A question to our local science fiction buffs: what are some of the logistics of orbital bombardment...

Hama, 1982.

Anyways, most posters here think of orbital bombardment as planet-glassing operations or fire support for invasions. Another paradigm is a series of hit-and-run raids on vital targets, causing strategic confusion and eventual dislocation on the enemy prior to the knockout blow.

It depends on how advanced is the tech.
If your orbital bombardment ends up being the equivalent of an old time 'strategic bombardment', well... there's a reason we don't really do those anymore, they're expensive, wasteful, and what you break in the bombing you can't steal later, if you conquer the country you'll have to even rebuild, and you aren't really hitting any target, unless the manufacturing plants are so fucking big and dispersed that hitting 'anywhere in the city/county/state' would be good enough.

If your orbital bombing is on the level of a tactical bomb run, or a missile strike... well, just like air power trumps everything else nowadays, you've got the new trump card.
Anything in the shadow of your ship is yours to take or break, the only assets that matter are those that
>are space ships and can do tactical bombings
or
>can destroy space ships
and the only reason to ever use anything else is if those ships are expensive as fuck, and easily destroyed by something stupid like a fighter squadron doing a run-of-the-mill bombing run.

Can you detect nuclear submarines from space?

Is there a possibility doing conventional bombing runs but from the upper atmosphere is more practical in certain scenarios?

Flying a fucking star destroyer over your target isn't exactly discreet, you're basically always open to broadside fire. Having smaller craft designed for bombing and nothing else is certainly good, and there's a chance enemy space craft won't all be able to operate in atmosphere well so the chances of interception from starside defenses are lower.

Obviously this is all assuming a somewhat more realistic version of standard sci fi tech, I assume it'd be difficult if not impossible to launch a high-altitude bomber from a stereotypical "battle cruiser" in even low orbit.

I think with gas giants and floating cities in general no kind of bombing is going to be very effective. But seeing as how they're floating I'd bet their capacity for heavy anti-air weaponry is limited, just stroll in with VTOLs and surround the place.

Unless that starship of yours is powered by magic pixie powder or another mcguffin of infinite free energy, it needs at least fuel.

Fuel takes space. It might be very compact depending of the setting but there's still a limited quantity of it.
This means the captain of the ship might consider an orbital bombardment "too costly".
The "either we bomb them to the stone age OR we can all breath during the trip home" dilema.

This is assuming energy-based weaponery.
If you used mass driver or similar matter-based ammunition, the same logic applies slightly differently.
All space used for fuel isn't used for other things like carrying a stockpile of ammunition.
Sure, you can take the nearest asteroid and drop it but that will require a lot of fuel and time.
And time IS fuel... which is limited.

Aside from all that, this user has good points.

What if the planet keeps firing more interplanetary/antiship missiles an laser than the fleet can manage?

Pic related is my go-to answer for this sort of question, although I guess is more in line with your actual question.

Sounds like a good time to call it quits then.

...

Sure why not. Going at this from a 40k/ star war old republic era/ USN in WW II

1. How accurate is the weapon system in a orbital to ground role? IRL we use CEP (circular error probability) to talk about how big of a circle HALF of the shots fired will land in. This leads into the Issue of collateral damage and the needed number of shoot to get a kill, thus...
2. Cost per shot. Missiles and heavy artillery shells cost a lot and do not have a 100% percent hit rate. For orbital weapons systems this is likely the same. Past a point it is just cheaper to do combined arms or even a pure ground operation rather then just blast at it. This point is also linked to...
3. Service life of a weapon system. Thing is that guns can not keep firing forever nor planes keep flying. first example: the 16"/50 caliber Mark 7 ( US WW II battleship cannon) had a barrel service life of 290 shots fired after which the gun needed a new barrel. Replacing it at sea was a royal pain in the ass. second example: during the second Iraq war the US put so much wear on our air fleets that the supplie chain/funds could not keep up. A good part of it is still not combat ready because of that and will not be for years at current rate. The marines only have 71 combat ready F-18s right now and they had to raid museum planes for parts to get to that number. Heck Obama loved drone strikes so much our stocks of hellfire missiles will be at the same level before he took office by around late 2018 at current rate. Lockheed Martin just can not roll said missiles off the assembly lines as fast as they were being fired. The end effect is that over use of a weapon system can cause a strategic window of vulnerability before resupplies and replacement can happen.

