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Space Chess

  1. Nov 7, 2013 #1
    Well I'm planning a story, that would play in the not so far-far away future. I'am aiming around Mohs scale level 4, i wonder do i reach it?

    Basics about the plot, to understand the reference frame.

    Earth is de facto ruled by five gigacorps, they are little better then organised crime (present day drugs replaced by similarly addictive happiness pills and virtual reality with brain stimulators), even those government officials who didnt became their corrupt yesmen, are powerless against them, since they control most resources and military power in the Solar system.
    (There are no starships, warp drives.)
    The government is happy, that they at least dont make World War III on Earth, but rather make wars in space and on other planets and moons.

    Asteroid mines are particularly valuable, many times, they want to capture them. Or own a bigger area of Mars, Merkur (valuable metal mines also) Moon (He3) since theese bigger celestials shared by more than one corps.

    They use both lasers and missiles, since lasers rather meant to take out the outer defence systems than blowing up ships. (And cannons firing inflating shells, almost exclusively used for self defence.)


    The chess analogy came, because like chess, you can see every step of the enemy in space, yet you still have to be a good strategist.
    (Although i wondered about a slight chance. If everyone expects to see the flames of a nuclear or fusion drive from billion kilometers away, maybe a magnetic sailed ship is rather identified and dismissed as some big meteor by the system? Hibernation exists in this fictional universe, so it can cool down.)

    And the different units would be (following this analogy) :

    Bastions : battlecruisers, big delta V and firepower, too bad they cant be everywhere.

    Runners : frigates, top speed and manueverability on the big scale, they meant to threaten, attack enemy convoys and undefended colonies. But they arent really powerful against serious enemy.

    Queen : motherships, giant spinned ships meant to regroup surface and orbital forces to capture and keep colonies. While they arent really meant for deep space superiority, but they can counter most threat.

    Footman : fighters, small cheap orbital craft (mostly controlled by drone operators), meant to protect from missiles (they can shoot them in the back, to take out their engines and backward sensors, that enables the missile to be controlled remotely to the target, and only open their vulnerable frontal sensors in the last seconds) do orbital combat and close range combat - you cant capture something if you dont come close.
    If you want to capture an asteroid mine for example, a defender unit can seek cover from missiles and long range laser fire. Even if you risk divide your fleet and come from two opposite directions, half of the missiles at least would be wasted, while in this case, double amount of fuel is far enough for the fighters contrary to the classic deep space example.

    Knights : destroyers, heavy firepower and armor but a lower delta V, good to counter small light ships, but primary target for missiles.


    Civilan craft armed to do some privateering also exists.



    http://gizmodo.com/5426453/the-physics-of-space-battles

    I didnt browse the entire gizmodo.com, this one isnt crackpot to me, although i wondered maybe it used the word radar instead of IR sensors to make it more understandable to people?

    That suggested that combat spaceships should be ball like, although i rather imagine them rocket like, since the enemy usually comes from one direction, and rocket like shape minimises their cross section, but as i said above, i imagine fighter like craft to do close range combat. If they are near spherical, could they at least land on the surface of a planet with air? And take off?


    About propulsion, i thought : interplanetary crafts with a delta-V about a few hundred km/s, and acceleration in the range of tenth g. Some nuclear electric or fusion drive.
    Orbital crafts delta-V around 50 km/s, and 1-2g acceleration, some nuclear power source, possibly nuclear thermo drives.
    Missiles with chem fuel (they dont nuke each other, its an unwritten agreement, and bombing with nuclear propelled spacecraft is quite similar...) around 20km/s delta-V and 10-20 g acceleration.
    That means against manueverable spacecraft, their range is limited to a 100.000km max, if i calculate correctly. They use long range bombardments against stationary targets like colonies to soften up the defence system, so the arriving fleet dont have to face a thousand batteries.


    --------------------------------------------------------------------
    The rather mystical stuff that would play a plot role :

    self sustaining alien nanobots found in a cavern of Merkur, the only remains of a destroyed would-be starship. They would be a bit like midi-chlorians, allow someone to sense and manipulate brain activity and electronics - it should be noted theese abilities are from omnipotent, determined humans and electronics protected from anti-electronic warfare, secure laser comms rather then simple radios are quite resistant at least.

    I wondered also about quantum nonlocality and phonon based instant far-away communication.
     
  2. jcsd
  3. Nov 12, 2013 #2
    Another question, linked to the plot.

    Based on existing design plans, could a fusion reactor go off like a bomb?

