; read Bravo Two-Zero by Andy McNabb), Scuds are lineal descendants of the V-2, so we have a minimum size of launch equipment to deny low orbit.
A "real" ASAT or ABM will have much better performance and a large cross range in order to maximize coverage, and we certainly know how to build these sort of high performance missiles that can be launched from trucks, ships at sea and silos on land (Patriots, SM-3 Standard and the ABM squadron based in Alaska. The Russians have similar missile systems).
So the problem is far harder than "park your constellation in high orbit and bombard the surface. Pick off survivors with lasers". By the time you fight your way through the space defenses and down to low orbit, you might not have enough resources to actually force an invasion.
This is SF after all, so just fling something into the Sun at a large fraction of c and wait for the flares to die down. Most of the space assets will be fried and the effects of the solar flares will have scrambled the electronics on the ground. Move from your parking orbit behind Jupiter (shielded by the huge magnetosphere and distance) and then invade. Just hope the defenders didn't institute a laser in the solar photosphere as part of their defense line before you start the war....
Raymond
Also, at what kind of altitude would the plasma sheath of a missile disperse, and allow the missile to be guided?
This depends on the altitude at which its speed drops below about 5 km/s (give or take, I'm too lazy to look up a more accurate number right now). For a kinetic, which relies on massive speed for causing damage, it has a plasma sheath right up until impact.
Fine. From FM 3-0:
MASS
Concentrate the effects of combat power at the decisive place and time.
MANEUVER
Place the enemy in a disadvantageous position through the flexible application of combat power.
Both can be used to migatiate the disadvantage of the invader, it's going to take a tremendous amount of luck (which isn't an operational principle) to win a ground campaign.
Thucydides, that's not exactly plausible midfuture.
Luke:
"For a kinetic, which relies on massive speed for causing damage, it has a plasma sheath right up until impact."
That's what I suspected, and was afraid of. Now I should start building MANPADS-like cluster bomb pods, too, if I want to attack armored units. And probably a few cruise missile launchers. I'd be giving up Ricks, but sub-nuke damage doesn't help much if I can't hit the broadside of a tractor-trailer.
Those superfighters are looking mighty tasty right about now.
Good quickie read of the Gulf War Scud problem here. Definitely warrants consideration.
Note also that the only SAS team which chose to patrol on foot (the other took one look at the terrain and said no thanks) was the one to be captured. If teams are to be sent to the surface which are not part of a larger invasion force, they get vehicles, period.
Byron:
"Both can be used to migatiate the disadvantage of the invader, it's going to take a tremendous amount of luck (which isn't an operational principle) to win a ground campaign."
You're thinking too literally. A planet has only so many resources. It can't be strong everywhere. If it has a thick crust anti-orbit/anti-landing defense, then it probably doesn't have much in the way of ground combat power. If you are forced to concentrate on a single spot to punch through, once you get on the ground, it should be relatively (not absolutely, relatively) easy to engage the sky-facing defenses on the surface. In this case the application of maneuver is that you go after stuff pointed at the sky from a direction it's not designed to defend, and the application of mass is concentrating force so that a hole can be punched through to get the necessary force on the ground.
Study suggestion: the Israeli Suez Canal crossing operation in 1973. Pay close attention to how the initial Israeli forces across the canal engaged the Egyptian anti-air defenses on the ground, and how that helped to enable further operations on the African side.
Why Logistics Make Large Ground Forces Impossible
There is a fundamental difference in the size of space forces and ground forces. This difference, which is in favor of space forces, makes deploying conventional ground forces without orbital support in quantities that are able to face a world's army impossible.
As an illustration, a Stryker Battalion has a strength of 35 officers and 638 enlisted men. It has 79 Strykers and 28 other vehicles. During the course of a month, the unit will consume 50 tons of food. It will probably take at least 2 tons per person of life support and accommodations. This is a total of 1346 tons. The total vehicle mass (assuming all Strykers are ICVs and all vehicle are light HMMVWs) is 1367 tons. This doesn't count personal gear, weapons, or supplies. Despite my best efforts, I can't find estimated supply numbers. Still, that probably doubles the numbers for any sort of long-term combat.
(to be continued)
Byron:
"Why Logistics Make Large Ground Forces Impossible
There is a fundamental difference in the size of space forces and ground forces. This difference, which is in favor of space forces, makes deploying conventional ground forces without orbital support in quantities that are able to face a world's army impossible."
Sorry, but this is incorrect. There is only so much money for a planet's armed forces, space, anti-space defense, air, ground, navy, whatever. The planet has to make a choice about how to allocate that money to build those forces, train them, supply them, etc. Correct me if I'm wrong, but you seem to be assuming strong space forces (eliminated before the discussion starts) and strong orbital defenses. That doesn't leave much money for surface and air power.
The attacker may not be able to land more than a division or two of motorized troops, and maybe a company of tanks. But if the defender's money went into his lost space navy and making a landing hard on the approach and on the way down, he didn't leave himself much to build a ground army.
If, on the other hand, the plaentary government put money into a strong and effective surface army and air force, he didn't have that much to invest in defenses designed to keep them from having to fight.
As always, TANSTAAFL.
Tony, if the planet can't be strong everywhere, it can be strong where it matters. So what if you drop a bunch of troops in the middle of their equivalent of Africa or northern Canada? (No offense, Raymond). There's nothing vital there to capture, so they might not care. If you do go for somewhere vital, you'd be lucky to get even odds. And then there's the distance to the defenses, which we've already discussed. You're probably a couple days away before you reach them.
And let my stuff play out before you start criticizing.
I wrote:
"If, on the other hand, the plaentary government put money into a strong and effective surface army and air force, he didn't have that much to invest in defenses designed to keep them from having to fight."
I should also add that the defenses that keep a strong army from having to fight would be the same defenses that keep them from being sitting ducks (or effectively immobilized under cover lest they become sitting ducks) for attacking forces in space and in the upper atmosphere. So even if you opt to let them come down and fight you on the ground, you're still going to have to expend sufficient resources to keep your ground/air force from being neutralized (either through destruction, imobilization, or both) by the attacker's orbital and suborbital forces.
Raymond:
Kinetics seem like a bad choice of weapons for engaging mobile targets. I expect that inertial guidance should be adequate for taking out fixed targets. This is helped somewhat by the economy of scale of large kinetic impactors. Small kinetics will be slowed down by aerobraking, any kinetic will have a certain length of its front ablated away from the heat of re-entry. You probably will not lose more than the first meter of a dense, tough, refractory impactor (possibly less with a good design, although the shapes that minimize mass loss due to ablation maximize drag). Note that the requirement of dense, tough, and refractory leaves us with a choice of tungsten, platinum, iridium, and osmium. Choose whichever is cheapest.
So, for effective use of kinetics we will want a multi-meter rod of our preferred material. You can probably get an aspect ratio of 20:1 to 30:1 without buckling, so a 3 meter rod might be about 10 cm wide and mass half a ton. If it loses the first meter on re-entry, it will hit with about 3 tons worth of TNT equivalent when launched from a 6000 km orbit (using my previous figures of a specific kinetic energy of about 40 MJ/kg). This seems like the minimum effective size for a kinetic - although you might be able to get a bit smaller with good aeronautical engineering to reduce front end ablation.
With 3 tons TNT worth of boom, this probably lets you blow up stationary targets even with the larger targeting errors of inertial guidance (especially advanced mid-future inertial guidance). If 3 tons TNT equivalent isn't enough, either send in more or send in a bigger one.
Why Logistics Make Large Ground Forces Impossible, Part 2
I managed to get some numbers for the supplies. I'll assume 100 kg/soldier/day for combat. For a 30-day campaign, that will be a total of 2020 tons. What about the soldiers themselves? Each solder plus assorted equipment (weapons, gear, etc.) will probably be about 500 kg, totaling almost 320 tons. Drop equipment will probably total at least 25% of the dropped stuff, making it 925 tons.
So how much would it take to bring a Stryker Battalion from Earth to Mars via Hohmann, then hold it for three months, then drop it to the surface for a 30 day campaign? (Rounding to the nearest 5)
Shipboard Accommodation/Life Support: 1345 tons
Shipboard supplies: 725 tons
Troops & Equipment: 320 tons
Vehicles: 1365 tons
Combat Supplies: 2020 tons
Drop Pods: 925 tons
Total: 6700 tons
That's 6700 tons of stuff that has to be bought on your planet, put in orbit, and pushed to the other planet. And that's one medium battalion. How many battalions will you need to capture the enemy capital? 10? 20?
I'll compare space forces in Part 3.
Byron:
"Tony, if the planet can't be strong everywhere, it can be strong where it matters. So what if you drop a bunch of troops in the middle of their equivalent of Africa or northern Canada? (No offense, Raymond). There's nothing vital there to capture, so they might not care. If you do go for somewhere vital, you'd be lucky to get even odds. And then there's the distance to the defenses, which we've already discussed. You're probably a couple days away before you reach them.
And let my stuff play out before you start criticizing."
Once again, I'm trying to use real-world economics here. If one opts for a hard outer crust, the inner defenses aren't all that deterring, even close to major objectives. As an attacker, I couldn't GAS about the defender's Capitol Armored Division, if I can capture an outlying province, chew through neighboring provinces' militias and light regular forces -- which becomes progressively easier as I destroy defending anti-space/air defenses on the ground -- and eventually surround the capitol city. The armored division then has a choice of coming out from it's air/space defense umbrella and getting defeated in detail, or waiting for the eventual starvation and capitulation, without fighting.
See, Prime Minister (or President, or Viceroy, or whatever) Byron, you were strong where you thought it counted, but now I own most of the planet (considerably easing my logistics problems), while you have a shiny new armored division and no hope.
Byron:
"So how much would it take to bring a Stryker Battalion from Earth to Mars via Hohmann, then hold it for three months, then drop it to the surface for a 30 day campaign? (Rounding to the nearest 5)"
Mars? Setting aside terraforming as magitech, just how many centuriesi n the future are we talking that Mars would have a large enough population that it could manufacture it's own space and ground defenses to be anything more than a few isolated infantry fights?
If we're talking an insterstellar strategic landscape, we can't get into technical and tactical details, because we can't predict the size of forces, their detailed composition, or their effectiveness. All we can do is assume that they would be proprotional to the supporting economies, operate in a spectrum of environments from sea to land to air to space, and go from there with very general discussion of strategic and operational options.
Oh pretty please let me land in Northern Canada. (Ignore the fact that during the Cold War it was the most intensely monitored airspace corridor in the world, and a lot of missiles are aimed through it.) As it stands currently (and we'll take it as a proxy for the sorts of industrial concerns we'd face in our scenario):
- I take Fort MacMurray, Grand Prairie, and hit the refineries in Edmonton, and I've deprived the United States of its single biggest oil source while giving me control of local fuel supplies, which cuts down exponentially on orbital resupply.
- There is also major food production in central Alberta and the interior of British Columbia, so I can slash and burn and commandeer local supplies, which further reduces logistical requirements.
- I go a little further west, and cut off the LNG pipeline from Alaska to Montana.
- I have access to the Pacific, Arctic and Atlantic oceans (the latter through Hudson's Bay).
- I go as far south as Calgary, and I can cut the transcontinental railroads and highways for the latitude.
- The local forces are based out of Cold Lake and Camrose; both areas are flat, open terrain, and frightfully easy to bombard (and hard to hide in).
- Once the counterattack comes, I can head into the Rocky Mountains, and either dig in or disperse. Your tanks will be useless, my powered armor barely notices, and in those mountains (without the satellite intelligence you used to have) any forces you send to dig me out get chewed to pieces.
- If I have fighters and air transport available, all of the above and then some.
We can't go into details because your numbers aren't to my liking. Great Red Herring, Tony. I'm trying to demonstrate why deploying ground troops will be expensive. For the same 6700 tons I could probably launch two 3000 ton laser stars, which, unopposed, could take out a division in a single pass. I used Mars because there would be some travel time, and it seemed reasonable. Would you have preferred we launched from Luna to invade Earth? And got a hole in the defenses in an afternoon?
When I said Northern Canada, I meant out in the middle of nowhere strategically. If aliens invaded Northern Canada, it would hurt, but most of what they'd have is woods and snow. Plus, all your vehicles are nuclear-powered. I'm trying to point out that the places you're suggesting invading are non-vital.
That's exactly the kind of thinking I'd love to be able to exploit, Byron. Northern Canada (here I'm thinking specifically northern Alberta and the Northwest Territories) isn't really close to anything, except three oceans, polar orbits, energy infrastructure, food supplies, major transportation routes, a civilian population concentrated in a handful of cities (the better to move around freely) and a ready-made fortress better than anything you could build yourself. Perfect beachhead material. If you leave it comparatively undefended, and think you can afford to give me the woods and snow, please do. I can toss more missiles at the eastern seaboard and Cheyenne Mountain, have my forces land with their plasma trails seen only by a few scattered people, and away we go.
Raymond:
"the internet isn't down, it's just in chaos; full of forum-dwellers like us :)"
Ouch. That planet is doomed.
Byron:
"Yes, but they will have to replenish the stockpile, unless you destroy the factories. And industrial capacity will dictate how big of a stockpile they have."
Yes, but at the start of the war you will be wanting to hit their stockpiles more than you will want to hit their factories, unless you have a time machine that can retroactively destroy their factories three months ago.
Thucydides:
"This is SF after all, so just fling something into the Sun at a large fraction of c and wait for the flares to die down."
...What? That is not plausible midfuture tech.
Luke:
"This depends on the altitude at which its speed drops below about 5 km/s (give or take, I'm too lazy to look up a more accurate number right now). For a kinetic, which relies on massive speed for causing damage, it has a plasma sheath right up until impact."
I think Raymond meant for an upwards-going missile, which crosses into vacuum to hunt spaceships.
Byron:
"That's 6700 tons of stuff that has to be bought on your planet, put in orbit, and pushed to the other planet. And that's one medium battalion. How many battalions will you need to capture the enemy capital? 10? 20?"
10-20 spaceships massing something like a small/medium modern nautical ship sounds like an entirely affordable cost if you're even thinking about taking on an entire planet.
Tony:
"If we're talking an insterstellar strategic landscape, we can't get into technical and tactical details, because we can't predict the size of forces, their detailed composition, or their effectiveness."
We do, however, know that we are talking about most of the forces that one or more planets can field, fighting against the full forces of another planet.
Tony, your initial criticism of my plan was on logistical grounds. You thought it would take too long to reduce the planet my way. Somehow starving out my capital is supposed to make that faster? Specifically, after you've reduced all of my forces in the area, then you lay siege.
Milo:
Nah, I meant coming down. SOMs don't even have 5 km/s worth of delta-v total, so they can track all the way up.
Byron:
"We can't go into details because your numbers aren't to my liking. Great Red Herring, Tony."
Don't put words in my mouth, B. We can't go into details because we have barely an inkling of a clue what the relevant economies and technologies will look like. That forces us back on first principles and historical parallels.
From my perspective, your insistence on trivial and irrelevant details is the fly in the soup.
It's not that I don't like your numbers. It's simply that your numbers are meaningless. Which brings us to:
"I'm trying to demonstrate why deploying ground troops will be expensive. For the same 6700 tons I could probably launch two 3000 ton laser stars, which, unopposed, could take out a division in a single pass. I used Mars because there would be some travel time, and it seemed reasonable. Would you have preferred we launched from Luna to invade Earth? And got a hole in the defenses in an afternoon?"
How do you (or any of us) know what kind of weapon systems will be available hundreds or thousands of years from now, what they will mass compared to their targets, and where they will be used to fight? This is what I mean by irrelevant detail. You can't compare (wholly speculative) 21st Century weapons with 21st Century vehicles and say anything relevant about unkown weapons and vehicles in the future.
"Tony, your initial criticism of my plan was on logistical grounds. You thought it would take too long to reduce the planet my way. Somehow starving out my capital is supposed to make that faster? Specifically, after you've reduced all of my forces in the area, then you lay siege."
Getting forces down on a habitable planet and establishing a sufficient lodgement area relieves my life support burden considerably. I still have to bring in a large mass of munitions and ordnance supplies, but I'm not trying to keep an army alive in space.
Albert: 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")
If you can get good numbers on the planet's rotation and such, I don't see why dropping rocks couldn't be more accurate than that (the main issues would be intercept missions and the shape of the asteroid itself if it hits the atmosphere or if you're not strapping rockets to it WRT its centre of mass), and if you're going after a homeworld like I was proposing, it's probably the most cost-effective solution too. If they're not going to surrender after you've taken out their orbital infrastructure, space fleet and such, why risk your people's lives when you can bombard them from impunity from afar? All that talk about space being the ultimate in high ground... it isn't nice, but it's a hell of a lot safer from your point of view.
Milo: 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?).
That's rather my point: if the sub can fire its missiles out of the the sea without a target lock, a missile smart enough to find its own target (which doesn't seem that implausible, unless friendly & hostile ships appear very similar) would be a nasty way of striking at an orbiting enemy with minimal risk of effective counterattacks. Assuming the missile also survives the trip through the atmosphere of course...
Anyway, the lack of visibility does hurt submarines in one way. Point defense doesn't work nearly as well for submarines as for spaceships.
It'd be a case of eggshells equipped with sledgehammers I suspect, yes.
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.