> planet's rotation

4. In a energy efficient orbit a satellite over earth comes to the same are once every 45 mins or so. Better coverage means more energy use and thus wear on the ship.

5. If the tech level of the setting. con

.. means that low orbit is needed to have accurate ( I use this term loosely) fire that means the ship is vulnerable. Part of is sensor field of vision is blocked by a planet and enemy's can use the plants gravity to sling shot themselves at the ship. Plus even if the enemy ships come from a different angle then around the plant breaking orbit will slow the ship's acceleration for a bit. The enemy will thus have a better chance to hit you and to chase you down . Sure you could try to sling shoot yourself via the plants gravity, but what if the enemy has more ships on the other side of the plant ready for that. Thus it may be a good idea to either not go into low orbit or strongly limit the time in low orbit if you only have one ship. Or if you have more then one ship having several of them watching for the enemy with only a small number of your ships nuking the planet from orbit. 40k does both of those things.

Damn... the first part is very interesting !!
Especially point 3 : I hadn't realized how short-lived a specific weapon could be.

Yup. To give a idea the 16"/50 caliber Mark 7 as to were it was on service life the early and weaker 16'/45 mark 6 had a serivce life of 395. Germeny and french cannons were about the same as the mark 6, but the Japanese... The big 46 cm Type 94 guns of the Yamato had a effective service life of about 160 shots.

Smaller 8 inch guns had service lifes of 400 to 600 based on how advanced the design was. For field artillery I believe 1200 to 1800 was a common range of service life.

Now for a subject that is more linked to the thread, railguns! The USN is working on making them a thing and is talking about what its possible service life will be. The first number that was floated was 1500, then 1200. Right now they are keeping with a likely service life of 600 to 800 shots fired, but that may still be a hopeful number.

The aliens in the book Footfall did this. Mass bombardment of major military targets was followed by on-call tactical support for their ground troops. Overhead imagery helped them identify and eliminate human military initiatives.... but it didn't catch everything.

You can't hold or use ground without ground troops. There are limits to what you can do with just satellites and signals intercepts.

Also, orbital bombardment CAN be city-flattening superguns. Or it can be lasers that hit the ground with no more force than a rifle bullet. The sci fi extreme version of the SDB. Satellites can already spot and track individuals in real time. You COULD pop a whole building to get the guy inside... or wait for him to come out and dial down to a dozen kilojoules and sit him in the open.

So holding and using orbit is an incredible, overwhelming advantage. But it's not everything. Just like air power, you need assets on the ground to work in cooperation with your orbital forces.

The actual tactical strikes would be done-- still from orbit-- by very low orbit gunships or satellites deployed by the main ship. The main ship is mostly armed for space warfare, though its weapons can help out in a pinch. Square-cube law, the volume you can put support vessels into will grow faster than the surface area you can mount guns and radiators on. Loiter times will be excellent, especially if they're unmanned. The case isn't so clear cut with projectile weapons but it's still the smart play IMO.

They'd be coordinated by the mothership, but it would stay in the comparative safety of high orbit. This also gives you global coverage for both strikes and surveillance.

Space fighters aren't super realistic, at least not as they are portrayed in sci-fi. I'd expect air assets to be deployed with the ground troops. Yes, you still need ground troops.

Service life and maintenance are still issues, but directed energy weapons like particle beams and lasers seem like they'd have a much shorter logistical tail. There's the thermal problem, but if you have orbital dominance or if you fire from dedicated ground attack satellites that's not such a big issue.

I see a case for missiles and even guns, but not as a primary weapon.

You'd also want some kind of countermeasure against orbital-denial tactics, like gravel fired into retrograde orbits. If your setting doesn't have shields, this can do considerable damage, especially to mirrors, radiators, and other exposed components.

Orbital dynamic mean that the windows in which the spacecraft can provide fire support are incredibly predictable and the longer they last (up to constant coverage) the higher the spacecrafts altitude is effecting accuracy. (High resolution spy satilites function form fairly low orbits, geostationary spy satilites are usually for radio interception.)

Fucking this.
Heat capacity of a planet is so great that in any realistic scenario it could be armed to the teeth for a fraction of costs of a fleet.

If you have scanners good enough. Though every scan would take out a portion of the marine life.

Heat capacity is small consolation when you're trapped on a fixed orbit with no way to change it. The first c-fractional weapon that hits you basically knocks you out of the fight.

Well it's all very complicated, God forbid something goes wrong during development and you lose the ability to conduct orbital bombardments and all you can do is launch obibital bombardments.

It sort of depends on your war goal. For all practical purposes, the american wars in Iraq and Afghanistan were orbital bombardments. But we cared about efficiency in ammo expenditure and thus had a lot of trouble actually hitting our targets because we didnt have the ground intel to find them. If you can afford to glass a continent (which probably means sailing home with empty ammo dumps) the calculatikn probably changes.

Most defensive systems have this advantage. What they lack is strategic mobility and initiative. If nothing else you can beseige them.

>tossing RKVs at a habitable planet
>trashing anything that made it valuable to you
Fucking Belter trash, go bang rocks together somewhere else

>lives on a giant floating target
>gets mad when he gets shot
planetfags. Not even once.

>besiege
>a planet
If the planet can produce food then the besiege can last for decades if not centuries.

Depending on the state of the setting, it might be possible to demand tribute from its cities/nations/governments in exchange for not smashing urban areas with bombardment. There are probably better long term arrangements, though.

The idea isn't to starve them into submission, but instead to isolate them from expanding into their solar system and beyond. I suppose the word I'm looking for is a policy of containment, rather than a siege.

If you have C-fractional weapons, you don't need spaceships.

Very curious as to how you intend to get people and goods from point A to point B intact with C-fractional weapons but no spaceships.

user, if you have c-fractional weapons, the thing you don't need is planets. Anything that is in a fixed orbit is a deathtrap.

Ships, on the other hand, you need a ton of.

Why do you assume the planet would be self-sufficient?

Anyway, even if, imagine for exampe that there is megalopolis and you can starve THAT to death by destroying transport infrastructure, ships and so on...

If you have c-fractional weapons, you don't have ships, you have Dyson Spheres.

If the other guy has c-fractional weapons, you don't have dyson spheres.
Because they've all been blown up.
With c-fractional weapons.
Like all your static emplacements.

Stop me if this is too fast for you.

>I assume it'd be difficult if not impossible to launch a high-altitude bomber from a stereotypical "battle cruiser" in even low orbit.
This reminds me of something I was wondering about - would having atmospheric/semi-atmospheric aircraft deploying from a ship in orbit to do their missions make sense?

Having your big starship safe in orbit "dropping" the vehicles to the planet where the fighter/bomber can do its job efficiently, accurately and without risking your main ship, and generally the whole thing acting like a modern day aircraft carrier and carrier wing, would that work transplanted to space, do you think?

I know 40k does it with their Lightning atmospheric fighter (which also deploys from ground bases) and the Fury starfighter proper, TIE fighters do it in the newer films.

Could even justify "fighters in space" - they're not FOR space fights, they just need to be able to get back to the carrier and thus have engines that work in space. Deploying them in a space battle would thus be a last-ditch move, and the fighters could look sleek and aerodynamic.

Seems cool to me, though getting out of the gravity well if you get hit would be a huge bitch (not that crashing into the sea is much fun for IRL carrier wings)

What if you keep bombarding water supplies until they are all vaporized or radioactive?