    I think about, what could you do against an "indestructible" lunar fortress that has a 100km long shaft, with a mega coil gun, and a reactor at its basement? (And of course a very serious defence net at the top.) Provided that you can do an inside hacking job, you can reach the position necessary for it.

    My other idea : while i cant really imagine reversing that mega coil gun to blast itself without serious rewiring... but it could simply stop, when just lifted the missile to its top.

    If it is simply falling back, then... Moon's gravity is 1/6 g (roughly 10/12 m/s2), if something falls from 100km, then it will impact with more than half km/s impact am i right?
    (t2 = s / (a/2) v = a X t kinetic energy = 1/2 m X v2)
    That doesnt do that much damage if it is a light missile, but if it is a heavy asteroid bomb, for example a 100 kg, or a mass of a ton one... that could do critical damage to the reactor block nearby to the cannon, and the pillars also, possibly collapse the whole structure, couldnt it?
     
    Last edited: Nov 12, 2013
  4. Nov 13, 2013 #3
    These gigacorps, do they fight to win?
     
  5. Nov 13, 2013 #4
    "These gigacorps, do they fight to win? "

    The conflicts are limited to colonial warfare, and industrial espionage. Maybe i could say they rather want to gain, than destroy their enemies entirely. War is an extension of business.

    I think it is not without example, countries of Europe rather fought on the colonies for much time, instead of World War.
    It is one thing that they could have fought the conflicts of the Cold War era with nuclear missiles, but in reality they used conventional weapons, and fought smaller local conflicts.


    Well I thought that one of the corps would be in the middle, and the other ones are hardly making any serious aggression against them, since they have built the Vault, the lunar fortress i mentioned above, a 100km deep shaft with the main treasury on the bottom, and with two mega coilguns that could fire heavy guided asteroidbombs to bomb Earth, and they can be also launched to an elliptical path to bomb the other side of the Moon also.
    (My calculations for the later : 2g along the 100km way, reach 2km/s vertical speed then around 1km/s horizontal speed with rockets.)
    So they could totally destroy their enemies on Earth and Moon even without nukes if they are really pissed off.

    But they dont really want to destroy their enemies they want them to pay, offer them help in times of need, then demand usury.


    I plan, that only the main villain would be THAT ruthless, that when she see, she is defeated, she orders the computers of the fleet to crush into Earth, effectively acting as a really big dirty nuclear bombs...
    (Another ones will be crippled also but their leaders rather flee than now i will nuke you for revenge, and dont care about that i will suffer the same fate...)
    That would be thw time for the conflict between the heroine and her, with some good old cliche.
     
  6. Nov 14, 2013 #5
    Well about the nature of warfare... i thought, that after the Vault is destroyed, the conflicts will escalate... the one corp (Destiny) that built the Vault and got usury from others is hated by everyone, they will launch to finish the crippled corp.

    (The government can announce : Please gentleman we ask you kindly seek diplomatic solution... and by the way if someone escalates the conflict to the level of using nuclear missiles, they will be hunted until death... on the contrary if someone ends the conflict, they will be forgiven...

    The leaders of Destiny take that as a message scripted by other corps (since the government was almost their puppet since decades...), their enemies arent afraid of a possible nuclear retaliation, and they can still flee and enjoy their old days... well, stripped from their might, but still alive and rich.)

    After they tasted "real blood" a big battle, there will be bigger conflicts, although still not we use everything from nukes to bio weapons to destroy others.


    I wondered about Martian colonies also.
    I think they can be founded by miners sent to the asteroid belt, many of them are exiled from Earth, others cant return to strong gravity, on Mars, at least they can see a sky, drive a car through the desert, a combo of leaded glass and magnetic fields can protect from cosmic radiation, arent they?

    I thought about a little bit Western like feeling. Maybe as they dont want to puncture the habitats, they can even use swords developed from plasma cutting tools?
    Well i dont intend to turn them into Jedi lightsabers deflect bullets and lasers... but still, as i wrote above also i see justification for kind of close range combat in the future also (at present day, most people still killed by knives and clubs, and commandos can have missions where they fight with autopistols and even use bare hands and combat knife instead of calling the artillery.)
     
  7. Nov 14, 2013 #6
    A man named Winchell Chung has actually created a website completely dedicated to hard sci-fi writers.

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

    You'll find a lot of good stuff there, including hard numbers. I suggest looking at the engines and weapons sections first.

    I think that your gigacorps would use nuclear engines of some sort(lots to choose from). The performance of nuclear engines for combat purposes so vastly outclasses electric and chemical that the factions would be morons not to use them anywhere they aren't in an atmosphere.

    Weapons are a little trickier. We know, now, how to make something called a casaba howitzer. These are nuclear warheads that spit a nuclear death beam out one end when they explode. If this seems infeasible to you, consider that it uses the same principle behind Orion pulse units. Note that, even if these are a primary armament, the captain wouldn't necessarily use them on things like colonies. Nukes of any sort would just obliterate the colony and leave his faction with nothing to show for it, so he'd give the colony a chance to surrender at the very least. At lower tech levels, these are, by far, the most effective weapons your factions will have available to them.

    Free-electron lasers are also worth mentioning. These scale quite nicely. The high end of these is an X-ray doom beam able to hard-kill targets out to a light minute. Downside is such a monster needs an accelerator ring a kilometer in diameter. Not going to putting an X-ray FEL on anything small. Naturally, lower power lasers require smaller accelerators.

    There are a bunch of other weapons I could talk about, but those are my favorites.
     
  8. Nov 15, 2013 #7
    I read articles from atomic rockets already, although in certain cases, i liked the analysis of (for example) TV troupe better.

    Maybe i'm too down to earth, but yet, i dont really think about combat distances bigger than 100.000 km, focusing a beam properly with all the waste heat deform your mirrors, enemy jam your sensors etc...
    And nuclear propelled spacecraft can easily outrun chem fueled missiles over a big distance, although when things escalate from small games to the final battle, i can imagine the villain's forces launch a number of nuclear missiles and stuff like that.

    There will be also room for some alien magitech, i thought about short range plasma cannons, hypervelocity harpoon, self repairing liquid like armor.

    About the magic stuff, i revised the plot, i think its better if a science team goes to investigate a strange asteroid really close to the sun, then the stuff just found by the chosen one in some cavern.
    I think it deserves an explanation, that the alien nanobots are self repairing even in dormant state, they arent entirely immune to decay caused by heat, cosmic rays, quantum uncertainity whatever...

    And as magic stuff also needs consequence : i thoguht about quantum nonlocality based communication, but wide band FTL comm would allow droning spaceships from any distance, killing all fun. So bandwidth of that speculative communication would be somewhat like one word or feeling / day.
    Even if they could reproduce the equipment with human technology, they would still need to build a receiver more expensive than hibernation and life support.
    (Also others aware of the existence of the alien magitech might possibly find a way to jam it.)
     
  9. Nov 17, 2013 #8
    Is there any graphic program, that simulates the orbital mechanics of the Solar system?

    Is it possible that a fleet can reach Earth from Mars faster than a fleet not that long ago sent to Merkur from Earth, could return? (Both would go with full speed, and yeah return means four times as much fuel, unless they order to ships to crash into Earth.)
     
  10. Nov 17, 2013 #9

    Ryan_m_b

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    Staff: Mentor

    You're going to be hard pressed to make this a Moh 4 hard sci-fi story but that doesn't mean you can't have a good milSF setting. Regarding ship design I'd advise you to take a look at this page on atomic rocket: http://www.projectrho.com/public_html/rocket/spacewarship.php

    Specifically the trade off section. Basically it's a simple way of designing a ship based on what percentage of its systems are devoted to propulsion, weapons or defences as well as how big it is. Also if you're looking for a good example already in fiction along these lines I'd recommend the Lost Fleet series. It features some interesting discussions on tactics regarding different ships based on their capabilities.

    Regarding the giga-corps that's a fairly standard SF trope, and a good one for illustrating the problems of unbalanced economic power IMO. I'd suggest though that you're careful in how you word it. Some works like the Mars Trilogy do a good job of illustrating that huge corporations are essentially social constructs supporting a plutocracy. Other stories I've read try to pass off such organisations as stereotyped evil corporations that only care about profit (in which case a lot of what they do like genocide doesn't make much sense). TL;DR I suggest making it clear that the giga-corp system is a tool of the economic elite.

    Lastly regarding transfer and fuel for any transfer to happen in an interesting amount of time (i.e. not months-years) it's pretty much going to be a straight line sprint accelerating til halfway then turning over. That would require an insane amount of fuel and a magic propulsion system but this is science fiction. You should know though that it's not as simple as requiring four times the fuel, it's actually far more as you have to bring fuel for the extra fuel, and fuel for that, and that...etc. A back of the envelope calculation tells me that to get from Earth to Mars (median), at 0.1g continuous (giving a roughly two week travel time) with a propulsion system with an isp of 25k (which is IIRC the estimate for some things we could actually build) you'd need 14kg of fuel for every 1kg of ship. TL;DR again: Remember to use the rocket equation if you want realism.
     
  11. Nov 17, 2013 #10

    Bandersnatch

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    Science Advisor
    Gold Member

    There's Orbiter(http://orbit.medphys.ucl.ac.uk/). It lets you fly around the Solar system in a variety of crafts, both within and without the boundaries of reasonable plausibility. If you dig around in the modding section you'll find even more, or just learn how to mod one with the capabilities you like.
    While it won't let you model various scenarios in a simple way, it should let you establish good intuitions of orbital mechanics, typical maneuvers, fuel economy and time scales involved.
    It's also fun to play with.

    Alternatively, there are gravity simulators like these ones:
    http://www.gravitation3d.com/
    http://www.orbitsimulator.com/gravity/articles/what.html
    You should be able to load up a solar system model, and introduce a new body(spacecraft) to see how it behaves.
    In my opinion they're a poorer choice if you want to educate yourself from scratch. They're difficult to use, more about pure gravity and less about powered flight, and also much less fun.
     
  12. Nov 18, 2013 #11
    Thank you.

    Ryan :
    About the corps, well, i dont intend to go into some communist like propaganda, and yes, genocide isnt their agenda... except maybe one, as the main villain intend to build a totalitarian regime with robotic armies.
    An other one is basically drug pushers.
    Two of the five arent really much worse than present day countries (one's leader could say I did nothing that others in my place, with theese powers wouldnt do), just should respect common people a bit more.

    I will read the ship design part for sure.

    Yes i read the basic rocket equation, and thought ~e^4 mass ratio could be acceptable for smaller spacecraft, that is how i approximated delta-V 20 or 50 km/s, although i didnt really calculated with beginning acceleration (they could have a launchpad or something like that) and maintaining acceleration, interplanetary travel, i try to do some.
     
  13. Nov 18, 2013 #12
    Well, while i am still processing the links, do more research job (i dont intend to make it that HARD but trying to avoid too much magic), i thought about certain things...

    Basically, a fighter needs delta-V 1,66 X 2 km/s to take off from a lunar base and launch a bomb somewhere to the Moon, then land for reload.
    Earth to Moon is still around 11 km/s. With an exhaust velocity of roughly 10km/s (nuclear thermo, or speculative upgraded super nuclear thermo whatever) it is still around a mass ratio of e.
    That can be their inherent ability.

    However I can imagine possible situations where bigger delta-V is needed, you want to launch a force from a distance, and the purpose is beyond hit something with full speed.

    I thought in that case, three or two of them can surround a big propellant tank, attach to its arms, and accelerate, slow down together. They could detach (and reattach) also to move more freely.
    (A bit similar mechanism to aerial tanker, however the propellant isnt explosive you dont have to calculate with that kind of hazard.)

    Of course i cant deny that the big propellant tank will be vulnerable... but the same applies to anything comes close. If you need big delta-V you need big tank, or big reactor.
     
  14. Nov 18, 2013 #13
    While Bandersnatch suggested Orbiter, a more entertaining learning tool would be Kerbal Space Program. Design and fly a few rockets, and you'll discover that you have learned to intuitively understand rocket science and orbital maneuvers.
     
  15. Dec 2, 2013 #14
    Thanks.
    Are there any map of Mars?

    I wonder, how could i apply the biggest mountain, canyon system into the tank battle on Mars.
     
  16. Dec 3, 2013 #15
    Olympus Mons is so huge that if you were standing on it, the horizon would still be the mountain. So I don't know how you'd make that interesting in the context of a tank battle. Valles Marineres is even larger scale, but it has interesting terrain.

    As for a map, there is always the Mars map in Google Earth.
    http://www.google.com/earth/explore/showcase/mars.html
     
  17. Dec 6, 2013 #16
    Thanks, hmm maybe Olympus Mons could be a fortress to siege.

    " http://www.projectrho.com/public_htm...acewarship.php" [Broken]

    Read it again, but I didnt see too much engineering suggestion. But i'll process again the mothership section. :)

    So my following speculations are based on gizmodo.com, some basic equations, present day navies (destroyer isnt the lightest attack or patrol ship, no dreadnought) and what is cool.


    Basic Situation 1 : frigates intercept convoy halfway, course is near perpendicular, closing speed somewhat 100km/s. Missiles add a 25 km/s either with lots of chem fuel, or some nuclear thermo, although i prefer the first, dirty bombs directly vs spacecraft isnt as bad as use them against planetary defence but still...

    Phase 1 long range combat : distance 90-60 thousand km-s.

    Due to focusing and targeting problems caused by heat deformation and jamming, even lighter ships can be expected to survive at least one laser hit.
    Cool down and recharge rate one minute / shot.
    Five laser shots in this phase.

    Big cannons only fire once, then shuttered, otherwise a series of smaller lasers melt them.
    (Focusing mirrors are narrow band dielectric mirrors, while they are very effective against their own wavelength, they arent effective against other wavelength, and they are already heated by their shot)

    Acceleration have a significant role, while 80 cm (light lag 2/5 sec from 60 thousand km and 1g ) arent enough to dodge a laser, but it can be enough not to hit the same location twice (ablative armor), or not to hit a middle sized focusing mirror.

    Phase 2 : inertial combat 60-20 thousand km-s

    As light lag becomes smaller and smallet maintaining acceleration is only wasting your energy into heat.
    Laser arrays already lost a significant amount of accuracy due to other laser hits, even near miss can be bad.
    That is the phase when lighter ships suffer the most, make them impractical to use against destroyer or battlecruiser in deep space.


    Phase 3 : Closing in 20.000 km-s (10-12 laser shots till this phase)

    Laser arrays are almost completely ruined, overheated.

    Missiles reach their target, as they are long titanium rods, they are pretty hard to kill from front with lasers.
    (Multilayered point range defence is better.)
    Lasers meant to focus over great distrances arent really good to burn shrapnels, or kinetic penetrator pellets closing in with high speed. Armor is also barely useful, at least, the pellets can ruin the rest of the defence and attack systems.

    Point range defence shells and size, acceleration matters in this phase.

    Possibly in big fleet battles a final terminal phase, where they use even point range defence shells against each other.


    Of course, this is only one possible situation.
    In cover and orbital combat (if you intend to capture a mine for example) with the closer initial range even smaller lasers can ruin the defence system, missiles reach their target fast, so it is practically a battle of glass cannons, the redundancy of smaller vessels is better.
     
    Last edited by a moderator: May 6, 2017
  18. Dec 7, 2013 #17
    Basics with fleet design : i would say four-five main things

    Production capacity and cost (fighters dont need orbital shipyard, and reactor, so they have a great production capacity)
    Delta-V (frigates expected to have a high score in that to threat as many targets as possible)

    The sum of theese two is availability, an important thing when there are lots of scattered targets, transports, colonies.

    Firepower : lasers and missiles (a bit like WWII, missiles are slow like torpedos, lasers are unguided and they arent like bombs to just blow up a ship)

    Defence : active and passive
    Passive is armor, good against less focused lasers, can be countered by kinetics, multiple shots to same place or close range laser fire
    Active defences are
    A : acceleration, good against kinetic penetrator pellets, long range laser fire (avoid hit damaged area, focusing mirrors)
    B : point range defence the effective range of shells can be also dependant on the closing speed of missiles, at 100km/s collide with grams can damage the electronics, at 10km/s you need hundred grams or kilo to do that


    Fighter :
    50 ton base mass, mass ratio around e, 150 ton loaded, delta-V 10km/s top m/s2 around 1-2g
    Enough firepower and active defence that a squadron of 3-4 can counter frigate
    Shape is rather spherical


    Frigate
    100 ton reactor 100 ton equipment, mass ratio e^2 total 1500 ton, delta-V over 200 km/s
    Top flexibility on strategic scale, more frigates to one target to counter slower escort or scatter them if enemy dont employ enough small light ships to protect enough area
    Shape is rather rocket like because big mass ratio


    Destroyer 100 ton reactor 200 ton equipment mass ratio around e total 1000 ton, delta V lesser than 100 km/s
    High firepower and armor to counter light ships in long and middle range combat
    Shape is rather spherical, giving it more mass ratio and delta-V would result in rocket like shape, that would allow frigates to counter it by divde and attacking sides, or further decrease its availability score


    Battlecruiser 200 ton reactor 300 ton equipment mass ratio around e^2 total 3500 ton delta-V lower than 200 km/s
    Rocket like shape due to bigger mass ratio and delta-V its sides are more vulnerable, against serious enemy it needs escort


    Mothership very high mass (like 10 kton) spin ship, top score on defence however it still needs escort most times
     
  19. Dec 13, 2013 #18
    What are the chances to discover a low orbit satellite from the surface (Earth or Mars like planet with air), without radars, just passive sensors?
    (If they dont know its orbit already.)
     
  20. Dec 19, 2013 #19
    I thought that Io would be a nice scene.
    But how should i imagine the electric flux between it and Jupiter?
    Does it make a series of lightnings, aurora borealis, jam nearby radio communications?

    In an Asimov book they needed some magitech to reach Io, is it really so deep in the gravity well?

    Could a bomb like the Tsar destroy a moon like Deimos?
     
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