That depends on what's left of the defender's fleet really. Presumably, attacking a major enemy world when their fleet is still out & about falls under the "Bad Idea" chapter of most space fleet training manuals, along with leaving your tugboats helpless in the event of enemy raids ;) . However, the psychological advantage the attacker has in this situation (nigh-unlimited ammunition, the high ground, and as above a clear "naval" advantage) should be... helpful... in encouraging the defenders on the planet below to give up before you start chucking lots of rocks their way at once. Or heavy coilgun rounds, or what-have-you (asteroids with PD lasers bolted on :P ?). Sorry if I wasn't clear, I assumed that as we were discussing a siege scenario where a ground invasion was possible, the defender's fleet was already either a non-issue or a fairly small one - and my main point was that ground invasions are a hell of a lot more dangerous to your own side than "ballistic missile spam". Take the high ground, and use this position to force them to let your people land and assume control.
Milo: And submarine crews won't have been?
Not to the same extent as the starship crews, as presumably you'd want your best (in this case meaning most psychologically stable) people on your ships in this situation, rather than in a submarine.
Raymond: 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.
Yeah, I agree with you on this point; my comment was concerning things like patrols and such, rather than landing on a hostile planet :) . I'd expect APCs to be down in the second wave, ready to support the guys who've cleared out the worst of the local AA defences, help control the area, and so on.
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?
Couldn't tell you, sorry :( .
Milo: 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.
Surely it'd depend primarily on the distance to the space station & quality of your telescopes? I'd've thought the changing reflections would be enough to tell you how fast it rotates...
Tony: 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.
Flatten their industrial base and watch them revert to steam-engine technology. Faced with the threat of that, I think I'd do as I was told: far better to find a way to overthrow the occupying force much later down the line than risk the worst-case Cold War scenario.
Byron: For the spacecraft size issue (I hate calling them ships! Rick, we need a new short term...)
Spacecraft = craft?
Seemed obvious to me anyway :P .
Raymond: 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.
*Cough*Doc Smith*Cough*
Milo: Oh, there will be no eviscerating. That only happens with sharp weapons. There is no melee combat in space
My Valerian space marine battalions say otherwise ;) .
Sorry, blame Raymond for making me think of Doc Smith. It's all his fault! *Points desperately*
Byron: Yes, but in this case, neutralize includes destroy. They're both doctrinally correct. What will we do?
Use the more colourful one, of course :) . Destroy, annihilate, obliterate, pulverised, volatilise, vaporise, demolish, EX-TER-MIN-ATE! ...
Tony: Professionals use the terms they use because those terms remove the emotion from the discussion.
Yes, hence "collateral damage" instead of "friendly fire" and all that PR. So what? I think in this case the clarity of "destroy" over "neutralise" works better, and nobody here (so far as I can tell) is getting hung-up over the topic in question, so I'd rather use plain language. If the DoD, MoD or whoever want this typed up in Pentagonese, they can do it themselves :P .
Milo: Obviously, we need to use real military protocol.
I'll organise a departmental sub-committee to investigate the possibility of conducting preliminary hearings on the necessity of enacting a new, compulsory education system designed specifically to enhance and standardise all posters' useage of terminology and vocabulary as it pertains to the armed forces. You should have the sub-committee's findings and recommendations by the end of 2012.
Civilian ships can use tricks like using their water tanks as proton shielding material, but that's way too fragile for a warship.
Still a sensible idea though, although in the case of a warship you'd want lots of compartmentalisation in your water tanks to avoid losing too much of it when hit.
Thucydides: For fairly advanced planetary economies, I suspect that orbital bombardment will not have the effect of throttling their supply chains.
Depends on what you hit. Germany today, for example, is the source of a huge % of all precision machine tools for the whole world. Without those machines, a hell of a lot of other high-tech industries are in real trouble. Admittedly, this is more of a long-term target, because cutting off the supply of such tools won't make the existing ones disappear or break down, but consider for example a world with limited storage of He3 for its fusion reactors suffering heavy damage to its seawater processing plants. The example in question may be a poor one, but the point remains that, especially with high-tech stuff, you have to be pretty careful not to over-centralise.
Albert: What you wanna throw at me now?
Lots of stuff on ballistic courses, aimed at key economic targets, and without much worry if a city gets wiped off the map by accident. You can be bombed back to the stone age or you can surrender and permit my forces to land and seize power. Unless you can take out all the incoming missiles and build a new space fleet on the ground in enough secrecy that I won't risk a closer strike to take out the ships being built (!), I can keep this up pretty much indefinitely by rotating out ships & crews from my own territory as necessary, confining you to your planet and giving me access to everything else. Eventually though, I'll have bolted on some big lasers to some asteroids, manoeuvred them close enough to your planet, and will start frying targets. Your own defences will have to deal with the enormous shielding and heat sink potential of the asteroids being used, as well as whatever point defence weapons they have mounted on them as well.
Byron: However, I have yet to hear a reasonable plan to use a reasonable number of troops for a reasonable mission, except for artillery spotting.
Beyond other, similar surgical strikes (kidnapping?), I can't think of much. Full-scale planetary invasions require either a huge technological disparity or the sort of numbers that only a softer sci-fi nation can realistically come up with.
Raymond: When do we break out the bioweapons?
Preferably never; I want the world, and unleashing super-duper diseases sounds like a way to make my eventual occupation all the more harder.
Byron: So what if you drop a bunch of troops in the middle of their equivalent of Africa or northern Canada? (No offense, Raymond). There's nothing vital there to capture, so they might not care.
More than that, conditions for the attacker in the region make it much easier to send what defenders you do have against the attacking forces, before they can hit too much. If you're dropped into the middle of the Sahara, have a fun week or two driving / flying to your target. You presumably also can't rely on too much orbital support initially, else you'd employ different tactics in the first place, so I assume I've some ability to move what ground forces I do have into position to counterattack your invasion forces.
Re all the talk about radiators, Atomic Rockets has pointed out before now that it is possible to armour them. Won't be perfect, but if it can help your radiators survive some of the debris / shrapnel you're likely to find around an inhabited planet, it may be useful.
Teleros:
Bioweapons aren't necessarily The Virus. They can be locusts, blights, colds, or tailored concrete-eating bacteria. Hell, in some ways you could use rabbits as a bioweapon. Or blanket a division with a naturally-occurring neurotoxin.
Radiators can and likely will be made of a carbon material. Like our Super Nano Carbon Stuff. They can be made of armor. So can we please stop mentioning the horrible, horrible vulnerability of radiators? They're a structural problem, not a combat one. Anything which will take out more than a few square meters of rad (amongst thousands) will also eat through your faceplate.
You seem to think that "first principles" are a set of rules. Whoever follows them best wins. What if you concentrate all your forces on the key point, and I only send part of mine. I might still win, particularly if I have a lot more to start with.
Also, I'm sure that Haig had lots of historical parallels for his actions on the Somme. While grand strategy doesn't change, tactics do. And tactics are the methods used to implement strategy. What used to be a good idea during the Civil War, such as putting your headquarters at a crossroads, is now an invitation to death by MLRS.
As to ground troops being expensive, it's basic economics that shipping stuff over long distances is more expensive than shipping stuff over shorter distances. And ground troops are cheap compared to spaceships. Rick estimates them at $1 million per ton. An M1 costs around $60,000/ton. You make it sound like the defender having decent space defenses means that they'll have at most a couple divisions of tanks. They could easily have a couple of full armies available to push around. Good luck shipping 100,000 troops, all their gear, and all their supplies.
I will now explain my comments about landing ground troops in Canada using a syllogism.
1. Any area you can land troops in, you can destroy anything within by bombardment at will.
2. If there is something vital that you can force them to surrender by threatening to bombard, you can also force them to surrender by capturing.
3. If there is something vital you can force them to surrender by capturing, you can also force them to surrender by threatening to bombard.
Thus, 4. Any area that has a vital object in it can be taken either by ground troops or clearing the area of defenses.
Thus, 5. There is no point in landing troops to capture anything you can bombard.
6. ASAT weapons have long range.
7. Any vital target will be defended.
Thus, 8. Any attempt to land ground troops to take out a vital target or ASAT weapons will have to land far from its target.
Thus, 9. Any attempt by troops to capture a vital target will take time to reach said target and will be opposed by dug-in forces at said target.
Teleros:
"Flatten their industrial base and watch them revert to steam-engine technology. Faced with the threat of that, I think I'd do as I was told: far better to find a way to overthrow the occupying force much later down the line than risk the worst-case Cold War scenario."
It depends on the nature of the alternative. If the future is something like Hellenistic Greece, I don't think I'd be very interested in surrendering, thank you very much.
Then the attacker has to make sure the alternative is better. It's not guaranteed, but I'm working on "How to take a World" which is what to do, not how to mess it up.
Speaking of which, when you're being threatened with lasers, fighting in the shade is a pretty good idea.
Provided the shade isn't the vapor trails of incoming missiles.
Byron:
This is an analogy, but it will have its equivalents on any world. Find a map of Canada, go to the northen border of Alberta a NWT, move west until you hit BC, then tell me what will have ASATs within a thousand km of that point.
Tell me again how taking a some woods and snow with water, power, food, breathable air and defensive advantages doesn't get me anywhere useful, then go tell Tony again how the fact he needs to bring all his food, water, power and air from home means a ground campaign is doomed.
OK, but you still can't force me to capitulate from there. And if you try to go somewhere from there, where you can force me to capitulate, you'll probably run into a couple of armored divisions. Which is more guys than you have for logistical reasons. Oh, and while I'm surrounding you, I'm also bringing up ASATs to cut off your reinforcements. You need to have enough troops to exploit the situation, which is the sticking point.
Okay, so what we're discussing here is:
5. Mars is invading Earth and has already trashed Earth's space assets. All governments on Earth are united, or at least allied, even the ones that really didn't like each other back in the barbaric early days of the 21st century. Earth has lost most of its surface-to-orbit defenses in Canada and Alaska, and Mars is now landing troops there. Earth still has most of its surface-to-orbit defenses everywhere else in the world (and can attempt to move some of these to Canada if it wishes, limited by the vehicles' speed and by the fact that it is now facing fire from below as well as above). Over Canada, Mars's ground troops have space support through the use of elliptical orbits, while over the rest of the world neither side has space superiority and an uneasy standoff reigns. Mars lost quite a few ships in the task of clearing Canada, and does not have sufficient space forces remaining to have them provide an effective orbital barrage except over the area which they have already cleared. Earth has surface-to-surface forces in Canada, but they cannot act too openly because of the enemy's space support. Earth's surface forces elsewhere can move unopposed until they go near Canada. You know that if Mars had space superiority everywhere (which they currently don't) then their present troops would likely suffice to squash resistance, while if they didn't have space superiority in Canada (which they currently do) then Earth would be able to easily defeat their cut-off ground forces with Earth's own groud forces. What would you do as Earth? What would you do as Mars? Do you think either side has committed a serious mistake in getting to this position in the first place, and if so how? (If so, they still have to figure out how to work with it. Real militaries do make serious mistakes.)
(I think that's rather similar to scenario 4, actually. Just change "southern continent" for "Canada", and make the enemy's space superiority less undisputed.)
Earth:
Surround them. Move all the military forces you can get to the edge of ASAT coverage around the beachhead and wait. Concentrate on any routes they may have to use. Defend the ASATs well. Then wait. They have to attack, and I can wait until they get tired and go home.
Mars:
This was a serious mistake. I should have bought fewer troops and more bombardment ships, and cleared China or the eastern US. As is, attack as fast as possible, hoping to keep them off balance, and pray for the best.
Um, the decision to land doesn't have to be made before the decision to wait for your second wave of craft to arrive with more missiles. What? No second wave? What the hell kind of invasion is this?
As for the Mars half of the scenario, they have power, water and time. Thus, propellant. They can lift their entire force back into orbit if they have to.
Byron:
"You seem to think that "first principles" are a set of rules. Whoever follows them best wins."
That's why they're called "principles", not "practices". Principles are the rules that are valid unconditional of time and place. Practices are the means of (hopefully effectively) implementing the principles in a given time and place.
"What if you concentrate all your forces on the key point, and I only send part of mine. I might still win, particularly if I have a lot more to start with."
If you have a lot more to start with, then I made a poor decision WRT the principle of Mass. If you don't have a lot more to start with, but a portion of your forces is sufficient, then obviously your practices are better than mine. It hardly invalidates any of the principles of war or strategy.
"Also, I'm sure that Haig had lots of historical parallels for his actions on the Somme. While grand strategy doesn't change, tactics do. And tactics are the methods used to implement strategy. What used to be a good idea during the Civil War, such as putting your headquarters at a crossroads, is now an invitation to death by MLRS."
See, here you are all wrapped around the axle over practices, thinking they somehow represent principles. 0/10
Also, you seem to be unaware that tactics are the practices used on the battlefield to achieve specific mission objectives. They are not a direct implementation of strategy. Between tactics and strategy lies the operational art, which is the level at which the principles are mostly applied.
"As to ground troops being expensive..."
More appeal to irrelevant detail. All we can reasonably surmise is that military forces in the future will be roughly proprotional to the economies that generate them. And within the overall amount of resources allocated, there will be tradeoffs between various types of forces, based on the priorities of the governments making the decisions. If you highly prioritize some things, then others will, quite logically and undeniably, suffer.
Once again: TANSTAAFL.
And once again, you are proposing to ship troops across interplanetary space, then punch a hole in the planet's defenses away from anything vital, then land the troops there, then march 500 kilometers or more to attack the vital target. And your troops are outnumbered by 10 to one because of shipping costs. If they aren't, you have a hideous economic overmatch.
I'm proposing to leave most troops at home, replace them with more bombardment ships, and punch the hole over the vital target. It requires a bigger economy, but not as much of one.
Now that the rant is out of my system, why don't we call this a draw. We're all too suborn to back down, and we're probably all right given a specific set of circumstances. Instead, let's wargame it out (hint, hint)
And I am going to remind you, again, that equal forces are not going to conquer each other. If two planets have roughly equal power, then they will have a stalemate with maybe some harrassment between their space forces, but no surface landings. If two multi-planet empires have roughly equal power, then it might be possible for one to capture a planet or two from the other by juggling fronts, but that's tricky, and it'll be hard to keep the planet once taken.
The question is what you can do when you outnumber the enemy "merely" 2, 3, or 5 to one, rather than 100 to one.
Byron:
"And once again, you are proposing to ship troops across interplanetary space, then punch a hole in the planet's defenses away from anything vital, then land the troops there, then march 500 kilometers or more to attack the vital target. And your troops are outnumbered by 10 to one because of shipping costs. If they aren't, you have a hideous economic overmatch.
I'm proposing to leave most troops at home, replace them with more bombardment ships, and punch the hole over the vital target. It requires a bigger economy, but not as much of one."
Landing the troops "away from anything vital" is pure spin, and it belongs solely to you.
The proposal -- at least as I conceive it, without making any claim to specific knowledge of a situation hundreds or thousands of years in the future, on a planet yet unknown -- is to punch a hole in the defenses where one can be made, then insert ground troops to attack the defenses from a direction and with means that they are signifcantly less capable of defending against. The caveat here is that the principles of economics do not undergo a tectonic shift and that to be strong in air/space defense, the defender had to skimp significantly on ground defenses. I have yet to see you offer a rational argument why that is not the case.
Because you have to be able to beat the defender's ground defenses, despite the logistical burden of shipping your troops across interplanetary distances, and the tactical disadvantages of attacking known targets. I'm not saying it will never work, but I see the resources invested in the troops are better spent in bombardment ships.
I think the conflicting assumption here is the cost of troops versus troopships.
Byron is assuming that troops are trivially cheap compared to the effort it takes to ship them across space.
Tony is assuming that well-trained troops with proper equipment are quite expensive in their own right, and that their cost at least approaches that of spaceships or surface-to-orbit defenses.
Just more points
The idea of KE impactors striking mobile targets is valid, Jerry Pournelle wrote about this proposal as "Project THOR" in the late 1970's or early 1980's as a means of countering Soviet superiority in surface warships and tanks. The THOR unit would be given the general target area, deorbit and release the warheads (which were to be about the size and shape of a standard broom handle). After re entry, the ablative shield would be jettisoned and a seeker protected by a synthetic diamond or sapphire window would activate. Guidance could be effected by four tiny tabs on the tail.
A plasma jet from a HEAT warhead weighs a less than a kilogram and can move at Mach 25 while burning through armour. A multi kilo THOR warhead moving at about the same speed (and attacking at a near vertical angle) would have orders of magnitude more effect. Even a near miss would be like having a 250 Kg bomb landing beside you.
Dumping something into the sun at a fraction of c may not be "near future" tech (although clever arrangements using ORION type drives, solar sails or gravity assist might do the trick), but then again, neither is a planetary invasion. Powered battle armour, MABV's, "fire ant warfare" and cross continental artillery weapons, unfortunatly, are plausible midfuture tech.
Thucydides:
If a THOR is going slow enough not to be blinded by the plasma sheath in front of it, it is only going to deliver about as much bang as its own mass in high explosives. This is not inherently bad, and can still be used as a long rod penetrator much as modern tank-to-tank munitions. Note, however, that you need to slow down a lot to use this - you are not going to be delivering hyper-velocity strikes that deliver explosions of ten times your mass in high explosives. Plus, it takes more than half an hour for the kinetic to arrive from our nominal 6000 km altitude, and the target can see the incoming projectile. This gives it time to move out of the target area.
The jet from a HEAT warhead is not plasma. It is generally liquid copper (from the lining) plus bits of soot, grit, and gas. It does not burn through armor - there is no time for heat transfer. Instead, the dynamic pressures are so high that it pushes armor aside - much like a thumbtack driven into drywall.
At Mach 25, anything traveling through the atmosphere will be surrounded by a sheath of plasma that is opaque to visible light, infrared, microwaves, radar, and radio. A Mach 25 THOR couldn't see anything, couldn't receive communications from someone who could see something, and thus can't target anything (except via inertial guidance, against a pre-determined location).