The primary benefit fighters give is their range of striking. They let you give quasi-artillery support to troops far beyond your artillery umbrella, or take out targets beyond the range of your ground guns.

Once you're in orbit, you're already the best artillery ever. Throwing kinetic impactors at the ground should be relatively cheap, retain full guidance capabilities, and be a shitload easier from an engineering standpoint than making a space-ground-space ground support craft work.

You could use fighters, yes. It just doesn't get you anything if you're already in orbit.

>retain full guidance capabilities
On a kinetic impacter?

Also sometimes you might not want to flatten a city, as this thread has mentioned several times.
Having a squadron down in the planet's atmosphere gives you a lot more flexibility with what you're deploying and a much shorter response loop if you're supporting troops on the ground.

I do agree that it'd be a bitch to make the planes though, even when compared to orbit-to-ground missiles

>On a kinetic impacter?
Sure. It's basically a bomb dropped from a really high airplane, so put a sensor and some fins on it and voila, guided impactor.

And impactors aren't city killers. Their yields would be on the order of our bigger air-dropped bombs nowadays unless you accelerated them heavily.

>Having a squadron down in the planet's atmosphere gives you a lot more flexibility with what you're deploying and a much shorter response loop if you're supporting troops on the ground.
Not really. Things to consider - a THOR-like rod drop does not need to slow down to cruising speeds, so it'll deorbit much faster than a fighter wing. So assuming you haven't launched the wing preemptively, the impactors will reach the target first.

If you have troops on the ground, you probably have airfields to host planes, which will be much cheaper and easier to provide air support with.

If high energy lasers are a thing, then planes are probably obsolete.

>If high energy lasers are a thing, then planes are probably obsolete.
If the enemy has high energy lasers, you're not safe even remotely near orbit.

>but directed energy weapons like particle beams and lasers seem like they'd have a much shorter logistical tail.

Your logistics would be in the acquisition and exploitation of focusing crystals and esoteric fuel sources.

Explosives are pretty easy to manufacture, but lasers and other energy weapons - at least at the scale we're talking - require a shit-load more investment to make them happen.

They typically have longer shelf lives, yes, but IF something gets damaged it is usually much more expensive to replace.

Esoteric fuel sources? Focusing crystals?

If we're talking solid state lasers like DoD is rolling out right now, the "fuel" is a battery of capacitors and a hydrocarbon combustion powerplant. And focusing is accomplished via mirrors.

If a dm wants a logistical train for energy weapons, then sure you can make one up, but it's not necessary and not needing it is one of the technologies' selling points.

If you want game balance, assume that it has higher maintenance costs.

>assuming you haven't launched the wing preemptively, the impactors will reach the target first.
Oh, yeah I was talking about a pre-emptive launch or supporting flight, rather than as a strike - but again, you go straight to the thor shot.
That's what I mean about flexibility - dropping block-busters is alright, but what if you need to hit different types of targets?
Enemy vehicle squadron?
Counter-battery fire?
Danger close?
Enemy aircraft?

I'm not saying they should be the only weapon, or even the primary one, but there's a reason monitors and arsenal ships aren't much of a thing but everyone and their mother wants a carrier

The energy source of the future are Proton-sized Black Holes synthesised with the use titanic lasers powered by Dyson Spheres. Kugelblitz, Ball of Light.

At that size, the Black Hole slowly disintegrated for a couple of years while producing tons of energy (Hawking Radiation) and can easily power ships to reach near-C speeds.

If you have secured the air superiority to perform an orbital bombardment without losing your fleet, then there's no need to do the orbital bombardment.

One exception: the planet is contaminated with some sort of biological contamination that absolutely 100% cannot be allowed to move off world

You need Dyson Spheres to produce the energy necessary to do that. You won't find micro-black holes to farm around.

You don't need c-fractional weapons to blow up dyson spheres, though.
I was being factious, and pointing out that "surrounds a star" is a giant fucking target.

