Hello Everyone:
I'm writing a sci-fi space combat story for my creative writing
class. So far I've got most of the story fleshed out. However, I want to be as
plausable and scientific as possible. (The only place where I want to be
technically vauge is hyperdrive.) I have some general questions for all of you
armchair physicists out there in GZG Mailing List land. 1. Which would be
better suited for space combat: lasers or particle beam weapons? 2. How does a
directed energy beam weapon damage a target? 3. Which sort of missile warhead
would be better suited for space combat? Nuke or kinetic kill? 4. I've heard
that it would be a good idea to depressurize a warship before going into
combat (the crew would be in space suits). Why would that help? 5. How would
one target a enemy ship in space (realistically that is)? 6. There would
happen to be a "Theoretical Space Combat FAQ" somewhere on the net? If there
isn't there should be.
I'd love to hear your responses. Later,
> 1. Which would be better suited for space combat: lasers or
> 2. How does a directed energy beam weapon damage a target?
from what I understand (very little) the damage is done through thermal
transfer, heat it up quick enough and you will explode something. (I may be
totally off base on this)
> 3. Which sort of missile warhead would be better suited for
Nuke, see #5, but the best way to hit a fast moving starship is with an area
or proximity weapon. ex: in WWII hitting an aircraft with a AA shell was at
best chancy, if you threw enough lead at it you would it. Once proximity fuses
started to be used cances got much better because you didn't have to hit the
plane, just get the exploding shell close enought to do enought damage to
bring it down. same principle applies here.
> 4. I've heard that it would be a good idea to depressurize a
explosive decompression. if the ship is hit and is pressurized (sp) your
valuable crew could get sucked out of the damaged section. Fires could start
(from what my Navy friends tell me that is a bad thing). and the very fragile
firing solution goes straight to hell, because of all the yawing and pitching
as your atmosphere vents into space.
> 5. How would one target a enemy ship in space (realistically
using radar/IR/Visual and advanced computers, combat would have to be
close, due to the relative slowness of weapons. the ships could probably be as
fast as the missiles they are firing. you would have to be careful to plot
where the ship would most likely be when your weapons reach it. this firing
solution is very fragile, the farther out you go the more likely you are going
to miss, I would say anything beyond a 100km range would be impossible. All
the target ship would have to do is move slightly and you would miss. A
combination of the three types of Sensor would be needed because one is easy
to jam, but all three add redundancy.
hope this helps.
> Hello Everyone:
snip
> I'd love to hear your responses.
Mark, a long out-of-print source that makes interesting reading is "War
in 2080" by David Langford. This is a book of comment, speculation,
explanation etc. on the future of military technology. Generally, I'd say the
answers to your questions depend very much on the overall tech level you've
chosen. I assume that as you want to be plausible with respect to
current science, the tech is not _too_ far advanced compared with our
own-
more B5 than Star Trek, as it were.
> 1. Which would be better suited for space combat: lasers or
I suppose it depends to an extent on fighting range and maneuvreability-
Laser will arrive first (and tend to spread less? I'm a biologist, Jim, not a
phaser technician! (A caveat for all my answers)). If the target is able
to move unpredictably/evasively during the travel time of the shot,
lasers might tend to outrange particle beams. Presumably the PBs would use
neutral(ized) particles, to avoid the effects of magnetic fields etc.
> 2. How does a directed energy beam weapon damage a target?
By heating it, mainly, I think. BTW, don't be fooled by that old SDI laser
demo film where the laser shoots at a missile fuel tank which disintegrates.
They put a big weight on top and pressurised the tank, and the laser puntured
it like a balloon, allowing the weight to crush the tank.
> 3. Which sort of missile warhead would be better suited for
How close are your missiles going to get? Relative speeds may be too high for
reliable close explosions, so your nuke will do damage by EMP and radiation
rather than blast. I can see a case for a kinetic missile consisting of a
sheaf of hard dense bolts, with a motor and guidance at the back, boosting
hard to the predicted vicinity of the target (and dumping its booster so that
it coasts cold for minimum detectability), then doing another boost to
intercept the target, with the sheaf separating (not really "exploding") to
produce a pattern of separation of e.g.
(target diameter/4) between bolts.
> 4. I've heard that it would be a good idea to depressurize a
Avoiding explosive decompression. I think it would probably be better to
_lower_ the pressure a bit, harden the ship's equipment against vacuum,
and
have the DC teams in space-suits, the rest in a compromise that would
let
them work more effectively (like the difference between anti-flash gear
and
serious fire-fighting gear at present). A high level of
compartmentalization would minimize the effect of any hull breach.
Alternatively, I can see that high accellerations would mean that nobody's
going anywhere while the ship's in combat (a la "Mote in God's Eye"),
everyone could be in individual space-tight accn. couches/combat
stations/lifepods scattered through an otherwise depressurized ship.
> 5. How would one target a enemy ship in space (realistically
Apart from the obvious radar, lidar, etc. I can imagine silent running ships
preceded, surrounded and followed by swarms of recce drones, one of the
purposes of which would be to tempt/force enemy ships into disclosing
their positions. I can imagine ships with multiwavelength long baseline
optical rangefinders using powerful telescopes on masts or superstructures,
and also triangulation from drone data.
> 6. There would happen to be a "Theoretical Space Combat FAQ"
somewhere
> on the net? If there isn't there should be.
Dunno!
Cheers, (that was fun!)
> I'm writing a sci-fi space combat story for my creative writing
Before we get into these questions, let me heartily endorse the tactical
manual that accompanies Renegade Legion: Prefect. EXCELLENT
discussion of the strategies and considerations of high-speed
high-thrust space combat and gives plausible and sound
tacticat/strategic considerations of the solar system as a war
theatre. Co-written by the Canadian War College, so you know its
good.
> 1. Which would be better suited for space combat: lasers or
Both of them suffer the same problem in high-speed space combat, and
that's the problem of delivering enough energy to the target in a
short enough time to do any damage at all. Lasers/masers are Time On
Target weapons. That means that the more time you can concentrate your fire on
the hull of your target, the more likely you are to pump enough energon
(sorry, obligatory Transformer's reference) into it to heat it up, making it
do whatever that material does at high temp.
Particle beams throw bunches of high-mass high-energy particles out of
an accelerator at a target, hoping for the `tally ho, cascade!'
(sorry, obligatory Heavy Gear reference) of lower-energy showers
through the target's hull. They too are Time On Target, but if you're lucky,
you can take out the computers in the target or utterly irradiate the crew
with a good shot. This probably won't blow up the ship (unless you get really
lucky and take out the engine control
functions just /so/).
They both suffer from their Time On Target nature and the fact that quantum
uncertainty catches up with you beyond a fairly short range. You start either
hitting them with a monochromatic flashlight as your laser disperses too much
to transfer enough point energy or your particle beam can't get enough density
on its cascades to matter. Both are going to be more likely seen on fighters
than capital ships, because of the range limitation, but the TOT is going to
really agonize for fighter intercept velocities, making both weapons require
jacked-up energy requirements to pump enough in in a short enough time
to matter. On a cap ship, the only way you'll use a laser/maser or
particle beam are in /immense/ massed batteries, huge gang-fired
coherent arrays, so that your target is almost literally swimming in a sea of
quanta when you fire. Big energy, big beam. Other than that, they'll depend
more on missiles (see below).
> 2. How does a directed energy beam weapon damage a target?
See above.
> 3. Which sort of missile warhead would be better suited for
Depends, really, on the tech level you're dealing with. Missiles are going to
be the heaviest weapon you can deliver to the target at the
most range at /every/ tech level; missiles at heart are little
autonomous ships that direct energy into the target. The better your ship
tech, the better your missiles.
Whether or not you go nuke or kinetic kill in the end is really a matter of
taste. Nukes do big damage and throw off omnidirectional heavy radiation, very
briefly, which gives them a bit of a particle beam effect at certain ranges.
Cap ship to cap ship, you'll probably see a lot of nukes thrown about when the
closing groups are at extreme range and really throwing hell at one another to
try to win quick by
attrition. (This means your ship groups shouldd probably /never see a
huge multi-cap-ship mass combat as depicted in Full Thrust/. Cap
ships that densly maneuvering make easy pack kills with waves of nukes.)
Closer in, there's a bit more chance of sensor blinding so nukes would
probably be reserved for things like taking out entire squadrons and flights
of fighters with one fell blow. Kinetic kill
missiles only /really/ need to put submunitions (which may be as
simple as ball bearings or as complex as nuclear limpet mines)
throughout your maneuver sphere (the area in which at tine n+x your
ship could be through any application of its thrust). With a high incident
velocity, you're going to be shredded as soon as you hit it, and since
missiles are typically fired from your forequarter, incident velocity will be
evilly high. Fired from behind, it'll be almost entirely a matter of how much
more thrust the missile has than you that it can apply in the terminal part of
its attack, almost certainly
a lot, but much less than head on. A side-on attack will be just as
bad as head on, because it'll just drop submunitons ahead of you in your
maneuver sphere and again, your own velocity will slam you through them.
Kinetic kill missiles are a lot better for close in
dog-fighting between fighters and mass waves thrown at cap ships as
they close. Missiles will /always/ win out, in the end, over directed
energy weapons, I feel, because of their inherent range benefit and
the self-directing nature of the beast, quite possibly light-seconds
distant from both firer and target.
Then, of course, there's the truly massive `spinal mount' Gauss accelerated
crowbar, but I don't think its a realistic weapon to use against other cap
ships unless they're nearly dead in the water.
They're mother-evil against ground-based targets, though.
> 4. I've heard that it would be a good idea to depressurize a
As mentioned in another email to you, its an excellent fire control measure
(as in, `controlling fires'). Without O2, no fires except in materials that
give off O2 as oxidized or heated. You don't have your atmo blowing off into
space twisting your arc of fire. No crewman sucked out into space
dramatically, either.
> 5. How would one target a enemy ship in space (realistically
Very carefully. Depends on your technology level. At the very highest, you use
gravitic warping detectors to locate areas of mass that are moving incident to
you. At lower levels, you'd probably use a combination of radiation detection
(most visible when the drives are running) and checking out who's firing at
you.