OK, I really think this debate has passed it's useful life. I'm going to try to sum up what I believe are the closing arguments of both sides.
Raymond/Tony:
It isn't possible to force a decision from space, so ground forces must be used.
Byron/Milo:
For economic reasons, it isn't possible to ship enough people for the attacker's ground forces to be able to conventionally take on the defender's without space superiority. Also, if the attackers do have space superiority, then the defenders can't face the attackers conventionally, provided the attackers have a reasonable amount of troops. However, if the attackers have the space superiority required to be able to force a decision with ground troops, they can also force the decision with space forces.
I hope I got that all right.
More thoughts on kinetics against mobile targets ...
From references I gave in an earlier comment on this same post, we have a reasonably good theory of long rod penetration, which is in general agreement with the data for projectiles ranging from smokeless powder centerfire rifle bullets through tank-to-tank kinetic penetrators to HEAT jets. From this, the maximum penetration occurs when the penetrator is harder than the surface being penetrated, at a velocity of about 2 to 2.5 km/s. Faster than this, and the penetration decreases slightly, to an asymptotic value given by a pure hydrodynamic theory which is independent of velocity. Thus, if you can target mobile ground troops with space-based kinetics without them moving out of the way (perhaps you shot out all of their space early warning sensors, or something), you would have your kinetic aerobrake to about 2 km/s before deploying. This is slow enough that it will not be blinded by a plasma sheath, allowing self-targeting, and gives maximum penetration against armor. You may want to use some external guidance for gross course corrections, since there will be a period during aerobraking when the kinetic will be blind and will lose its target. This will allow rapid target re-acquisition using data from a spotter spacecraft.
Hmmm. Ideas. Tasty, tasty ideas.
Even given the time-to-target, we could easily give our Orbital Death Bolts some maneuver delta-v, increasing cross-range. We can then feed telemetry to them until somewhere in the stratosphere. Between those two items, the dodging time drops from tens of minutes to tens of seconds - enough for tanks and trucks, maybe enough for ships, but still much better. It also makes targeting last-known positions more useful, forcing the target to keep moving.
So now we also break out the Orbital Death Pods. A little larger (almost man-sized), full of guided kinetic penetrators. Same kind of cross-range before reentry as the ODBs, but shaped for higher-drag reentry, to bleed off speed until the plasma sheath dissipates and the pod's contents are at optimal penetration velocity. Once it can see again, it can engage moving targets on the ground (probably not aircraft, but most certainly anything with wheels, treads or legs).
And it would probably look a lot like a drop pod.
So if you can figure out a way to entice/force the defender's ground troops to start moving (*cough*ground troops*cough*) you can inflict a lot of damage.
But if this pod has a similar profile to a drop pod, what's to stop them from shooting it down? Unless, of course, you have space superiority. Which makes my point rather conveniently.
Simple: the first few pods you target are filled with rocks, and congratulations, you shot down rocks. When you stop shooting them down and start moving troops in to surround them (remember, I can still see everything you move around), the next one is filled with antitank kinetic seekers, not men.
And I shoot it down, too. While I can't be sure what you've got in them, it probably won't be terribly hard to decide to shoot down anything you send in. Plus, I can check impact points. If it's coming down in range of my overt defenses, it doesn't have people in it. If it isn't then I can't shoot it down, which again makes my point about space superiority.
Byron:
"But if this pod has a similar profile to a drop pod, what's to stop them from shooting it down? Unless, of course, you have space superiority. Which makes my point rather conveniently."
There's a logical disconnect here. You're conflating "space superiority" with low orbit and air superiority. One can rule space around a planet, but not have the resources to decisively defeat the anti-orbit/anti-air forces of the planet itself from space. If the defender is competent and has looked to his defenses, it's almost a given. He can calculate what a potential attacker can bring overspace to engage his planetary defenses and build up over time a stockpile of defenses weapons and munitions.
That's the point at which alternate means would have to be sought, if one wants to conquer the planet. I suggested a means which I think would work. Maybe you can suggest another. But you can't appeal to overwhelming force, terror bombing, or general destruction of the planetary economy. If you have overwhelming force, there's no discussion to be had, because you're saying that unless one can marshall overwhelming force, there's no operation to begin with. Terror bombing, while frightful, is generally counterproductive, if the defender believes the enemy is all that terrible to begin with. It only reinforces resolve in someone already committed to resist. Finally, general economic destruction would have to be counted on by the planetary defenders before a choice to defend was ever made. Their tipping point for capitualtion won't be when some percentage of their economy is destroyed, because that's already been factored in. The decision point will come if and when the attacker can degrade the prepared defenses before his logistics forces him to go away.
You misinterpret my use of the term "space superiority" As I use it, it includes superiority in low orbit. It includes having defeated the low-orbit defenses in an area, the same criteria you use for dropping troops.
As you yourself say:
He can calculate what a potential attacker can bring overspace to engage his planetary defenses and build up over time a stockpile of defenses weapons and munitions.
This is exactly my point with respect to ground troops, which are a lot harder to bring across space than orbit-to-surface weapons. They have to have living quarters, stuff to do, and food. A kinetic impactor doesn't. You keep referring to logistics, but from the a personnel standpoint, from the supplies of one Stryker battalion, I could keep probably 15 laserstars/bombships at 45 crewmembers apiece. The munitions are a bit harder for the bombships, but my point stands.
Byron, why are you so convinced I have any intention of doing any of this without space superiority? When did I say anything of the sort?
Let me back up to the point I made at the beginning of this whole bit: there will come a point at which you can no longer fire at everything that comes down. Whether that's because you're out of ammo, or waiting for the occupation forces to get to low orbit, or waiting for them to come down so your guerrillas fight with tanks instead of AKs, it still means I'm sending down ODBs and ODPs and Happy Fun Time Orbital Smiley Bombs Of No Great Effect and you're holding your fire. When you stop shooting, I don't know if you can't or simply won't. If General Byron realises the situation is hopeless and surrenders, great. If General Albert says "come get me", then it's on to stage two.
Whether stage two is an escalating ground invasion (which will be hard - not necessarily impossible, but hard) or is me breaking out the bioweapons to blight your crops and eat your buildings, has yet to be determined.
And there are differing degrees of space superiority. My point of contention is that orbital mechanics makes it possible to drop smaller amounts of ground forces from medium orbit before I fully control low orbit (which is necessary to drop large ground forces as well as have the option of retreat).
OK, maybe I was talking to Tony, who has repeatedly said that the object of his conventional ground campaigns is to destroy the anti-orbit defenses. I don't believe that will work. If the defenses are wiped out, then I believe a rational defender will surrender, as he can't win. If he doesn't, then your plan goes into effect. However, if the defenses are there, then ground assault probably won't work. You could use ground troops to force them to reveal their positions if necessary. Either the forces they have facing the troops get smashed, or the defenses fire.
And these small ground forces are your special forces spotting teams, right? You're not planning on landing conventional forces like that, are you?
The problem with "come get me" is that it's like trying to wage mechanized warfare with your enemy in possession of total air supremacy. And the bombs don't miss, in the case of lasers. It's doomed to fail, so I'm assuming that people won't try it.
The usual rebuttal is that "the consequences of surrender are worse than fighting on" I can see that being the case sometimes, but it's the attacker's job to make it so it isn't. If it is, then you've made a bunch of trouble for yourself. Again, I'm writing "How to take over a world." That includes advice such as "Make sure they are not ready to fight to the last."
Byron:
"You misinterpret my use of the term "space superiority" As I use it, it includes superiority in low orbit. It includes having defeated the low-orbit defenses in an area, the same criteria you use for dropping troops."
I would call that "local air/space superiority", with a very clear emphaisis on "local", because the attacker hasn't defeated the whole planetary defense, just the defenses in one area.
"This is exactly my point with respect to ground troops, which are a lot harder to bring across space than orbit-to-surface weapons. They have to have living quarters, stuff to do, and food. A kinetic impactor doesn't. You keep referring to logistics, but from the a personnel standpoint, from the supplies of one Stryker battalion, I could keep probably 15 laserstars/bombships at 45 crewmembers apiece. The munitions are a bit harder for the bombships, but my point stands."
Here we go again with technical analogies that have no demonstrable relation to what conditions may be in the future. Also, your laser/bombardment platforms face a lot of the same logistics problems that troops do, as well as a lot of the tactical problems. Beam weapons need power, coolants, spare parts, etc. They aren't logistics free. Bombardment weapons need projectile mass at least, and maybe more sophisticated munitions as well. If you allow that they have crews, well then they have all of the human logistics burden that a similarly sized ground unit does.
Beyond logistics, they have tactical problems as well. They're in sky, where the defender can easily see and target them. The defender is on the ground, where he has all of the terrain available for cover and concealment. (One of the advantages of putting troops on the ground is that they can use cover and concealment too.) Also, in order to minimize exposure, the bombardment forces would probably have to use long orbits with low exposure to planetary defenses. In any case, any single bombardment platform would only be over the target area a few minutes out of each sidereal day. It's possible that bombardment platforms could be concentrated in time over the target area. The upside is the possibility of overmatching the defenses for a short time. The downside is the free time that such concentration would give the defenses to reorganize and reinforce between passes.
I still don't think that dragging ground troops across space is a good idea. And you can't possibly believe that I will need as many men in my bombardment fleet as you would need in your ground army. My big problem with you denying the relevance of numbers is that we've been using them quite a bit in other areas. So prove them irrelevant. What sort of future could result in your logistical requirements being lower than my numbers? Or orbital bombardment requirements being high enough that, even with my numbers, your answer is more efficient? Answer that, don't just claim "we don't know."
And "Long Orbit" is a relative term. You could probably hit a given target twice a day with planning, and if you go from 100 km to 6000 that takes you out of practical defense range.
And the only things my lasers will need are spares. A nuclear reactor will last for the entire campaign, and coolant isn't vented.
The bombardment ships will need munitions, but if you can get a moonbase, all you have to do is bring the guidance systems.
Raymond:
We can then feed telemetry to them until somewhere in the stratosphere.
Technically, it is in the mesosphere where you lose communication. But that's a minor point.
And it would probably look a lot like a drop pod.
Probably, but tungsten (or platinum group metals, if that is cheaper for you) is a lot denser than meat. So the orbital death pod will have a slower deceleration profile than a drop pod filled with soldiers (or a soldier, depending on how big these things are). Unless, of course, you put in fewer rods, which gives you a less optimal saturation of targeted ground forces. If this is acceptable for the misinformation you are trying to achieve, then go for it.
Simple: the first few pods you target are filled with rocks, and congratulations, you shot down rocks.
An orbital death pod might be expensive, it could very well be as pricey (or more pricey) as the munitions it carries. If so, you might as well put munitions in it, so if it is not shot down it can do something useful. Putting rocks in it for a decoy is only useful if the pods are cheap.
Luke:
"Putting rocks in it for a decoy is only useful if the pods are cheap."
If carbon nanostuff is our armor for most everything else, a couple square meters for a heatshield is cheap. So's aluminum for the rest of the body. I mean sure, it'd be nice to only fire death pods, but the seekers are going to be expensive, too. I'll only be using decoys once there are no more targets out in the open to hit, and I'm trying to draw the defender out and test his remaining defenses. Why waste good tungsten and functional seekers on dirt?
Byron:
"I still don't think that dragging ground troops across space is a good idea. And you can't possibly believe that I will need as many men in my bombardment fleet as you would need in your ground army. My big problem with you denying the relevance of numbers is that we've been using them quite a bit in other areas. So prove them irrelevant. What sort of future could result in your logistical requirements being lower than my numbers? Or orbital bombardment requirements being high enough that, even with my numbers, your answer is more efficient? Answer that, don't just claim 'we don't know.'"
"We don't know" is a much more valid assertion than claiming a technical comparison made with 21st Century technology will be relevant centuries or millenia in the future. Once again, all we can reasonably surmise is that the laws of physics won't change, whatever economic principles that prevail will therefore be reasonably congruent with those that prevail today -- before you go there, I said "principles" not "pactices" -- and military forces will be in proportion with the economies generating them. So we can only discuss things in principle, not in detail.
"And "Long Orbit" is a relative term. You could probably hit a given target twice a day with planning, and if you go from 100 km to 6000 that takes you out of practical defense range."
You could hit a target twice a day from the same platform in the same orbit by passing to the west on one pass and to the east on the next. However, that involves a fairly regular close orbit that exposes one to other planetary defenses when not engaging the intended target. Also it involves shooting at low angles from a relatively long range (using Earth as an example, at 40 degrees latitude, 960 km on the ground from a 90 min orbit, 1,280 km on the ground from a 2 hour orbit). One of the big reasons to use eccentric orbits is that they take you out of range for most of the orbit, yet let you come in close, right over the target, once a day.
And the only things my lasers will need are spares. A nuclear reactor will last for the entire campaign, and coolant isn't vented.
The bombardment ships will need munitions, but if you can get a moonbase, all you have to do is bring the guidance systems.
Making (highly favorable) assumptions about technology centuries to millenia in the future. Nice work if you can get it, huh?
I wrote:
"You could hit a target twice a day from the same platform in the same orbit by passing to the west on one pass and to the east on the next."
I got that backwards. The first pass would be to the east, and the next to the west, for a prograde orbit.
Tony:
Why would you bother with eccentric orbits? Stable, circular orbits at 6000 km altitude still give good time-to-target for munitions, excellent surface visibility, and plenty of warning time to intercept surface-to-orbit missiles. Said missiles must be ICBM class to even attempt it.
Raymond:
"Why would you bother with eccentric orbits? Stable, circular orbits at 6000 km altitude still give good time-to-target for munitions, excellent surface visibility, and plenty of warning time to intercept surface-to-orbit missiles. Said missiles must be ICBM class to even attempt it."
You can only be directly over the target once per day no matter what you do. The advantage I perceive in an eccentric orbit is that it lowers your closest exposure to planetary defenses, while maximizing you time away from them to repair, resupply, etc. In principle, without making technological assumptions, that should be a good thing.
Tony:
But having a series of bombardment platforms in the same orbit allows for simultaneous coverage of the entire ground track. You don't need to time your passes when you always have something overhead.
And if you didn't bring enough craft to pull that off, you didn't bring enough in the first place.
Raymond:
"But having a series of bombardment platforms in the same orbit allows for simultaneous coverage of the entire ground track. You don't need to time your passes when you always have something overhead."
If you're objective is to pass platforms directly over the target, or at least through a relatively small window, then only one per orbit is going to be capable of doing that. The others will pass either east or west of the optimum firer-target relationship on their closest approaches. What one can do is use a series of orbits in the same class, each one with a periapsis slighty advanced or retreated in time from the reference orbit, with one platform in each orbit. With enough firing platforms, the target area always has a firing platform over the horizon.
This approach, by the way, is not dependent on any particular eccentricity of orbit. The highly eccentric orbits I suggest have to do with operational issues of exposure to defensive fire when not in line-of-sight of the target.
"And if you didn't bring enough craft to pull that off, you didn't bring enough in the first place."
Of course. This goes without saying. But one has to consider the physical mechanics of the problem in order to pick the best orbits for the job.
Maybe I'm missing some part of what you're saying, Tony, but at 6000 kilometers I'm really not worried about getting in close. The flight time figures Luke worked up earlier indicate the platform's orbital period was a little under four hours, and the munitions would be launched a quarter-revolution away. So no, getting the platform's closest approach overhead isn't a concern in the slightest. I was interested in a position on the edge of ICBM range, and munition flight times of under an hour. That's the kind of nigh-invulnerable sit-back-and-lob-stuff siege position I'm interested in occupying to facilitate subsequent stages of the attack.
Figuring out how to minimize the ground track of a reentry trajectory where a drop pod would be within range of THAAD-class surface-to-orbit weapons would be the mechanical problem I'm interested in.
Raymond:
"Maybe I'm missing some part of what you're saying..."
I think you're making technological assumptions that I'm not making. I'm not assuming that 21st Century ICBM class energies are all that the defender's missile engineers will have to work with. Or that he won't have hypervelocity guns of some type (whether projectile or beam, I'm agnostic) that would make 6,000 km an unhealthy parking altitude. I'm taking the position that, when a minimum of assumptions are made, distance is good when you're not shooting, that more distance is better, and that when you are coming in to shoot, minimizing time in range is also a good thing.
"Figuring out how to minimize the ground track of a reentry trajectory where a drop pod would be within range of THAAD-class surface-to-orbit weapons would be the mechanical problem I'm interested in."
Well, without doing any math, in principle the best approach orbit would be a trade off between time close-in to the defense, and how much of a beating your cargo can take. The limiting factor would be the maximum acceleration your drop troops could stand. So the approach orbit would probably be something in the class of an Apollo Earth return trajectory.
Tony:
6000 km was an example - tweak as required. I'm using it as a member of the larger class of orbits suited to both bombardment and close fire support, which are (generally speaking) out of range at all times of the class of weaponry capable only of attacking low orbit and being easily hidden before use.
This class would a) play little role in the initial space battle (or at least some will be held in reserve and in hiding), and b) can be used to engage occupation forces if/when they attempt to land, thus c) must be neutralized to a sufficient degree to compel surrender or allow unfettered access to low orbit.
I am working from the assumption that the weapons capable of reaching medium orbits of this class would have been expended or neutralized long before the point at which ground forces of any composition and size would even be considered (the ostensible point of this thread). Medium-orbit weapons are larger, more expensive, more visible, and do not have the same incentive to hold them in reserve. If the march from high orbit to medium is a separate phase from the initial assault on the planetary system, then consider that phase complete.