In a WMD-hot war between two comparable powers at that scale, static emplacements are just deathtraps.

We already make proton sized black holes in our particle coliders and they decay in the tiniest fraction of a second.

>We already make proton sized black holes

No, we don't. You would need far, far more energy to make a Proton-sized one. You need a Black Hole with a mass of 600 billion kg or two Empire State buildings. Such a black hole would radiate nearly 160 petawatts, which is the equivalent to 10,000x today's world power consumption and it would last for 3.5 years.

So are ships, or are you going to evade every five minutes? Besides the reality is that a real-life Dyson Sphere would look more like a swarm of satellites, trillions of them orbiting the star in multiple orbits.

That is honestly and unironically terrifying.

>I hadn't realized how short-lived a specific weapon could be.
It does seem like a short life, and in a way it is. But on the other hand 290 16" shells is one hell of a lot of fire power for the lifespan of a barrel.

For reference here is a picture of the size of the shell. They weighted in at 2,110lbs (960 kg) and a full power shot used 700lbs (320 kg) of propellant. Looking at it that way, 290 such shots seems a little like a technological miracle.

So, one 300 billion kg of antimatter + 300 billion kg of antimatter to make a Kugelblitz (without taking the loss of efficiency of the lasers into account).

after skimming the thread there's one I didn't see.

Area coverage

look at this map, if it takes one bombardment capable ship to cover one square (perhaps specifily built ships could cover 2 or three squared) then that's 180 ships needed to fully bombard that planet, and those are BIG squares.

obviously some squares may not need bombarded but that's a lot of ships. A modern CBG is like 8 ships IIRC, so even i you doubled it's space equivalent to 16 ships, that's just enough to cover one line at a push.

Orbital weapons could hit any point on earth, given enough time. A single ship could theoretically cover all the major landmasses, albeit not at the same time, as it orbits around the planet.

You definitely want more for quicker response times, but range concerns are different from orbit looking down than they are from the ground looking out.

In what universe would a planet be valuable once someone has space infrastructure?
The planet is being sterilized to ensure no competing life can emerge.

Dyson spheres are more accurately swarms and they are not static emplacements, not are they made of static emplacements. They're most likely to be made of trillions of O'Neil and Mckendry type habitats, vast sheets of solar panels, and the occasional artificial gas giant for fuel storage. You can blow holes in the sheets, take out a couple habs, and maybe cause temporary issues with a fuel tank, but to take out a Dyson swarm with RKVs you'd need to fire a Dyson swarm worth of RKVs at it, meaning one on one neither of you have dyson swarms any more, congrats. You would need a massive head start in stellar colonization to have a sufficiently high multiple of dyson swarms more than you opponent to win such a war. Which the fact that we can't see any dyson swarms makes unlikely. Then theres the problem that by the tin you see the others guys first swarm hundreds more will have been started and many will be nearing completion (assuming thousands of light years apart since we haven't seen any alias closer).
For all functional purposes dyson swarms are immune to RKVs, in the same way a planet is immune to .50 calibre rounds, good luck firing enough to do appreciable damage. Planets on the other hand are giant easily predictable targets.

As for the original question of OPs, if you had a starship and you want to bombard the planet I think the main annoyance would be your engine pushing you away from the planet as you're torching it, so depending on the strength of your engine you may have to fire for a bit, then wait for the gravity to pull you back closer and repeat. Not vessels following the laws of physics is going to have a weapon more powerful than its engines, bar pseudo engine ships like solar sailers. And even they have a big fuck off solar death ray assuming passable sail control.

Except in orbit is the one place where kinetics beat lasers, as both have a hard time going up through an atmosphere, but one has a significant advantage going down.

Also, if your ships are big enough they might just be able to eat the thermal flux without damage, radiating it out from areas that aren't under attack.

REMOVE OPA

You're thinking black holes that start as protons and are so small and last for so little time I don't know the proper words to describe it. He's talking about black holes that start with the mass (in energy form) of a small hill or mountain and end up about the size of a proton when in black hole form.
Any ships powered by one would need a way to jettison it at the end of its life, and they would be one way vessels because the black hole will only last so long and without perfect gamma reflectors it's a use it or lose it power source with no throttle.

