Orbital Fighting [Star wars is a good example]

[Rune]

Well guys, it seems we are in distinguished company here! Seriously, Nyrath, I've spent a lot of hours on your page, and it is bookmarked for future reference. Your drive table is what I use as isp reference. Keep up the good job!

Rune. When you think about it, it makes sense you would play this game.

[Rune]

Yes, but in space battles, presumably they would be in approximately the same orbit. Otherwise it would be like people in wars on Earth dropping their troops off to fight with each other in seperate countries and telling them to hike towards each other. It would require a lot of energy and simply be wasteful, and thus it's something nobody in a war would do.

Actually, space battles would probably be high-speed interceptions, preferably on orbits retrograde to each other. Considering how little sense armor makes (one shot is usually one kill, even with kinetics), and that computers can make an eternity out of one second, staying on the same orbit would guarantee a very bloody outcome with only one side walking away, and very badly mangled at that. You want to have the chance to avoid the confrontation if things are looking to go the other guy's way, and regroup/run away before the next pass. 99% of the time maneuvering/targeting/preparing, then a few milliseconds of stuff blowing up, then count your losses and get ready for the next one.

Rune. The old hurry up and wait thing.

[Kerbface]

Actually, space battles would probably be high-speed interceptions, preferably on orbits retrograde to each other. Considering how little sense armor makes (one shot is usually one kill, even with kinetics), and that computers can make an eternity out of one second, staying on the same orbit would guarantee a very bloody outcome with only one side walking away, and very badly mangled at that. You want to have the chance to avoid the confrontation if things are looking to go the other guy's way, and regroup/run away before the next pass. 99% of the time maneuvering/targeting/preparing, then a few milliseconds of stuff blowing up, then count your losses and get ready for the next one.

Rune. The old hurry up and wait thing.

Okay, but if you're going with the split second computer battle thing, you don't have to worry about thrust at all, there would be no time to make meaningful changes to thrust, you certainly wouldn't be reversing orbit (which is what the comment I originally replied to was talking about).

[Person012345]

One could assume they have some sort of anti-gravity drive, which should theoretically allow them to negate inertia to some degree as well.

As for "would they have to stop all forward momentum to change course", no. All they would have to do, much like you do when docking, is alter your speed relative to another object. For example, to make a pass on a battleship, turn around and come back at it, one would not need to reverse orbit, only to slow down relative to the battleship. Then the battleship would come to you (of course, there is no distinction between you going to it and it coming to you).

Edited May 1, 2013 by Person012345

[Kerbface]

As for "would they have to stop all forward momentum to change course", no. All they would have to do, much like you do when docking, is alter your speed relative to another object. For example, to make a pass on a battleship, turn around and come back at it, one would not need to reverse orbit, only to slow down relative to the battleship. Then the battleship would come to you (of course, there is no distinction between you going to it and it coming to you).

My point exactly.

[Fractal_UK]

Considering how little sense armor makes (one shot is usually one kill, even with kinetics), and that computers can make an eternity out of one second, staying on the same orbit would guarantee a very bloody outcome with only one side walking away, and very badly mangled at that.

I'm not sure that armour is quite so pointless as you suggest though. Yes, a very high kinetic weapon is likely to do severe damage to anything it impacts but such weapons have to actually connect to do anything. A realistic space combat will be decided in almost all cases by the ship with the longest range guns. Aiming at and hitting a target at extreme ranges in space combat is not a trivial problem given that you're constrained on how quickly you receive information by the speed of light.

Having no armour practically invites an enemy to strap a laser on to their ship with just enough power to cook all of your exposed systems, even with ludicrously fast kinetic weapons, a laser will still hit the target orders of magnitude faster. Also, while armour would provide little protection against a direct hit by a nuclear weapon, explosions do not propogate through vacuum very well meaning that armour could quite comfortably provide reasonable protection against proximity detonation of nuclear weapons.

My expectation would be that space-battleship designers might adopt an armour policy similar to the "All or Nothing" model used on naval battleships of the 1st World War era, i.e. you heavily armour anything that the destruction of which might cause large secondary explosions or that might result in the battleship ceasing to function and leave everything else unprotected. With decent protection from lasers and proximity explosions, you have made your opponent's job much more difficult.

[Rune]

I'm not sure that armour is quite so pointless as you suggest though. Yes, a very high kinetic weapon is likely to do severe damage to anything it impacts but such weapons have to actually connect to do anything. A realistic space combat will be decided in almost all cases by the ship with the longest range guns. Aiming at and hitting a target at extreme ranges in space combat is not a trivial problem given that you're constrained on how quickly you receive information by the speed of light.