And yeah, Apollo return was mostly what I had in mind. Maybe a bit steeper, since IIRC Apollo reentry was limited to 3g, but with training and equipment we could probably get away with 5-6g.
And, pray tell, why I would need to use something other than a nuclear reactor on my laserstar? You seem to deny numbers when it's convenient, but use terms like "Armored Division" when it suits you. Most lasers under discussion are solid-state and get rid of heat with radiators.
And you haven't answered my question. Under your assumptions, your scenario is no more valid than mine.
And a given orbital path will pass over a target twice a day. The period has to be right to get two passes, but it can be done.
Close approach only applies to lasers, which would work best from overhead. However, kinetics will be best launched from a fairly narrow window, even if it isn't "overhead."
ICBM-class refers to delta-V capability. It has to have similar delta-V to a modern ICBM to threaten the orbit. And I really don't see any way to improve much over modern solid rockets for this use. Unless we go with Orion interceptors, but that's a completely different issue.
With proper positioning, you could get away with 8 or 9 Gs. The person would have to be on their back, though. That increases pod signature, which might not be worth it.
Byron:
"And, pray tell, why I would need to use something other than a nuclear reactor on my laserstar? You seem to deny numbers when it's convenient, but use terms like "Armored Division" when it suits you. Most lasers under discussion are solid-state and get rid of heat with radiators.
And you haven't answered my question. Under your assumptions, your scenario is no more valid than mine."
How do you know what power supplies might be available/necessary hundreds or thousands of years in the future, and what consumables they, and auxiliary machinery like cooling systems, might use? You could very well be right that orbital weapons platforms might not need a large supply of comsumables. But they might. You seem to think, for example, that a radiator can be hardened, and therefore you can use recirculated coolant. There's one little problem with that -- what if the defender attacks the radiators with energy weapons? They suddenly stop being radiators and become a potentially catastrophic vulnerability. I certainly don't know all of the answers, but that alone is a strong argument for expendable coolant, dumped overboard after use.
And I'm kind of amused that you think "Armored Division" is a number. It's just a widely recognizable placeholder, shorthand for "Generic Super Bad Assed, Highly Maneuverable, Highly Effective Ground Force". In other words, you're reaching.
"And a given orbital path will pass over a target twice a day. The period has to be right to get two passes, but it can be done."
It would have to be an eccentric orbit with the "overhead" passes occurring on the way up and on the way down from the apapsis. It's tough to visualize, but my instincts tell me closest approach would actually occur in the opposite hemsiphere from the target.
"Close approach only applies to lasers, which would work best from overhead. However, kinetics will be best launched from a fairly narrow window, even if it isn't 'overhead.'
Close approach applies to any system where you want to minimize time of flight, increasing accuracy, and decreasing what the defense can do about it. It's also advantageous for immediate, short range sensing of battle damage.
"ICBM-class refers to delta-V capability..."
Of course it does. What if future missile engineers can specify something besides chemical rockets? Your rejction of that possibility out of hand certainly seems like a case of denying something when its convenient.
Wow. Okay, I ended up skimming a little. Sorry if I missed anything important.
Luke:
"From this, the maximum penetration occurs when the penetrator is harder than the surface being penetrated,"
A good reason to use tungsten, since besides being cheaper, it's also harder than your other dense material suggestions (platinum, iridium, and osmium). In fact, it's one of the harder materials known, but isn't normally used for hardness-requiring applications due to its high density - which is actually beneficial to us. Still isn't harder than carbon nanostuff, though.
"at a velocity of about 2 to 2.5 km/s. Faster than this, and the penetration decreases slightly, to an asymptotic value given by a pure hydrodynamic theory which is independent of velocity."
...Really?
"Thus, if you can target mobile ground troops with space-based kinetics without them moving out of the way (perhaps you shot out all of their space early warning sensors, or something), you would have your kinetic aerobrake to about 2 km/s before deploying. This is slow enough that it will not be blinded by a plasma sheath, allowing self-targeting, and gives maximum penetration against armor. You may want to use some external guidance for gross course corrections, since there will be a period during aerobraking when the kinetic will be blind and will lose its target. This will allow rapid target re-acquisition using data from a spotter spacecraft."
The elegance of this solution appeals to me, although I still have to wonder about a bolt that takes a long time to arrive and can still only kill one tank per rod.
I think I prefer atmosphere-penetrating (low-frequency) lasers for hitting moving targets, and kinetics for strategic bombardment of bunkers and factories. Perhaps these antitank bolts might be used for some heavier vehicles, though (like, well, tanks), while using lasers for softer targets that don't warrant spending the mass.
Tony:
"You're conflating "space superiority" with low orbit and air superiority."
The way I see it, "space superiority" does mean that you've been able to enter low orbit. If you control high orbit but can't safely enter low orbit, then that's a blockade or standoff, not superiority.
And remember, "low orbit" here means "the distance from which you can shoot the ground and the ground can shoot you", not any specific altitude.
"In any case, any single bombardment platform would only be over the target area a few minutes out of each sidereal day."
With ranges of 1000 km or so, you'll be spending 1/20th of your time over the area, which is more than a few minutes. Even with ranges of 100 km - which is absurdly small - you'd be spending 7.2 minutes per day.
Also remember that if you have more than one target area, you can cover them with the same ship, so you're not necessarily doing nothing during the rest of your orbit. Any two points lie on a line, and three or more might depending on how you chose your target areas.
This is assuming, though, that you can safely stay in low orbit permanently. Otherwise things are harder.
"It's possible that bombardment platforms could be concentrated in time over the target area. The upside is the possibility of overmatching the defenses for a short time. The downside is the free time that such concentration would give the defenses to reorganize and reinforce between passes."
Which is better depends on whether I'm trying to engage a bunch of dangerous surface-to-orbit defenses, or provide orbital spotting and fire support against guerillas on the ground. In the former case, I'd bunch up. In the latter case, I'd spread out.
If I think I defeated the defenses and spread out, but it turns out you still had some hidden defenses...
Byron:
"And you can't possibly believe that I will need as many men in my bombardment fleet as you would need in your ground army."
Even accounting for Burnside's Zeroth Law (that is, warships will have human crews on them, period, end of discussion), automatisation is still far more effective in space than on the ground, and especially when it comes to insurgency/counterinsurgency operations. So yeah, spaceship crews probably aren't going to be all that big.
"The bombardment ships will need munitions, but if you can get a moonbase, all you have to do is bring the guidance systems."
Depends on your munitions. If you just want to drop rocks then sure, but if you want tungsten bolts then you aren't getting those unless you can capture a preexisting mine/supply depot.
Tony:
""We don't know" is a much more valid assertion than claiming a technical comparison made with 21st Century technology will be relevant centuries or millenia in the future."
Yeah. Sometimes I have to wonder if this discussion is kind of like a Greek hoplite being taught about biplanes, and wondering how having access to those would influence his phalanx tactics.
Tony, this has gone on long enough. Rick invented a term to use for this sort of technology debate. It's called "Plausible Midfuture" It's when a lot of the things that are just numbers on the internet now are real technologies. While Milo is somewhat right, we can still make assumptions about what's coming. Weapons will be lasers and kinetics, not stuff we know of as magic. No fundamentally new engine technologies will appear. You will still have a choice between ISP, thrust, and radiation. For example, you attack my use of "solid fuels" by saying we can't see what might be coming. The point of the plausible midfuture is that we can. We're looking at what we can see, and discussing how we would deal with it. You've latched on to ground troops, and are throwing the above out the window, because you can't justify them within it. If you can, you certainly haven't done a great job of it.
OK, that may be a little harsh, but we usually discuss things that are currently plausible. When you attack my statement that they will likely use chemical rockets, and we're in plausible midfuture mode, you need to provide an alternative. What do we have?
Electric. Not enough thrust.
Nuclear. Too expensive, and if it does have thrust, it also has radiation.
Chemical. Cheap, and it has enough thrust. That looks good.
What's left? Nothing. So you posit that some magitech is going to overthrow chemical in that role. I'm going to posit that a magitech shields a planet from having living flesh land, and blocks radio signals so drones don't work. Ha! Now your troops don't work at all.
Hoplites and biplanes? Whee. I can run that metaphor right off a cliff. In fact, I will do so in a bit. But first...
Byron, Tony:
Flesh-eating nanoswarms and ionoshperic discharge weaponry. Magiteched. Byron wishes to force the popualtion to sumbit to forced mind uploading and reconstruction nanoswarms under pain of asteroid bombardment. I say some EMP weaponry at specific points and dropping my own seeker swarms under cover of particle-beam storms to ferret out the Ark bunkers and computronium caches might help force the issue. See? We can play that game, too. Plausible Midfuture tech just lets us compare numbers, since honestly I have no idea what the propagation time of a seeker nanoswarm is. So let's stick to the hard stuff, eh? That means it's ICBMs for Tony and armored divisions for Byron, and circular medium orbits for me out of range of either.
Milo:
The Orbital Death Pods let you fire a whole bunch of antitank seekers at once. Which means Byron's tanks speeding towards my recon teams are big fat targets...
My point is that even if the hoplite had an accurate understanding of how biplanes work, he would probably not derive a correct prediction of what WW1 would look like.
I look forward to your cliff-dive :)
But the hoplites who sat around discussing how it would affect battle would be closer than the ones who said "we can't be exactly sure, so it won't change anything" or more precisely "we can't be exactly sure, but we'll assume war will work the way it has in the past."
Milo:
Take away guns and high explosives, and I'm pretty sure the Hoplite could make some pretty good first approximations. Call the biplanes Da Vinci Flying Machines, if you're feeling nitpicky. Swan-dive will have to wait until after I've cooked supper, though.
Byron:
And the hoplites who say their job is obsolete (except for the showing up and taking loot bit), because who wouldn't surrender to biplanes, would also be wrong. More specifically wrong, but still.
If I'm feeling nitpicky, I would point out that Da Vinci postdated the last hoplite by some eighteen centuries.
Just trying to take the internal combustion engine out of the equation, Milo, that's all.
If I call them Icarus wings, does that help?
They can have the internal combustion engine - it's kind of hard to have a biplane without one. If you're worried about the existance of internal combustion engines having ripple effects and messing stuff up on the ground, just have the hoplite say that obviously automobiles are impossible because the ground is too rough and cluttered for a wheeled vehicle to work without horses, a machine like that only works up in the air where the environment is clean!
Hey, I said Greek, not Roman. They weren't known for their road-building, that I've heard.
Oh, and the hoplite doesn't need to know how the combustion engine works, any more than we need to know how to build a fusion reactor to postulate rockets using them. So that takes care of ripple effects from having advanced chemistry.
Also keep in mind that the Greeks already had steam power. They just didn't have steels strong enough to contain the pressures of an industrially useful steam engine, so they ended up using them as fancy toys.
Speaking of which, improvements in metallurgy is another thing you're allowed to let the hoplite know about. And yes, he'll realize how the Bessemer process would allow him to make cheaper and sharper speartips.
Raymond said...
General Albert, for the sake of argument (no hiding behind strategic privilege, here), where is the point where you stop trying to intercept what's coming down, and start hiding and waiting with your surface-to-orbit weapons?
I'm just borrowing the hat of General for this discussion, but I don't need a rank in a military to state that there are tactical situations that call for a little more thought than simple "shoot at everything in range until the magazine is dry".
The objective is leaving a few "holes" in the defences, where the attacker can shoot to kill unpunished (and obviously there will be some juicy targets to allure him), then after he thinks the area is safe and brings troop transports over there, they get swarmed and killed. Or the pods are killed.
Hell, is this so hard? For the D-Day they wasted lots of resources to let the german think the real attack would come somewhere else and were so successful that the german command thought the D-day was a decoy for nearly a week. (and left tanks and other responce forces partolling the wrong site for that time).
Byron said...
Yes, but they will have to replenish the stockpile, unless you destroy the factories.
As I said, in the first months of (unexpected) war, the army lives of stockpiles. You expect to stay there peppering them for how much more than a "few months"?
And as I said, they can (and will) overstockpile because they know of your visit in advance.
Industries are useful before the war, and if the war becomes too long. But before the war you can't do a lot about it and if it becomes too long, your constellation will probably have much bigger problems.
But if you say "Surrender or I kill all of your leaders with my laser" Sure, because they don't know how to build bunkers or even decent hidden underground facilities. You expect the US president to stand in the white house during a soviet nuclear launch? This ain't a movie. He has at least 5 different escape-and-hide plans.
Two words: Orbital bombardment. If your laserstars can survive the anti-orbit barrage to cover them, of course.
There is also friendly fire. You risk to kill your units too if I get too close or if I use smart tricks like ECMming the hell out of them.
But nuking the landing site just after landing with tactical nukes thrown from relatively close launchers lets me use the stealthyness of medium-range missile launchers and not enough people to alert your guys in orbit until is too late.
And if the blast doesn't kill them, the radiation surely will.
Also, that just makes the attacker mad. An added bonus. Enemies full of anger often make slips that allow you to beat them again. Like getting into the range of some hidden anti-orbit missiles with too much laserstars.
Or bring your laserstars in range of the group of badass ground laser cannons that I kept in reserve during the first attack. And then I PWN your constellation.
He won't land until he has orbital superiority Which, by your own words is "I shoot and if they don't shoot back I have orbital superiority". That makes the attacker easy to fool by accepting some losses.
Then order all of the factories on your planet destroyed. Distributed production or not, you can't maintain an army very long that way. As I said above, my stockpiles can go from "some months" to "some years".
You are just reducing the planet's capturing value. If you blast everything down what the heck are you doing trying to conquer it?
You want to ship new stuff from your home planet to rebuild it (costly) or wait it to do by itself while under your rule(lenghty)?
-General Albert, Ground Defence Command
Raymond said...
General Albert, for the sake of argument (no hiding behind strategic privilege, here), where is the point where you stop trying to intercept what's coming down, and start hiding and waiting with your surface-to-orbit weapons?
I'm just borrowing the hat of General for this discussion, but I don't need a rank in a military to state that there are tactical situations that call for a little more thought than simple "shoot at everything in range until the magazine is dry".
The objective is leaving a few "holes" in the defences, where the attacker can shoot to kill unpunished (and obviously there will be some juicy targets to allure him), then after he thinks the area is safe and brings troop transports over there, they get swarmed and killed. Or the pods are killed.
Hell, is this so hard to do?
For the D-Day they wasted lots of resources to let the german think the real attack would come somewhere else and were so successful that the german command thought the D-day was a decoy for nearly a week. (and left tanks and other responce forces partolling the wrong site for that time).
-General Albert, Ground Defence Command
Byron said...
Yes, but they will have to replenish the stockpile, unless you destroy the factories.
As I said, in the first months of (unexpected) war, the army lives of stockpiles. You expect to stay there peppering them for how much more than a "few months"?
And as I said, they can (and will) overstockpile because they know of your visit in advance.
Industries are useful before the war, and if the war becomes too long. But before the war you can't do a lot about it and if it becomes too long, your constellation will probably have much bigger problems.
But if you say "Surrender or I kill all of your leaders with my laser" Sure, because they don't know how to build bunkers or even decent hidden underground facilities. You expect the US president to stand in the white house during a soviet nuclear launch? This ain't a movie. He has at least 5 different escape-and-hide plans.
Two words: Orbital bombardment. If your laserstars can survive the anti-orbit barrage to cover them, of course.
There is also friendly fire. You risk to kill your units too if I get too close or if I use smart tricks like ECMming the hell out of them.
But nuking the landing site just after landing with tactical nukes thrown from relatively close launchers lets me use the stealthyness of medium-range missile launchers and not enough people to alert your guys in orbit until is too late.
And if the blast doesn't kill them, the radiation surely will.
Also, that just makes the attacker mad. An added bonus. Enemies full of anger often make slips that allow you to beat them again. Like getting into the range of some hidden anti-orbit missiles with too much laserstars.
Or bring your laserstars in range of the group of badass ground laser cannons that I kept in reserve during the first attack. And then I PWN your constellation.
He won't land until he has orbital superiority Which, by your own words is "I shoot and if they don't shoot back I have orbital superiority". That makes the attacker easy to fool by accepting some losses.
Then order all of the factories on your planet destroyed. Distributed production or not, you can't maintain an army very long that way. As I said above, my stockpiles can go from "some months" to "some years".
You are just reducing the planet's capturing value. If you blast everything down what the heck are you doing trying to conquer it?
You want to ship new stuff from your home planet to rebuild it (costly) or wait it to do by itself while under your rule(lenghty)?
I'm going to guess that missiles and drop pods can be told apart. Which goes in favor of the defender. Killing your ground forces is a very high priority worth some sacrifices, because you don't have a lot of them. And I don't even need the costly anti-orbit weapons.
I don't think we can hit moving targets, simply because the missile will be in a plasma sheath the whole way down.
The plasma sheath has a hole in the direction of the reentry vector facing space. I read about people that wanted to place satellites to take advantage of that hole to communicate with Shuttle during reentry.
So, you can hit moving ground targets with kinetics if you want to.
But you need something that sees where the target is, of course. And that will be vulnerable to eye-frying from low-power lasers.
Planets are hard to take, but it is possible. I've been focusing on what happens when you have enough of an edge to possibly do so. I'm concentrating on the defender side because you need to know what a good defender can do to find a good reason why it doesn't do that in your story. Otherwise your book becomes TV-Tropes fodder, and people like me start screaming at it, losing their suspension of disbelief.
-General Albert, Ground Defence Command
Byron said...
Yes, but they will have to replenish the stockpile, unless you destroy the factories.
As I said, in the first months of (unexpected) war, the army lives of stockpiles. You expect to stay there peppering them for how much more than a "few months"?
And as I said, they can (and will) overstockpile because they know of your visit in advance.
Industries are useful before the war, and if the war becomes too long. But before the war you can't do a lot about it and if it becomes too long, your constellation will probably have much bigger problems.
But if you say "Surrender or I kill all of your leaders with my laser" Sure, because they don't know how to build bunkers or even decent hidden underground facilities. You expect the US president to stand in the white house during a soviet nuclear launch? This ain't a movie. He has at least 5 different escape-and-hide plans.
Two words: Orbital bombardment. If your laserstars can survive the anti-orbit barrage to cover them, of course.
There is also friendly fire. You risk to kill your units too if I get too close or if I use smart tricks like ECMming the hell out of them.
But nuking the landing site just after landing with tactical nukes thrown from relatively close launchers lets me use the stealthyness of medium-range missile launchers and not enough people to alert your guys in orbit until is too late.
And if the blast doesn't kill them, the radiation surely will.
Also, that just makes the attacker mad. An added bonus. Enemies full of anger often make slips that allow you to beat them again. Like getting into the range of some hidden anti-orbit missiles with too much laserstars.
Or bring your laserstars in range of the group of badass ground laser cannons that I kept in reserve during the first attack. And then I PWN your constellation.
He won't land until he has orbital superiority Which, by your own words is "I shoot and if they don't shoot back I have orbital superiority". That makes the attacker easy to fool by accepting some losses.
Then order all of the factories on your planet destroyed. Distributed production or not, you can't maintain an army very long that way. As I said above, my stockpiles can go from "some months" to "some years".
You are just reducing the planet's capturing value. If you blast everything down what the heck are you doing trying to conquer it?
You want to ship new stuff from your home planet to rebuild it (costly) or wait it to do by itself while under your rule(lenghty)?
(continued)
Byron said...
Yes, but they will have to replenish the stockpile, unless you destroy the factories.
As I said, in the first months of (unexpected) war, the army lives of stockpiles. You expect to stay there peppering them for how much more than a "few months"?
And as I said, they can (and will) overstockpile because they know of your visit in advance.
Industries are useful before the war, and if the war becomes too long. But before the war you can't do a lot about it and if it becomes too long, your constellation will probably have much bigger problems.
But if you say "Surrender or I kill all of your leaders with my laser" Sure, because they don't know how to build bunkers or even decent hidden underground facilities. You expect the US president to stand in the white house during a soviet nuclear launch? This ain't a movie. He has at least 5 different escape-and-hide plans.
Two words: Orbital bombardment. If your laserstars can survive the anti-orbit barrage to cover them, of course.
There is also friendly fire. You risk to kill your units too if I get too close or if I use smart tricks like ECMming the hell out of them.
But nuking the landing site just after landing with tactical nukes thrown from relatively close launchers lets me use the stealthyness of medium-range missile launchers and not enough people to alert your guys in orbit until is too late.
And if the blast doesn't kill them, the radiation surely will.
Also, that just makes the attacker mad. An added bonus. Enemies full of anger often make slips that allow you to beat them again. Like getting into the range of some hidden anti-orbit missiles with too much laserstars.
Or bring your laserstars in range of the group of badass ground laser cannons that I kept in reserve during the first attack. And then I PWN your constellation.
He won't land until he has orbital superiority Which, by your own words is "I shoot and if they don't shoot back I have orbital superiority". That makes the attacker easy to fool by accepting some losses.
(continued)
OMG, It gave me an error for all my posts above... I thought they weren't there and reposted. Terribly sorry for the mess. :'(
Tucydides said...
informations on how hard is to find and destroy missile fabsThank you for the fire support (pun intended). :)
Lots of stuff on ballistic courses, aimed at key economic targets, and without much worry if a city gets wiped off the map by accident. You can be bombed back to the stone age or you can surrender and permit my forces to land and seize power.
What I said for byron applies to you too. Assuming you didn't miscalculated and my defences stop your kinetics...
What the heck are you going to do with a planet in stone age and population declining due to famine?
Hello? What if they don't surrender because they think you are Evil? (and this kind of actions kinda reinforce their beliefs)
Tony said...
Correct me if I'm wrong, but you seem to be assuming strong space forces (eliminated before the discussion starts) and strong orbital defenses.
Well, if the attacker managed to kill off the space fleet without enough losses to make him think to abort the mission I woudn't call them "strong space forces".
I'm assuming that the money the defender hasn't spent on spacecraft has been spent on ground defences/army.
Maybe because he has not the engineering expertise to do decent combat spacecraft and knows that Byron's Empire is hungry lately.
Teleros said...
If they're not going to surrender after you've taken out their orbital infrastructure, space fleet and such, why risk your people's lives when you can bombard them from impunity from afar? Maybe because you will need to wait years without torch engines to redirect an asteroid of a decent size? You know, the rocket equation and stuff... anything very big will either require unrealistic amounts of propellant or unrealisitc amounts of time.
Both are commodities you don't have.
Or maybe because any other race will join and kill you on sight.
And no. You can't aim a reentring asteroid with any decent precision.
Its shape and/or composition (it can break up during reentry) will simply prevent any non-magical guidance.
Your own defences will have to deal with the enormous shielding and heat sink potential of the asteroids being used, as well as whatever point defence weapons they have mounted on them as well. Sure. Because I cannot have laser cannons with at least the same performance on the planet that have never fired and thus you have never bombed.
Here people ignores the concept of "reserve". You never throw all you have to the enemy.
-General Albert, Ground Defence Command
Byron, just because you can't effectively land troops without controlling low orbit, does not mean you won't need to land troops even after you control low orbit. People will not always surrender just because you have the bigger stick. That just isn't how it works in reality. And for that matter, that also isn't how it works in wargames.
Albert:
I'm assuming the intelligence back-and-forth and the I-know-that-you-know games and the fog of war will be very much the name of the game, even with blanket satellite coverage. What I failed to ask you properly was more a question of where physics and reasonable numbers define the boundaries of the possible responses. So pretend a) I'm willing to sacrifice a few advance teams (or better yet some drones or rocks of similar mass) to draw out your forces, b) I'm able to monitor radio transmissions sufficient to estimate location and activity, and c) I'm likely to do some tac-nuking of my own. Oh, and d) I've got spies and infiltrators and disinformation sources already on-planet, because unless your planet is the most xenophobic place in the system, people from my planet will be on yours. (If it is the most xenophobic place in the system, I seriously consider cracking out the bioweapons and saying good riddance.)
In other words, where exactly is the wall your back is to? At what point are you forced to change strategies, as opposed to doing so intentionally?
The implications of the THOR system as reported by Jerry Pournelle (or the more recent iteration as "Rods from God") is the weapons do indeed strike their targets at near orbital velocity.
How this trick is done is above my pay grade, so there is either disinformation, wishful thinking or something we don't know about going on here.
Incidentally, THOR, Rods form God or Common Aero Vehicles (CAV's) ejecting weapons at hypersonic speed during reentry manouevres all operate in LEO, with potential response times measured as low as minutes depending on orbital parameters when they are called into action.
I have barely managed to skim this discussion!
Let me ask everyone to be careful of tone and patient with each other. One commenter has already felt pushed out, and I don't want more feeling that way. Mostly, though, the tone has been very good.
On the merits of the debate, I'm agnostic. Obviously no one can seriously think of invading a 'major' planet unless you have enormous resources. As I said (far!) upthread, planetary invasion is an Empire-sized job.
And to get in position to land troops, few or many, you'll have to muscle your way down from high orbits to lower ones, suppressing defending fire.
If the defender holds fire until you attempt to land, this phase of the campaign will be compressed, and either your landing storm saturates his defensive storm, or it doesn't.
Landing a small number of troops, I think, is useful if and only if they can get 'inside' the enemy's response cycle. Determining whether this is viable is rather fine-grained, but it seems to require that the defender have a flawed doctrine, the way fortresses taken by German paratroops were designed under a flawed doctrine.
Okay, I have a hypothetical scenario:
The factions are the New Earth Order (a recently formed federation of earthbound territories and their colonies in the Earth sphere) and the Martian Colonial Union (a federation of Earth colonies on Mars that won its independence a generation ago against the NEO's predecessor, the Earth Federation, and contributed to the Federation's collapse and subsequent balkanization). Both factions are at roughly the same tech level, have substantial population bases in support of the war, have access to nuclear weapons, maintain sizable constellations of space warships (including fighters for atmospheric and orbital combat, and the carriers to ship them) as well as standing armies.
(continued)
Lasers are the primary ships' cannon, but there is a defense in the form of anti-beam dispersal charges (which spreads a cloud of a McGuffinite nanomaterial that serves to weaken, but not deflect, energy weapons when in particle form (thus explaining the reason for its deployment method instead of as armor) across the ship's magnetic anti-radiation screen (added protection against cosmic rays and solar flare backwash)). ABDCs are not invincible, however: every time the cloud takes a hit, much of the cloud is burned away in the process, requiring the cloud to be replenished periodically during combat. Military ships are propelled by Orion-style nuclear pulse drives powerful enough to reduce transit time between Earth and Mars to about a week, assuming favorable orbits. Ground forces (including space-based infantry), most fighters and older warships use kinetic weapons almost exclusively, except for ASAT weapons, which are either surface-to-orbit ballistic missiles or high energy laser emplacements.
(continued)
Mars, while an open-air planet like Earth due to terraforming (although the atmosphere's still pretty thin) still has its population centers mostly contained in large cities where the original colonies were established, and each one is its own city-state with its own militia and its own government. These city-states disagree so much with each other that it's often said that the Martian Colonial Union's provisional government can't agree if they're even a government; the only reason why the planetary government even exists is because despite its balkanization a generation previously, Earth is still seen as a threat.
On the other side, the government of Earth does not recognize the Martian Colonial Union as a legitimate government, as they still consider Mars to be a colony in rebellion. Earth's purpose in this war is to reclaim Mars and restore it to its colony status. As a result, they don't want to level the planet's population centers if they don't have to as they want the planet's people, resources and infrastructure, not just the planet. In addition they don't want to look bad (at this stage, anyway) and break any treaties the various Earth states may have made with Mars in the past.
(continued)
Speaking of which, after the bloody, destructive and complicated mess that was Mars' war of independence (and every colony in the solar system not on Earth's doorstep's), several technologies and strategies were banned by all sides in the conflict, among them orbital bombardment, genetically or biologically enhanced supersoldiers, antimatter in any form, autonomous combat drones, biological weapons and asteroid/comet/space colony drops. Of course, there are loopholes in these treaties that were initially made for practical considerations, but can be used for warfare, such as the orbital bombardment ban, which only prohibits weapons fired from orbit or suborbit; landers or aircraft launched from orbit are permitted.
(continued)
Mars' strategic planetary defense system is primarily spread around the equator and both poles, although each city is also capable of defending itself against anything in low orbit above it. The strategic command center is located in a bunker deep beneath the major (and most heavily defended) city on the planet, and coordinates planetary defense actions with everyone. Due to the quarreling between city-states, this command center is the lynchpin in the planet's strategic defense grid; the only way to get through to it is to penetrate half a kilometer of hardened structure engineered to withstand direct hits from things like small asteroids and nuclear weapons. There is only one ocean on the planet, in the northern hemisphere, leaving ASAT subs with a significant blind spot. Missile and laser trucks are on alert all across the planet, but more heavily concentrated in the southern hemisphere due to the presence of ASAT subs. As mentioned previously, each city has its own standing militia. In space, there are numerous satellites and space stations, as well as several clusters of colony structures in high orbit and a military base on Deimos (Phobos is a civilian spaceport). Before Earth's reunification, Mars' space force was roughly equivalent to that of Earth's most powerful state, based primarily in North America but with colonies on the Moon and several Federation-era asteroid bases. Now that Earth is unified, Mars' space force is outnumbered approximately 3-to-1, but Earth still needs to defend its territory and Mars' forces are backed up by surface and subsurface ASAT elements.
Mars has an ally in Ceres and, by extension, most of the colonies in the asteroid belt, but their military, such as it is, is sufficient only to defend themselves against an attack by a small military task force. The colonies around Jupiter prefer to wait to see how the war between Earth and Mars pans out before siding with anyone.
So, if you were the supreme commander of the Earth forces, how would you conquer Mars?
Mars has an ally in Ceres and, by extension, most of the colonies in the asteroid belt, but their military, such as it is, is sufficient only to defend themselves against an attack by a small military task force. The colonies around Jupiter prefer to wait to see how the war between Earth and Mars pans out before siding with anyone.
So, if you were the supreme commander of the Earth forces, how would you conquer Mars?
Mangaka2170:
"There is only one ocean on the planet, in the northern hemisphere, leaving ASAT subs with a significant blind spot."
Have Hellas and Argyre been filled in with landlocked seas? That would give you some more sub coverage, although there would still be a lot of uncovered land.
"Missile and laser trucks are on alert all across the planet, but more heavily concentrated in the southern hemisphere due to the presence of ASAT subs."
There is no real point to laser trucks. The idea of missile trucks is that you mount a single expensive missile on a cheap truck, and once the missile is fired, the truck is worthless as a target. Lasers aren't expendable that way, and trucks are too slow and visible to move away after firing, most of the time. The dominant laser defenses on land are likely to be immobile, heavily armored bunkers, and highly mobile planes (ideally supersonic interceptors that can quickly redeploy where necessary). Planes have better defense to kinetics but worse defense to lasers.
On another note, I'm not sure how well planes would do on Mars - the thin air hurts them, but the low gravity helps them. As long as they can stay up, they will have an easier time getting high speeds due to reduced friction.
"Mars has an ally in Ceres and, by extension, most of the colonies in the asteroid belt, but their military, such as it is, is sufficient only to defend themselves against an attack by a small military task force."
Is the asteroid belt an important source of trade? If cutting off their trade would deny Mars valuable resources, then it's worthwhile for Earth to attempt to do so, if they think they can put up with the additional front to their war. Otherwise, there's no real point worrying about them. Also keep in mind that even if trade is important, blockading Mars (if you can pull it off) would stop it without needing to tangle with Ceres directly.
Also keep in mind that the asteroid belt is quite scattered. Nearby asteroid orbits are actually very hard to travel between, because Hohmann windows only come up very infrequently. Thus remote asteroids would actually have a pretty hard time defending each other in case of an attack.
Mangaka2170:
"So, if you were the supreme commander of the Earth forces, how would you conquer Mars?"
I don't have a full battle plan, but some notes:
- Try to turn Mars's factions against each other, using spies if necessary. Convince them that the thugs next door are a bigger threat than the far-off Earth armada. Obviously, you do this before performing any overt fleet movements.
- Capturing Deimos should be a high priority in any full-scale invasion. If you can capture any of its facilities intact that would be awesome, but destroy them utterly if necessary - the point is to deny their use to the enemy.
- Capturing Phobos is also important for an entirely different reason - since it's a poorly defended civilian installation, it's much more likely to be possible to capture it mostly intact. Also since it's a spaceport, it's likely to have ample resources of reaction mass, which will greatly ease your logistics. Leaving this treasure trove undefended was a grave mistake on Mars's part.
- Attempt to engage Mars's spaceships while in high orbit. Try to avoid getting into range of surface-to-orbit defenses until the space fleet has been defeated and both Deimos and Phobos have fallen.
Oh...
Mangaka2170:
"Military ships are propelled by Orion-style nuclear pulse drives powerful enough to reduce transit time between Earth and Mars to about a week, assuming favorable orbits."
That implies delta-vees of 500-600 km/s, well beyond the reach of any Orion type propulsion. We're talking terawatts for a ship of any significant size.
Incidentally: I've calculated that the synodic period between Phobos and Deimos is about 6 hours and 7 minutes. So they'll pass at closest approach quite often (though closest approach is still 14083 km, more than the Phobos-Mars distance).
Milo:
Good catch with Phobos. Maybe intrigue is to blame for the lack of a huge constellation with ground support around it (politics, after all, is often the root of some really stupid military decisions), possibly in conjunction with getting a few colonies to stop trusting the rest.
Mars' space forces would probably be in orbits that intersect with Deimos' (if nothing for practical reasons), which would make the moon a tough nut to crack (plus, Deimos is probably in range of Mars' surface defenses, given its close orbit around the planet).
I suppose that the travel times are more unreasonable than I first thought. Maybe 25~40 days, instead?
Raymond said...
I'm assuming the intelligence back-and-forth and the I-know-that-you-know games and the fog of war will be very much the name of the game, even with blanket satellite coverage.
Carve. It. In. Stone.
I just wanted to point out that we were gettin a little too far from reality with our assumptions.
War isn't only about physics.
Satellite optics can be fried by ground/sea lasers, btw.
where physics and reasonable numbers define the boundaries of the possible responses
Being a real general would have helped.
I have no numbers for you (war isn't a science).
I can only say that in war reliable intelligence is much more valuable than powerful guns.
And units in orbit have no stealth, while ground units can hide all day in the ground clutter.
This means gathering intelligence is much easier for me than it is for you.
a) I'm willing to sacrifice a few advance teams (or better yet some drones or rocks of similar mass) to draw out your forces,
They need to decelerate at the end. So they must be reentry pods. Either for robots or for humans. No rocks please.
This means you will have to bring them with you, or build them with stuff you find in my orbit/system (with manufacturing facilites you have brought with you).
Anyway, you see how they get blasted if I manage to do it correctly. It may be useful for the next time if I make mistakes, but unless you manage to see where my units are before drop, you will still be uncertain if that (new) patch of land is free or not.