No, a small fraction of a Dyson swarms output stored I'm a useful and portable form to allow for relatively quick interstellar travel.
In theory once you can create a kugelblitz it is a much better form of energy storage than antimatter, and oddly enough much safer. In theory. Black holes are still sketchy.

The feasible methods of detection from orbit at the moment are analyzing wave patterns that a moving submarine leaves in its wake, and some less effective methods like infrared radiation detection. USA, Russia and China probably have some capability to detected underwater submarines at the moment, but subs are likely to be undetectable in the right conditions, for example if they're far from shallow coasts where they'd have to stay near the surface, they're moving slowly enough not to cause meaningful disturbation, the ocean floor's features are largely unknown by the satellite operator, or if there's a storm or rain on the surface.

atimes.com/atimes/China/LE13Ad01.html

Though you can build much, much bigger lasers on a planet

But a planet cannot dodge and it's location is easily predicted. Lasers usually functionally outrange kinetics but against a planet kinetics have infinite range, merely a variable delivery time.

A planet seems like a stupid choice for your lasers. The only thing it's got going for it is the resources are easier to ship, otherwise you can build bigger in space without worrying about weight concerns in zero-g. Other than that lasers travel better in a vacuum. Firing from your own planet will weaken your weapon as it travels through the atmosphere. And then of course you haven't made your planet the primary target. Honestly venting excess heat may be your biggest problem, but it's doable.

Send a lightsail-driven Von Neumann constructor to build a downloading terminal, then ship your people to it in data form on a laser.

Overall, orbital "superiority" is wildly overrated. If it's a soft scifi space opera where energy is cheap enough for people to own SSTO shuttles, a measly ~10km/s delta-v advantage on your missiles is tiny.

If it's hard SF, the heat sink capacity and armor and mass of a planet >>>> the "advantages" of being non-static.

Functionally, there's a "death zone" around any lasers. As kinetics enter their range, the lasers start shooting them down. The more space a kinetic has to cross, the more time a laser has to burn it up. Against effective lasers, kinetics are only useful at point-blank, where the lasers can't burn/explode/deflect them in time.

This already factors in armored (to prevent soft-kills like burning out the camera and datalink), smart cluster kinetics delivered by ICBM-size bus. There's a place for kinetics in ship-on-ship knife fight range in planetary orbits (where 99% of fighting would happen anyway), but if lasers start going over the half-gigawatt mark, kinetics are useless even there.

Unless you're going to discoball your entire planet your coverage zone hardly be total. Lasers burn through focused intensity, they're pinpoint, so you still have to have a pretty damn good detection system. This is where most people pull out the RKV which, honestly, I can take or leave. There's also laser resistant materials and you can make projectiles that are extremely heat resistant and don't rely on warheads (Rods from God approach).

Feels like lasers are hardly the best point defense for a planet, especially when you're building them on the surface.

>non-external reasons that could stop it from being the answer to any ground based issue

> It's hard to hit stuff at that range.
> It's hard not to destroy the whole city and not just the building you want.
> Ships in orbit are expensive. Troops on the ground life off the land.
> Large impacts/nukes/laser strikes tend to fuck with the local weather patterns after a while.
> Someone WILL find a way of shooting back.
> You can't just obliterate half a block of downtown because a bunch of people are protesting about equality.
> If you annihilate blocks to quell riots, nobody will sign up to be police for fear of being annihilated.
> You run out of population to bombard and infrastructure to wreck after a few years.

Diffraction applies at long range.

That's why hard SF spacecraft often need armor. Armor isn't very useful vs close-range kinetics or mid-range lasers. But it keeps "dodging" spacecraft at extreme range (a lightsecond+) from being softkilled by lasers anyway.

