Interplanetary WAR!

[Jouni]

The rod of tungsten that is used in a railgun could be made invisible to most detection methods, plus it is very small. If properly aimed a rail gun could launch a projectile the opposite side of a planet and hit its target before anyone can do anything about it, to this day we can't track objects that small that are in orbit.

"Our satellites have detected a massive EM spike from the other side of the planet. Everyone make small random course changes, and launch a few thousand drones to deal with the target."

Satellites are small and cheap, so it can be assumed that they are everywhere if there is a risk of combat. Firing a railgun is an extremely visible activity, so there is no way you can avoid detection after firing it. If the projectiles are unguided, there is no reason to track them, as the probability that they will hit anything after the course changes is negligible. Guided projectiles, on the other hand, are much easier to track once they become active.

[krona14]

"Our satellites have detected a massive EM spike from the other side of the planet. Everyone make small random course changes, and launch a few thousand drones to deal with the target."

Satellites are small and cheap, so it can be assumed that they are everywhere if there is a risk of combat. Firing a railgun is an extremely visible activity, so there is no way you can avoid detection after firing it. If the projectiles are unguided, there is no reason to track them, as the probability that they will hit anything after the course changes is negligible. Guided projectiles, on the other hand, are much easier to track once they become active.

the projectiles could be guided, the railgun would be simply to get then to a rough intersect with the target, that the projectile would handle an minor changes that would be nessisary for it to hit its target

[Jouni]

the projectiles could be guided, the railgun would be simply to get then to a rough intersect with the target, that the projectile would handle an minor changes that would be nessisary for it to hit its target

A railgun is pretty much the worst way to fire long-range guided missiles. It guarantees that the enemy receives a warning a long time in advance, and the ship has to deal with a lot of waste heat. It's much better to accelerate such missiles slowly, using some kind of low-power engines that are hard to detect.

Of course, guided missiles are much easier to detect than dumb projectiles, because they have all kinds of electronics that can reveal them.

[krona14]

A railgun is pretty much the worst way to fire long-range guided missiles. It guarantees that the enemy receives a warning a long time in advance, and the ship has to deal with a lot of waste heat. It's much better to accelerate such missiles slowly, using some kind of low-power engines that are hard to detect.

Of course, guided missiles are much easier to detect than dumb projectiles, because they have all kinds of electronics that can reveal them.

you may be able to see the projectile being launched easily, but if the projectile can have simple hard to detect corse maneuvering thrusters that are hard to see, also even if you say the projectile launch, you don't know where its going and you cant just move an entire fleet and if you do, you will have wasted a lot of fuel not to mention railguns can be aimed in an area to predict where the enemy would try o move to and they would be unable to know wether they are moving in or out of fire. its the same as artillery, you can hear it fire from a long way a way, but you don't know where the shell will hit.

[Seret]

Of course, guided missiles are much easier to detect than dumb projectiles, because they have all kinds of electronics that can reveal them.

Modern missiles tend to only use active homing in the terminal phase, if at all. No reason you couldn't be using IR missiles in orbit.

[Jouni]

you may be able to see the projectile being launched easily, but if the projectile can have simple hard to detect corse maneuvering thrusters that are hard to see, also even if you say the projectile launch, you don't know where its going and you cant just move an entire fleet and if you do, you will have wasted a lot of fuel not to mention railguns can be aimed in an area to predict where the enemy would try o move to and they would be unable to know wether they are moving in or out of fire. its the same as artillery, you can hear it fire from a long way a way, but you don't know where the shell will hit.

A 0.1 m/s burn to a random direction is enough to dodge anything passive fired from the other side of a planet. For reasonably-sized ships, this requires less energy than firing the railgun. (For reasonably-sized ships, firing the railgun changes the velocity by more than 0.1 m/s.)

The problem with guided missiles is that their sensors can reveal them. There are many tricks that can momentarily turn passive sensors into active transmitters. The more you know about the enemy, the more likely you're able to use one of these tricks successfully.

[Seret]

There are many tricks that can momentarily turn passive sensors into active transmitters.

Can you give some examples?

[Red Iron Crown]

Can you give some examples?

Not sure if it was the one that Jouni was thinking of, but a superheterodyne receiver is an example. It's the concept that makes radar detector detectors possible.

[Jouni]

Can you give some examples?

Many passive sensors can be detected by the reflections they give. Camera sensors are so easy to detect that people have considered installing detectors in movie theaters. Radio antennas respond quite strongly to EM pulses close to their resonant frequencies. More generally, passive sensors often reflect the stuff they're supposed to detect.