If my plan goes well (wishful assumption), you just see a rocket for a few seconds and a bright flash.
Or some anti-air missiles taking off and frying your pods.
Or some shooting and massive ECM that prevents you from telling who is who. Remeber, drop pods can be more guided than thrown rocks, but have still a pretty low accuracy, so your units will be more or less disperse over km of land, and my troops should be able to divide your forces easily just after drop (just as if they were more conventional paratroopers).
This is what can happen, but IF happens depends from the size of your units, the efficiency of my defences, the intelligence about me and about you, some careful hoax by me or by you, troop morale, and sheer luck.
There are too much variables to have a definitve answer. But you can tweak them to have the story follow what you (the author) want to happen.
(continued)
Raymond said...
b) I'm able to monitor radio transmissions sufficient to estimate location and activity, They faked radio transmissions from non-existent infantry divisions preparing for the D-Day, from moving trucks cruising around Britain's shores, to let the germans pinpoint them and think they were going to do the attack in a wrong place.
Trucks and radios are still available in the future, so I can do it too.
But don't be afraid, you can do it too to me for the places you are going to bomb/drop.
Frankly, I have no idea of how powerful a standard walkie-talkie is (you can detect it from orbit?), but I can use directional radio antennas or telephone lines, or even send messengers. (do laser-communication work in ground conditions?)
You are much more lucky, with laser-communicators that I cannot intercept (until you are transmitting orders to a craft with Earth behind it, at least).
c) I'm likely to do some tac-nuking of my own. Glad to see militaries not afraid of nukes.
They can be a nice force multiplier if given to your ground forces, but dropping them from orbit would be redundant imho (you can use kinetics or lasers instead).
d) I've got spies and infiltrators and disinformation sources already on-planet
The smartest strategy of all.
I'll have my own agency to counter your spies, who wins the information war will make the difference in the shooting contest.
Although generally building a decent information network is costly and very time-consuming.
Not every nation will be able to have a powerful spy network on each and every other nation.
Around 5 years of preparation seem ok to have an organization difficult to root out but still useful.
If you spend 10 or so years you'll have infiltrated up to my leaders, and can take control without even sending a trooper.
-General Albert, Ground Defence Command
I said above...
There are too much variables to have a definitve answer.
Let me clarify, there are variables that have at least the same impact on the outcome, but aren't linked to phisics and thus were ignored in the previous discussion.
(the most important being intelligence about your enemy)
I think we have talked enough of weapon capabilities, but war isn't necessarily won by the guy with the best hardware. Nor by the one with the highest number of guns.
So, anyone more knowledgeable in the field of intelligence and sensors? To what degree can ground forces get info about enemies? And orbital forces about the ground forces?
How both can be fooled and countered?
-Albert
Albert:
"(do laser-communication work in ground conditions?)
"
IR laser wireless links are all over the place already. But I wouldn't put it past the future to be able to read atmospheric scatter, even from orbit. Whether it could be deciphered is another question, but at the very least it would give a signals analysis expert (or expert system) good raw data on ehre communications are happening, and how much. That could be used to direct other, more sensitive and discriminating sensors.
Mangaka2170:
"Mars' space forces would probably be in orbits that intersect with Deimos' (if nothing for practical reasons), which would make the moon a tough nut to crack"
Well, it being a tough nut to crack is obvious. That's the point. However, it's a nut that's going to keep shooting at us as long as we leave it alone. If you have some way to shortcircuit its defenses and take it out an easy way, then by all means go for it, but if you don't, you're going to need to take it out the hard way, and as fast as possible.
"(plus, Deimos is probably in range of Mars' surface defenses, given its close orbit around the planet)."
Deimos is 23460 km above Mars's center, and Phobos is 9377 km above Mars's center. Mars's equatorial radius is 3396 km, so that puts Deimos at 20064 km above the surface, and Phobos at 5981 km above the surface. Phobos might be in range depending on your defenses (which would seriously complicate capturing it, although that depends on whether the most important structures are on Phobos's shadowed side or not), but I doubt Deimos is.
"I suppose that the travel times are more unreasonable than I first thought. Maybe 25~40 days, instead?"
That would need like 60 to 125 km/s. The slow end is within reach of numbers I've seen on Orion engines, and the fast end might be if your technology has improved somewhat over current projections.
Albert:
"You are much more lucky, with laser-communicators that I cannot intercept (until you are transmitting orders to a craft with Earth behind it, at least)."
If at all possible, I would transmit via a relay that in sight of both the sender and the receiver. (This relay wouldn't be anything special - all my ships would be equipped to act as one when necessary.)
If I only have two ships and they happen to be on opposite sides of the planet, then yeah, they can't communicate. My tactics would make a point to keep this from happening.
"So, anyone more knowledgeable in the field of intelligence and sensors? To what degree can ground forces get info about enemies? And orbital forces about the ground forces?"
Some assumptions I am making:
- Sensors are cheap and hard to spot, and so any planet with space-age technology can afford to have an effectively unlimited amount of them scattered all over the planet, and will retain this unlimited amount for the entire duration of the war. Thus, the ground forces always know everything that's going on in orbit, unless it's behind the shadow of a moon that doesn't have its own sensor platforms, or inherently very hard to see (which doesn't happen much in space). These ground sensors still have to see through the atmosphere, which limits them somewhat compared to more vulnerable sensors on satellites, but this probably only matters much for seeing very distant things. Ground sensors should suffice for the current battle.
- The attacking side also has cheap sensors, but still has to mount them on expensive ships. Thus the attacking side only has coverage over areas their ships are looking. If all your ships are on one side of the planet, you can't see what's on the other side. If some of your ships are on one side of the planet and some are on the other side, then they can all see everything because they share their sensor data over the laser communication network. And the lower your orbits, the better your sensor coverage of the ground.
- Stuff on the ground is generally much harder to spot and identify than stuff in space, due to: being smaller, being stealthier (no superhot exhaust flares), being in a cluttered environment, and potentially actually hiding behind cover (including clouds), or being camouflaged. Thus the space side will have much poorer data on the ground side than vice versa. Whether high or low quality, you will still most likely have sensor coverage of the entire planet.
Tony:
"Whether it could be deciphered is another question, but at the very least it would give a signals analysis expert (or expert system) good raw data on where communications are happening, and how much."
That's all any communication interception could give you anyway. You're never going to be able to tell what the enemy is saying.
Current encryption is essentially uncrackable unless you use it wrong.
However knowing where the enemy is would of course be very useful, although succeptible to decoys.
Milo:
"Current encryption is essentially uncrackable unless you use it wrong."
Enigma was cracked through operational errors made by users (e.g. operator laziness) compounded by overuse (e.g. using high level codes for administrivia). So never say never.
Albert: Maybe because you will need to wait years without torch engines to redirect an asteroid of a decent size? You know, the rocket equation and stuff... anything very big will either require unrealistic amounts of propellant or unrealisitc amounts of time.
Both are commodities you don't have.
Really? I can see the operating costs of a space force go up if you're sticking them on blockade duty, and now that all the flying from Planet A to Planet B has been done and the enemy's fleet wiped out propellant use should go down as well.
Or maybe because any other race will join and kill you on sight.
Or maybe because another race will join and help you win.
How about we try & cut down on the extra variables :P .
And no. You can't aim a reentring asteroid with any decent precision.
Its shape and/or composition (it can break up during reentry) will simply prevent any non-magical guidance.
Oh well.
Launch anyway.
Sure. Because I cannot have laser cannons with at least the same performance on the planet that have never fired and thus you have never bombed.
Here people ignores the concept of "reserve". You never throw all you have to the enemy.
I'm sure you will have them. However, either you start beaming the armed asteroids from far out, thus giving me a fix on your reserve laser cannons, or you have to engage them once they're much closer, in which case they can still do plenty of damage. Plus, whilst you're shooting at the asteroids, the asteroid crews / AIs / what-have-you can be focusing their own lasers on targets other than your reserve laser cannons... like the nearest laser mirror factory. Fair exchange in my book - and of course if the asteroid survives, once it's out of range I can re-arm it whilst it cools off a little in space.
Mangaka2170there is a defense in the form of anti-beam dispersal charges (which spreads a cloud of a McGuffinite nanomaterial that serves to weaken, but not deflect, energy weapons when in particle form
Oh lord, not anti-laser sand again.
*Points to Atomic Rockets*
several technologies and strategies were banned by all sides in the conflict, among them orbital bombardment, genetically or biologically enhanced supersoldiers, antimatter in any form, autonomous combat drones, biological weapons and asteroid/comet/space colony drops
"Orbital bombardment? Banned you say? Wups too late, there goes the Olympus Mons colony. Send in the Adeptus Astartes to clear up."
According to the rest of the blurb, the asteroid colonies won't be able to interfere much if this happens because it can be done to them (and more easily too). So Earth blockades Mars from its asteroid belt allies (or hell, maybe just hoovers up the asteroid colonies as well), grab both of Mars' moons (or at least neutralise them), then threaten the Martian colonies with destruction unless they give in. Meanwhile starts dealing with several key (that is, with control over enough of the planetary defences that you can land okay) colonies on Mars - ie, if they let NEO forces land, they'll be guaranteed some additional autonomy when the dust settles and Mars is back under Earth control - perhaps even full independence, if that's what's required. Can always invade them from the ground later after all :) .
This might be straying from the ground pounders, but as to the defensive shield possibilities in space...
I believe we have some big mirrors that are actually liquid (I think Mercury) rather than solid. What if a magnetic field was used to shape a shield of liquid reflective medium into a cone shape (possibly with a small hole in the middle to shoot through). You then point this cone at your enemy. Hopefully, most of the laser energy would get deflected off at a low incidence angle. What does get absorbed will be constantly moved around and replaced so that lasers pretty much just heat up the shield rather than penetrate it. This would have the added benefit of intercepting very high speed kinetics when placed in front of a moving vessel. Biggest drawback is that you can't see through it.
Citizen Joe:
"I believe we have some big mirrors that are actually liquid (I think Mercury) rather than solid. What if a magnetic field was used to shape a shield of liquid reflective medium into a cone shape (possibly with a small hole in the middle to shoot through). You then point this cone at your enemy."
Please explain to me how this would work better than a swiveling solid dish on a gimbal.
Unfortunately, mirrors don't work all that well as a laser defense. They may reflect some light, but the portion that they fail to reflect will still be enough to vaporize your mirror, unless it's very thick (in which case it's just armor).
"This would have the added benefit of intercepting very high speed kinetics when placed in front of a moving vessel."
Practically every device can intercept high speed kinetics... once.
Solid doesn't repair itself. A liquid mirror will just flow back into any hole you burn with a laser. That means that you'd have to vaporize (not just melt) a significant fraction of the shield material before you could penetrate. Anything below that threshold and you're just heating up the shield. That takes away the precision firing bonus of the laser where you would target a vulnerable spot, or drill away at one spot. At that point you're basically just pumping energy into the system hoping that they can't dissipate it fast enough.
By contrast a relatively slow missile could pass right through. That may open up the rationale for space fighters which get inside the shield wall and then do their damage.
To return to our discussion of lasers before: I said a handheld laser would have a shot energy in kilojoules, and Luke suggested it would fire over less than a millisecond. That means the capacitor needs to be able to discharge at a rate of megawatts - and that's before accounting for the fact that the laser isn't firing continuously over this time but is actually generating a series of smaller pulses.
That's just for handheld lasers. Vehicle-sized lasers would need even more energy, and quite possibly would need to finish their shot in less time if they expect to be shooting at things moving at multiple kilometers per second.
So do we actually have capacitors that can discharge that quickly? Wikipedia's best number for ultracapacitors is 6 kW/kg. Even if we accept Luke's smaller value of 0.5 kilojoules per shot, that would still give a capacitor which weighs more than the soldier.
Ultracapacitors (generally electrochemical) are a class of power storage somewhere between batteries (with their high energy density and low charge rates) and capacitors (the opposite). They might be used for the power storage (they charge quickly, and that's a priority on a battlefield), but the actual energy used in each shot will be in a proper electrostatic capacitor. And those, even today, have specific power rated in megawatts.
Teleros said...
Oh well.
Launch anyway.
Hell, you assume you can redirect asteroids?
I assume I have a Cold War-ish stockpile of nukes. Which isn't so wrong, if I know that a preferred tactic is asteroid-kill civilizations.
I can blast away any asteroid that you can realistically redirect (up to 3000 meters of diameter, mass at around 10'000'000'000 tons) with a nuke (up to 120 megatons, which is largely doable) when it is getting near to the atmosphere. And some defence saturation from ground missile launchers to keep you from shooting them down.
And please note, there won't be only "decoys" but shots aimed at your laserstars. You wanna try protect your precious asteroid? You lose a good percentage of your laserstars. You choose.
http://www.stardestroyer.net/Empire/Science/Asteroids.html
Or maybe because another race will join and help you win.
How about we try & cut down on the extra variables :P . Sure. Because noone has ever cared of bad PR when in war (saved for insane german dictators).
USA nuked Baghdad with a borrowed Tsar Bomba, and then proceeded to kill any resistence with "nukes from the orbit" (ICBMs).
And nuked afghanistan with whatever they had until it became a radioactive hell.
I bet someone would have preferred it this way, but generally you go to war to conquer, not to exterminate.
And conquering requires
A: that there is something left
B: that the other nations around you don't feel threatened by your actions
However, either you start beaming the armed asteroids from far out, The idea was "frying your optics". You start shooting, your optics die shortly afterwards. You can do the same to me, and we get to an annoying stalemate. Although you wasted resources and time to build a frikkin laser asteroid and cart it around the system. And now I can launch nukes to blow it up undisturbed.
That laser-asteroid from Atomic Rockets was supposed to fight spacecraft, not a planet.
Because its lasers aren't in the atmosphere so weren't hampered by it. But being that atmosphere is between attacker and defender, this no more applies.
A planet has the same if not even better conditions than a laser asteroid attacking it. Like an ocean to cool it down, or even more rock to protect it, or underground bases full of replacement mirrors and not-so-detectable fabs to build them. And nukes to blast asteroids to pieces.
Like the nearest laser mirror factory.Because any laser mirror fab will be clearly labeled as such.
But anyway, I'll laugh looking at my stockpile bunkers full of mirrors, and at my nukes.
and of course if the asteroid survives, once it's out of range I can re-arm it whilst it cools off a little in space.
With your lasers fried, or saturated I can launch a few nukes to blow it up.
Then laugh at all the time and resources you wasted to give me the opportunity to see some nuclear fireworks.
-General Albert, Ground Defence Command.
Duh! I fail at linking.
Asteroid destruction calculator
Milo said...
Some assumptions I am making: Which is more or less what I am assuming too.
The point is, can someone from orbit see what is the purpose of a big building? (a fab, and determine what they are doing in it)
Or realize if an armored division is in fact a bunch of beggars driving modified pickups?
Or see through clouds, or through water.
I was curious to know if anyone had more knowledge about spy sats and UAVs and what they can help discover.
-Albert
General Albert, I think you're overestimating the stealth abilities of a ten-meter-wide reflective dish (which would be required to rival my orbital lasers in range), as well as the survivability of its optics against a large laserstar constellation with overlapping fields of fire. I also believe that you overestimate the capability of nuclear weapons to deflect an asteroid when closer to the surface of the planet than the planet's own radius. If you wish, by all means, fire away - by the time it's in range of your missiles, it's too late. By the time you could hit it with a long-range missile, said missile has been burnt to ash.
Or realize if an armored division is in fact a bunch of beggars driving modified pickups?
After the first batch of beggars has been wiped out, you won't find many more willing to put on the costume, methinks.
Change "beggars" to "convicts", then. Those don't have much choice in the matter.
Better yet, change "beggars" to "robots". Robots might have limited flexibility in combat, but we're not that far off from AI-controlled cars that can convincingly pass for human traffic when viewed from orbit. Nevermind the possibilities of remote-controlled or pre-programmed routes.
The question is whether decoys would actually be that useful. Sure, you got the enemy to blow up some of your cars, but that only matters if it distracted the enemy from doing something else.
Milo:
A good reason to use tungsten, since besides being cheaper, it's also harder than your other dense material suggestions
Tungsten carbide is particularly good for a combination of density and hardness. However, while it is good for the front part of the impactor to be hard (as long as the velocity isn't too high), you can make the back end out of whatever is the highest density since the back end just adds inertia to drive the front end.
With cheap interplanetary traval, the platinum group metals might end up being fairly cheap since you can mine them from asteroids.
...Really?
That's what the models predict, and that's what seems to be born out by experiment. In the limit where the impactor has enough kinetic energy to simply blast out a huge crater, you pass outside of the realm of applicability of long rod penetrator theory, but you have to be going pretty darn fast for that.
It makes a certain amount of sense, if you think about it. At velocities that are high enough that the target yields significantly but the impactor less so (because the impactor is harder, remember) you will get less erosion of the impactor for a given amount of erosion of the target. As the velocities get higher and material strength becomes less relevant, the erosion of the impactor increases relative to that of the target, until you reach the hydrodynamic limit where material strength ceases to matter and only density determines the ratio of impactor eroded to target eroded.
although I still have to wonder about a bolt that takes a long time to arrive and can still only kill one tank per rod.
Same here. Formations of tanks could be taken out at once by MIRVing the kinetic anti-tank penetrators. Just send 200 or so down at once, in one drop pod.
I think I prefer atmosphere-penetrating (low-frequency) lasers for hitting moving targets, and kinetics for strategic bombardment of bunkers and factories. Perhaps these antitank bolts might be used for some heavier vehicles, though (like, well, tanks), while using lasers for softer targets that don't warrant spending the mass.