Having no armour practically invites an enemy to strap a laser on to their ship with just enough power to cook all of your exposed systems, even with ludicrously fast kinetic weapons, a laser will still hit the target orders of magnitude faster. Also, while armour would provide little protection against a direct hit by a nuclear weapon, explosions do not propogate through vacuum very well meaning that armour could quite comfortably provide reasonable protection against proximity detonation of nuclear weapons.

My expectation would be that space-battleship designers might adopt an armour policy similar to the "All or Nothing" model used on naval battleships of the 1st World War era, i.e. you heavily armour anything that the destruction of which might cause large secondary explosions or that might result in the battleship ceasing to function and leave everything else unprotected. With decent protection from lasers and proximity explosions, you have made your opponent's job much more difficult.

Hum. You acknowledge the targeting issue, but you don't explore the ramifications: if I blind your ship's sensors (which have to be unprotected if they are to work) with a high-power laser, how are you going to connect your kinetics/lasers? How are you going to get out of the way of mine? And at orbital velocities, there is no such thing as "low" kinetic impacts, even motes of paint make decent projectiles. As to nukes (which make very poor space weapons IMO), they kill by radiation up there, so they actually propagate much better than in atmosphere, and armor at less than tons per square meter is useless.

Rune. Still a case of one shot, one kill.

[Xeldrak]

I'd say that the best weapon for space-warfare are self-guided missiles. Direct energy is unpractical and simple kinetic weapons to easy to dodge if you are fighting over hundreds of kilometers. Also just think of the recoil of a Battleship-class gun on a spaceship - the mounting for these guns would be massive, otherwise they would rip the ship to parts - and heavy stuff is be avoided. So, selfguided missiles - no recoil to handle and even at long range they are accurate. With sufficienty advanced computers on board they could even go after vulnerable parts of the enemy ships like sensors, engines or radiators...

[nyrath]

Thanks!

Forum says (You must spread some reputation around before giving it to Rune again)

[nyrath]

Aiming at and hitting a target at extreme ranges in space combat is not a trivial problem given that you're constrained on how quickly you receive information by the speed of light

Yes, light speed lag does complicate things. It can put an upper limit on the maximum percentage chance to hit the target. It depends upon the target's cross section, the target's current maximum acceleration, the range to the target, and the velocity of the weapon you are firing at the target.

Equation here:

http://www.projectrho.com/public_html/rocket/spacewardefense.php#id--Evasive_Maneuvers

Also, while armour would provide little protection against a direct hit by a nuclear weapon, explosions do not propogate through vacuum very well meaning that armour could quite comfortably provide reasonable protection against proximity detonation of nuclear weapons.

That's what I thought as well, until I learned about the dreaded Casaba Howitzer. Nuclear detonations do have their destructive potential fall of drastically with range, due to the fact they are radiating all their destruction spherically. Inverse square law is a harsh mistress.

But what if you could make the blast radiate in one direction. A nuclear shaped charge. This changes everything. Among other things is can make armor more and more pointless.

http://www.projectrho.com/public_html/rocket/spacegunconvent.php#id--Nukes_In_Space--Nuclear_Shaped_Charges

I'd like to find more details about the casaba howitzer, but after fifty years the blasted thing is still classified.

[nyrath]

I'd say that the best weapon for space-warfare are self-guided missiles. Direct energy is unpractical and simple kinetic weapons to easy to dodge if you are fighting over hundreds of kilometers. Also just think of the recoil of a Battleship-class gun on a spaceship - the mounting for these guns would be massive, otherwise they would rip the ship to parts - and heavy stuff is be avoided. So, selfguided missiles - no recoil to handle and even at long range they are accurate. With sufficienty advanced computers on board they could even go after vulnerable parts of the enemy ships like sensors, engines or radiators...

In some spacecraft combat simulations I've seen, kinetic energy weapons are not weapons so much as they are terrain. The idea is that you spew a hail of shrapnel or buckshot into the vectors that you want to discourage your target from using. You are sort of using them to herd your target in the direction you want it to travel, counting on the fact it wants to dodge away from the weapons fire. Generally there is no terrain in space other than the odd planet or two, but clouds of kinetic weapon fire will count as such.

Directed energy weapons, kinetic energy weapons, and missiles. Ken Burnside compared it to a policeperson armed with a service revolver, a shotgun, and a police dog. The revolver (beam weapon) cannot be dodged or outrun, but can miss. The shotgun (kinetic weapon) is more likely to hit, but with reduced lethality. The dog (missile) can be dodged or outrun (or shot, that would correspond to point defense), but the blasted thing will chase you, and will always hit unless you actively prevent it.