A ship painted black, that accelerated way out in the area outside your solar
system, with most everything powered low, could fall down the gravity well of
your sun, right by your listening posts and you'd probably never see them.
Putting off no radiation. They could be just a big rock, for all you know. If
they released a flight of fighters that are coasting into your system on a
different trajectory to do a recon of some of your sites, the only way you'll
see them is
when they do some course correction on their high-speed fly-by. You
may or may not have some interception forces that can get into their maneuver
sphere and envelop theirs with yours. If not, they'll likely burn like mo'fos
and rendezvous with their dark carrier once they outmaneuver you. All they
have to do is get your forces in a position where the open part of their
maneuver sphere points them toward the rendezvous trajectory, give a few quick
burns and then go dark. Good luck finding them again without insane luck.
You've been sussed.
In real space combat, thrust is going to be the coin of battle. The larger
your maneuver sphere, the more options you have and the more choices you have
about whether to engage or avoid. The larger your
maneuver sphere and your opponant /knows/ it, the more targets in his
system you /might/ be attacking at any given time up to 0-hour and the
more targets he's got to allocate his system defenses to. Its a guessing game.
[Can you tell I dearly love Prefect? Its a great entire Theatre of
War sim game... `Where are those Cheetah fighter groups going? Can I catch
them with my Spiculums? Are they going to be backed by a dark carrier I'm not
catching out yet?']
> 6. There would happen to be a "Theoretical Space Combat FAQ"
somewhere
> on the net? If there isn't there should be.
The tactical guide with Prefect is about the only one I've ever seen, and it
includes cool little diagrams, etc.:)
Geez, this turned into a regular dissertation...
Since I've been working on the same thing (in a longer form) for quite some
time, I'll lend some ideas. First off, at the normal speeds of interplanetary
warfare, ranges will, by neccessity, very large. This creates a problem of
time lag. Even a second or two lag increases the need for computer weapons
guidance. Optical systems will be at a premium. Also, when you fire a weapon
it keeps going, so if near planets you have to keep that in mind. Another
thing is the glare of the sun.
Directed energy beams basically heat a target a bore a hole in it. Unless you
have a VERY powerful energy source, not much damage can be achieved (in the
near term).
Thats about it. If there is the elusive "Theoretical Space Combat FAQ" I would
have found it by now. Hope this helps a little
Win Barker Imagineer Solutions onQue As to missiles, blast effect is reduced
in vacuum so direct contact is necessary. I'm talking about blast, not
fragmentation, which is much
more destructive. A cloud of peanut-sized balls exploded into the path
of a ship will, depending on the relative velocities, probably rip it to
shreds.
> ----------
> Win Barker
What about heat generated in the coldness of space? The reason for my question
is this, if heat generation is flesible, then a missle with a modern HEAT
(High Explosive Anti Tank) war head, could the weapon of choice. On contasting
ship the war head would burn through the ships hull and into the inside
causing alot of damage.
If not then nuclear weapons in space would not be that good, little
fragmentation and not much/no heat. What is left is blast and radition
and the electronic impluse. Shielding for space travel would probably make the
last two not that effective. ( i've seen star trek.)
> Mark A. Siefert writes:
@:) I have some general questions for all of you armchair physicists @:) out
there in GZG Mailing List land.
Well I've already proven my keen understanding of physics:) You probably could
immediately notice that I was actually a Physics major for a year at WPI.
@:) 1. Which would be better suited for space combat: lasers or @:) particle
beam weapons?
C) Railguns, for reasons already given by other list members. Current research
("Star Wars" SDI Program) was working mostly with railguns because they're
relatively easy to produce with current or
near-future technology and because they are power-efficient compared
to lasers. For a railgun (one was demonstrated at one point) you need a bunch
of whoppingly big capacitors which, I believe, destroy themselves when the gun
is fired. Replace these with smaller
capacitors that don't self-destruct and you've got a viable weapon.
That may not sound like a great prognosis but compare it with the
X-ray laser Teller was trying to get funding for: that device would
harness and focus the emmissions of an exploding hydrogen bomb!
Plenty of power but obviously a one-shot weapon.
@:) 2. How does a directed energy beam weapon damage a target?
The particle beam situation has also been discussed by other list members. The
laser idea is generally to heat up the skin of the target (a missile in SDI's
case) so fast that it 'explodes', the skin, that is, which will kick the
missile hopelessly off course.
@:) 3. Which sort of missile warhead would be better suited for @:) space
combat? Nuke or kinetic kill?
Kinetic kill. Nukes look real impressive when you set them off in Nevada but
remember that as desolate is it may be, there's still AIR in Nevada. There's
no air in space. No air means no shock wave and precious little blast from the
explosion itself. I wouldn't want one glued to the side of my ship but if it's
relatively far away (like if it's a missile) then we're mostly talking about a
radiation problem. We need to wrap the ship in lead or some such. Not easy but
doable.
Contrast your kinetic kill flying crowbar (or telephone pole) -
there's no defense against this weapon at all. It does have to hit however.
@:) 5. How would one target a enemy ship in space (realistically
@:) that is)?
Toughie. For close-in stuff (SDI again) you can use radar.
Obviously radar would be good for terminal missile guidance. For longer range
combat, I would recommend telescopes. Track the target with an array of
optical, IR and UV sensors. If it's got a nuclear engine running (likely when
it's manouvering) you can probably use a
gamma-ray or radio sensor as well.
So my suggestion would be to track it with these kinds of long-range
sensors, figure out what path it's following, and lob a missile at it.
Remember that in the near future, the target is not going to be steering very
much. The missile accepts guidance from the mothership until it can pick up
the target on radar, and after that it makes its own course corrections
(which, being small and having a sickening amount of fuel, it can do more
readily than the target ship). When it gets close it launches submunitions.
If you ask me near-future space combat will probably be pretty
boring (I'd still like to make a game out of it to find out). Right now
spacecraft (once they're in orbit) have very little thrust compared with other
vehicles. Giving them the kind of manouverability that would make combat
interesting would require a lot of fuel. So until somebody invents an engine
that can impart some real steering to these ships, we've got mostly targets
moving along predictable paths (because they're not applying any thrust) which
can be intercepted by
missiles or whatever. Don't get me wrong - I'm not saying it's EASY,
just kinda dull.
> Darren Douglas writes:
@:) > As to missiles, blast effect is reduced in vacuum so direct @:) >
contact is necessary. I'm talking about blast, not @:) > fragmentation, which
is much more destructive. A cloud of
@:) > peanut-sized balls exploded into the path of a ship will,
@:) > depending on the relative velocities, probably rip it to shreds.
As you mentioned, it depends on their relative velocities but it certainly
could hurt. The only research I know of on this topic has been done on or in
the Space Shuttle (has Mir done anything like this?). I know once they were
hit by something pretty small, small
ball-bearing sized or less and it put a hole in (almost through) their
windshield. But the Space Shuttle isn't an armored space combat vehicle. It
might be that with dedicated combat spaceships, you'd need a larger projectile
to cause significant damage.
@:)... a missle with a modern HEAT (High Explosive Anti Tank) war @:) head,
could the weapon of choice. On contasting ship the war head @:) would burn
through the ships hull and into the inside causing alot @:) of damage.
This would work but you still have to hit the target. If we assume we're able
to hit the target, given the kinds of velocities we're probably talking about,
you don't really need any kind of warhead. Your typical AP shell hits a tank
at (somebody help here), I'm guessing in the low 1000's of miles per hour.
Mach 2 or 3 or so. Anyway in space we're probably talking about velocities
easily ten times that. Even if you're approaching the target from behind it
should be possible to put a rocket booster engine on your missile that'll
bounce its speed up by 10,000 mph before it impacts, given the large distances
which the missile will have to manouver in.
@:) If not then nuclear weapons in space would not be that good,
@:) little fragmentation and not much/no heat. What is left is blast
@:) and radition and the electronic impluse. Shielding for space @:) travel
would probably make the last two not that effective. ( i've @:) seen star
trek.)
Yup. Although you have to figure out how much the shielding costs and weighs.
It's possible it could be more than armor. Or it's
possible that a sandcaster-type weapon could make kinetic-kill weapons
useless.
@:) > 5. How would one target a enemy ship in space (realistically
@:) > that is)?
Oh and I keep forgetting: if you're planning on avoiding optical detection by
painting your ship black you might want to get a BIG RADIATOR 'cause you'll
need it. This will probably make you even more detectable in IR, of course.
I don't know how true this is in really deep space, but if you're
near the sun (and you will be in any plausible near-future space
travel scenario) keeping warm and keeping cool are both serious problems.
Point well taken. If the relative velocity between the missile and the target
is low, contact explosives will be the most effective...whatever the
explosive. If a nuclear missile contacts a target it will obviously do more
damage than a HEAT missile, but the concepts are basically the same.
> ----------
> @:) I have some general questions for all of you armchair physicists
> @:) 1. Which would be better suited for space combat: lasers or
railguns firing explosive (nuclear perhaps, I'll explain why later) rounds.
more damage then a laser, less spread problems then a particle beam.
> @:) 2. How does a directed energy beam weapon damage a target?
it heats it up. you'd have to keep the beam aimed at the same spot for a
while, and hope that the target isn't really well heat shielded...
> @:) 3. Which sort of missile warhead would be better suited for
nuclear. (wait a minniit! let me explain!)
most folks here agree that you can't use nuclear bombs in space. No air to
transmit EMP or a shockwave. so they suggest kinetic kill devices which must
hit the target directly. However, once you hit the target directly, you
introduce the superstructure of the ship to your missle. The superstructure is
PERFECT for transmitting EMP, the atmosphere of the ship (if it has one) would
help as well... and wouldn't you rather hit the target with an EXPLODING
telophone pole instead of a regular telephone pole?
> @:) 5. How would one target a enemy ship in space (realistically
fire-and-forget bullets for your railguns that get in proximity of the
target then activate a quick burst of thrust to redirect and aim from up
close...
> In message <9704091126.AA30373@zeorymer.alf.dec.com> you wrote:
> > I'm writing a sci-fi space combat story for my creative writing
Sounds good, but I don't like Renegade Legion itself too much, and getting
hold of it is a real pig anyway.
> > 1. Which would be better suited for space combat: lasers or
There's also drive systems to take into account - ask any Kzin :)
(a reaction drive puts out lots of energy, over a reasonable range, so even an
'unarmed' freighter has at least one weapon).
> > 3. Which sort of missile warhead would be better suited for
Another type of missile is a nuke which is used to power a (one shot) gamma
ray (or other high frequency) laser. A good example of this sort of combat is
at the end of Footfall, by Niven and Pournelle. Lots of use of burst lasers.
The big problem in space is delta-vee - or rather the lack of it.
This is a measure of how much velocity change a vehicle can perform before
running out of propellant. For missiles, you generally want
to close with the target as quickly as possible - which means
burning lots of thrust early on. Which leaves almost nothing for
the close-in manouevering needed at the end of the flight to get
a direct hit.
For kinetic kill, you probably want railguns rather than missiles, they're a
*lot* cheaper giving that success ratio is going to be extremely low in either
case. If you've got a guided missile, it's probably best putting a nuke on it.
> through them. Kinetic kill missiles are a lot better for close in
I have my doubts about the use of fighters in realistic space combat, but then
I'm part of the 'big ships are better' crowed, and fighters are just a very
small ship.
What may be useful are drones - unmanned fighters carrying limited
duration weapons (a few missiles, or limited power for direct energy weapons).
For a small fighter, too much of ship mass is wasted on life support for the
pilot. At close range, they're fragile enough that survivability probably
won't be acceptable for a manned weapon system.
> Missiles will /always/ win out, in the end, over directed
Very true, but lasers make for good point defence against missiles.
Something else that should be said, is that any ship with a
limited delta-vee can't keep on dodging for ever. It's often
claimed fact is that you can't hit a target at light-second
distances, because it can dodge in time. But since the ship doesn't know
'when' it's going to be fired at, it has to dodge all the time, which is going
to burn propellant way too quickly.
I tend to see ships as going for heavy armour rather than manoevrability, with
lots of direct energy weapons. At any decent range the lasers won't do much
damage (laser intensity falls off with the square of the distance), but it
persuades the enemy to keep away from you enough so that they can't use their
direct energy weapons. Greater range also means longer flight time for
missiles, giving you a better chance of detecting, tracking and destroying
them before they get you. Regardless of armour, a single nuke can really ruin
your day.
> Then, of course, there's the truly massive `spinal mount' Gauss
If the enemy controls orbit, then don't *ever* fight an open ground battle,
unless you're absolutely positive all enemy weapon platforms will be over the
horizon.
> > 5. How would one target a enemy ship in space (realistically
A ship with a human crew will have at least part of the ship at around 300K,
against a background of about 4K. That's ignoring heat from reactors, drives
(they don't cool to background temperature as soon as they're switched off)
etc.
> A ship painted black, that accelerated way out in the area outside
The problem with this is, either you're willing to wait months or years to get
to the target, or you have to start your 'fall' at
extremely high velocity - which means flashing past the target
at several thousand kps.
This isn't as bad as it seems though, because you just launch a big volley of
missiles before you close, which will hopefully close to within killing range
of the enemy before they can react (or even detect them). In a matter of
seconds, you could destroy the enemy fleet.
You then spend the next six months decelerating, and coming back to the target
world to actually capture it:)
> Putting off no radiation.
That would be putting off relatively little radiation.
> They could be just a big rock, for all you know.
If attack a world, this is of course what you'd use. A world can't dodge, and
follows a totaly predictable orbit. Launching the rock two years ago isn't
implausible.
> If they released a flight of
As soon as they make a burn though, you know where they are, and where they're
going. Even if they go dark, and are undetectable, you still have a very good
idea where they are over the next few seconds, minutes, hours or even days or
weeks (depending on how good your computers are).
On top of that, they *will* be detectable. If you know where to look, it is
very easy to detect something in space. If the enemy isn't expecting you,
creeping up on them undetected may well be an option.
> burn like mo'fos and rendezvous with their dark carrier once they
Good. The enemy wants you to do this, because you've just told him where the
carrier is. One dead carrier. Want you want to use are disposable weapon
drones which you leave to die. The carrier only reveals itself if the battle
is won. If not, it follows its trajectory out away into space.
> > 6. There would happen to be a "Theoretical Space Combat FAQ"
somewhere
> > on the net? If there isn't there should be.
The "Aliens Technical Manual" has some good discusion on space combat
(somewhat strange, since space combat never occurs in any of the films...). It
brings up the good point that battles will generally be fought around planets.
There's no point defending empty space, since it's not useful, so it makes
more sense to concentrate your forces at some strategic points.
Also, try rec.arts.sf.science - this subject crops up quite
often there, and there's lots of physicists etc who know what they're talking
about (excellent source of info for
power outputs of lasers, delta-vees of engines etc).
> Geez, this turned into a regular dissertation ...
> At 01:06 AM 4/9/97 -0500, you wrote:
Well, I've had an SF story published, and three friends of mine are
SF/Horror writers (one of which co-edited the book Tesseracts 4, a
collection of Canadian SF, and one who's horror story was recently filmed in
Montreal for a US cable channel) so I might be able to help.
> 1. Which would be better suited for space combat: lasers or
Laser beams make rotten weapons. You have to hold the laser on the same point
of the target for a certain amount of time in order to heat through the
target. Being made of light, it's fairly easy to bounce the laser beam with
ablative armour. Of course, in the future, high speed, high energy lasers
might be reasonable weapons, however the beam's cross section would probably
still be pretty small. You aren't going to get the B5 "slicing and dicing"
effect from a laser.
A suggestion: come up with a weapon system and DON'T EXPLAIN IT! The is
essentially the same thing you are doing with your hyperdrive system. Run with
it. The best example that I've seen is in Dan Simmons' novel
_Hyperion_. The second "story," about the ex-military man, is excellent
Combat SF. He uses, throughout the book, a weapon called a Hell Whip. You have
no idea what it does, other than the fact that it's destructive, but the name
and vague descriptions evoke an image of what the weapon does. I got the
impression of energy beams waving around from spaceship to ground like the
tentacles of a squid. It was a GOOD image. This is the secret to SF for those
who don't have degrees in physics: don't explain ANYTHING. Remember, you are
out to evoke an emotional or visual response, not a set of diagrams on
building the weapon.
Think in terms of modern combat fiction. Most writers don't go into the how's
and why's of chemically propelled slug throwers. Instead, they describe the
look, feel, and sound of the weapon, both in how it fires and in what it does
to the target. Don't call the weapon a laser, just explain its effects. What
bugs SF fans most is when you get things wrong. Simmons couldn't "get things
wrong" with his Hell Whip since he never tried to tell anyone how to build a
Hell Whip. If you use lasers you run the risk of making a physics booboo. Make
up a weapon (similar to lasers, if you like) and you won't run into this
pitfall.
The above assumes that you are writing some far future (i.e. 100+ years
in
the future) story, where Clarke's Law applies--any sufficiently advanced
technology is indistinguishable from magic. A near future story should include
weapons we have today, only a bit more "up gunned." In this case, there are a
number of sources for checking out near future weaponry which you can use as a
technical basis for the story. In a near future story,
you'll be spending more of your time working out the geo-political and
social aspects of your background, anyway.
> 3. Which sort of missile warhead would be better suited for
Depends a lot on your background. If your ships have hulls made out of
"metallic hydrogen" (a neat little concept I picked up from Tony Rothman's
_The World is Round_), then kinetic kill weapons might not have much
effect. If your story is set on a world with little in the way of heavy
metals, radioactive material may be scarce and so they don't have nukes. You
could probably justify either weapon. The deciding factor, as has been true
throughout history, is the best "bang for your buck." Muskets were not better
weapons, 1 on 1, than longbows, but you could field a lot more untrained
peasants with muskets than you could field trained bowmen. Economics will
drive weapon choices more than anything else.
How strong are your ships' hulls? Will they crack under a near miss by a nuke?
If so, nukes are probably your best bet. Are the ships "jousting" at high
speeds and require direct hits in order to achieve a kill? If so, a long thin
kinetic missile may be just as nasty as a nuke. In David Brin's
_Startide Rising_ he showed how a simple thing like water can become a
deadly, starship-killing weapon when high speeds are involved.
> 4. I've heard that it would be a good idea to depressurize a
A number of reasons. If you get a hull breach, you don't get explosive
decompression throwing your crew into space. If you don't have an oxygen rich
atmosphere in your ship, it's harder for fires to spread. If you depressurize
the ship, you can store all that precious oxygen in well protected tanks deep
in the hull. An explosive weapon breaching the hull could send a shock wave
through the hull that could, in turn, kill the occupants; no atmosphere, no
shock wave. If your atmosphere is vented into space, it acts like a jet which
will push your ship in the opposite direction of the hull breach.
So, you can make use of this in your story. If the ships regularly
depressurize, how do the crew feel about operating in a combat situation stuck
in a pressure suit for hours on end? What do you do about itches, dripping
sweat, and other little distractions that could hamper you at the critical
moment in the story? For that matter, what does a pressure suit smell like 6
hours into a battle, when the old suit's fluid filters have reached maximum
and you haven't bathed in a couple of days...
Everyone in suits would also affect weapon design. Instead of big "ship
crackers" you might want weapons that penetrate the hull and explode in a
cloud of shrapnel (penetrating oxygen lines and pressure suits). Maybe the
insides of the ship are draped in shrapnel blankets (ala modern tanks) in
order to dampen the effects of shrapnel and fragmentation weapons.
Wouldn't a depressurized hull make boarding actions a bit easier for the
boarder? After all, they don't have to worry about someone opening a
pressurized door and blasting them back into space. Would you even use humans
for boarding, or would you use AI controlled robots? For that matter, with the
assumption of advanced AI, how many humans do you actually NEED in a starship?
How about a dreadnought with a crew of 5? Can anyone say "Nostromo?" If the AI
is pretty much running the show, then EMP weapons might be more useful than
weapons causing hard damage.
> 5. How would one target a enemy ship in space (realistically
Well, like today there are two ways: active detection and passive detection.
In active detection you have essentially electromagnetic pulses (be they
radar, lasers, whatever). They have the advantage of giving you range and
bearing information. However, they are fairly easy to angle away from a ship's
hull or be absorbed, and they give away the position of the detecting ship.
Passive sensors read reflected or emitted energy. This can be in the form of
visible light, other forms of electromagnetic radiation (i.e. heat,
ultraviolet), or maybe particles from the ship's drives. I personally like the
SF idea of neutrino detectors. The disadvantage is that they usually only give
you a bearing on the target, not a range. You can calculate range if you have
a second detection source on another ship (actually, if the ship is big enough
you should be able to mount a number of detectors on the same ship and get a
reasonably accurate range calculation).
You could use a hybrid of the two systems. Seed approaches to your planet with
active detector buoys and then try to read the active pulse from your ship. If
the enemy get between you and your buoys, you might get a confirmation from
the buoy. If you are also detecting the buoy's active pulses, you'll notice if
something absorbs them or deflects them (because you won't get the pulse). The
same thing if they destroy the buoy. You won't know PRECISELY where they are,
but you'll know they are between you and the buoy. Create a field of buoys in
various range bands and you've got a
difficult-to-penetrate sensor field that doesn't give away your
position. Of course with space being 3D, you'll need a LOT of buoys...
These systems (and combat in general) is difficult if the ships in question
are moving at near relativistic speeds. If this is the case, drop a load of
water (or a blanket of sand) in front of them ala Brin and let their momentum
be their downfall.
> 6. There would happen to be a "Theoretical Space Combat FAQ"
somewhere
> on the net? If there isn't there should be.
Not that I know of, but I do have a number of books on writing SF that deal
with theoretical SF technology. Things like building believable spaceships,
weapons, aliens, and worlds. I have a couple of these at home (I'm at work).
I'd be happy to give you a short bibliography if you are interested.
> Joachim Heck - SunSoft wrote:
Sandcasters /are/ kinetic-kill weapons on their own; would you want to
plow your fighter at 6Gs acceleration through a cloud of debris that could
etch a hole in your engine?
At 01:06 AM 4/9/97 -0500, Mark S. asked about details to make a SF story
about space combat realistic.
The first question obviously has to be about the tech level of the races in
question. The most basic of these has to be regarding power plants. If you're
not able to operate a fusion power plant, you are not going to have anything
near what we see on B5 or even Space:A&B. The real killer is the mass to
energy ratio of not just your ship but the fuel you use. Remember
M(V^2)=M(V^2) is an inescapable physical law (unless you have reactionless
drives). Even if you use ION engines you have to get the power from somewhere
and you are spitting mass out to move the rest of the ship's mass. If we
assume fusion energy and its not extremely efficient then you have relatively
large clouds of hydrogen that are super heated by what little fused into
Helium, being exhausted out the back to create your thrust. Therefore, you
don't have unlimited fuel, and the guy with the most fueld (or better fuel
efficiency) is going to win the maneuver battle. If you can sustain at least
1G of acceleration, you can get out to the edge of the solar system in less
than a week. The critical issue is sustained.
The next issue is armor/shielding. Force fields (Langston, Star
Trek, etc.) are fun but not within the physical laws we know of yet. The only
ones we really can do are magnetic fields that stop charged particles from
stars and accelerators. The real problem are those Neutrons running around.
The only thing that stops them is a minimum density of material. Water vapor
and air protect our planet, and while Lead etc is more dense it still requires
the same amount of Mass to stop them. So you will never escape the mass
issue...no matter its material form. The High Frontiers Foundation was
examining the best kinds of armour to use. You need a heat sink (Mass again)
to try to spread you enemies heating weapons (lasers etc.) out and then use
radiant heat exchangers to remove that heat. You also need something to stop
those kinetic kill weapons. It turns out that infantry have known all this for
years, they call it sandbags, High Frontiers calls it Shaving Cream and
Concrete. By placing sandbags around concrete bunkers you prevent shaped
charges from detonating properly, and high enegry kinetic weapons lose energy
as they burrow through the sand (like shooting into water). On cars today they
do
this with honey-combed plastics backed by steel cages. The honey combs
collapse absorbing energy and the steel cage protects the passengers.
Therefore hardened space stations would use the same methods. The result is
having enough mass to absorb all forms of energy (KE, Gamma, Coherent light
etc.) and get those radiators working.
> 1. Which would be better suited for space combat: lasers or
The real issue here would be if Particle Accelerators can be turreted. Lasers
can operate with axial mirrors. I don't know if partical accelerators can. If
your PA is in the Bow but you need to slow your closure with an enemy
(assuming the engines are in the rear), then your main battery is not ready.
Lasers lose coherency after a certain range based on
the size of their focusing mirror/lens.
> 2. How does a directed energy beam weapon damage a target?
For a laser, build up enough heat to cause the armor to vaporize. If enough is
pumped then you might get a burn through, or better yet, it will spall on the
inside, killing the crew. From what I've read, Gamma Weapons can actually
impell momentum on a target, if the jolt is strong
enough you can kill the crew, but I think the warhead/reactor on this
one has to be big. For now we would be happy if the laser has enough energy to
blind all of the sensors and turn the antennas into slag, tus neutralizing a
sattelite.
> 3. Which sort of missile warhead would be better suited for
A Combination of the two would be effective. If you have two missiles of the
same mass, then put a nuke in it. As either weapon gets closer to the target
you want a rapid bloom of material fragments (Nukes accelerate material pretty
well and dense liquified material is just as bad if not worse than solid
chunks). If you assume your warhead is salvaged fused (It goes of when the
missile is hit or hits something) then you get a bloom close to the target.
The bloom is larger and deployes faster. However, a simple KE weapon still has
to maneuver close to the target. If we assume that the targets close in
weapons destroy the two missiles at the same range then the KE one has a
smaller bloom and thus a smaller chance of hitting the target. The best of
both weapons is a nuke that physically hits the target... You get all the KE
energy (Mass on both is the same) and all the NUKE stuff. Bad day for the
target. But since the target probably has Close in Weapons, a salvage fused
Nuke pumped Gamma Laser is best. Gets as close to the target as possible, goes
off and directs the nuke explosion towards the target. Called a Spurt Bomb in
Footfall.
> 4. I've heard that it would be a good idea to depressurize a
Fires on ships at sea are bad, even worse on space ships I'm sure. Plus
atmosphere is another medium for bad things such as shock and heat to travel
on and kill your crew...
> 5. How would one target a enemy ship in space (realistically
Other postings have dealt with this better. One possibility is based on what
kind of power plant your foe is using. You could track the Neutrino emmision
of a fusion plant. This would give a passive bearing, there are some things
you can do to maniplulate that data but, I've used way too much room already.
For Weapons selection there are a number of issues to consider: Lasers are
best at Medium range in that they spread at long range (lose coherency) but
are very high speed (I.E. C). Hitting you target and getting Battle Damage
Assessment is fast. I need to hear from a real Physicist about the spreading
of a Particle Accelerator beam at range... Missiles are best at long range.
They travel, are self seeking if you put the brains in them, they can deliver
a serious punch. Fighters have
the same advantage plus they can be recalled and re-used.
Rail guns, Auto cannons, etc. are best at close range. You'll need to "lead"
the target and predict where he will be, etc. On the other hand they make
excellent counters to the Missiles and fighters. They have a serious mass
problem though. You are expelling a lot of mass that you spent all that energy
to bring with you... All of this assumes that you have a fusion power plant
(or greater) to run these weapons with. Otherwise at best you will have a
chemical laser with limited shots, some missiles, and an assortment of Close
in Weapons on a vessel that has a maximum acceleration of.5G and a limited
fuel capacity. For that Play LNL. Phil P.
By all means post the bibliography...I probably have them, but I'd like to
know if anything else is out there.
Win Barker Imagineer Solutions onQue
> Not that I know of, but I do have a number of books on writing SF that
** Reply to note from "Mark A. Siefert" <cthulhu@csd.uwm.edu> Wed, 09
Apr 1997 01:06:05 -0500
> Hello Everyone:
No expert myself, but in terms of story telling, use lasers. You dont have to
justify them technically as much as partical weapons (everyone knows what a
laser
is).
Remember that lasers are invisable in space (no ionisation of astmoshere)
> 2. How does a directed energy beam weapon damage a target?
Melting the metal. All weapons that penitrate metal do this in one way or the
other (except microwaves). In layman terms, the energy hits the hull, and
causes the metal to boil.
> 3. Which sort of missile warhead would be better suited for
Bomb pumped lasers. Nukes are not as efective in space (no air to carry
shockwaves) and KKK need damn good targetting.
> 4. I've heard that it would be a good idea to depressurize a
As the hull is punctures, air presure would escape outwards. Anyone caught in
this would have a fun day.
> 5. How would one target a enemy ship in space (realistically
Passive or active sensors. Radar, Lasar Radar (LADAR), heat dissapation, light
sources, radio transmission, light obscuration (blocking out a
star,planet)......
> 6. There would happen to be a "Theoretical Space Combat FAQ"
somewhere
> on the net? If there isn't there should be.
> I'd love to hear your responses.
> At 01:06 AM 4/9/97 -0500, you wrote:
<snip>
H'lo, Mark. I'll try to field some of these in hopes that I'll help a little.
Sorry, but not a clue of an answer for questions 1 and 2. With re: question 2:
with a laser, aren't you essentially focusing energy at a single point of the
hull and trying to burn through. Given enough energy, you would burn through
and start burning beyond the hull.
> 3. Which sort of missile warhead would be better suited for
Given the difficulty of targeting a spaceship (a small object) in space
(a
kinda large area), I would think the nuke would be better. Sort of on the
grounds that you can just get it close and get a kill. Remember, no shock
effect as no air to form a shock wave, but you still get a burst of high
energy radiation that could go through the hull. I rather liked the idea from
Traveller 2300 AD of using the missile's nuclear warhead as the power
source for a bomb-pumped X-ray or Gamma Ray Laser. You get the missile
close...the warhead goes off... for a split second, a lensing/focusing
element channels the radiation into a coherent, focused laser.
> 4. I've heard that it would be a good idea to depressurize a
This way if the hull is punctured, you avoid a catastrophic decompression and
all the problems that go along with it. You also save the air for use again
later.
> 5. How would one target a enemy ship in space (realistically
If you don't invent some kind of exotic technology, i.e. a Maser scanner, then
you're probably using active or passive radar or ladar. Sort of like airplane
targeting. The problem then is given the distances involved, if you're far
enough away, speed of light becomes a limiting factor. By the time you get the
returned signal, the target could have evaded.
> I'd love to hear your responses.
Hope this helped a little.
Hi people,
I won't reply individually to the questions because I've seen all the replies;
however, I will make mention that a great source for this sort of thing is
"Fire, Fusion and Steel", from 3rd Generation Traveller. (When GDW made it.)
It's out of print right now, but you could probably find it second hand
somewhere. (A lot of interesting ideas in there.)
If somebody wants, I can look up the sections and post accordingly.
Thanks,
J.
I think Railguns/ Mass drivers can be extremely effective considering
you can tailor the ordinance you can fire. For instance:
1. Stealthy Penetrator rounds! 2. Stealthy missiles that flip on their drives
just outside the target's defensive envelope!
3. Bomb pumped x-ray lasers!
4.Big Rocks! 5.Frozen Chickens!
In combat I think that you would lay down a "probability pattern" of most
likely hits. The current first generation Mass drivers GE is testing for Main
Battle tanks is performing at 5400 FPS (feet per second) muzzle velocity with
a kinetic penetrator round. Assuming your Starship has a Railgun that is 10
times more efficient (not unreasonable, I think) in space you should be able
to get fractional C velocities since there is no Atmosphere or Gravity to
interfere. The thought of being hit by a 1 kilo Frozen Chicken moving at 5% of
C is enough to give ME the willies!
Later.....
OK, I did the math.
5% of Lightspeed (C) is 49,104,000 FPS -or- 9300 Miles Per second
So let's scale back to 1% of lightspeed -or-1860 MPS
I think that's achievable given tech of the 2050-2075 era.
And it's still pretty horrifying in terms of impact energy even with
small projectiles. Given a head-on engagement you get the added bonus
of the target's velocity added to the equation!
> At 01:06 09/04/97 -0500,Mark S. you wrote:
Neither, Sand or smart missiles that detonate to sand at close range.
> 2. How does a directed energy beam weapon damage a target?
By heat build up
> 3. Which sort of missile warhead would be better suited for
K.E. kill, the radiation will spread at c and get you too!
> 4. I've heard that it would be a good idea to depressurize a
Hull breach resulting in a rapid decompression-killing crew,unrestrain
objects flying around. On a plus, it stops oxygenated fires
> Jon (top cat)
> [quoted text omitted]
SDL
> Mark A. Siefert wrote:
> 1. Which would be better suited for space combat: lasers or
Laser for destroying Fire Control: Neutral Particle Beam (ie non
de-focussing) for
inducing radiation. Charged particle beams are low-tech, easy to do, but
short range.
> 2. How does a directed energy beam weapon damage a target?
By heat, by direct blast (photons even) or by inducing a radiation shower.
Please note that Space is a hi-Rad environment anyway. A good solid
solar flare can really make life difficult unless your ship has a lot of
radiation hardening. Enemy action would have to be Very Intense Indeed to
match a class 1 flare from a slightly variable star. Like ours.
> 3. Which sort of missile warhead would be better suited for
Good question. A contact blast with a Nuke would be nasty. A Nuke-pumped
X-ray laser (looks like a sea urchin) would be probably the most
practical. But a KE projectile, IF you can hit, would be the most devastating,
short of a Nuke in the very close vicinity.
> 4. I've heard that it would be a good idea to depressurize a
Stops decompression, but more importantly, reduces fire hazard and stops
random course changes and such, due to outgassing. See 'Apollo 13' for a very
realistic picture of how this can screw you up. Also, a cloud of gas around
you would completely bollix your sensors.
> 5. How would one target a enemy ship in space (realistically
With Great Difficulty. And not a little effort.
A realsitic next-century combat ship might have a StarLite Plastic
exterior (for protection against lasers) facetted to be stealthy, then
an inner layer of neutron-absorbent material - Ice is good - to keep the
occupants healthy due to Solar Weather (and nearby nukes or particle beams).
But the main defence would be by expendable decoys. Baloons mainly. The thing
would be 'black' to most wavelengths in the EM spectrum, and the chance of
occluding a star is minute.
Sensors - Coherent radiation Radars/Lidars for active, Infra-Red and
longer wavelengths for passive. The idea is to find the propulsion
snip
> 4. I've heard that it would be a good idea to depressurize a
> SDL
Oh I SEE- you lot breathe _Oxygen_...
:-)
> I like the idea, however as you start to examine the
OK. Assume solid slug 1 kilo penetrators (bigger than necessary, but a lot
cheaper in mass and space than missiles) let's say your railgun fires a salvo
of 1000 penetrators in a cloud spaced 500 meters apart in a spherical array.
that's a thousand kilos of ordinance (2200 pounds) A single modern Tomahawk
guided missile is about a thousand pounds (give or take) with 500 lbs being
the warhead (As per Jane's all the worlds weapons 1993) I think that that's
not a bad tradeoff for mass vs. lethality. Chances are good that you will get
a solid hit with a penetrator on a 500 meter target. you could tighten or
loosen your pattern based on you "firmness" of target acquisition. If your
penetrators are sheathed in Radar Absorbent materials, there you go!
> I think Railguns/ Mass drivers can be extremely effective considering
This railgun idea for near future space combat reminds me of the GDW game
Triplanetary, now owned by Steve Jackson Games. The rules for that game
depicted the armaments by the various spaceships as high rate of fire machine
guns, which was lampooned in the Murphy's Rules section of the Space Gamer.
Given that turreted Gauss guns or railguns would be able to lay down a pattern
of projectiles into the anticipated path of an enemy and the high kinetic
energy results from an impact, would make these viable weapons.
Defenses would be high manueverability and a low target silouette. Trying to
build an armor defense against these would be pointless.
> Given that a target can maneuver in a very large threat cone
That's a 500 meter SEPERATION between individual penetrators in a spherical
cloud. All you NEED is one hit. with a thousand Penetrators your cloud would
be Kilometers wide AND deep. Also, the amount of delta Vee you can put into a
maneuver depends a lot on mass vs thrust. First you detect the incoming
penetrators. If they are stealthy that might be as little as several hundred
kilometers (after all there is no energy signature to pinpoint them and they
are wrapped in RAM materials) If they are not stealthy, you might "see" them
at several Thousand kilometers. That would give you (assuming
you have a sabot cloud moving at 100k/s) 2-20 seconds to classify as
threat and initiate an evasive burn. Not the easiest task, I think.
> Given that a target can maneuver in a very large threat cone
That's a 500 meter SEPERATION between individual penetrators in a spherical
cloud. All you NEED is one hit. with a thousand Penetrators your cloud would
be Kilometers wide AND deep. Also, the amount of delta Vee you can put into a
maneuver depends a lot on mass vs thrust. First you detect the incoming
penetrators. If they are stealthy that might be as little as several hundred
kilometers (after all there is no energy signature to pinpoint them and they
are wrapped in RAM materials) If they are not stealthy, you might "see" them
at several Thousand kilometers. That would give you (assuming
you have a sabot cloud moving at 100k/s) 2-20 seconds to classify as
threat and initiate an evasive burn. Not the easiest task, I think.
> Mike Wikan writes:
@:) 5% of Lightspeed (C) is 49,104,000 FPS -or- 9300 Miles Per second
@:) So let's scale back to 1% of lightspeed -or-1860 MPS
@:)
@:) I think that's achievable given tech of the 2050-2075 era.
Isn't Voyager moving at something like 50,000 mph? That would be
13.89 mps. So we're talking a factor of 100-150 (133.92). That's a
lot but in space there isn't anything really preventing you from going fast,
as long as that's all you want to do. So far there's never been any reason to
make something go fast in space so we haven't done it. So I agree it's
conceivable in the near future. I don't know whether it'll be practical in the
forseeable future but it is possible.
I certainly wouldn't want to have a head-on with voyager, much less
something moving.01c.
> Given that a target can maneuver in a very large threat cone
That's a 500 meter SEPERATION between individual penetrators in a spherical
cloud. All you NEED is one hit. with a thousand Penetrators your cloud would
be Kilometers wide AND deep. Also, the amount of delta Vee you can put into a
maneuver depends a lot on mass vs thrust. First you detect the incoming
penetrators. If they are stealthy that might be as little as several hundred
kilometers (after all there is no energy signature to pinpoint them and they
are wrapped in RAM materials) If they are not stealthy, you might "see" them
at several Thousand kilometers. That would give you (assuming
you have a sabot cloud moving at 100k/s) 2-20 seconds to classify as
threat and initiate an evasive burn. Not the easiest task, I think.
> snip>>
That's a 500 meter SEPERATION between individual penetrators in a spherical
cloud. All you NEED is one hit. with a thousand Penetrators your cloud would
be Kilometers wide AND deep. Also, the amount of delta Vee you can put into a
maneuver depends a lot on mass vs thrust. First you detect the incoming
penetrators. If they are stealthy that might be as little as several hundred
kilometers (after all there is no energy signature to pinpoint them and they
are wrapped in RAM materials) If they are not stealthy, you might "see" them
at several Thousand kilometers. That would give you (assuming you have a sabot
cloud moving at 100k/s) 2-20 seconds to classify as threat and
initiate an evasive burn. Not the easiest task, I think.
> snip>>
That's a 500 meter SEPERATION between individual penetrators in a spherical
cloud. All you NEED is one hit. with a thousand Penetrators your cloud would
be Kilometers wide AND deep. Also, the amount of delta Vee you can put into a
maneuver depends a lot on mass vs thrust. First you detect the incoming
penetrators. If they are stealthy that might be as little as several hundred
kilometers (after all there is no energy signature to pinpoint them and they
are wrapped in RAM materials) If they are not stealthy, you might "see" them
at several Thousand kilometers. That would give you (assuming you have a sabot
cloud moving at 100k/s) 2-20 seconds to classify as threat and
initiate an evasive burn. Not the easiest task, I think.
> At 09:00 AM 4/10/97 +0000, Mike Wikan wrote:
I like the idea, however as you start to examine the probabilities at varrying
range, you start to run into the problem of needing a LOT of rounds to fill
that threat cone... That's a lot of Mass that you spent precious fuel to carry
with you.
> You wrote:
... Your typical AP shell hits a tank at (somebody help here), I'm guessing in
the low 1000's of miles per hour. Mach 2 or 3 or so....
Typical muzzle velocities for APDS (Armor Piercing, Discrding Sabot) start @
2000m/sec
> Joachim Heck wrote:
Black is the best color for a near perfect absorber of energy.
> I don't know how true this is in really deep space, but if you're
I like an idea presented in the MegaTraveller's Starship Operator's Manual.
They described a chameleon exterior hull coating that could be programmed to
display various paint colors and schemes from an onboard interface at any
time.
> At 12:13 PM 4/10/97 +0000, Mike Wiken wrote:
> OK. Assume solid slug 1 kilo penetrators (bigger than necessary, but
Given that a target can maneuver in a very large threat cone on the order of
several thousand meters per G maneuver, your 500 meter radius cloud does not
guarrantee a hit at all... You would have a better bet against an orbiting
target given that his threat cone is a LOT smaller, but then do you want 1,000
rounds orbiting your planet where you might want to put sattelites
yourself...? Phil P.
> Samuel Penn wrote:
Not like RenLeg? Heretic! He must be burned! The Terran Overlord Government
will see you crucified, Commonwealth scum.;)
> There's also drive systems to take into account - ask any Kzin :)
Depends on what you consider reasonable range. If you're using ionized
Hydrogen or Helium for acceleration mass, you're probably not going to be
throwing enough out to provide a decent impediment to someone not
/incredibly/ stupid, flying up your tailpipe, as it were. Dispersion'll
take it to less than the density of a nebular area darn quick.
> Another type of missile is a nuke which is used to power a (one shot)
I'm not altogether sure I buy the science behind `porcupine
Gamma-blasts,' as it were. You have to have a damn quick means of
focusing the energy before the focussing equipment itself gets blasted.
> The big problem in space is delta-vee - or rather the lack of it.
Two-stage, definitely, with a seeker period before final terminal
impact. Good way to sow a quickie minefield, to shake pursuers, for instance.
Fire missiles, then have the seeker wait for some time before going terminal.
> For kinetic kill, you probably want railguns rather than missiles,
For the mass invested, a smart missile is going to be a /lot/ more fuel
efficent for /you/ to carry around. Successful hits will be much more
oft seen because the seeker will take the missile in as close as possible
before turning loose the submunitions. Gauss cannons have to
compute based on the information /you/ can see, not from far closer to
the target.
> I have my doubts about the use of fighters in realistic space
Think of fighters as drones with organically produced seeker modules
with recoverability. All a missile really /is/, at core, is a drone
aircraft/spacecraft that carries some means of dealing death to the
target.
If its difficult (for whatever reasons) to build sufficently smart seekers,
pilots will be the guidance system to take death from the cap ship to near the
enemy, within the maneuver sphere to where the AI seekers are good enough to
impact. If AI's are sufficently intelligent to take the death there
themselves, there won't be much need or use for fighters. Its a function of
sensor and intelligence technologies.
> Very true, but lasers make for good point defence against missiles.
Both missiles and Casters (gauss cannon, sandcasters, anything that throws out
mass in the way) will be good against missiles on the close. Lasers have the
advantage of not leaving a huge mass floating near your
ship to provide a hazard to /other/ ships.
> Something else that should be said, is that any ship with a
Of course.
> I tend to see ships as going for heavy armour rather than
If you go for heavy armour and plodding maneuvers with laser weaponry, my
fleet that's built on fast maneuvering and projectile weaps will
/always/ be able to get around your maneuver sphere, stay out of your
effective range and throw things into your maneuver sphere that you won't be
able to dodge. Of course, I'll have limited endurance before
I'm out of mass to hurl and if I /am/ hit, I'll be reeling. Both
strategies have their uses, which is why a balanced interstellar fleet
should make use of /both/. A fast picket line and escort groups
supporting a solid line of cap ships with much /larger/ projectile
throwers and the energy output to support a bristling array of
short-range beam weaponry. The smaller ships really are better off with
projectile weaps because their effective range is so much larger at incident
velocities.
> If the enemy controls orbit, then don't *ever* fight an open ground
If the enemy controls orbit, you're done for /anyway/. Your surveilance
sats will be very short lived, you're going to be washing in a rain of THOR
and arty missiles and anytime you stick a nose out of cover, you're going to
be seen if not bitten. Once orbit is taken, unless the
attacker is understrength, you might as well give in. If the enemy /is/
understrength, their best tactic is to take and hold local orbital power and
consolidate through ground forces.
(Prefect models this /very/ well. You can take any strategy you like,
but unless you have at least temporary orbital local control, you're about to
get pasted.)
> A ship with a human crew will have at least part of the ship at
IR /is/ radiation, you know. :)
> The problem with this is, either you're willing to wait months or
Flashing past may be perfectly fine on a recon pass. Especially for the
carrier, which will be out of the ecliptic, anyway.
> This isn't as bad as it seems though, because you just launch a
High-speed attack passes can be /loads/ of fun.
> You then spend the next six months decelerating, and coming back
Hopefully, you're smart enough to have a second wave invasion fleet.:)
> If attack a world, this is of course what you'd use. A world can't
Of course, you may want to /inhabit/ the world after, but for relatively
genocidal bombardment, big rocks down the well are perfect.
> As soon as they make a burn though, you know where they are, and
All you know is where they are /right that minute of the burn/.
Directional information is something you /don't/ have. That's why you
know the maneuver sphere, not cone. I /might/ be decelerating to a
stop, or accelerating to twice my original velocity, you have no way of
knowing. Further, if you guess wrong and look in the wrong direction for my
next burn, you may miss it, and even if acquired later, have no real idea of
my true velocity and momentum.
> On top of that, they *will* be detectable. If you know where to
Space is a big place. Looking is hard.
> Good. The enemy wants you to do this, because you've just told him
You can't track predictibly if all you know is that a burn took /place/.
And that's all you can really tell at the ranges and velocities we're talking
here. You just did your final burn to bring you into contact
with your carrier. The observer has /no/ idea whether you've just
burned toward out-system (to rendezvous) or are doing a six-point turn
to high-speed attack his outer rim outpost. If its in your near-term
maneuver sphere, it /could/ be either.
> any of the films...). It brings up the good point that battles
THIS is absolutely true, and something you learn very quickly playing Prefect.
On the other hand, as attacker, its oft very useful to bring a
group of ships into inner-system space at some outre' location and set
up a transient resupply base out of a bunch of tenders lashed together. Its
unlikely you'll be spotted if you're careful, and then you can burn
almost anywhere in-system and they'll be confused as to your real
destination if your maneuver sphere also intersects a few target localles of
theirs.
> At 01:50 PM 4/10/97 -0400, you wrote:
Are you sure about that? Even black holes aren't perfect absorbers of
energy. They absorb a lot but give off x-rays. Black paint and fabrics
(such as my car!) absorb visible light, but that energy is radiated off as
infrared (heat). I think if you paint your ship black, you'll have to channel
that heat out somewhere. Mind you, if your ship was all black and you could
channel the heat behind you then your opponent in front of you still won't see
you coming. If he gets behind you, you'll light up the sky on his infrared
detector.
> I like an idea presented in the MegaTraveller's Starship Operator's
Probably of more use in a ground warfare (i.e. DS2) environment than in space.
> Michael Brown writes:
@:)... Your typical AP shell hits a tank at (somebody help here), I'm @:)
guessing in the low 1000's of miles per hour. Mach 2 or 3 or
@:) so....
@:)
@:) Typical muzzle velocities for APDS (Armor Piercing, Discrding
@:) Sabot) start @ 2000m/sec
= 7200 kph. Or about 4500 mph. Ok, so it's better than mach 3 but it's still
pretty slow for space.
> Allan Goodall writes:
@:) >Black is the best color for a near perfect absorber of energy.
@:)
@:) Are you sure about that? Even black holes aren't perfect absorbers
@:) of energy. They absorb a lot but give off x-rays.
Well you're right about the black, that's why blackbody objects still radiate
and all. As far as the black holes are concerned I think you're wrong but I'm
not absolutely sure. Black holes give off
so-called "Hawking radiation" which I think is lower energy than
X-rays. Real-life black holes generally have a lot of crud spiraling
into them from nearby stars and the crud rubs up against itself and
gets very hot and THAT emits X-rays. I think that, to within a
quantum theory, black holes are in fact perfect absorbers of energy.
@:) I think if you paint your ship black, you'll have to channel that @:) heat
out somewhere.
This is the real problem. I think even channeling heat out the "back" of your
ship (which requires knowing where your enemy is of course) is pretty tough
because it's going to diffuse into a big cloud eventually. I don't know how
you could control it once it's out of
your ship. In Brin's Sundiver, they had some kind of thermo-electric
gizmo that allowed them to convert heat into power and they used the power to
fire up a laser which they shot out of the back of the ship. This would be a
cool way of getting rid of waste heat but I don't think it's feasible now or
in the near future.
> Phillip E. Pournelle writes:
@:)... You would have a better bet against an orbiting target given @:) that
his threat cone is a LOT smaller, but then do you want 1,000 @:) rounds
orbiting your planet where you might want to put sattelites
@:) yourself...?
Here is an intriguing idea I'd not thought of. How do we model this in an
orbital combat game? My first idea is to have every round of ammunition fired
(and every ship damaged) increase the "space garbage" factor, which affects
everybody. A ship takes damage just by moving and the higher the space garbage
factor the more damage taken per inch moved.
> At 03:03 PM 4/10/97 +0000, Mike Wikan wrote:
> That's a 500 meter SEPERATION between individual penetrators...
Deja Vu all over again...
> Joachim Heck - SunSoft wrote:
One trick is to have a high temperature superconductor layer.. then you have
no hotspots and your entire ship's surface is a radiator.
> Allan Goodall wrote:
> Are you sure about that? Even black holes aren't perfect absorbers of
Yes, black is the best color for a near perfect absorber of energy. I did not
say it was perfert, it comes very close. Of all colors in the visible
spectrum, black reflects the least amount of energy. Many systems designed to
absorb energy with little reflected back(such as surfaces used for stealth
aircraft) use the color black for this reason.
> From what I remember, black holes emit radiation outside the event
> I like an idea presented in the MegaTraveller's Starship Operator's
I think interface craft would benefit highly, requiring very dynamic schemes
to work in any environment, and also would be visible before any ground units
were deployed. In space, you could adjust to blend in with a larger body, if
one existed behind you, or just use a dark color such as black to help reduce
reflected energy emissions. Of course some snazzy shark teeth always looks
cool even if no one ever really notices.;)
> From: Mike Wikan <mww@n-space.com>
But don't forget "for every action there is an equal and opposite reaction".
This can really play havoc with navigation (especially if the
railguns/mass drivers are turret mounted or not along the thrust axis of
the ship).
> At 05:39 PM 4/10/97 -0400, you wrote:
Of course. My mistake.
> I think interface craft would benefit highly, requiring very dynamic
Heeheehee. Yeah, interface craft could also make sure of it. I like the idea
of the shark teeth, though. "Real" camo schemes can be boring. Mind you, I
once one a WWII microarmour game because my Tiger's paint scheme blended it in
with the artificial grass I used for the terrain boards. It wasn't a
particularly snazzy paint job, but it worked.
> Mike Miserendino wrote:
> Yes, black is the best color for a near perfect absorber of energy. I
Just a little known fact for ya, the actual color of the RAM on F117s is
brown/tan. The USAF had them repainted because the origional color
would not be "manly" enough for the pilots. Hence the sinister black paint
job. The only thing the black paint does is make it harder to see at night.
er, RAM=Radar Absorbent Material
Enjoy,
So you look like one big UNIFORM glowing brick. :-)
Brian Bell pdga6560@csi.com
http://ourworld.compuserve.com/homepages/pdga6560/fthome.html
Includes the Full Thrust Ship Registry Is your ship design here?
> Nezach@ix.netcom.com writes:
@:) Just a little known fact for ya, the actual color of the RAM on
@:) F117s is brown/tan.
I beg to differ. All RAM chips are black, with gray or white printing. Nobody
makes tan RAM chips. What a silly idea. I can't believe you would post such
nonsense!
@:) er, RAM=Radar Absorbent Material
Oh. Uh, oops.
> In message <334D36F9.2781@alf.dec.com> you wrote:
> Samuel Penn wrote:
Having said that, I wandered into my local game shop this morning, and saw
both Prefect and Leviathan for sale. I've bought them both.
> From the quick skim read I did of the tactics section, they seem
> Not like RenLeg? Heretic! He must be burned! The Terran Overlord
Only ever played Interceptor, and I found the damage system interesting, but I
didn't think it added enough to the game given its relative complexity. It's
definitely not unplayable, but could do with a few tweeks.
> > There's also drive systems to take into account - ask any Kzin :)
Dispersion'll
> take it to less than the density of a nebular area darn quick.
For a standard drive yes, though a big freighter could probably put out quite
a punch. If the drive has been designed with this feature in mind, its use
might be practical. Unfortunately, I don't know enough physics to do the
maths. If someone is trying a boarding action against you though, it could be
a last ditch option.
> > For kinetic kill, you probably want railguns rather than missiles,
Each gauss cannon round is much less massive, and also a lot cheaper (and
lower tech) than any single missile. Stopping a single missile is also a lot
easier than stopping a thousand lumps of depleted uranium.
I don't know what the cost difference between a smart KE missile and a smart
nuke missile would be, but it may not be worth going just for a KE missile,
when a nuke is more effective.
> Think of fighters as drones with organically produced seeker modules
I don't expect space combat to occur at this level until at least the late
half of next century, by which time we should have decent enough AI (as in
targetting and tactical skill, not personality) systems. If we don't, then
yes, fighters are definitely useful.
> > I tend to see ships as going for heavy armour rather than
But if I'm protecting a planet, I can afford to have high thrust low
efficiency drives, massive arrays of active sensors (so what if I give away my
position? You knew I was here anyway), and well dug in laser and missile silos
on a moon, or in a conviently captured asteroid. Assuming of course that I'm
going for a purely defensive posture.
If I'm attacking a planet, then I'm going to that planet. I don't
_need_ to manouevre a great deal. So you send out half your forces
to outflank me, so what? In space, if my armour and point defence systems are
as good on my rear (and top, bottom and sides) as they are in my front, it
doesn't grant you that much of an advantage.
Where manouevrability does come into it (as described in Prefect), is that you
can move your defences from other outposts to the one I'm attacking in time to
help defend it. Also I don't have
the delta-vee to keep options open for many targets to force you
to split your defences between all of them.
> a balanced interstellar fleet should make use of /both/.
As always, very true.
> > If the enemy controls orbit, then don't *ever* fight an open ground
Not true. America lost in Vietnam despite having air superiority, better
technology etc etc. Iraqi forces were decimated because they had to fight a
war in the open, and stealth bombers and
what-not-else could pick them off at leisure.
If you have the guts to continue fighting a guerilla war, hitting soft
targets, performing terrorist actions within cities etc, then there's not much
that orbital superiority can do (unless it's
_really_ good).
The only way you're only ever going to kick them off your planet, is to keep
on nibbling at them until they get fed up and go home, or you get extremely
lucky. Don't ever think of building big bases, moving large amounts of
equipment and supplies, or performing any long (where 'long' could be as short
as a few seconds) engagements though, because you'll loose.
> attacker is understrength, you might as well give in. If the enemy
Or build Archangel Michael (if you don't understand that reference,
then why haven't you read _Footfall_ (Niven and Pournelle) yet? :) ).
> (Prefect models this /very/ well. You can take any strategy you like,
Guess what I'm going to be reading this afternoon?:)
> > If attack a world, this is of course what you'd use. A world can't
The rock may be an improvement. Chuck a big ice asteroid at Mars, you wipe out
it's unwanted colonists, and give Mars a bit of
surface water and atmosphere as well, ready for _your_ colonists.
:) :)
> All you know is where they are /right that minute of the burn/.
The burn has to be for a period of time greater than zero though. If it's long
enough, I can plot the ships course. How long 'long enough' is depends on
available sensor systems. You want
to make a high-thrust short burn to reduce my information as much
as possible. If the ship is crewed, then you've got a limitation on how high a
thrust you can safely achieve.
In practise, I should have a good idea of your vector, but there will be a
fair amount of uncertainty.
> > On top of that, they *will* be detectable. If you know where to
Looking is easy if you know where to look. If you don't know where the enemy
is, or even if they're there, then looking is hard.
> > Samuel Penn wrote:
Prefect's a pretty good buy, Leviathan's really not all that
`keen!'ness-inducing, at least in my mind. FT with a few tweaks
(improving the amount you can carry in a side-arc or decrease the
amount in front/rear) would probably be a far superior product. The
armour system is pretty good (Centurion-esque) but a little on the
pointless side given the weapon profiles of most of the damage-dealing
death-gurlers in Lev.
> Only ever played Interceptor, and I found the damage system
For my RenLeg money, I'm a /big/ Centurion/Prefect fan. Interceptor's
fun, but the damage system's funky (not like the others in the system)
but definitely captures the /flavour/ of what they were trying to
achieve. The `Pushing the Powerplant' rules, in particular, I've always
thought keen. A good pilot can get more Thrust, but if you blow it, you're
a'tumblin' or you've burnt your own engine.
Most of the complexity seems to be in adhering to hexes. Throwing it onto FT's
Newtonian motion rules would alleviate a lot of that and make things a lot
more fluid.
[One of these days I'll get around to converting RenLeg's games, from
Centurion to Leviathan, to FMA-based systems. I feel like a heretic
myself, sometimes...:)]
> For a standard drive yes, though a big freighter could probably put
If someone's trying to board you and they haven't disabled your drive, via one
method or another, they deserve everything they get. That's one of the biggest
nightmares I can imagine in space: trying to grapple onto a ship that doesn't
want you to. Its worse in an orbit:
forget even attempting it, because if you /try/, you'll both be eating
atmosphere.
[Sidreal thought: Anyone played SGII on a Space Hulk random ship
corridor map?]
> Each gauss cannon round is much less massive, and also a lot
Taken as a whole, the technology to acquire a target at light-seconds'
range to really-darn-close, predict its motion for the intervening
flight time, then fire chunks of metal into the maneuver sphere in a way that
fills their maneuver sphere equally would seem to require as much technology,
or even a little more, than a sensor package on much the same guidance system,
strapped to an engine with a smaller mass of submunitions (because the
maneuver sphere you have to fill is much smaller the closer you are to the
target, for the same density). Mass may turn out to be less for ten missiles
vs the mass of multiple Gauss burst reloads plus the mass of the cannon plus
the mass of the power system to support it.
Can't argue that its easier to stop a single missile, but its also
/much/ harder to detect a single missile than it is to detect a
thousand Gauss rounds, even RAM-plated ones. You /may/ be able to
tell I've dropped a missile (the thrust bloom might give it away, if you don't
think I'm trying to do a small course correction) but you
won't be able to tell if its operating in mine-mode, a pre-programmed
position-and-mine mode, a search pattern or just keyed on the
radiation signature of your boat.
> I don't know what the cost difference between a smart KE missile
Probably not significant at the scales we're talking about here. You might
split the difference and use a nuke that impells a large amount of material at
the point of detonation. Best of both worlds.
> I don't expect space combat to occur at this level until at least
Its hard to second-guess what AI is going to be like by then; it
depends on more factors than even someone that's done a fair amount of work
and research in the field (like me) can predict. Certainly, if something
happens `before we're ready' with the right technology at the right time, odds
are we're going to see at the very least transat fighters capable of orbital
launch and recovery, possibly some kind of manned fighter that's purely
orbital as well.
> But if I'm protecting a planet, I can afford to have high thrust
Not necessarily; I know you're there, you know I'm coming, but not
necessarily where in orbit I'll do so. Plus, with your high-thrust
low-efficency drives you're going to have /much/ more limited dV than
I am, particularly if I take up an attack position higher in the gravity well.
You'll be fighting the well to get up to me, further
cutting your dV and /far/ cutting your endurance. I can drop things
down the well at you. If you invest in low-thrust low-efficency
ships, that becomes even worse. It becomes easier to hit you.
Spy sats /probably/ wouldn't last long enough in a high-orbit conflict
to be meaningful, except for single-pass disposables you lob out as
`recon' just before a thrust. Any attacker worth the name will concentrate on
wiping your sats from the sky on contact. The missile
and laser defenses based planetary have one /major/ flaw: once they
fire, they're revealed. Orbital bombardment will be swift and sure.
> If I'm attacking a planet, then I'm going to that planet. I don't
See below. Keeping that maneuver sphere open to as many targets as possible as
long as possible keeps you guessing. In orbital battles, this is just as true,
just on a far contracted scale; the larger my maneuver sphere, the larger area
you need to fill with submunitions to
have a chance of hitting me. If you can't /fill/ my maneuver sphere,
the larger it is (the higher my thrust possible) the more likely I'll be able
to evade your attack.
Odds are every space vessel for the forseeable future will have at
least /one/ vulnerable arc: the rear. Anywhere you vent thrust from
is going to be a very weak spot.
> Where manouevrability does come into it (as described in Prefect),
Precisely. The defenses /might/ be this squadron of fighters vs
/that/ squadron of fighters at shorter ranges, but the principals' the
same. Who do you reinforce and when?
> If you have the guts to continue fighting a guerilla war, hitting
One doesn't do that and still hold territory, though. Once you're reduced to
guerilla fighting, for the most part, if your opponant knows how to deal with
it, you're not going to hold together as a
governmental entity long. Under planetary siege/interdiction, your
populace is probably going to capitulate before they suffer too long
unless they're /all/ fanatical. Your guerillas are going to be
hurting since their logistics can't be done at /all/ on the open road
(part of civillian control/siege would be to take theirs out, too).
If terrorist actions in cities result in the attacker pulling their forces out
... and then bombarding the city to rubble and ash, you're probably going to
lose support before too long (or get your planet turned into fanatics like N
Ireland). If your opponant is willing to
go toe-to-toe with you with guerillas and terrorism, the problem
resolves to two opposed countries on a single planet... its just one will have
neither orbital nor air superiority (since airstrips will be one of the first
orbital strike points).
> The only way you're only ever going to kick them off your planet,
You'll only be able to win by making it logistically unfeasible to retain the
planet. This might be because your planet isn't considered too important and
the attacking force is undersupplied for the fight you put up, or you just get
lucky and kick serious booty early in the conflict.
> Or build Archangel Michael (if you don't understand that reference,
I've always liked the TALONS of Heaven (geo-sync sats over the poles
poised to fire nukes into the polar icecaps and flood us out).
They're the /manly/ doom-weapon.
> Guess what I'm going to be reading this afternoon? :)
You'll be hooked by night.:)
> The rock may be an improvement. Chuck a big ice asteroid at Mars,
You also knock out all their nice techie toys /and/ you have to wait
for the dust to settle. Messy.:)
> The burn has to be for a period of time greater than zero though.
If you're close enough that a fast burst burn is more than a few angstroms
wide, then you're probably far enough into my maneuver sphere that you know
what my most probable target is and can either phone ahead or intercept.
Crewed or not, out at ranges enough that my burn vector would matter, you
won't have it. In close combat, it'll
be a lot like slow-motion fighter jockying in an infinite plain, you
may can see my burn vector, but there may just not be enough time to do
anything about it unless your maneuver sphere is much larger than mine.
> Looking is easy if you know where to look. If you don't know
If you know where to look, you don't /need/ to look. :)
> In message <9704131238.AA19327@uxtlaser.alf.dec.com> Alex wrote:
[snipped lots on Renegade Legion]
> Most of the complexity seems to be in adhering to hexes. Throwing it
Especially true of Leviathan, which can't seem to decide whether
4-hex ship templates are really 4 hexes long, or just look big.
Give me proper vector movement, with no grid, any day.
> [One of these days I'll get around to converting RenLeg's games, from
I'm sure we can find it in our hearts to forgive you:)
> > Each gauss cannon round is much less massive, and also a lot
I'd only assume use of gauss cannons for short range weapons. A few tens of
thousands of klicks at most. For anything longer, use missiles. At light
second ranges, I'd say don't use anything other than missiles.
> > I don't know what the cost difference between a smart KE missile
I prefer nukes because they don't have to hit. Even if the nuke misses by a
couple of hundred metres, the heat is going to hurt. If a KE missile misses by
1 metre, it does no damage (though it could do more damage than the nuke does
if it does hit).
> > But if I'm protecting a planet, I can afford to have high thrust
> Not necessarily; I know you're there, you know I'm coming, but not
But I haven't just travelled half way across the solar system. I might
actually have more dV to play with than you do, since you've used a good
portion getting here, and may be wanting to keep some in reserve to go back
home in case you lose.
Further, I might even have as good, or better, acceleration (and hence a
larger manouevre sphere) than you do. A massive, well armoured and bristling
with point defences defence battleship, with low mass ratio and very high
thrust could dance rings around your interplanetary assualt force.
Of course if the engagement drags out too long, then I fall
foul of my low delta-vee, and I'm buggered :(
> gravity well. You'll be fighting the well to get up to me, further
I really need to be at the bottom of the well though, in order to intercept
anything you might through at the planet. So whatever force I've got, I have
that disadvantage, unless I split my forces to meet you much higher up.
> Spy sats /probably/ wouldn't last long enough in a high-orbit conflict
Doesn't matter for ground based missile silos - they're one shot
anyway. Laser implacements could be _very_ vulnerable though. Spy
sats could be low in orbit (which gives them a short horizon, so I'd need lots
of them), protected by planetary defences.
> Odds are every space vessel for the forseeable future will have at
One word. Orion.:)
> > If you have the guts to continue fighting a guerilla war, hitting
If you've got orbit, then I sort of take it for granted that I've lost any
territory I care to lay claim to by default.
If you're really keen to keep hold of the planet, and especially if you're not
too squeemish about punishing the locals for any acts performed against you
(one hundred Narns killed for every Centauri killed sort of thing), then I've
lost.
> You'll only be able to win by making it logistically unfeasible to
Or of course, I'm the hero in a Hollywood movie, in which case you don't stand
a chance!:)
> > Guess what I'm going to be reading this afternoon? :)
Been side tracked by umpteen billion other things. Story of my life:(
> > The burn has to be for a period of time greater than zero though.
> If you're close enough that a fast burst burn is more than a few
> > Looking is easy if you know where to look. If you don't know
Okay okay, I'll rephrase that! If your burn wasn't sufficient for me to
compute a vector, then I still know where you are now.
At now+1, you're not going to be more than a few seconds or
minutes away, which gives me a very narrow window to look in, in order to find
out *exactly* where you are. I do this again
at now+2, now+3 etc, until at now+x, when I've plotted your
vector and can track you at leisure.
> Samuel Penn wrote:
For Lev, proper vector movement and targeting done to nearest part of
model to firer would probably be best. Leviathan cap ships /are/
supposed to be multi-km long, after all.
> I'd only assume use of gauss cannons for short range weapons.
I'm not even sure 10k kliks are even doable... unless you have really
/really/ good intelligence on their future movements. Missiles are
going to be your /surest/ long-range attack, for good or ill.
> I prefer nukes because they don't have to hit. Even if the nuke
The heat (IR rads) is really going to be secondary to the cascading
through the hull you're going to see. I'd /really/ hate to be in a ship
near either a nuke -or- a solar flare.
> But I haven't just travelled half way across the solar system.
If I'm smart, I'm coming/going in high-storage carrier ships, retaining
fuel for the attack or planning to scoop hydrogen/water/ice from
somewhere in your system to refuel with. Given those resources, I may
have more dV fuel/accelerant than you at that point. This, of course,
is highly tech-dependent.
> Further, I might even have as good, or better, acceleration (and
Now, if you have more outright thrust, I'm in deep kaka, no matter
/what/ is in the offing. Your maneuver spheres easily overlap mine, so
I'm going to have to be a tactical genius to get anything done,
outguessing and out-maneuvering you in the details, not just the
outlines.
> I really need to be at the bottom of the well though, in order
A split is probably the best bet for you, probably with forces
moon-based in a Terra-like system with one moon, and planetary defenses.
> If you're really keen to keep hold of the planet, and
Being the TOGgie I am, you know where I fall on being gentle to native
populations. (See Kes'Rith.:)
> Or of course, I'm the hero in a Hollywood movie, in which
In anime, I still have a chance, you being the hero or not.:)
> Okay okay, I'll rephrase that! If your burn wasn't sufficient
Really, this is the whole idea behind maneuver spheres. Your problem is
that if it takes you Now+X to track me entirely and it takes me
Now+(X-1) to get enough burn to do what I want, you're screwed ... Fast
burns, high-G maneuvering is the only way to sustain the cloak of vector
secrecy.
> Alexander Williams writes:
@:) > But I haven't just travelled half way across the solar system. @:) > I
might actually have more dV to play with than you do, since @:) > you've used
a good portion getting here, and may be wanting to @:) > keep some in reserve
to go back home in case you lose.
@:)
@:) If I'm smart, I'm coming/going in high-storage carrier ships,
@:) retaining fuel for the attack or planning to scoop
@:) hydrogen/water/ice from somewhere in your system to refuel with.
@:) