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PhD Candidate Talks About the Physics of Space Battles 361

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darthvader100 writes "Gizmodo has run an article with some predictions on what future space battles will be like. The author brings up several theories on propulsion (and orbits), weapons (explosives, kinetic and laser), and design. Sounds like the ideal shape for spaceships will be spherical, like the one in the Hitchhiker's Guide movie."

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PhD Candidate Talks About the Physics of Space Battles

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  • by Tablizer (95088) on Thursday December 17, 2009 @03:23PM (#30477356) Homepage Journal

    Sounds like the ideal shape for spaceships will be spherical

    That'll be boring: round ships, round planets, round explosions, and round movie goers.
       

    • Re: (Score:3, Funny)

      by 2.7182 (819680)
      Hey it worked for the death stars. Sort of...
    • Re: (Score:3, Insightful)

      by Z00L00K (682162)

      It also depends on the size and if it's going to be a new way of creating artificial gravity aside from spinning the ship.

      Space battles wold be much like battles between submarines.

      And then - there may be other reasons to not have spherical ships - like requirements for propulsion. It may be easier to keep the engine away from the habitation part than to have a lot of heavy shielding.

  • Round ships? (Score:3, Informative)

    by Duhavid (677874) on Thursday December 17, 2009 @03:27PM (#30477442)

    "Sounds like the ideal shape for spaceships will be spherical, like the one in the Hitchhiker's Guide movie"

    Or maybe like Doc Smith predicted in the Lensman Series?

    • by dpilot (134227)

      I was thinking of Doc Smith, wondering if for some real, technical reason the logical spherical shape would give way to the "teardrop-shaped superdreadnaught".

      But I guess if you're on Skylark instead of Lensman, I, II, and Valeron were all spherical, only III was cylindrical.

      • by Chyeld (713439)

        I would imagine that there are things that you don't want sitting as close to your centrally located "super gyroscope+power plant+fuel cells" as a sphere would dictate. Possibly radiation/interference issues with things things like sensors or communications.

        While you could compensate by making a bigger sphere, if your 'required distance' is small enough, it's easier just to shove it out as an extension.

        • by dpilot (134227)

          While you're giving me a perfectly serious and reasonable answer, I hope you've read your Doc Smith, and understand the references.

    • Re: (Score:2, Informative)

      Or the jacket illustrator [wikipedia.org] for at least one of Robert Heinlein's 'juvies'?

      Okay, so it's actually lightbulb-shaped. Close enough.
  • by WillAdams (45638) on Thursday December 17, 2009 @03:28PM (#30477452) Homepage

    that I've found thus far in her Merchanter / Alliance-Union books ---esp. Heavy Time / Hellburner --- though I'd be very interested in suggestions on other authors to read who've put forth a similar effort to have realistic physics and effects thereof.

    William

    • by Chris Burke (6130) on Thursday December 17, 2009 @03:55PM (#30477902) Homepage

      I thought Neal Stephenson's Gap series had very good handling of space battles. Outside of lasers the weapons were pure fantasy physics, but the battle tactics that resulted from them were pretty realistic. Battles took place at distances on the order of light-minutes, such that your knowledge of the enemy ship's position was perhaps minutes old, your light-speed weaponry took minutes to reach them, and it took that much time again for you to know if you scored a hit. Defensive tactics consisted of trying to move your ship in unpredictable patterns. Ships were often cylindrical so they could have rotational gravity, but this was off for battle. Kinetic weapons existed, but were rarely used since at distances where they had a chance of hitting anything, it would have been basically like two old ships broad-siding each other only with deadly energy beams and in space.

      • Re: (Score:3, Informative)

        by maxume (22995)

        Do you mean Stephen Donaldson?

        I'm reasonably familiar with Stephenson's work and do not recognize his 'Gap series'.

        • by idontgno (624372)
          The Gap Series [wikipedia.org] is, indeed, Donaldson, and GPP's description is approximately consistent with what I remember. The space battles weren't the major point, of course; The Ring Cycle [wikipedia.org] was the major point.
      • Re: (Score:2, Informative)

        Just a minor correction: the "Gap..." series was authored by Stephen R. Donaldson. http://www.stephenrdonaldson.com/ [stephenrdonaldson.com]

      • Re: (Score:3, Interesting)

        by WarlockD (623872)

        A decent amine called Starship Operators [wikipedia.org] had some interesting concepts. I like the idea that the warp engines don't work inside of a sun gravity well and a majority of the weeks of travel was between the outer edge of a gravity well to the planet itself. No force fields just really good heat plating designed to reduce heat. It could be said that the whole point of these space battles was just trying to microwave the other side faster:P

        How most ships were built around a decent long range weapon designed t

  • by Anonymous Coward on Thursday December 17, 2009 @03:29PM (#30477470)

    When the future Enterprise flew at the other ship all perpendicular?! That was crazy.

    • And then it flew it straight lines over cool impressive scenery while an orchestra played classical sounding music for the rest of the movie, that was like so totally cooler than Star Wars....

  • Not much surprising (Score:5, Interesting)

    by JoshuaZ (1134087) on Thursday December 17, 2009 @03:32PM (#30477514) Homepage

    The point that nukes wouldn't generally be useful is a good one. And the point that kinetic weapons would be ideal also makes sense. However, I'm not completely convinced by the emphasis on orbital mechanics. In order for that make sense, one needs space travel to be cheap enough and convenient enough that one can easily have lots of ships in space. If that's the case, one needs efficient enough propulsion systems that will make orbital mechanics not matter as much. They'll still matter probably (and certainly matter more than they do in standard scifi) but I'm not at all convinced they'll matter as much as he makes it out.

    Also, he doesn't address the issue that long-range kinetic impactors can make most space combat irrelevant if they are going fast enough. There's not much Earth could do if there were large mass drivers on say Demos and Phobos sending fairly small projectiles at targets on the Moon or Earth or targeting large space installations. Again in this situation orbital mechanics would matter. But when the planets are in the correct positions, such setups would render local space combat irrelevant.

    • by alen (225700) on Thursday December 17, 2009 @03:37PM (#30477608)

      just like fighter pilots use energy and physics today, you'll need to use gravity in space combat. it's everywhere and if you use it properly you'll be able to maneuver faster than the other guy and probably kill him

    • by nschubach (922175) on Thursday December 17, 2009 @03:45PM (#30477732) Journal

      You make a point, but I would like to add a bit on that subject...

      All you have to do is knock the Moon off orbit and Earth could be in for a fun ride... You wouldn't need to directly attack Earth. Just an object big enough (or a small object traveling fast enough) to change or degrade the orbit of the Moon. If you planned it well enough (and I'm assuming computers in that time would be able to calculate multiple trajectories...) you could simply upset the balance of the meteor belt and send objects hurling at us without us knowing where it came from.

      In fact, it's making me wonder why we'd want to remain on such a fragile environment (when/if space travel becomes viable) and we start a conflict in space or piss off the natives of a more advanced society.

    • by sznupi (719324)

      Even with very efficient means of propulsion, why fight against orbital mechanics when you can exploit it? Or to put it another way: which side do you think will win - the one exploiting it, or the one not doing it?

      This of course assumes roughly equal technological level. A fair assumption IMHO, because in most of scenarios when that isn't the case (civilizations alien to each other), the difference might be such great that it would be no contest - alien civilizations are likely to be millions of years "out

    • http://en.wikipedia.org/wiki/Lensman_series [wikipedia.org]

      and how in the end it was about making sure your opponent didn't have the time to react, FTL planets are fun.

    • I have a question about the Nukes in space thing. I know that, without an atmosphere, you don't get the massive shockwave which causes much of the damage that you see in atmospheric detonations. . . but, wouldn't the Nuke still generate several million degrees of thermal energy? Wouldn't it tend to vaporize anything nearby, and melt things that are a little farther away, but still within like a mile or two? Wouldn't it also release a massive amount of Neutron radiation? (I'm not sure - could you effectively

      • by idontgno (624372)

        I'd imagine the most chilling thing a space warship commander might hear is a loud hull thump followed by damage control declaring "Contact nuke!" A nuclear detonation would be dramatically less damaging at range, but up close and personal it'd still trump nearly everything else.

      • by lgw (121541) on Thursday December 17, 2009 @04:24PM (#30478400) Journal

        There's little radiant thermal energy directly from a nuke, and even in the atmosphere where there's a lot more, a sheet of bright white posterboard would be 100% eccective as a defense. Drop and cover.

        The energy directly from a nuke is mostly expresses as gamma and x-rays. These are planty damaging, but fall off with the square of distance. You'd need to get a pretty large nuke in pretty close to your target to produce more radiation than bad weather. Space this close to the Sun is harsh, radiation-wise.

        So the solution is to use the energy of a nuke, but overcome the range^2 thing: nuke-pumped X-ray lasers. This is not a new idea - it's why Reagan's missile defense program was called "Star Wars". For all I know, we have this weapon in orbit already.

        • by idontgno (624372) on Thursday December 17, 2009 @05:12PM (#30479184) Journal

          Those gamma and X-rays are bad news when absorbed by stuff like a spacecraft hull. The photon flux is so high that even transparent substances like air absorb ghastly amounts of those. That's the source of the atmospheric shock from a nuke, and the source of the distinctive thermal double-flash: initial infrared pulse, occluded after a few nanoseconds by the atmosphere flashing into opaque plasma, and the resuming after the shockwave begins to dissipate the opacity. Any substance more opaque than air will just immediately flash to plasma and create its own shockwave in the rest of the target.

          Yes, the inverse-square law applies to the photon burst from a nuke in space, so a nuke is not the large-area weapon it is in atmosphere. But to write off the huge pulse of ionizing radiation is mistaken. A contact or near-contact nuke would hurt bad.

          A perfect x-ray laser would be immune to the inverse-square law, but a perfect laser doesn't exist. Every real-world laser will have a divergence angle; that would give the beam with an inverse-square behavior with a constant coefficient based on the ratio of the divergence angle as a solid angle [wikipedia.org] and the solid angle of a unit sphere (4 pi).

          • by Rei (128717) on Thursday December 17, 2009 @05:48PM (#30479806) Homepage

            Actually, nuclear weapons are likely to be far more lethal at great distance in space than in the atmosphere. The atmosphere absorbs most of the radiation from a nuclear weapon. The vacuum of space doesn't. It continues on and on, at dangerous levels for hundreds or even thousands of miles.

            A ~50 megaton blast releases ~1e18 joules of energy. At 1000 miles, that's spread over 12.6 million square miles, or about 30 joules per square meter. 1 rad is 0.01 joules per kilogram, so a 100kg mass taking up 0.5 square meters would receive 15 rads. If we assume a Q factor of 5 for a nuclear weapon, that's 75 rem. That's enough to cause radiation sickness. Cut the distance in half (500 miles) and that's 300 rem -- the LD50 for humans.

            The danger radius for nuclear weapons in space is *big*. Even if you add in enough shielding to reduce radiation exposure by 95%, and drop the nuclear weapon yield tenfold to 5 MT, you'd still kill over half the crew of the spacecraft from a dozen miles away. You don't really need to be even close. And radiation poisoning is not a nice way to go.

      • I have a question about the Nukes in space thing. I know that, without an atmosphere, you don't get the massive shockwave which causes much of the damage that you see in atmospheric detonations. . . but, wouldn't the Nuke still generate several million degrees of thermal energy? Wouldn't it tend to vaporize anything nearby, and melt things that are a little farther away, but still within like a mile or two? Wouldn't it also release a massive amount of Neutron radiation? (I'm not sure - could you effectively shield against that much neutron radiation? I know that space craft have to have a certain level of shielding just to remain safe from 'normal' Solar radiation, but could you effectively shield against the radiation released from an H-Bomb?)

        You're right about how an H-bomb would generate a massive amount of radiation. The problem is that getting a bomb within a mile or two of a ship isn't easy. The most important part is that the bomb can't cover that kind of distance really quickly, in terms of detection. Sure, you can shoot it at your opponent at high rate, but remember that in space you'll probably be considered "engaged with the enemy" from hundreds of miles out. They'll see the nuke coming, and can easily take measures to shoot it as

      • Re: (Score:2, Interesting)

        by bluecoffee (1702800)
        wrap the thing in polystyrene and depleted uranium rods boom hypersonic kinetic energy penetrators, fuck yo armour
      • Re: (Score:3, Interesting)

        by Chris Burke (6130)

        Wouldn't it tend to vaporize anything nearby, and melt things that are a little farther away, but still within like a mile or two?

        Well, let's think about this using the power of the maths! Let's assume a 300 kT TNT =~ 1300 TJ yield bomb (most common in our arsenal today, and bigger thermonuclear devices are probably impractical to carry into space), detonating at 1km from the target. Let's assume a normal warhead with a spherical energy dispersion pattern, and that's an energy density of 103 MJ/m^2 at the

    • by samkass (174571)

      IMHO, the best science fiction depiction of this type of space combat was in the Neutronium Alchemist/Night's Dawn trilogy. All the mechanical (non-living) spacecraft were spherical, and space-to-space combat was accomplished through volleys of pods that contained weapons and countermeasures launched in swarms. The series depicts several space battles, as well as some space-to-ground attacks that are pretty fascinating reads. The series is highly recommended except for the ending-- in paperback it's spli

      • Re: (Score:2, Interesting)

        by dakohli (1442929)
        I enjoyed Hamilton's work as well, of course the ending was not satisfying at all. I suspect he just ran out of plot, and finished it up quickly.

        How about Larry Niven's "Protector" which featured dueling Bussard Ramjets if memory serves?

    • From the Strange Horizons website, oldie but still a goodie: http://www.strangehorizons.com/2005/20050606/hunter-1-a.shtml [strangehorizons.com]. It comes in 2 parts and there is a link to it at the end of the article. Also, while you're there, this is my favourite (off-topic) article: http://www.strangehorizons.com/2004/20040405/badger.shtml [strangehorizons.com].
    • by fermion (181285)
      Mass drivers, as used to destroy planets in fiction such Babylon 5 is ideal. Proper use of the technology will insure victory, just like the atom bomb ended world war two.

      If we are talking about some sort interplanetary war, the winner will be decided by the planet that has the technology of efficiently shifting the orbit of the solar detritus so that there is high probability of impacting the desired planet. It would be reasonable that planetary defenses could destroy several of these rocks before they

      • by lgw (121541)

        If you have the physics for interstallar travel, you likely have the physics just to mess with the opponent's star, creating a solar flare violent enough to burn away the atmosphere of the planet you don't like.

        If you really want to throw mass around, solar sails and patience do the trick.

        Heck, any weapon that isn't just turning the power of the nearby star against your opponent is probably second-rate.

    • Heinlein (Score:5, Informative)

      by Garrett Fox (970174) on Thursday December 17, 2009 @04:31PM (#30478502) Homepage
      Sounds like the premise of Heinlein's "The Moon Is a Harsh Mistress". Revolutionaries on the Moon take control of a mass driver and start flinging multi-ton barges at Earth, with just enough remote-control maneuvering that the shooters can call up Earth afterward and ask if they'd like to surrender.
    • The point that nukes wouldn't generally be useful is a good one. And the point that kinetic weapons would be ideal also makes sense. However, I'm not completely convinced by the emphasis on orbital mechanics. In order for that make sense, one needs space travel to be cheap enough and convenient enough that one can easily have lots of ships in space. If that's the case, one needs efficient enough propulsion systems that will make orbital mechanics not matter as much. They'll still matter probably (and certainly matter more than they do in standard scifi) but I'm not at all convinced they'll matter as much as he makes it out.

      That's all a question of the posited tech for the battle. There's the old question of whether it's better to build bigger ships with bigger weapons or smaller ships with smaller weapons. Bigger ships are assumed to be better-protected. But what's the damage model like for taking a critical hit? In the age of sail, combat effectiveness was whittled away with the cannon fire. The bigger ship always lasted longer in a fight. In the age of battleships, sudden critical hits could happen but armor still ruled the

  • by sznupi (719324) on Thursday December 17, 2009 @03:36PM (#30477582) Homepage

    More powerful weapons, with greater range. Any direct hit with intended kind of weapon knocks out of the action at the least. Mostly only active countermeasures are effective, unless you can exploit the environment somehow or are good at camouflage. Never stay put. One big cat & mouse game. And so on.

    The factors that shaped this will be even more pronounced in space, with the added fun of predicting position (speed of light limit). Which makes majority of SciFi depictions that more disappointing; limited in popular formats to somewhere between WW1 and WW2 state of affairs.

  • I've long been looking for a space-fighting video game that actually uses real laws of physics. The closest I've seen so far are things like 2D Gravity Wars (sort of like Scorched Earth except your shots are affected by gravity of small planets between you and your target. Heck, even the classic Asteroids is more realistic than just about any other space shooter these days.

    Most space games since Wing Commander and even Descent have strange limits like maximum speeds, and never let you go into uncontrolled

    • VegaStrike has indirect speed limits. Your shields can only handle a certain amount/speed of debris before it starts depleting. You can go as fast as you want, but if you go too far over your rated speed for too long, space junk blows you up.
      (comment based on VS from some years ago, so may be different in more recent builds)
      Admittedly, EVE doesn't explain why there should be speed limits. Other physics elements such as thrust, mass, and rotational velocity/acceleration are taken into account in fairly reali

    • I would love to have a video game where if you accelerate to c. you end up flying past the battle so that by the time you turn around and come back 1,000's of years have passed and there is no more battle and peace has been around for most of the time....

      MISSION FAIL!!

      • by Imagix (695350)
        Independance War somewhat had this (Speeds around c), as did Elite II: Frontier (having to slingshot around your combat due to realistic physics).
    • by JSBiff (87824)

      Wrt maximum speeds, I've always figured that was an allowance for the reality that computer frame rates are limited, so it's probably difficult to render over a particular speed with good results, and particularly with PC titles, different computers have different limits, but you are trying to provide a consistent experience on any computer which meets at least the minimum requirement.

  • I have always respected JMS for how 'realistic' he chose to portray space physics with the movement of his StarFury ships and the beam weapons. (As a side note, I could never understand how the station was able to rotate under the support struts when the station was obviously move massive.

    • The "support struts" only really supported the Solar arrays and microgravity bays, things you wanted to either keep in zero-G or keep pointed at a star.

      But most of the mass you wanted to have gravity so most of it rotated....

      Of course Babylon 4 was batter station but some jerkass stole it. It had counter rotating sections whicvh meant it would spend less in fuel to stabilize itself that B5. Probably why they torn down B5 after about 20-30 years worth of service....

    • by c6gunner (950153)

      I have always respected JMS for how 'realistic' he chose to portray space physics with the movement of his StarFury ships and the beam weapons.

      Too bad he ruined it by having psychics and alien space-gods, and messiahs coming back from the dead. Love the stories anyway, but as far as realism goes .... not so much.

      (As a side note, I could never understand how the station was able to rotate under the support struts when the station was obviously move massive.

      I always assumed that the stationary portions of the station had thrusters. You use the stationary structure to induce a rotation in the rest of the station, and then use the thrusters to counter the natural reaction. Once everything's rotating at it's proper speed you'd only need the thrusters once in a while in order to counter whatev

      • I generally prefer sci-fi to use mysticism and magic when they want to get some unexplained magic, so I quite liked the psychics / gods. I prefer the approach (I'd say there's a fair helping of it in BSG and even Star Wars) to, say, Star Trek's tendency to just make up crazy bits of science. Star Trek's science focus *was* quite cool and in a sense made it all somewhat believable. But if they need a magic solution, I find it less jarring for it to be actual magic than for people to repeatedly do stuff th

      • Re: (Score:2, Insightful)

        by cthulu_mt (1124113)

        psychics and alien space-gods, and messiahs coming back from the dead

        Did you miss the memo about sufficiently advanced technology? I believe it was sent by Mr. Clarke in the Long Term Projects department.

  • Only point I'd add is that differences in velocity between enemy ships in nearby (but not identical) orbits may be on the order of thousands of mph.

    Targeting such a fast moving object is difficult, and launching any kind of projectile or missile to intercept it will require enormous energy and reaction mass to get to it, assuming even that you launch it at the most efficient instant.

    High power lasers are easier to point and shoot, but you'll only have a few seconds with the target in range. I don't think b

    • Re: (Score:3, Interesting)

      by lgw (121541)

      but aiming at something hundreds of miles away, moving at thousands of mph, the slightest vibration in the ship will send the beam several feet off course by the time it gets there. You won't be able to steadily drill a hole in the enemy ship, you'll just illuminate different parts of the hull w/o much heating or impacting any specific area.

      The Airborn Laser program has to cope with the same problem, and shoot through an atmosphere. It's not that hard once you realize that you lens doesn't have to be made of glass. When you can change your lens geometry microsecond-by-microsecond, you can easily keep the beam on target over distances as short as hundreds of miles (and ever correct for atmospheric turbulance). If you dump enouh energy into the target it won't matter much that it's spead out a little. Of course, you want your laser to delive

  • I predict... (Score:3, Insightful)

    by hatemonger (1671340) on Thursday December 17, 2009 @03:41PM (#30477668)
    Assuming technology exists to accelerate space ships to interplanetarily practical speeds, what's to stop warring planets from accelerating an asteroid in the same way and in the direction of the enemy planet? Or take that acceleration technique and speed up some ball bearings to ridiculous speeds and send them on their way towards something with a predictable position like a space station? Hell, you could use millions of ball bearings like a mine field, because any ship traveling through the bearings will have such a high speed relative to them. I just wonder that if we currently get so butthurt about orbiting space debris, a space war will focus on simple kinetic weapons at huge speeds and from huge distances.
  • His last option, Peace, is the most likely. Space is so dangerous that most battles would end with both sides dead or dying.
  • not quite (Score:4, Interesting)

    by wizardforce (1005805) on Thursday December 17, 2009 @03:50PM (#30477826) Journal

    we'll be able to tell exactly what trajectories our enemies could take between planets: the launch window.

    That assumes that there aren't technological advances that allow spacecraft to brute force the problem. Launch delays in terms of orbits mostly occur because of energy and fuel requirements. If you've got propulsion licked, you can pretty well launch when you wish.

    to point high-power radar-reflection surveillance satellites at certain empty reaches of space

    That isn't going to work for stealth spacecraft which are a trivial engineering problem next to propulsion. Space is huge, you're going to need very very powerful sensors to find anything the size of a ship.

    Second, there are only a few ways to maneuver the attitude of a spacecraft around – to point it in a new direction. The fast ways to do that are to fire an off-center thruster or to tilt a gyroscope around to generate a torque. Attitude maneuvers would be critical to point the main engine of a space fighter to set up for a burn, or to point the weapons systems at an enemy. Either way, concealing the attitude maneuvers of the space fighter would be important to gain a tactical advantage. So I think gyroscopes ("CMGs," in the spacecraft lingo) would be a better way to go

    Correct. Burning fuel just to change the ships' direction is a waste. Utilising conservation of angualar momentum with a gyroscope is efficient and technologically feasible. Sapcecraft that are large and non-sperical are going to be very difficult to manoeuvre. Concentrating most of the ships mass in tight near the center is the way to mitigate this problem.

    A kinetic impactor is basically just a slug that goes really fast and hits the enemy fighter, tearing through the hull, damaging delicate systems with vibrations, throwing gyroscopes out of alignment so that they spin into their enclosures and explode into shards

    I don't think kinetic impactors are the way to go here. A high energy neutral particle beam is demonstrated to work effectively and doesn't spread out too much over a vast difference. (not more than a few cm over 1000 km) There is no hope of stopping it either. A few GEV beam of particles shows no mercy and can punch through several meters of shielding.

    lets just go with a tool that we already use to cut sheet metal on Earth: lasers. In space, laser light will travel almost forever without dissipating from diffraction

    Lasers ablate material off the hull which obscures the target. Not quite the most effective weapon.

    Deflector shields like those in fiction are not possible at present, but it would still make sense to armor combat spacecraft to a limited extent.

    modified plasma window technology can function as a shield in a sense. Thick armor on the hull impedes the ship's ability to rotate.

    What do we do to hit them on the ground? Well, strategic weapons from space are easy: kinetic impactors again.

    Ammo is a problem. How many impactors can you have on an orbital defense platform? Just use particle beam technology to wipe out the ground force.

    So, I think the small fighter craft would be nearly spherical, with a single main engine and a few guns or missiles facing generally forward.

    Only if you don't plan on re-entry as a sphere is non-optimal for utilising the effect that shaceship one was supposed to use; that is using a flat surface to force a ubble of air to pool in front of the craft and buffer against the heat.

    • So, I think the small fighter craft would be nearly spherical, with a single main engine and a few guns or missiles facing generally forward.

      Only if you don't plan on re-entry as a sphere is non-optimal for utilising the effect that shaceship one was supposed to use; that is using a flat surface to force a ubble of air to pool in front of the craft and buffer against the heat.

      Isn't an ablative/heat-dissipating re-entry surface only needed because of limited fuel for propulsion?

      If we assume that the propulsion problem is licked (as you did earlier), wouldn't you be able to use the engines to continually slow down as you descend lower into thicker atmosphere, thus avoiding the intense heat of friction braking?

  • by L3370 (1421413)
    Lasers lasers lasers! I'd imagine long distance battles (10's, 100's, 1000's of km) so anything traveling less than the speed of light would be horribly ineffective against evasive maneuvers.

    And someone needs to invent something that makes laser pew pew sounds in the void of space!
  • If you fly at near the speed of c. since time on your ship would slow down, looking out your view port would it appear as if your ship was traveling faster than c.?

    • by julesh (229690)

      If you fly at near the speed of c. since time on your ship would slow down, looking out your view port would it appear as if your ship was traveling faster than c.?

      Yes, and no. While from an inertial frame your acceleration appears to reduce as you approach c, from your own frame it appears constant, but c appears faster: c always appears to be a constant amount faster than you're travelling.

      (IANAP, YMMV, which it almost certainly would if you were travelling anywhere close to c.)

  • in the war of 1812 (Score:5, Interesting)

    by circletimessquare (444983) <circletimessquare AT gmail DOT com> on Thursday December 17, 2009 @04:01PM (#30478020) Homepage Journal

    the peace treaty was signed in december 1814. but a major battle in the war, the one that made andrew jackson's name, took place in new orleans AFTER the peace treaty. the combatants didn't hear about the peace until february 1815

    http://en.wikipedia.org/wiki/Battle_of_New_Orleans [wikipedia.org]

    i think we'll see a return of that in space warfare. sure the wide open vacuum of space changes everything, but so does the sheer vastness of it all. in future space battles, it wouldn't be surprising for a peace to be signed, the agreement beamed to combatants at light speed... and yet the battle still rages on for weeks, months, maybe even years. the battlefield might be lightyears away from the capitols

    i don't even know if the idea of central command will work. we're used to modern tom clancy style special operations nowadays where forces engage the enemy while analysts watch them in realtime in pentagon/ cia warrooms as infrared images on massive screens, caught from spy satellites high above

    but you can't do that in space

    so warfare in space will deevolve from this sort of highly vertically integrated command and control aspect. you can't, for example, have a commander on earth relaying instructions to his troops on mars in real time, simply because the radio signal takes 10-20 minutes, one way (depending upon orbital locations)
     

    • and yet the battle still rages on for weeks, months, maybe even years.

      At such distances, why would anyone bother to attack someone else? The time and resources required to even bother would be immense. Even in ancient times, information traveled to the battlefield in less than a month or two let alone years. Then there's the problem that sending a space fleet on a several year voyage carries the risk that by the time it got there, the enemy would have made several years of advancements in terms of techn

  • . . . i'ma gonnin' ona' space battle!"

    But the LHC thing seems to have the reliability of a blunderbuss.

    For my next space battle, I'm planning to pack something that ejects gamma ray bursts.

    Y'all behind the weapon might want to take cover . . .

  • "Therefore, I contend that the most effective kinetic space weapons would be either flak shells or actively thrusting, guided missiles."

    Right...because flak shells which emit hundreds or thousands of tiny projectiles are a great idea in orbit. Some will probably reach escape velocity, some will impact the orbited body, but a many will likely remain in orbit. I don't think it's in the aggressor's interest to generate a load of space junk.

    "If launched from the ground, armor must be minimized to reduce the l

    • by julesh (229690)

      Until we have active mines on asteroids or the moon, space-based construction doesn't buy anything. If you still have to haul the raw materials out of Earth's gravity well, then you still have to pay the launch costs, sorry.

      Until we have such mines, there's not really a lot in space to fight over.

  • Martian colonists get angsty, and decide to get liberated. The Earth-based companies that own the colonies decide (naturally) to launch a transport full of a few thousand space marines to retake control. That trip takes a few months, minimum, even on the fastest, least fuel-efficient course that the transport is capable of making. So the colonists know that the marines will be dropping in, well in advance of their showing up in orbit.

    Now, instead of using the ship's main engines to decelerate completely on

  • Space battles are still the realm of science fiction. Depending on how far out we push the speculative technology, we could stick with relatively hard SF with direct extrapolations of current technology or softer SF with more fanciful tech employed in a plausible and self-consistent fashion.

    There are certain things you would expect, regardless of the technology. For example, consider the Starfury from Babylon 5. You have omnidirectional thrusters. This would be expected in a combat ship. It might be conside

    • One example I could think of is if the ship's primary armament is a big gun running the length of the ship necessitating the entire ship be maneuvered to aim it.

      One of the most influential battles of the United States Civil War arose from the battle between the Monitor and the Merrimac. The Monitor had a turret which swiveled, thus freeing the Captain to manuever the ship as he wished while allowing his crew to aim and fire at the Merrimac without interruption. The Merrimac had fixed guns which required

  • FTA: "It's different than land, sea and air battles in that the enemy can come at you from any direction". I don't know what kind of aircraft you fly, but mine generally operate in 3 dimensions.

    Second, are we assuming that the aliens have equal technology as us? If we set up our defense network in an orbit as they suggest, and the aliens have alternative means of propulsion, we are hosed.

  • Do we really need to fight over it?
    • by ZaMoose (24734)

      Ahhh, but the habitable planets in said big place are rather few in number and thus all the more valuable.

      • One would assume that what's habitable for Species A, wouldn't be normally habitable for Species B.

        Unfortunately I'm guessing that in most space battles it will be the case that A=B=Homo sapiens.

  • In earth battles its the assault on the senses: incredibly loud noise all the time, the smells of gunnpowder and burning. And you are in hand-combat situation, you have the bitter smells of sweat and blood, the shooting and screaming. This all helps pump up the adrenaline. In contrast space battles would be mostly sterile and silent, until you took a direct hit.
    • I don't know about that. I am tempted to agree with you, but I have played plenty of video games where nothing was at stake...yet, my adrenaline levels got really high!
  • Because of the distances, missiles won't work. Too easy to stop them. They need some kind of sensor to detect their target, a laser should be able to blind whatever sensor they are using, even if the laser can't destroy the missile.

    Has to be some speed of light weapon, laser being the most obvious one. The hard part will be predicting where the target is

    • going to be, when the laser arrives

    . Even if you are 3 light seconds away, that is more than enough time to zig zag your way to safety.

  • SPOILERS FOR THOSE THAT HAVEN'T READ STEPHENSON'S "ANATHEM"

    I'm surprised no one has brought up Neal Stephenson's "Anathem" yet. True, the Geometers vs. Arbreans is (initially) a space-based weapons platform vs. ground-based targets affair, but there's a ton of discussion of orbits, etc. that make for very interesting (and compelling) reading.

  • Somebody what actually awarded a PhD for that tripe?! It better have come from a school that also offers a degree in small engine repair.

    As a PhD in a hard science, that is offensive.

    Sheldon

  • In combat, you want to minimize the surface area the enemies can fire at, to increase the chances that they'll miss. If your ship is at the back and it's elongated, you can point it in the right direction and you'll have a very low surface area in which the enemies can hit with the same firepower. You could say that with computer assisted aiming everyone has 100% accuracy, but in reality that's way incorrect - space battles will not be occurring at 200m distance like in Star Trek, you'll start firing at a h

    • by selven (1556643)

      Also, I disagree with the idea that weapons will be scattered around the ship's hull. That's by definition, increases your weapon hardware expenditure by 100% at least (two weapons on opposite sides can still draw from the same energy pool though). You can control your direction to point at your enemy even while your orbit is speeding you along in some completely different direction, so pointing all weapon forward works best.

  • by earlymon (1116185) on Thursday December 17, 2009 @05:23PM (#30479364) Homepage Journal

    I read the article - despite many correctly spelled words, it is absolutely devoid of strategic or tactical thought and shows evidence that the author has no combat planning experience - and I'll go out on a limb and say that there are so many artificial constraints that I very sincerely he ever read - or understood if he did - the Art of War.

    You're a Mars Colonist. You revolt. OK - you're _expecting_ an attack. You won't wait for anything orbital from Earth - you'll pre-position killer drones - a mine field if you will - beginning at the LaGrange point between Earth and Mars and in layers anticipating the attacking fleet. Somewhere within the field - or to its edges - you'll arrange tracker-transmitters that will generate fake attack messages seemingly from Earth friendlies in an effort to steer the attackers into the mine field.

    You're an Earth administrator and you're not idiot - your agents on Mars tells you that not only is the violent revolt coming, deep space assets are being prepared to thwart your approach.

    You're a Mars propagandist - you shape public messages in order to inflame Earth, but one of your messages is seeming fuck-up, and you accidentally give away a secret regarding your strategic forces - but it's a plant to entrap Earth forces at a point besides the (kinda) mid-flight-point minefield - you're actually planning to outflank Earth.

    You're a Mars agent - you seize an Earth civilian spaceliner and announce terrorist demands. You're not Earth, so you're not evil, it's a complete distraction, so your partner agents already on Earth can try to mess up launch logistics for Earth forces while paying attention to the wrong crisis.

    And after a mile of more text like this - you can have all the space opera that the author wanted.

    Space is simply not Earth.

    TFA reads to me like Mars is supposed be some kind of Fort Apache - and I don't buy it.

  • by citizenr (871508) on Thursday December 17, 2009 @06:19PM (#30480212) Homepage
    As far as I know Independence War series (1 & 2) are the only PC games that implemented 100% true Newtonian physics. They took care of movement, heat issues, detection by heat and visual, whole shebang.
  • Atomic Rockets (Score:3, Interesting)

    by Nyrath the nearly wi (517243) on Thursday December 17, 2009 @06:48PM (#30480646) Homepage

    I have a few notes on space combat, lasers, railguns, stealth, tactics, delta v, nuclear shaped charges, ship design, and whatnot on my website. I am not a Ph.D, but many of the people who contributed are.

    Atomic Rockets (index) [projectrho.com]

    Space War: Introduction [projectrho.com]

    Space War: Detection [projectrho.com]

    Space War: Weapons Intro [projectrho.com]

    Space War: Weapons: Conventional [projectrho.com]

    Space War: Weapons: Exotic [projectrho.com]

    Space War: Defenses [projectrho.com]

    Space War: Warship Design [projectrho.com]

    Space War: Strategy and Tactics [projectrho.com]

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