(Holger Bjerre begs to differ. He points out that kinetic weapons are less likely to hit since it can be dodged, beam weapons lose lethality with range just like shotguns, and kinetic weapons do not lose lethality with range just like revolvers. Well, no analogy is perfect...)

[Xeldrak]

Well, just think of the sheer material that would be used needed to produce such a "terrain" - that quite inefficient.

If I could come up with a weapon to defeat other, capital spaceships, I would hurl a swarm of stealth-rockets in the general direction of the enemy from several hundred km away. During the cruise, they would be inactive. After a set time (or I could send an activation signal) the rockets would activate (as close to the enemy as possible), indentify their targets and attack them in the most efficient way. This way they would be safe from interception during cruise, I do not have to care about relativistic effects (depending on my hurling-technology I could throw them from VERY far away) and they are hard to dodge.

[Fractal_UK]

Hum. You acknowledge the targeting issue, but you don't explore the ramifications: if I blind your ship's sensors (which have to be unprotected if they are to work) with a high-power laser, how are you going to connect your kinetics/lasers? How are you going to get out of the way of mine?

I don't explore it because it isn't of too much relevance to my argument. Shooting at the sensors might be effective tactic in certain cases but it's not a guaranteed recipe for instant space combat success. Detecting ships in space is trivial via their heat emissions so there is no reason to believe that if you hit one such sensor package, there aren't many others ready to take over. Shooting at the computer systems that compute targetting vectors would likely be more effective but they can be armoured. Additionally, targetting the sensors requires being able to hit a specific part of a ship reliably. If my ship is armoured and yours is not - I simply need to hit your ship to cause significant damage while you are likely restricted to shooting small areas of my ship, of which I almost certainly have redundancies anyway.

That said, it still comes down to who has the longest range weapon, provided that weapon is capable of at least doing some damage it can kill the other ship at its leisure.

As to your point about radiation from nuclear weapons, then yes, gamma rays and neutrons will definitely propogate better through vacuum than atmosphere but do bear in mind that just a couple of cm of armour could easily reduce gamma flux by 1/4 - equivalent to doubling your distance from the blast. That could be done at the cost of mere kilograms per square metre, not tonnes.

[Kryten]

And how exactly do you 'stealth' a rocket in deep space? For starters, if they're anything much above 3°K they're going to stick out like sore thumbs on the right kinds of IR sensor.

Edited May 1, 2013 by Kryten

[Rune]

Okay, but if you're going with the split second computer battle thing, you don't have to worry about thrust at all, there would be no time to make meaningful changes to thrust, you certainly wouldn't be reversing orbit (which is what the comment I originally replied to was talking about).

Well, you have me there. But IMO, actual maneuvering during the battle is only possible at low levels of tech. When you have really fast weapons (directed energy of stupidly fast kinetics), no human would stand the accelerations to get out of the way in time. All maneuvering would take place before the encounter, to place your ships in a formation that maximizes simultaneous fire on the enemy while putting each ship in an orientation that puts the most mass between the command sections and their weapons, and the most weapons possible with line of sight to the target.

Thanks!

Forum says (You must spread some reputation around before giving it to Rune again)

Hahaha. Don't worry! Some day I will get back to my "on the road to a distinguished career"... even though it is mostly a useless title.

Well, just think of the sheer material that would be used needed to produce such a "terrain" - that quite inefficient.

If I could come up with a weapon to defeat other, capital spaceships, I would hurl a swarm of stealth-rockets in the general direction of the enemy from several hundred km away. During the cruise, they would be inactive. After a set time (or I could send an activation signal) the rockets would activate (as close to the enemy as possible), indentify their targets and attack them in the most efficient way. This way they would be safe from interception during cruise, I do not have to care about relativistic effects (depending on my hurling-technology I could throw them from VERY far away) and they are hard to dodge.

Xeldrak! There is no stealth in space! That is like the first law of sci-fi space combat geeks...

Also, don't dismiss direct energy weapons. When I run the numbers for near-future plain infrared lasers in the MW range versus kinetics, I pretty much always end up concluding kinetic weapons are a waste of time (1,000-100,000 kms kill sphere, depending on assumptions). And if we can make X-ray lasers work (and stuff like FEL says we should be able to)... well, those can kill light-seconds away. Good luck getting through such a point defense with your very detectable missiles.

Rune. I love talking this stuff.

Edited May 1, 2013 by Rune

[nyrath]

Well, just think of the sheer material that would be used needed to produce such a "terrain" - that quite inefficient.

That depends upon the range. On the other hand, you can replace dumb rocks with smart rocks. Throw kinetic weapons that have no propulsion, but they do have targeting sensors, an attitude control system, and a spacecraft sized shotgun shell on the nose. With these you do not have to fill an area with dumb rocks to create terrain. The weapon's engagement envelope fills out the terrain.

If I could come up with a weapon to defeat other, capital spaceships, I would hurl a swarm of stealth-rockets in the general direction of the enemy from several hundred km away. During the cruise, they would be inactive. After a set time (or I could send an activation signal) the rockets would activate (as close to the enemy as possible), indentify their targets and attack them in the most efficient way. This way they would be safe from interception during cruise.

sigh, here we go again.

There ain't no stealth in space

http://www.projectrho.com/public_html/rocket/spacewardetect.php#id--There_Ain't_No_Stealth_In_Space

It is a truth universally acknowledged that any thread that begins by pointing out why stealth in space is impossible will rapidly turn into a thread focusing on schemes whereby stealth in space might be achieved.

[GoldenShadowGS]

When attacking a ship with point defenses. A missile payload of self guided cluster bombs would be more likely to succeed. Before the missile is within point defense range, the missile deploys tens to hundreds of small frag grenades that use a small RCS thruster and Guidance computer to maintain an intercept course. Laser defense can not disable all targets dispersed in a large enough swarm.

[Rune]

When attacking a ship with point defenses. A missile payload of self guided cluster bombs would be more likely to succeed. Before the missile is within point defense range, the missile deploys tens to hundreds of small frag grenades that use a small RCS thruster and Guidance computer to maintain an intercept course. Laser defense can not disable all targets dispersed in a large enough swarm.

Depends on a bunch of assumptions, from closing speed, to point defense range, to dwell time on each target. A lot of targets may, or may not, be sufficient to overwhelm a point defense, depending on technological assumptions mostly. But with really long ranges, you can just dodge out of the way anyhow.

Rune. As a rule of thumb, X-ray lasers (or any other weapon with a range measured in light-seconds) make kinetics completely obsolete.

[Holo]

That depends upon the range. On the other hand, you can replace dumb rocks with smart rocks. Throw kinetic weapons that have no propulsion, but they do have targeting sensors, an attitude control system, and a spacecraft sized shotgun shell on the nose. With these you do not have to fill an area with dumb rocks to create terrain. The weapon's engagement envelope fills out the terrain.

sigh, here we go again.

There ain't no stealth in space

http://www.projectrho.com/public_html/rocket/spacewardetect.php#id--There_Ain't_No_Stealth_In_Space

Just paint the rockets black with white spots.

With a missile though, you could just deactivate everything except the minimal computing power needed to switch back on. Because it's unmanned, you can actually turn the engine off and run cold.

Edited May 1, 2013 by Holo

[Xeldrak]

That depends upon the range. On the other hand, you can replace dumb rocks with smart rocks. Throw kinetic weapons that have no propulsion, but they do have targeting sensors, an attitude control system, and a spacecraft sized shotgun shell on the nose. With these you do not have to fill an area with dumb rocks to create terrain. The weapon's engagement envelope fills out the terrain.

sigh, here we go again.

There ain't no stealth in space

http://www.projectrho.com/public_html/rocket/spacewardetect.php#id--There_Ain't_No_Stealth_In_Space

First: What do you mean by no propulsion but an altitude control system?

Second: Well, this Site is about hiding spaceships - a rocket needs no life-support and could be launched almost at "space-temperature" (2.7 k) if well isolated from the Ship. My idea was (why I used the word hurl), that the Ship takes care of this part (coil gun or something like that) so that the rockets stay cool. If everything else fails - I just hide them in a buch of you terrain-building kinetic weapons

[drakesdoom]

If we set aside deep space for amount and consider the position of defending a planetary body. I will also assume for this point there is some target on the planet that is wanted intact, most likely some sort of manufacturing or mining center. It could be safely assumed the defenders have eyes in all directions at all times and will know of all approaching ships. I would think that perhaps not as primary means of interception but useful secondary weapons could be kinetic rounds fired from the far side of the planet of approaching fleets on escape trajectories that intersect the incoming fleets path. Small projectiles launched from a station in mass both pro grade and retrograde from the stations orbit could intersect on the far side causing a hail that though not devastating could be enough a distraction for an opening and would require attackers to come armored. I would think a small chunk of steel for instance traveling at escape velocity curving through LKO would be hard to detect and harder to pinpoint for evasive maneuvers. If you wanted to put it at a stretch these types of blind side firing trajectories might be called "space stealth."

