Orbital Fighting [Star wars is a good example]

[bulletrhli]

I have been curious about this, learning like the majority of people here how your vector and thrust effects your speed, altitude, periapsis, apoapsis etc in orbit it has made me question how these principles would come into play with orbital fighting. If any of you have watched Star wars, or played games like Star Conflict, you will see them in orbit, doing crazy maneuvers slowly down, speeding up, doing insane changes of their direction. How could something like this happen? Would they not fall back to the planet they are around? Wouldn't they run out of fuel just turning around because they have to stop all forward momentum in one direction to alter their course?

What kind of mechanics do you think are at play here, what technology do you think could exist in the future to prevent them from returning to earth or whatever their planet is while still maintaining nice speed etc etc.

[Nibb31]

Star Wars is actually a pretty bad example. The dogfights were inspired by WWII movies, and were made to look good on film, a long time ago, in a galaxy far far away, where the laws of physics are not at all the same ones we have.

First of all, dogfighting is a thing of the past. Nowadays, jet fighters launch their missiles from 50 to 100km from their target. The winner is usually the plane that has the best radar system. Also, the F-22/F-35 are probably the last generation of manned fighter aircraft. Why would you risk a pilot by putting him in a plane, when you can put him in a control room and remote control a drone? Drones are becoming more capable than manned aircraft, with a longer range, longer loiter times, and they can take higher G loads in manoeuvers.

This is also true for space fighters. Why would you use a manned military spacecraft to fire a weapon when the weapon can be the actual spacecraft? It is cheaper and safer to just fire a missile rather than to launch a manned spacecraft to fire the missile and return safely without being hit in return. Something like XSS-1 isn't as sexy as an X-Wing, but it would probably work better.

Now, If you've played KSP, you know how hard it is to rendez-vous with a target. In our case, the target is usually a space station or a satellite, that is passive, and wants you to dock with it. Now imagine how hard it would be if the target was changing its orbit in a random direction every 5 minutes. You simply couldn't reach it at all.

Modern ASAT weapons are usually air-to-air missiles that have been modified to target a stable military satellite in a predictable LEO position. It is assumed that enemy satellites will not have time to detect the weapon or to try to evade it.

The best solution is probably a high-power laser system. This could potentially be able to burn a hole in a satellite in a couple of seconds. It's easier to hit the target, because you can aim for where the target is NOW rather than where it will be in 10 minutes. You don't need the power to blow up the enemy satellite. All you need is to burn a hole big enough in its solar panels to cut the power or in its tank to make it outgas and lose control. The problem is that these lasers are big and heavy and expensive, which makes them impratical to send to orbit. It is probably more efficient to fire them from an Aegis cruiser or an airborne platform, like the (cancelled) Boeing 747 YAL-1

But all in all, this would all make for a crappy movie, so lets enjoy Star Wars for what it is. Mindless entertainment.

Edited April 28, 2013 by Nibb31

[Britpoint]

Most orbital combat stuff you see falls victim to the "Space as an ocean" way of thinking. You know, big battleships move like aircraft carriers or submarines, fighters fly like aeroplanes. All this stuff simply could not happen in reality because objects in space do not behave like they are in water or in air - they are of course in neither of these. Pretty much the only thing that is vaguely believable is the flips that the Vipers in Battlestar Galactica do, where they roll their ship around to fight enemies from all angles while maintaining their trajectory. This could happen, but all the rest of the time where they move around like Spitfires couldn't.

Because there is no friction in space, things... can't turn very well. It would certainly take, as you suggest, huge amounts of fuel and energy to "turn around" to start flying back towards the enemy who is chasing you. This doesn't mean you would fall back to Earth if you tried it though, because speed is relative. If I reduce my speed on the motorway from 70mph to 60, the guy behind still doing 70 will overtake but I won't come to a standstill. The interesting thing about doing that sort of thing in space though is that by doing a retro-burn you actually end up lowering your orbit which means you will speed up. In other words, if you are in an orbital dogfight and you want to put some distance between you and your pursuer, point your nose at him and light the engines! The distance between you will reduce at first as you lower your speed, but the further along your new orbit trajectory you get, the more you will pull away.

Ballistic weapons are pretty much a no go in space for two reasons. Firstly, targets are very, very very small and very difficult to hit. The ranges you'll be fighting from will also be much larger than they are in atmosphere. Secondly, firing guns will alter your trajectory as the projectile and hot gasses being expelled from the barrel would work much like a rocket engine. Finally, anything you shoot stays in orbit and poses a threat to you and your allies as much as it does your enemies.

Long story short, I don't think "space combat" is likely to happen for a very, very long time if ever. It's just too much hassle. If there IS any kind of space fighting, I imagine it'll be fought exclusively with nukes because that's the only way you're likely to cover an area large enough to hit anything.

[K^2]

The best, by leagues, space combat simulation is in Babylon 5: I've Found Her. It's a free game, so I would recommend any KSP fan to download and try it. (Their main server is currently down, but you can find the download elsewhere.)

There is no orbital combat in the game. So it doesn't quite cover the question. However, after playing it, you should get a better idea of what the space combat is like in general. The biggest thing you would notice is that anything serious would require immense delta-V reserve for each ship. Ultimately, it means that once the actual combat starts, the orbital mechanics stuff is fairly minor effect. You are going to be more than compensating for them with your engines. Maneuvering before the actual combat could be a huge part of strategy, however.

[Scotius]

If you have time, patience and know exact parameters of your target's orbit you can send a missile up, put it in a orbit intersecting the one your target is in. Then you can either blow your missile up (gently ) or release a cloud of...well, whatever, even good ol' ball bearings. And then wait. And wait. And keep waiting until finally the target and your cloud of orbiting shrapnel come into one spot of space at the same time - which will happen eventually if both orbits intersect closely enough. No one sends tanks (as in vehicles covered in thick armour) in space - so even couple of hundreds m/s of relative velocity will be enough to seriously damage any satellite, space station or manned craft with a handful of pea-sized projectiles.

[Yasashii]

All this stuff simply could not happen in reality because objects in space do not behave like they are in water or in air - they are of course in neither of these.

Yes, that is all true. Star Wars is a sci-fi series though so let's consider an existence of technology we don't yet possess: anti-gravity. Today's real life spacecraft needs to be put into orbit to stay in space. In other words, it needs to constantly move fast enough not to fall. That's because big celestial bodies such as, say, the Earth, have gravity.

But what if we had some kind of a powerful, yet small anti-gravity device that would fit onto a fighter spacecraft and would compensate for every kind of gravity it encounters? That way, orbiting would no longer be necessary because celestial bodies such as stars or planets wouldn't pull the spacecraft down. That means you could point your vehicle up, fly it to space in a straight line and just stay there without moving at all. That also means you could make all the maneuvers you want and it would enable you to fly around more or less as you would through air. Well, kinda... if you picked up speed, you couldn't then just point the nose up and change direction in a matter of seconds (unless, of course, the anti-gravity device had the ability to manipulate gravity in such a way to move it like that)

...And that's pretty much how it was depicted in Star Wars. If you pay attention you will notice that before each spaceship flew into space, it just lifted itself up without any thrusters. That implies that all the ships had some kind of anti-gravity devices on them.

Edited April 28, 2013 by Yasashii

[Nibb31]

Frontier Elite had semi-realistic space combat too, in that it was all about vector thrusting around your target, which made it really complicated... It was more like medieval jousting, where you spent most of your time changing your vector to hit the target (who luckily also wanted to hit you, otherwise it would be impossible), and the actual fight, where your vectors crossed and you were in range, only lasted a few seconds. There were no orbital gravity physics though, only vectors.

[Canopus]

Take a look at this site: http://www.projectrho.com/public_html/rocket/spacewarintro.php It's pretty interesting to read.

And this is a nice video:

The ships are far too close and lasers wouldn't be visible but it's still a good video. Edited April 28, 2013 by Canopus

[wingnut]

Frontier Elite had semi-realistic space combat too, in that it was all about vector thrusting around your target, which made it really complicated... It was more like medieval jousting, where you spent most of your time changing your vector to hit the target (who luckily also wanted to hit you, otherwise it would be impossible), and the actual fight, where your vectors crossed and you were in range, only lasted a few seconds. There were no orbital gravity physics though, only vectors.

Pioneer is a open source space exploration game inspired by Elite. Anyone interested in orbital combat should check it out.

[Awaras]

Frontier Elite had semi-realistic space combat too, in that it was all about vector thrusting around your target, which made it really complicated... It was more like medieval jousting, where you spent most of your time changing your vector to hit the target (who luckily also wanted to hit you, otherwise it would be impossible), and the actual fight, where your vectors crossed and you were in range, only lasted a few seconds. There were no orbital gravity physics though, only vectors.

There WAS orbital physics, and it was pretty accurate, at least near planets (never tried a hohmann transfer in frontier). You could orbit just fine, its just that the average ship in frontier was able to pull 30-40 g's of acceleration and almost accelerate to lightspeed with a single tank of gas, which made any kind of orbital maneuvering kinda pointless... You just pointed towards wherever you wanted to go and burned at full thrust.

[Nibb31]

...And that's pretty much how it was depicted in Star Wars. If you pay attention you will notice that before each spaceship flew into space, it just lifted itself up without any thrusters. That implies that all the ships had some kind of anti-gravity devices on them.

If you have anti-gravity, then you wouldn't be bothering with manoeuvering and flying around. You might as well use teleportation and instant disintegration weapons.

[nothke]

I agree with everything Nibb says!

Future warfare is really 99% about information, and 1% about direct action. Everything is getting more and more distant and more and more automated. Hacking, making computer viruses, modifying systems to fail (Stuxnet), pinpointing exact locations of people in real time is future warfare... While direct action is really a total superiority, bullets will soon turn into guided missiles for taking out individual targets. Nanotechnology could make viruses that attack only specific DNA etc.. (read: Emerging Technologies) And don't forget that the warfare in last ~40 years is very asymmetric. Right now, US spends 4 times the money China spends on military, plus US has 10 the worlds top Universities, that's a huge advantage (I am not from US so I am not trying to be biased).

So, the future of warfare is pretty boring!! That's why Starwars looked back on WW1 and WW2, those were the last wars when the forces were symmetric and there was lots of hand to hand combat. Starwars is not supposed to be realistic, it's trying to be FUN! (and I have nothing against that, I love Starwars!) That is also the reason why most war video games are set in WW2.

NOW, there is another side to future warfare and that's that famous Einstein's quote "I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones."

So, imagine if all the high tech stuff was obliterated in some major conflict, then forces would need to improvise with what they have left, and therefore, it might be interesting to see that! For example, there's a lot of space ships, but no mechjeb!! xD Now fight in orbit without it!

Edited April 28, 2013 by nothke

[NASAFanboy]

I believe warfare in space will more likely be fought with ships shooting their lazers at each other and releasing missiles ( which will likely not be homing missiles.) Then changing their orbits for another rendevous. 99% orbital mechanics, 1% actual combat.

The ships might be anything from a X-37 attacking a NK satellite or the Venture Star vs a Another ship of its size.

While it would be possible to build a X-wing, the dogfights would.be clumsy and hard.

I think the future is large modular ships attacking each other with lazer turrents and railguns.

@Nothke. While I do agree, people fighting will have to face each other sometime. Perhaps almost all the direct combat will be ships attacking communication centres, ships releasing nanobots from orbit, or ships attacking communication satellites and solar power satellites.

[Scotius]

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...

[nyrath]

I agree with Nibb31. Media science fiction is pretty silly when it comes to depicting how orbital combat will appear. The great thing about KSP is that you can actually experiment with orbital combat and find out first hand what works and what does not.

I've gathered some information on the topic on my website, in the following pages

http://www.projectrho.com/public_html/rocket/spacewarintro.php

http://www.projectrho.com/public_html/rocket/spacewardetect.php

http://www.projectrho.com/public_html/rocket/spacegunintro.php

http://www.projectrho.com/public_html/rocket/spacegunconvent.php

http://www.projectrho.com/public_html/rocket/spacegunexotic.php

http://www.projectrho.com/public_html/rocket/spacewardefense.php

http://www.projectrho.com/public_html/rocket/spacewarship.php

http://www.projectrho.com/public_html/rocket/spacewartactic.php

http://www.projectrho.com/public_html/rocket/planetaryattack.php

[ziogatto]

Changing direction relative to another ship does not require immense delta v, if you fly over them at 50m/s then you want to change direction 180° and fly over them again at 50m/s you need only 100m/s of delta V.

That said there's a KSPer on youtube called Macey Dean who is roleplaying some orbital battles and they're really fun to watch.

[Awaras]

I agree with Nibb31. Media science fiction is pretty silly when it comes to depicting how orbital combat will appear. The great thing about KSP is that you can actually experiment with orbital combat and find out first hand what works and what does not.

I've gathered some information on the topic on my website, in the following pages

http://www.projectrho.com/public_html/rocket/spacewarintro.php

http://www.projectrho.com/public_html/rocket/spacewardetect.php

http://www.projectrho.com/public_html/rocket/spacegunintro.php

http://www.projectrho.com/public_html/rocket/spacegunconvent.php

http://www.projectrho.com/public_html/rocket/spacegunexotic.php

http://www.projectrho.com/public_html/rocket/spacewardefense.php

http://www.projectrho.com/public_html/rocket/spacewarship.php

http://www.projectrho.com/public_html/rocket/spacewartactic.php

http://www.projectrho.com/public_html/rocket/planetaryattack.php

That is your website? I bow to you sir! Wonderful site.

[nothke]

Changing direction relative to another ship does not require immense delta v, if you fly over them at 50m/s then you want to change direction 180° and fly over them again at 50m/s you need only 100m/s of delta V.

Yes, if they are in approximately same orbit. But to change direction in orbit requires lots of ÃŽâ€V. ISS eg. orbital speed is 7800m/s

[magnemoe]

Yes, that is all true. Star Wars is a sci-fi series though so let's consider an existence of technology we don't yet possess: anti-gravity. Today's real life spacecraft needs to be put into orbit to stay in space. In other words, it needs to constantly move fast enough not to fall. That's because big celestial bodies such as, say, the Earth, have gravity.

But what if we had some kind of a powerful, yet small anti-gravity device that would fit onto a fighter spacecraft and would compensate for every kind of gravity it encounters? That way, orbiting would no longer be necessary because celestial bodies such as stars or planets wouldn't pull the spacecraft down. That means you could point your vehicle up, fly it to space in a straight line and just stay there without moving at all. That also means you could make all the maneuvers you want and it would enable you to fly around more or less as you would through air. Well, kinda... if you picked up speed, you couldn't then just point the nose up and change direction in a matter of seconds (unless, of course, the anti-gravity device had the ability to manipulate gravity in such a way to move it like that)

...And that's pretty much how it was depicted in Star Wars. If you pay attention you will notice that before each spaceship flew into space, it just lifted itself up without any thrusters. That implies that all the ships had some kind of anti-gravity devices on them.

Anti gravity just give you almost unlimited ISP and extreme trust, it don't change the rest of the physic. KSP with unlimited fuel hack would be pretty similar. Yes you can do minimum time transfers to Jool, burn until halfway then brake.

It does not let you dogfight, However an gas giant with habitable moons would be an fun battleground.

My guess an realistic fight would use missiles / probes / mines, you can detect acceleration as it gives out heat. however if you accelerate early you might intercept the enemy and just use minor course corrections to get close. Either nuke powered x-ray laser or simply an mirror to focus light from laser closer to sun as warhead. It works nice in books but not in movies. this is why star wars is almost as unrealistic as star trek

[Kerbface]

Yes, if they are in approximately same orbit. But to change direction in orbit requires lots of ÃŽâ€V. ISS eg. orbital speed is 7800m/s

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.

[Holo]

I agree with Nibb31. Media science fiction is pretty silly when it comes to depicting how orbital combat will appear. The great thing about KSP is that you can actually experiment with orbital combat and find out first hand what works and what does not.

I've gathered some information on the topic on my website, in the following pages

http://www.projectrho.com/public_html/rocket/spacewarintro.php

http://www.projectrho.com/public_html/rocket/spacewardetect.php

http://www.projectrho.com/public_html/rocket/spacegunintro.php

http://www.projectrho.com/public_html/rocket/spacegunconvent.php

http://www.projectrho.com/public_html/rocket/spacegunexotic.php

http://www.projectrho.com/public_html/rocket/spacewardefense.php

http://www.projectrho.com/public_html/rocket/spacewarship.php

http://www.projectrho.com/public_html/rocket/spacewartactic.php

http://www.projectrho.com/public_html/rocket/planetaryattack.php

Holy...

You're actually Winchell Chung himself?

Sign my shirt!

[nyrath]

Holy...

You're actually Winchell Chung himself?

Sign my shirt!

Ah, shucks. Yes, that's me. I'll have to "air sign" your shirt though.

But I'm still convinced that KSP has done more for teaching astronautics than a zillion views of my website.

[czokletmuss]

You are the man? I want to thank you - your website is incredibily valuable for everyone interested in a space exploration and rockets. I would even say the best easily comprehendible (in comparison to some NASA papers) source out there in the net. So greetings from Poland!

[drakesdoom]

How much thought have you given too extremely high isp engines? Theoretical open gas cycle NERVA engines could reach 5000 isp, not to mention future fusion or antimatter powered engines. Fighter craft manned or unmanned could easily be used as a reusable first stage too a missile or torpedo to be fired at an enemy ship, would use a bit more fuel to being it back but engines are not cheap.

[nyrath]

How much thought have you given too extremely high isp engines? Theoretical open gas cycle NERVA engines could reach 5000 isp, not to mention future fusion or antimatter powered engines. Fighter craft manned or unmanned could easily be used as a reusable first stage too a missile or torpedo to be fired at an enemy ship, would use a bit more fuel to being it back but engines are not cheap.

Well, there are a couple of problems.

For space exploration, you want a high Isp engine. For space combat, you want a high thrust engine. An ion drive can reach up to around 210,000 seconds Isp, but you'll be lucky to get a miserable 10,000 newtons out of each engine (while a single Saturn V F1 engine can easily do more than seven million newtons). Maybe an ion drive can give you a much higher delta V, but it doesn't help you in combat if it takes a few months to accelerate up to speed.

But the elephant in the room that nobody wants to talk about is the fact that anything a space fighter can do, a missile or drone can do better. For many reasons. Like the fact the drone can use accelerations that will turn a human pilot into a thin layer of red goo covering the back wall of the crew cabin.

And the fact that the fighter has to carry fuel to delta V to transit to rapidly the target, delta V to match velocity with the target, delta V to transit back to the mothership, and delta V to match velocity with the mothership. A missile just has to carry fuel to delta V to transit rapidly to the target, period, because the missile does not have to come back home. If manned fighter only carried that little fuel, you'd soon run out of pilots.

There are more reasons here:

http://www.projectrho.com/public_html/rocket/spacegunexotic.php#id--Space_Fighters

*Having said that* I know that space fighters are too irresistibly romantic for science fiction writers and fans to avoid. So please carry on with what you were doing.