I think we are thinking along similar lines.
Luke:
"However, while it is good for the front part of the impactor to be hard (as long as the velocity isn't too high), you can make the back end out of whatever is the highest density since the back end just adds inertia to drive the front end."
So, a rod of tungsten or osmium-iridium with a diamond or carbon nanostuff ram-skull?
"Formations of tanks could be taken out at once by MIRVing the kinetic anti-tank penetrators. Just send 200 or so down at once, in one drop pod."
This also means the defender can stop 200 of your bolts at once with a single point-defense shot. (And it doesn't need to vaporize the rods, just disable their release mechanism.)
More importantly, how much would one of these antitank bolts weigh? That's what'll determine how many your bombship can carry.
Milo:
So, a rod of tungsten or osmium-iridium with a diamond or carbon nanostuff ram-skull?
Well, probably just a front piece of the same caliber, but yeah, that might work quite well.
More importantly, how much would one of these antitank bolts weigh? That's what'll determine how many your bombship can carry.
A meter long tungsten rod should be able to pierce at least a meter of armor when traveling at 2+ km/s. So lets say our rods are a meter long. You can probably get aspect ratios of about 30:1 without buckling, so we are looking at 3 cm widths for meter long rods. For tungsten, this corresponds to about 14 kg each. Guidance, sensors, aerodynamic control surfaces and so forth are extra.
Albert:
First off, you're talking about moving and/or camouflaging a mirror the size of a small building, which requires a) a powerplant an order of magnitude more massive than its spaceborne cousin (due to greater containment requirements) and b) fairly sophisticated industrial requirements to make (including some relatively rare and/or expensive elements like boron). If you honestly think you could pull that off without me noticing you're moving large stuff around and setting it up, and me hitting it anyways just to be sure, then I deserve to lose on the merits. Oy.
Second, if you have all these ICBMs and nukes and massive lasers, why the hell didn't you build a better space fleet to begin with, and spared your civilians the damage? (Not to mention locking yourself into a dangerous and strategically castrated position.)
Luke, Milo:
15-20 kg per antitank bolt sounds about like what I had in mind. Interception probabilities depend on the specific performance curves of the interceptors used and how high I can get the speed down to the bursting point.
Luke:
Past the hydrodynamic limit on long-rods, is there any point on the curve where the penetration goes back up? If it's purely a matter of density, wouldn't a solid tungsten rod penetrate better than tungsten carbide at that velocity regime?
Raymond:
At the hydrodynamic limit, pure tungsten (density 19.3 g/cm^3) penetrates better than tungsten carbide (density 12 g/cm^3). Tungsten carbide penetrates better at lower velocities where its extreme hardness allows it to erode less during penetration. When the velocity is high enough that the dynamic pressure is much higher than the material strengths, the hardness of tungsten carbide does not matter and tungsten works better simply because it is denser.
Note, however, that when you are firmly in the hydrodynamic limit, your kinetics will also be blinded by their own plasma sheath.
At some point, you will put so much kinetic energy into a penetrator that it will start to gouge a crater that is larger than its penetration length. At this point, penetration starts to go up again. For a 1 meter long, 30:1 aspect ratio long tungsten rod impacting RHA (yeah, yeah, no one will be using RHA, but its material properties are relatively handy) I get that the cratering penetration will start to become comparable to the hydrodynamic penetration at around 50 km/s.
At 20 kg per bolt, a single reasonably-sized ship can afford to carry hundreds or thousands of bolts for only a small fraction of its mass. That sounds pretty good, considering these are only going to be used against heavily armored vehicles.
The main challenge, then, is to equip them with targetting systems capable of homing in on a tank-sized object. There would be two countermeasures: trying to disable the weapon with point defenses, or confusing its sensors with ECM/camouflage/etc.
Raymond:
"Past the hydrodynamic limit on long-rods, is there any point on the curve where the penetration goes back up? If it's purely a matter of density, wouldn't a solid tungsten rod penetrate better than tungsten carbide at that velocity regime?"
As we've established, projectiles that go much faster will get sheathed in plasma, preventing them from getting a lock on their target. Thus, these super-fast projectiles would only be used for strategic bombardment, with kinetic energies large enough to cause an actual explosion. At that point the question isn't "what penetrates better?" but "what causes a bigger explosion?".
That's for orbit-to-surface. For spaceships firing on other spaceships, you can have kinetic missiles that go much faster, and potentially those will be small enough to still not cause much of an explosion, so your question is valid there.
A related question: what materials defend best against kinetic projectiles? I understand that for relatively slow projectiles (bullets, long rod penetrators), hardness is the critical factor - if the armor is harder than the projectile then the projectile will tend to flatten against it rather than penetrating. But what armor works best against hypervelocity projectiles? Yes, you can of course have a Whipple shield, but then you still need to know what the Whipple shield is made of. (Incidentally, I've seen current designs for micrometeorite protection that suggest the use of alternating layers of hard and soft material. The hard layers shatter incoming projectiles into dispersed fragment, which then get cushioned by the soft layers.)
Luke, Milo:
I was just trying to grapple with the quirks of the physics of penetration in general. I suspect the MIRV designs of the antitank pods will closely resemble those used for fights between spacecraft, though, so it's good to have the reference.
Luke:
Tungsten carbide is more like 15 g/cm^3, isn't it? And wow, I thought the inflection point would be a lot slower than 50 km/s. Do we have any data for hypervelocity impacts at that range?
I still question the usefulness of MIRVs. The point of MIRVs is to mount several warheads on a single boost phase. For orbital bombardment (as opposed to surface-launched ICBMs), I think the boost phase is going to be your spaceship's mass driver, not an expendable vehicle.
Milo:
I'll still want cross-range delta-v, and there are efficiencies in the heatshield design (unlike the bolts used for immobile targets, the antitank MIRVs have to slow down quite a bit). Packages can be scaled up or down, too. No reason why we have to pack fifty or a hundred bolts into every missile, but such a weapon would be very nice to have against Byron's tank formations.
Raymond:
You are correct, I had been using the wrong value for the density of WC. It is closer to 16 g/cm^3. This makes it an even better penetrator. I shall have to adjust my notes.
And no, our ability to launch test projectiles is limited to velocities of about 7 km/s (with light gas guns and ram accelerators) or less. As the aspect ratio of the rod decreases, the speed at which cratering becomes important should also decrease. However, I am not aware of any experiments probing this transition.
Even projectiles that don't make use of long rod penetration would still need to be designed with a shape that minimizes mass and velocity losses to atmospheric friction (a serious concern when you're trying to go at ultrahypersonic speeds all the way down), which will likely end up meaning something fairly rod-shaped anyway.
Milo:
Using a high aspect ratio uniformly increases the penetration (or, at worst, does nothing for it) - so weapon designers should go for long thin penetrators when armor penetration is a deciding factor.
Oddly, though, a wide, blunt shape serves to limit the amount of ablation a projectile experiences as it goes through the atmosphere. The amount of front-end heating seems to be inversely proportional to the drag coefficient. This leads to designs that have a wide, blunt shape for surviving re-entry. Of course, this is also effective at slowing down a projectile, so a kinetic penetrator will have to strike a balance between eroding away and being slowed down to ineffectiveness.
For kinetics designed to be used against static targets, you can probably afford to have the first meter or so of penetrator be eroded away (about what you might expect for a hypervelocity tungsten projectile punching through earth's atmosphere) and just make up for it with a very long penetrator that will explode when it hits. For kinetics designed to be used against mobile targets (such as tanks), you will probably have a blunt heat shield that will slow the projectile down to about 2 to 3 km/s before falling away.
Luke:
Would it be better for the ablative nose to be carbon instead of tungsten? (Cheaper, higher sublimation point, lighter?)
Raymond:
Carbon may well be better for the re-entry shield. I am not entirely sure. However, tungsten does seem to have a lower vapor pressure than carbon at temperatures around 3000 to 3600 K (which seems to be why it is used as filaments for incandescent bulbs). This means it will withstand temperatures of 3000 to 3600 K better than carbon in a non-oxidizing atmosphere. Both tungsten and carbon will burn in an oxidizing atmosphere (at least, when heated to temperatures where vapor pressure is a concern), and I really don't know which material will come out on top in this case.
If it's even close to even between the two materials, then carbon wins out by default. Save the tungsten for the parts which will survive reentry.
So any insight on hypervelocity armor?
Luke:
"(or, at worst, does nothing for it)"
Well, yeah, those are what I meant with "don't make use of long rod penetration".
"Oddly, though, a wide, blunt shape serves to limit the amount of ablation a projectile experiences as it goes through the atmosphere. [...] Of course, this is also effective at slowing down a projectile,"
Of course, reentry capsules, including drop pods for your marines, want to both minimize ablation and slow down.
"Of course, this is also effective at slowing down a projectile, so a kinetic penetrator will have to strike a balance between eroding away and being slowed down to ineffectiveness."
Finding the optimal balance could be interesting. Don't expect me to do the math, though.
"For kinetics designed to be used against mobile targets (such as tanks), you will probably have a blunt heat shield that will slow the projectile down to about 2 to 3 km/s before falling away."
Yeah, that sounds good.
Raymond:
"If it's even close to even between the two materials, then carbon wins out by default. Save the tungsten for the parts which will survive reentry."
Well, that depends. If 90% of your projectile is already tungsten anyway, then making the remaining 10% out of a cheaper material won't save much. Might as well use whatever works best. And having the entire projectile made of one material simplifies manufacture and prevents contact faults.
If a significant percentage of your projectile is going to get ablated, then having that percentage made from something cheap is more important.
Milo:
Luke mentioned earlier that a meter's worth of material will be ablated. Off a meter-long penetrator (length on impact). Carbon it is.
Raymond:
"Luke mentioned earlier that a meter's worth of material will be ablated. Off a meter-long penetrator"
The former value was for bunker-busters, the latter for tank-busters. Not comparable.
Tank-busters will be using blunt heat shields that suffer little ablation. Bunker-busters are likely to be somewhat heavier than tank-busters.
Also, speaking of Whipple shields: what material and shape would be best for defeating them (i.e., passing through a thin shield layer and still delivering most of your impact to what's behind it)?
Blunt-nose reentry shields don't get to the heat range where vapor pressure matters - which is why we use carbon-based materials now, and for the foreseeable future. The shuttle uses reinforced carbon-carbon, and SpaceX's Dragon capsule uses a carbon composite as well.
Milo:
Against Whipple shields, a long-rod design is also fairly good. The front end of the rod will be blown off by the "bumper" part of the Whipple shield, but the rest will fly through the hole and smack into the stuff behind.
Even better would be a stand-off design for the projectile. Have a little projectile traveling in front of the main projectile. Then the small stand-off section hits the stand-off bumper of the Whipple armor and blows a hole in it. Then the main part of the projectile flies through the hole and smacks into the stuff behind it. This way, you likely lose less mass to the Whipple bumper.
This works best if you know the thickness of the other guy's bumper armor. Then you can choose your stand-off precursor projectile to be just big enough to blast a hole in it without wasting extra mass. If the projectile is bigger than optimal, you waste mass. If it is smaller than optimal, it doesn't blow a hole in the armor.
Now, getting the aiming right on a stand-off penetrator is likely to be a challenge. If the main projectile doesn't hit that hole that the precursor blasts out, it doesn't get the benefit.
Also, multi-layered stand-off armors will require multi-partitioned stand-off penetrators.
If you don't know the spacing and thickness of the other guy's armor, a long rod may be the way to go.
Backing up a bit
How I would deal with Mars depends on what sort of threat I believe it to be.
If Mars is an annoyance, then the threat level is low and the amount of military preparation I am willing to make will also be low. I might be sending "Impossible Mission Forces" mixed in with tourists and business class visitors to Mars to indulge in a little sabotage, insert computer virii and maybe arrange an accident for important personnel to keep the Martians off balance and prevent them from mobilizing their full potential.
If Mars is an existential threat to Earth, then I will have factories on the Moon churning out high impulse ORION torch missiles with 100 G acceleration potential to hammer Mars, any space infrastructure in orbit and any incoming asteroids with a Gigaton of kinetic energy.
Since Mars can do the same to Earth, my defense forces will be arranged to suit (the best counter-intelligence and security forces against Martian Ninjas, or deep space sensors and interceptors that can hit incoming torch missiles).
In the event there is some sort of intermediate case, I think my interests would be best served by investing the Asteroid belt and cementing some sort of alliance with the colonies around Jupiter and any other deep space locations, securing the Solar high ground and isolating the Martians from the larger economy. They won't be forced to surrender, but they will be less of a threat as well
Raymond said...
moving and/or camouflaging a mirror the size of a small building, I understand it is unmovable. Camouflaging it is trivial though, just make it look like a big rock in a mountainous area full of big rocks.
a) a powerplant an order of magnitude more massive than its spaceborne cousin (due to greater containment requirements)
Due to better radiators, it is much more efficient, though.
But being unmovable, the above isn't exactly a problem. The reactor itself can be placed relatively underground without much problems, just as the power lines. I cannot surely afford to place those gigantic cooling towers most atomic plants have, but hopefully there will be water or ice available.
b) fairly sophisticated industrial requirements to make (including some relatively rare and/or expensive elements like boron) If my enemy is redirecting asteroids instead of attacking me directly, he is either a n00b wasting time to overkill puppies or I have defences he cannot pierce so easily.
If you honestly think you could pull that off without me noticing you're moving large stuff around and setting it up, and me hitting it anyways just to be sure, then I deserve to lose on the merits.
It was supposed to be a hardened *static* defence, just hidden from your view, ready to shoot at the first opportunity do deal serious damage to the attacking fleet.
Second, if you have all these ICBMs and nukes and massive lasers, why the hell didn't you build a better space fleet to begin with,
ICBMs aren't exactly new tech today, and ground defences are by definition easier to build than spacecraft (just as it is much easier to build some artillery emplacements in concrete bunkers than to build a battleship with a decent endurance).
And anyway, see above, if my enemy decides to redirect asteroids instead of attacking me directly, I must have defences he cannot pierce. Otherwise its behaviour doesn't make sense.
and spared your civilians the damage? Why are you bombarding my innocent civilians? You War Criminal! You kill Innocent Women and Children!!!!!! OMG!!!!!
Civilians are generally expendable to a certain extent, unless the political class is really frail (in that case you won't even fire a shot, just a few bribes and the planet is yours).
Some innocent losses with good propaganda from my side can make you appear Evil and make population go Berserk against you.
Just look at 9/11.
(Not to mention locking yourself into a dangerous and strategically castrated position.) I didn't had a lot of choice, you had to attack someone that was weaker than you, and my fleet sucked.
The best I can do is to postpone my demise, and deal you the most possible damage before failing.
But Hell! Any enemy will be *much* more cunning enemy than "shoot until everything is dry".
-Albert
I had another look and noticed that while platinum is soft, osmium actually has much better hardness than I gave it credit for. Iridium is intemediate in hardness.
I also have to say there is a certain appeal to killing people with iridium, given the famous history of iridiumy death from above. At least that's evidence of its availability in asteroid and meteorite mining... My first thought was it would be hard to use space mining for a material that's per definition heavy, but then I realized if you can afford to carry them in your warships, you can afford to carry them in your cargo ships, eh?
Interestingly, according to this, osmium and iridium are actually more common than tungsten in the solar system at large (as opposed to Earth's crust), and platinum is more common than either. I was not expecting that. It also claims that osmium and iridium are about the same abundance, which does not explain why we have an iridium anomaly and not an osmium anomaly.
Of course it has to be remembered that these rods won't be made of pure tungsten/osmium/whatever. They'll be made of an alloy that consists primarily of tungsten/osmium/whatever.
A question for Luke to clarify my thinking: at velocities where cratering becomes the primary damage mechanism, is it fair to say that a kinetic becomes, in a functional sense, an energy weapon? That is, it is doing damage by depositing lots of energy suddenly on a small area, not by punching through due to momentum?
This was the thinking behind that highly unofficial unit, the 'Rick' - that the relevant feature of a superfast impactor is the kinetic energy it packs, not its physical configuration or makeup, i.e. its shell-ness.
Rick:
You've pretty much summed it up. In the cratering limit, the size of the crater depends only on how much energy is deposited and the material strength of the thing smacked by the impactor. Of course, this does lead to details like where a penetrator of a certain velocity could be in the cratering limit for rock, say, but not for steel.
Hey, here's another laser question. Normally blooming is something bad you're trying to avoid, and currently the best answer to it is just "hurry up and finish your shot before it starts". But what if the blooming is what you want, i.e., an electrolaser? How much laser energy would you need to ionize a suitable plasma channel out to a given range?
I imagine that laser warfare would be very vertical - you can hit anything you can see and nothing you can't (no indirect fire). So any high ground is going to be tactically incredibly important. Similarly, anything that provides cover-from-view is going to be important.
Obviously, air (or at least atmospheric) warfare has a role to play. But air tactics in a laser world will be interesting - you don't have to lead the target, so an aircraft over a laser battlefield is going to be very vulnerable. Perhaps laserworld attack aircraft might operate rather like attack helicopters were expected to on the NATO central front, flying nap-of-the-earth..eh..planet and briefly popping up over ridgelines to fire from some distance.
Even if orbit-to-surface lasers have it easier to burn through the overcast, it's going to be much easier for the defenders to just build a bigger laser - if they have lasers, they presumably have industry, and therefore they'll have much more electricity available on the planetary surface than an invading orbiter will have. Also, orbiting spacecraft *orbit* - they're predictable, and the last thing anyone wants to be on a laser battlefield is predictable. If you can see it you can hit it - this implies that the first to fire will win, all other things being equal.
That also implies an extreme form of the "empty battlefield" - being seen, or rather, identified as a target, is instant death, so everyone spreads out, hides, camouflages themselves, and keeps on the move. Also, if you're using a high energy laser, I would imagine that once you fire the thing your infrared signature will spike. So you better have your next move thought out before pulling the trigger.
A civilian on such a battlefield might not even notice there was a war on until they happened to see a big flash.
Key reconnaissance sensor: IR camera with automated monitoring, like a tactical DSP satellite.
Logistics - you're going to need a source of power close to the battle. The Soviets actually built a road-mobile nuclear power station...
Defenders on a laser battlefield will have a few tricks up their sleeves:
Obscuration. Filling the atmosphere with fog, dust or chemical smoke to disperse or absorb some of the beam energy before it strikes the target. This also has the effect of making it harder to find the target in the first place.
Self-Blooming. This is preemptively heating or cooling the atmosphere at random intervals to disperse the beam. The enemy will need adaptive optics to overcome this, another drain on their logistics (building and maintaining adaptive optics is an extra expense).
Metamaterial shields. These use structure to force light through weird optical paths that basic material does not. I would foresee disposable shields placed between the target and the expected laser paths (something like the birdcage armour on military vehicles today)
Ablative shields. Similar in concept to expendable metamaterial shields, except they burn away when struck by the beam.
Swarm counterattack. Once a laser is detected, mass launches of KE weapons are undertaken against the emitter. The weapon either has to try and burn down the incoming swarm, shut off to avoid detection or displace rapidly. This can also be used against relay mirrors.
Cold Plasma. A shield of ionized particles over the surface of the target can absorb and deflect the incoming beam.
Thucydides:
Any weapon laser will need adaptive optics. It is already a sunk cost implicit in the technology.
Metamaterials could be used for concealment, but under the full power or a weapons-grade laser they will not last long.
A cold plasma will not have enough electron density to absorb near infrared or visible light.
This is weird - three times I posted a response to Milo analyzing the power requirements for an "electro-laser" type weapon. Three times it showed briefly, then vanished.
Milo - short story. Unless you can significantly reduce the recombination time, the power requirements look to be in the hundreds of kW to around 10 MW. A significant fraction of this will be delivered to the target. The resulting burns will mean the device no longer qualifies for a less-than-lethal device.
Luke:
I thought metamaterials didn't have the same kind of intensity limits that reflective materials did, due to them changing the configuration of spacetime relative to the incoming photons? Is that trick still much like reflective layers, unable to stand up to intense energies?
Raymond:
Metamaterials are still made of matter, and under high enough intensities any matter will break down. In fact, a problem plaguing many of the metamaterials with a negative refractive index (the kinds that can be used to make invisibility shields) is that they absorb about as well or better than they refract. This leads to significant heating of the metamaterial, shortly followed by the metamaterial no longer being meta (metamaterials rely on tiny structures - electric circuits built into the material on a length scale similar to the wavelength of the light they affect). However, even a fairly transparent metamaterial will still absorb some light. It might end up being as transparent as glass, for example, which is remarkably transparent, but it will still heat up a bit under the irradiation of a weapons-grade laser and once it heats up enough to affect the tiny electric circuits it is made of, it stops working as a metamaterial. (And there are no spacetime tricks, just mini electric circuits.)
Luke:
I thought the mini circuits created the spacetime tricks. But yeah, point taken about the intensity problem.
So still no laser armor.
Well, there isn't any magic-stops-everything laser armor. Carbon nano-stuff will work up to a point, especially past the range where you can focus blaster pulses effectively and the laser acts as a heat ray.
Luke:
"This is weird - three times I posted a response to Milo analyzing the power requirements for an "electro-laser" type weapon. Three times it showed briefly, then vanished."
Yeah. Keeps happening to me too.
"Unless you can significantly reduce the recombination time, the power requirements look to be in the hundreds of kW to around 10 MW."
For what kind of range is that? Also, what is a recombination time and how do I go about reducing it?
Also, what if you're using pulses (for both the laser and the electric shock) rather than continuous beams?
Milo:
I was assuming a range of ten meters. I had also been assuming a Taser-like electro-muscular disruption (EMD): a square wave current of 10 mA and 250 kV, with a frequency of 200 Hz.
A self focused laser filament produces about 1E20 ions per cubic meter. At this ion density, the recombination time is about 10 ns. The recombination time is inversely proportional to the ion density, so if you can reduce the ion density, you can extend the lifetime of the ions and you don't have to keep ionizing as often. The problem is that reducing the ion density also increases the resistance (for the cases I looked at, the resistance of the ion channel dominated the resistance of the human body, so increasing the resistance would decrease the current). To compensate, you would need to make the channels wider (effectively adding more channels in parallel, which decreases the resistance). The minimum channel area to support EMD at ten meters was 8E-7 m^2 for each channel. If you increased the cross sectional area to 1E-4 m^2 (a width of about 1 cm) you could have about two orders of magnitude lower ion density, ionization time would be two orders of magnitude lower, and your power for ionizing the air would drop by two orders of magnitude to maybe about a kilowatt for some as yet unidentified method of ionization that put most of the energy into ionization (perhaps multi-photon ionization using pulses of UV laser light would work). This would still cause surface burns, but while painful they would be unlikely to be deadly.
The state of the art in non-lethal electric weapons seems to be using square waves at around 200 Hz. If pulses would work, we do not yet have any evidence to support it. However, if you can make pulses work, perhaps by delivering 10 ns-long jolts at 200 Hz, you could drastically decrease the power requirements, by a factor of 1E8. Since continuous self-focused laser filaments require about 10 MW to allow EMD, then pulsed delivery would take about 0.1 W - under the assumption that the current remains the same. If you need more current, you need more filaments to carry it, and consequently you need more power.
Luke:
"I was assuming a range of ten meters."
Hmm. Doesn't sound very long, but I guess that's a reasonable pistol range, enough to shoot across a typical room, which is the kind of range at which much police and self-defense action will be taking place. I can see more range being useful, though, especially for police snipers.
Electrolasers also aren't necessarily purely police weapons. You can make them lethal by dialing up the current, and under certain circumstances this may give a better performance than a pure laser. They're also good at destroying electronics. They do have serious disadvantages for military use - they have very visible glowing beams that give away the shooter's position, and they might be stopped by insulating armor (I don't think "just pump in more electricity" works as an answer here, does it?).
"The state of the art in non-lethal electric weapons seems to be using square waves at around 200 Hz. If pulses would work, we do not yet have any evidence to support it."
Well, I figured lightning works as a pulse. Lightning of course is not non-lethal, but I thought that was just a matter of shock intensity.
An electrolaser is essentially a simulated lightning strike so it's a reasonable basis for a model.
"However, if you can make pulses work, perhaps by delivering 10 ns-long jolts at 200 Hz,"
Your PIKL laser was going to have pulses at 1000 Hz, so the (midfuture) laser must be capable of such numbers. So the question is whether your electronics can handle it.
Nice! some posts about tactics too!
:)
Alex said...
I imagine that laser warfare would be very vertical - you can hit anything you can see and nothing you can't (no indirect fire). So any high ground is going to be tactically incredibly important. Similarly, anything that provides cover-from-view is going to be important.
Critical for success is also the ability to switch between High Ground and Heavy Cover friggin fast. Because anything in high ground is going to attract lots of fire.
The reason why most aircraft will become more hovertanks/skytanks than anything else. You do a "jump", you shoot, then fall down again into ground clutter and zip away at frightening low altitude.
Tucydides said...
Obscuration. Filling the atmosphere with fog, dust or chemical smoke to disperse or absorb some of the beam energy before it strikes the target. This also has the effect of making it harder to find the target in the first place. OMG HAARP!!!! ARTIFICIAL CLOUDS!!!! ARTIFICIAL EARHTQUAKES!!! ARTIFICIAL NONSENSE!!!!
Back serious, weather will be a major pain for both sides (weather has *always* been a tide-turner). My home even without any weather control, would be more or less immune to lasers for most of the winter, due to heavy fog, for example.
I've read an article about lasers that were able somewhay to stimulate cloud formation (in laboratory conditions).
Won't stop kinetics, of course, but lasers are screwed.
Luke said...
Unless you can significantly reduce the recombination time, the power requirements look to be in the hundreds of kW to around 10 MW. A significant fraction of this will be delivered to the target. The resulting burns will mean the device no longer qualifies for a less-than-lethal device. Wait a minute, you mean lasers that electroshock people are impossible? (also, what has blooming to do with plasma generation to vehiculate an electrical discharge? I thought they were two different phenomenons)
Also, to resuscitate a little the Powered Armor affair...
Aluminum strong as steel
-Albert
Milo said...
Your PIKL laser was going to have pulses at 1000 Hz, so the (midfuture) laser must be capable of such numbers. So the question is whether your electronics can handle it. There is also the question about its effect over the human body.
Electrical discharge must have relatively precise charachteristics to cause what a tazer causes.
And also, would the pulses on the target drill a hole? (i hope the laser doesn't need to be so focused)
And last, is PIKL laser easier to do than this electrolaser concept?
-Albert
Milo:
You can make them lethal by dialing up the current, and under certain circumstances this may give a better performance than a pure laser.
The big problem seems to be that sparsely ionized channels have a high resistance, so you will be dissipating a lot of power on ohmic heating, whereas heavily ionized channels have a fast recombination of electrons with ions and so you spend a lot of energy re-ionizing the air molecules. If your goal is to deliver damaging energy to a target, electric currents through ionized air seem quite inefficient for the parameter space I have explored so far. That's not to say that there is no way to make it work - just that I haven't found it yet.
they might be stopped by insulating armor (I don't think "just pump in more electricity" works as an answer here, does it?).
The higher your voltage, the more current you can pump through insulating armor. There is a limit, however. At electric fields of more than 3 MV/m air undergoes cascade breakdown (where an electron is accelerated by the field to enough energy between collisions with air molecules that when it does collide, in knocks out more electrons, which in turn knock out more electrons, and so on, until the air is nearly fully ionized). So a high enough voltage will require your channels to be very far apart in order to prevent premature arcing between channels.
High voltages will also drive higher currents in uninsulated people. This can cause lethal heart problems.
Well, I figured lightning works as a pulse. Lightning of course is not non-lethal, but I thought that was just a matter of shock intensity.
An electrolaser is essentially a simulated lightning strike so it's a reasonable basis for a model.
There is more than just shock intensity. If the current goes above about 30 mA, it can cause ventricular fibrillation - essentially a heart attack - in healthy people. So you need to keep the current low. You also want to keep the total power low to prevent electric burns.
So you are looking for the most effective way to temporarily confuse nerves leading to peripheral skeletal muscles with low current and not too much voltage. So far the most effective method found is to switch between no current and full current at around 200 Hz.
Your PIKL laser was going to have pulses at 1000 Hz, so the (midfuture) laser must be capable of such numbers. So the question is whether your electronics can handle it.
The real question is whether 10 ns-long pulses of electric current are effective at stopping a person. The electronics for delivering pulses with this pulse shape and frequency should be simple.
Luke:
"If your goal is to deliver damaging energy to a target, electric currents through ionized air seem quite inefficient for the parameter space I have explored so far."
No, my goal is to kill people with ventricular filibration (or other effects of electric shock), or to kill machinery by overloading its circuits.
Milo said...
No, my goal is to kill people with ventricular filibration (or other effects of electric shock), or to kill machinery by overloading its circuits.
Luke is saying that to deliver enough electric current through the air to do it you would need something much more complex (and maybe unfeasible) than a simple laser beam.
Because the more electricity you want to deliver, the higher the "air's resistence" (thus the more energy you need to waste just to overcome it). That's a red queen's race as rocket's mass ratio.
-Albert
Milo:
my goal is to kill people with ventricular filibration (or other effects of electric shock), or to kill machinery by overloading its circuits.
Ah, okay. This still seems to be inefficient in the parameter space I have yet explored.
Albert:
Wait a minute, you mean lasers that electroshock people are impossible?
I don't think they are impossible - just that they may be impractical and dangerous. On the other hand, I may be overlooking an effective way to make this work.
also, what has blooming to do with plasma generation to vehiculate an electrical discharge? I thought they were two different phenomenons
I am not sure what you mean by vehiculate, but if I am understanding this correctly, you do not understand why the term "blooming" is being used for laser ionization. If so, then yes, as usually understood blooming is a separate phenomenon from ionization (although ionization can lead to heating and thus to blooming. In addition, ionization decreases the index of refraction of the air, which can also lead to blooming).
Yeah, you understood it correctly even if I failed to translate that word.
The correct translation would have been trasmit/carry/spread. My bad.
Anyway, thanks for the explanation. Blooming does not cause ionization, but ionization can cause blooming.
-Albert
Back to the original theme (I think), of this thread...surface warfare in the Plausible Near Future. Ok, two possible options:
1) if space transportation is only modistly expensive, then weapons, armor, ammo, and logistics involved in warfare between combatants on different worlds will use medium infantry and light combat vehicles.
2) if space transportation is very expensive, then combatants will be forced to use very light infantry (think paratroopers), and (maybe) some very light, basic vehicles, like open frame ATVs or motorcycle-live vehicles.
3) if space transportation is cheap, then you can afford to ship mechinized infantry units across the sky to invade someone that you've blasted a hole in their orbital defenses.
Orbital bombardment, unless it is literally pinpoint accurate, will not happen during a ground battle unless it is at long range. The risk of hitting your own people is usually too great.
Ferrell
Ferrel:
Lasers really are pinpoint accurate, and essentially real time. The big difficulty I see with orbital laser bombardment in the heat of battle is discerning what are your own troops, what are non-combattants, and where are the hostiles. One thing you might see is that all weapons will have GPS locators and laser rangefinders. An infantryman could point his rifle at the place he wants blasted, and transmit this information to the orbiting fire support. The laser stations will now know the position of the gun, which direction it is pointing, and the distance to the target being pointed at. This uniquely determines a point in space, and the laser zaps it.
Milo:
A further detail on the electro-lasers I thought of. A taser operating on 250 kV and 10 mA will draw 2.5 kW of instantaneous power. Its time average power is more like 18 W. This indicates it has a duty cycle of 18/2500 = 0.0072, or about 1%. This will reduce the power draw by two orders of magnitude. For filamentation, this is still about 100 kW - too much. For a more efficient way of generating ions, you could get down to about 4 kW - this is beginning to get reasonable. For 1 cm beam channels rather than the very narrow channels created by filaments, you reduce the plasma density and thus the recombination time by perhaps another two orders of magnitude, and you might be able to get Taser-like effects at 40 W. Add to this the 18 W for the electric current itself - except that because of the increased resistance of the ion channels, it is more likely to be around 200 W.
Looking back at a lot of the SciFi shows, planetary invasions by way of cheap interplanetary/interstellar travel does tend to get shut down when that magitech source gets stopped. A primary example is the whole stargate universe. Invasions come by way of the stargate rings. If you bury it or have a protective shield around it, they can't get through and you're pretty safe from invasion. In Star Trek, the transporter magitech was stopped by shield technology... or any other weird phenomenon of the week. BSG took a different approach, the cyclons wanted everyone dead so they basically glassed the planets and only sent in ground troops to make sure nobody was hiding out. If you pulled The Force out of Star Wars, the Empire would actually be a pretty effective invasion force. Of course, if you removed the Force, there wouldn't be an Emperor and thus no Empire.
...600 posts!?
Luke:
"Lasers really are pinpoint accurate, and essentially real time."
Are they accurate enough to hit inside the crater made a few seconds previously by the same laser, from huge ranges against a moving target?
"For 1 cm beam channels rather than the very narrow channels created by filaments,"
There's no reason not to use thick channels, is there? The total amount of electricity I transmit is more important than where I put it, so any spot size smaller than the size of the target should work fine.
"and you might be able to get Taser-like effects at 40 W. Add to this the 18 W for the electric current itself - except that because of the increased resistance of the ion channels, it is more likely to be around 200 W."
That's not bad at all. I think you get similar amounts of power just from standing sunlight.
So how would this beam work (when set to "stun" rather than "kill")? How long do I need to keep it on an enemy?
600 Posts! Wow, and it took me an hour to read through the last few.
Byron and others have mentioned the main problem of invading a planet with ground forces:
If your Space Battleship has punched a hole through the the Planetary Defense System, why not just load some Tungsten rods into the Mass Drivers of Turret # 1 and pull a Yucatan?
If the enemy's PDS is good enough to nail the slugs from SBB Plausiblio then you have the Somme, they can't beat you and you can't nail them.
In short Force Fields, Shields, Screens, whatever are going to be an essential. Yes, they're fairly Magictech but if the Drop Ships and Drop Pods have Force Fields they won't end up like the thousands of british grunts in WWI ;)
Or, you could have the BB get in as close as it could and hope the armor belts were good enough to sustain the beating it's going to take.
Meanwhile the Troop Carrier heads over to the otherside of the planet and starts landing men.
If the planet's defenders divert their PDS to deal with the arriving troops they end taking the full fury of the BB. If they continue fighting the BB you're troops can land pretty much unharmed.
So the planets defender's will need ground troops of their own to combat your's.
Byron made a comment about landing in Canada when the enemy force is on the other side of the ocean. But Heinz Guderian went through France in a week, a furturistic tank is going to be a lot faster and since it can hover it won't have to worry about terrain obstacles as much.
As for aircraft I think something like a VTOL A-10 Thunderbolt would be ideal.
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