[nyrath]

First: What do you mean by no propulsion but an altitude control system?

I mean it has what Kerbal calls a RCS Thruster Block, but no propulsion systems. So it cannot change its vector very much, but it can spin in place for the purpose of aiming its shrapnel warhead at the target.

Second: Well, this Site is about hiding spaceships - a rocket needs no life-support and could be launched almost at "space-temperature" (2.7 k) if well isolated from the Ship. My idea was (why I used the word hurl), that the Ship takes care of this part (coil gun or something like that) so that the rockets stay cool. If everything else fails - I just hide them in a buch of you terrain-building kinetic weapons

Well, first off, this is a railgun launching a projectile:

https://en.wikipedia.org/wiki/File:Railgun_usnavy_2008.jpg

Good luck insulating the projectile so its 2.7 K temperature stays intact.

Coilguns are almost as bad.

Second off: unless you are hiding behind a planet, there is no horizon to hide behind. The coilgun launch will be visible over most of the solar system. Your opponent will notice the launch, paint you with active radar, and notice the projectiles. If you are hiding behind the planet, you cannot launch the projectiles at your target. Also: hiding behind the planet presumes your opponent does NOT have space stations, observation posts, and spy satellites scattered all over the solar system. The more they have, the harder to be "behind the planet" with respect to all of them.

Third off: the farther away you launch your projectiles, the more you are depending upon your opponent to travel exactly the way you want. The longer the travel time, the bigger the chance the target will make a course correction, a trajectory change, or something that will put the target outside of the projectiles engagement envelope.

Fourth off: hiding an "invisible" weapon inside a cloud of visible weapons is counter-productive. Or in "terrain". The target will see the visible weapons, avoid them, and in doing so also avoid the invisible weapon.

For more, read the link I sent.

[Rune]

Just paint the rockets black with white spots.

With a missile though, you could just deactivate everything except the minimal computing power needed to switch back on. Because it's unmanned, you can actually turn the engine off and run cold.

Painting them is quite stupid, frankly, no offense intended. You don't find things by color, you find them by emitted radiation, and they can't help doing that, as basic thermodynamics tells us.

First: What do you mean by no propulsion but an altitude control system?

Second: Well, this Site is about hiding spaceships - a rocket needs no life-support and could be launched almost at "space-temperature" (2.7 k) if well isolated from the Ship. My idea was (why I used the word hurl), that the Ship takes care of this part (coil gun or something like that) so that the rockets stay cool. If everything else fails - I just hide them in a buch of you terrain-building kinetic weapons

In short, the launch is detectable and all particles launched can have their trajectories, and masses, projected just as the light reaches the target ship, just by the energy discharge of the launch. Any decent computer can keep track of them afterwards. If that was impossible because a planet is in the way, for example, think that inert, cold asteroids are detected all the time with current telescopes just because of the sunlight they reflect... or absorb, heating them up and re-radiating in the IR band. Their spectra tells a lot about them, too. And inert stuff is easy to sidestep.

Rune. But I don't want to feed the beast more than absolutely necessary, just think that a lot of smart people have thought about this, and thus the phrase was coined.

[Fractal_UK]

In short, the launch is detectable and all particles launched can have their trajectories, and masses, projected just as the light reaches the target ship, just by the energy discharge of the launch.

Indeed, I believe rail guns involve passing a large current through the projectile, likewise coilguns typically involve some kind of powered coil within the projectile, even with a permanent magnet projectile in a coilgun there would be some heating of the projectile making it standout like a sore thumb against the cold background of space. It's tough to imagine a launch mechanism that doesn't involve imparting enough wasted energy of some kind that would make it detectable.

[PIRATEONTHERUN]

Actually...will there even be a reason to wage a space wars? If we advance enough to afford space navies, we will be advanced enough to build self-sustaining colonies, industry and mining facilities etc. Solar system is so big, it will provide enough space for everyone to expand for generations to come. There should be no reason to fight for resources, energy sources, living space or valuable minerals. And, if there will be no anti-gravity, inertial dampers and engines with enough thrust to cut interplanetary travel time down to days, war will be logistically incredibly difficult to fight. It would be like XIX century America trying to invade and conquer Australia using paddle-wheeled steam warships. Yes, it would be doable - but at what cost? Alas, there is no end to human stupidity...

Yeah, but we're humans so we will find a reason to fight.

"Hey, you took the asteroid that I was going to mine even though there are 17,000,000 others. Prepare to die!"