"Discoballing" a planet desu is cheap and easy compared to building spacecraft. Even theatre-scale hundreds-MW range anti-air lasers reach up to the mid orbits. Planets have no worries about heat or mass or volume. They can build bigger reactors, which in addition to their pure size are also inherently more efficient. They can play "whack a mole" with one laser in a bunker redirected to a dozen different camouflaged, armored mirrors.

In a true "space war" in most hard settings, spaceships are irrelevant because planets are always there first, with the most stuff.

At the high end there's Dysons and at planetary scale the Hall Weather Machine (a swarming, atmospheric based solar powered phased array laser with petawatts of power).

At the low end, planets can use extremely simplistic armor. Mirrors are useless against lasers because of no perfect efficiency, but a foot-deep titanium-dioxide doped pool of water on the roof of any target provides a continually regenerating, 99% reflective, ablative armor that can stop >20MW impacts - for the price of some plumbers and painters supplies.

Ideally ofc the best of both worlds (for offense, atmosphere is a good ablative defence) would be mega lasers mounted on an airless moon.

Diffraction is a factor in atmosphere period. Lasers are just superior in a vacuum, hands down, no contest.

You seem to be handwaving away the problems of power generation and cooling but you still need to effectively apply this to your giant laser weapons. For instance how long can your laser fire at max intensity before it threatens to burn itself out and you're forced into a cooldown cycle? Cooling is EASIER on a planet, but not instantaneous and problem free. Meanwhile your enemy could just fire hundreds or thousands of warheadless tungsten rods at you letting gravity provide the bulk of the acceleration necessary for the big kaboom. If they have time, resources, and your star system has a handy asteroid belt they could divert rocks your way. Large scale EM accelerators and iron cored asteroids and plenty of handy ammunition around them as you sit there trying to turtle on your planet as much as possible.

Ammunition. That and if you're busy shooting a planet you can be blindsided by any forces trying to relieve the siege.

That's all I can think of.

Your lasers are going to be weak at limits of their range, user, so who cares if they can reach mid-orbit. You need to look for their maximum effective range, which will naturally be different depending on your target. Meanwhile the closer the target is to your planet the less of your laser defense you can effectively train on said target from other laser weapons on that side of the planet.

Honestly lasers suck. You'd be better off reinvesting in particle beams and building some underground particle accelerators, really putting your real-estate and power generation into some decent benefit.

Depends on the ammunition. If you really want your enemy dead shooting them is fun and all but is it really the most efficient use of your time? Saturation bombing of upper atmosphere with high levels of radioactive materials to poison them, or if you're fully versed in the biology of your enemies there's always engineered biological warfare. Sure they can survive in bunkers but if that is their victory condition it's sad when they've already lost the surface of their planet for generations, meanwhile their enemies are still up there with as much time as they want to devise means of detecting your bunkers and busting them.

>orbital bombarding a planet-wide city
>implying it wouldnt take at least 500+ ships and several days to do it

You could always sneak attack it. Artificial meteor with a canister of death concealed inside. If they detect it but believe it is small enough to just burn up in atmosphere they aren't likely to train any anti-air on it. Unfortunately the canister is designed to survive reentry after the rocky camo has burned off.

From that point it depends on the payload. Chemical or radiological are weak and non-propgating. Biological could be fun, but for maximum return of death on investment nothing beats a grey goo scenario.

That depends on what they're firing at you.

Realistic Thor rods do damage in the 10-20tons of TNT range, and take slightly longer to deorbit (which, remember, requires acceleration) than a conventional ballistic missile. They are also engulfed in a plasma sheath for most of that time, which blinds guidance (theoretically possible to overcome by making the sheath itself an RF antenna, but extremely impractical).

"if they have time and resources" is wishful thinking. The planet has more of both, and if we're using autonomous manufacturing capable of incorporating simple integrated circuits necessary for course correction, it could have turned the asteroid belt into a von-neumanned defence network long ago.