[Seret]

Many passive sensors can be detected by the reflections they give. Camera sensors are so easy to detect that people have considered installing detectors in movie theaters. Radio antennas respond quite strongly to EM pulses close to their resonant frequencies. More generally, passive sensors often reflect the stuff they're supposed to detect.

Can you give an example of an actual device deployed by the military that can acquire the passive sensor on a missile?

[Jouni]

Can you give an example of an actual device deployed by the military that can acquire the passive sensor on a missile?

If I could, I would not be allowed to tell about it. Electronic warfare is a field, where everything depends on what you know about your enemy, vs. what the enemy knows about you.

[Seret]

If I could, I would not be allowed to tell about it. Electronic warfare is a field, where everything depends on what you know about your enemy, vs. what the enemy knows about you.

Well, I spent most of the 90s in military aviation, and I never saw or heard of anything. Granted, my side of the picture was the missiles not the ECM so I'm not an expert, but I don't think the avionics boys were hiding some magic bit of kit. The only optical countermeasures that directly detect passive sensors I'm aware of are near point blank range and themselves passive acquisition.

[Jouni]

The 90's are pretty much ancient history by now. For more up-to-date real-world examples, you might want to ask the Russians or the Chinese, what kind of technology they have to shoot down stealth bombers.

[Seret]

The 90's are pretty much ancient history by now. For more up-to-date real-world examples, you might want to ask the Russians or the Chinese, what kind of technology they have to shoot down stealth bombers.

Lol, you're just winging it, aren't you? The technology to track stealth aircraft is pretty week understood, and doesn't require what you're taking about.

If my knowledge is it of date (which it is) then yours is even less substantial. You cite secret tech, but have you actually ever held any level of security clearance?

You might be surprised how few genuinely secret systems military forces actually have. There's an assumption amongst civilians that the military has loads of secret high tech stuff, but that's not generally the case.

Edited May 26, 2014 by Seret

[Jouni]

Lol, you're just winging it, aren't you? The technology to track stealth aircraft is pretty week understood, and doesn't require what you're taking about.

If my knowledge is it of date (which it is) then yours is even less substantial. You cite secret tech, but have you actually ever held any level of security clearance?

You might be surprised how few genuinely secret systems military forces actually have. There's an assumption amongst civilians that the military has loads of secret high tech stuff, but that's not generally the case.

I was talking about what's possible in principle, given the current understanding of physics and technology that might plausibly exist by the end of the century. After all, this thread is about space combat, not modern warfare.

It's obvious that Russia, China, and the US have spent a lot of money trying to find ways to counter stealth bombers in the last few decades. It's also very likely that no single person in the world knows the state of the art in such technologies, because it's distributed among three (or more) parties that don't like to share their knowledge. It's also obvious that nobody in the world knows how well such technologies would work in practice, because we haven't seen a major war between superpowers for a long time.

The general principles under which military technology works are well understood. The general designs of production-level stuff are also well known, even if the details remain classified. What remains secret is the middle ground: the concepts and prototypes that might become production-level technology in a few years, given sufficient funding and a real reason to develop them. Such reasons have been absent for the last 25 years or so, and the situation probably won't change in the next decade or two, as China and the US are more interested in trading than in fighting.

[Dominatus]

This is a very interesting idea for a game. In the example you gave, I imagine it would most likely be a group of colonists or miners from mars are being preyed upon by pirates in the asteroid belt. Asteroids are excellent places to hide ships... Or weapons. Popular shipping channels will pass nearby sections of the asteroid belt; cleverly hidden missile launch sites and targeting relays could be used for initial ambush scenarios. Say the pirates have several bases serving as colonies in the belts? In that case maybe they don't want to completely destroy the opposing fleet, and wish to capture ships for spare parts, resources, etc. Then it no longer becomes a war of who can kill the other guy faster. The pirates will have to have weapons to disable the other ships, get close safely, and board them. Maybe the Martians are sick of being preyed upon, and want to put a stop to the pirate menace. That means locating the asteroid bases, and taking them out. To do that they need an intact navigational computer with all data, one that hasn't been wiped clean.

Obviously just an example- perhaps the pirates are actually freedom fighters, rebelling against a more powerful regime and seeking shelter among established mining colonies. It's whatever you want... But to justify the types of combat you want, each side needs a reason to be fighting like that. Certain technologies we don't currently possess will be available by this point as well. Scientists estimate it will only be another 30 years until we achieve a sustained fusion reaction; call it another 10 before we figure out how to utilize it as a interplanetary drive. It's currently estimated that this will allow us to get to mars in about a month. The US army is developing an electromagnetic rail gun similar to those seen in Halo. This is in the works currently and test firing can be seen on YouTube. Imagine one on a much larger scale, mounted to the front of a space ship... Thorium is also being researched. It's a nuclear fuel source that cannot melt down and is much more common than uranium. Scientists say there is enough thorium in the US alone to meet our countries current power needs for 10,000 years. The best part is that this isn't science-fiction. India leads the global research on thorium. It is already powering one of their reactors and India is developing a hard water variation of a thorium-specialized reactor. They say that by 2050, thorium will meet 1/3 of their power needs. And this is India, not the wealthiest nation out there. Anyways, I wish you luck. Can't wait to see how this turns out!

(If you haven't already, check out World War K on YouTube, by EnterElysium. He does a pretty good job highlighting challenges resulting from space warfare in this series, and the concepts of his missions are all excellent, even if KSP's limitations prevent things from working out exactly as planned.)

[krona14]

A 0.1 m/s burn to a random direction is enough to dodge anything passive fired from the other side of a planet. For reasonably-sized ships, this requires less energy than firing the railgun. (For reasonably-sized ships, firing the railgun changes the velocity by more than 0.1 m/s.)

The problem with guided missiles is that their sensors can reveal them. There are many tricks that can momentarily turn passive sensors into active transmitters. The more you know about the enemy, the more likely you're able to use one of these tricks successfully.

if their is only one ship in the area, yes. but if their is a fleet, the entire fleet has to do a burn and if their was only one ship there would be no reason to use a railgun aganst it unless it was huge. also you could fire mutible shots in areas that you would tink they would try to move to, predict where they are going to go and you might hit them they would have no idea what your shooting at. if you use guided projectiles, all you have to do is have them only start making corce correction when they get very close to the target so it dose not matter weather they can detect it.

[Jouni]

if their is only one ship in the area, yes. but if their is a fleet, the entire fleet has to do a burn and if their was only one ship there would be no reason to use a railgun aganst it unless it was huge. also you could fire mutible shots in areas that you would tink they would try to move to, predict where they are going to go and you might hit them they would have no idea what your shooting at. if you use guided projectiles, all you have to do is have them only start making corce correction when they get very close to the target so it dose not matter weather they can detect it.

The defenders don't have to dodge every single projectile. They can wait for the enemy to fire for half an hour, before taking evasive action. If a 0.1 m/s burn is enough to dodge the projectile if done immediately, a 0.2 m/s burn is enough when the first projectiles are halfway to the target.

The situation favors the defender in other ways as well. If the defender doubles the magnitude of the evasive burn, the attacker has to fire 4x to 8x more rounds to compensate (I'm too tired to think how the scaling works precisely in this case). This is the whole point of making random evasive burns: the attacker can't predict the actual position of the target, but only a probability distribution it. Hence they have no better choice than to saturate the target area with a large number of projectiles.

Also, the defenders will be firing back. Given that the situation is somewhere between Lanchester's Linear and Square Laws, the side with more ships will inflict more damage and take less losses, unless the differences in quality are significant.

[bighara]

OP here: I haven't checked this thread for about a week. Wow! You people are amazing! Talk about information overload! I need to sift through all this for all the goodies.

[CavemanNinja]

As brought up earlier, (sorry for the late reply) Alcubierre drives would be extremely important in space warfare...

So important in fact, as to provide the only true stealth, accelerating past C to the point where the only way to destroy the craft is to launch an identical craft milliseconds after on the same trajectory so that when the target ship stops, it is annihilated by the second one.

As previously stated (I can't remember where), once you move faster than light, it is logistically impossible to counter your craft using computer systems (which have a speed limit, light) so even if hypothetical Country X has a 360-degree detection-and-counter probe that works by detecting heat or infrared reflection or any other heat/light method, all country Y has to do is clear an atmosphere with an Alcubierre-powered missile and you have effectively won the war, because the defense systems of Country X cannot physically detect it fast enough to retaliate.

At that point, Country Y basically just has to demonstrate its strike capabilities with another FTL missile, and Country X would have no choice but to surrender, their only safe place from the missiles being the far side of a planet/star or in an atmosphere. These possibilities are limited once Country Y has at least a few FTL missiles spread around the perimeter of the combat area, which only leaves the small but protective grasp of a planet's atmosphere.

Of course, since this is an interplanetary war, by this time Country X has effectively lost the war, being so crippled in detection to not even know how how much more FTL 'power' Country Y has.