If you have the magically efficient drives (like in the Expanse) needed to make kinetic kill vehicles useful at interplanetary ranges, then gravity wells don't matter! Earth to low orbit is about 10km/s. Those drives have delta-v in the high hundreds of km/s. Throwing rocks at attackers is advantageous when you're atop a well, but with hundreds of km/s dv, it's like both sides are using guns instead of throwing rocks.

There's also the Kirklin mine dynamic. Relativity means that from the defenders' perspective, the interplanetary thor rod might as well be stationary, vs the defending kinetic clouds. They are very easy to destroy, or simply deflect.

The beauty of lasers is damage at all ranges. Ideal range may punch through a ship, but at long range a laser can still fry the surface and force a ship to button up its sensors - at low dv, this can go on for days or weeks of melting armor away one millimeter at a time.

Particle accelerators are short ranged and hard to redirect. A laser can be on the far side of the planet and still fire through expendable mirrors popped up into the stratosphere or low atmosphere.

well C is already on the other side of B, so you just need to backtrack a bit

>As kinetics enter their range, the lasers start shooting them down.
>if lasers start going over the half-gigawatt mark, kinetics are useless even there.
I'm going to have to stop you right there user.
Lasers are well and good against things like missiles or ships where you have a relatively thin hull and puncturing said hull exposes either fuel (in the case of a missile) or vents an atmosphere (in the case of a ship). But against a solid slug kinetic a laser isn't going to have much effect, even at ridiculous power levels. Look at that is a ton of solid metal that in atmosphere is traveling at 800+m/s, even if we assume it is traveling at the same speed in space, that doesn't give your laser much time to vaporize that mass. Yes it needs to vaporize it, because if you just melt it then you still get hit with a ton of molten metal moving at 800+m/s (that would cut down on penetrative power so there is that).
Point is laser PDS is good against missiles/torpedos, but not so good against kinetics, if the kinetics have either large mass or high speed (since that would cut down dwell time), or a suitable mix of speed and mass.

Basically this.

A well prepared planet is just a much bigger, immobile ship.

Why are your Thor rods relying on guidance? Or bothering with any onboard systems at all? Damage is variable depending on the size of the rod and how long it takes to reach low planetary orbit for their gravity boost depends on what thrust you give them. You could do detachable booster rockets or iron bands/iron core or even a thick enough iron coating for rail acceleration.

If your enemy is in a ship they don't really have to come within your pitiful laser range.

And honestly the true wishful thinking is that any advanced race capable of weaponizing their asteroid belt is going to still be relying on bunkers and dinky lasers for their planet. What, did they waste their time and budget on the asteroids? Especially when you're talking smack about particle beam range when your lasers are just warm piss at mid orbit.

I don't know, man, I can't figure out this user. He's not thinking outside the box enough focused on planetary power generation, which is all well and good but really small time. Any decent space based culture will be looking towards using gravity power generation from their moon(s) and at higher ends a dyson array of solar collectors around the local star. That pretty much solves your power requirements for just about anything you'd want as long as you can solve the issues of beaming the energy around and storing all that lovely juice. From that point on your available weapons options are enormous.

The problem is when your laser doesn't actually do damage at most of those ranges. Lasers are projected energy weapons that rely on heating the surface of a target but the drop off in laser intensity fired within an atmosphere hardly makes it the ideal place for lasers. If your target has invested in armor that is extremely effective at dealing with heat you may not achieve the melt or heat penetration to vulnerable systems that you crave. Now you've left yourself open to .

Furthermore I don't see why an enemy ship would need to rely on only its own sensors when they could deploy a number of disposable satellite probes. These can actually be pretty stealthy if they don't rely on maneuvering rockets to position themselves and only use passive detection, cutting down on any heat generated by their internal systems. Their effectiveness at providing additional "eyes" is through the number used as opposed to needing to reposition them. And that's just a sloppy up close and personal approach. Frankly they could easily rely on remote long-range sensors sending in a stream of data. Why good is you trying to blind the ship when it isn't even the thing "looking" at you?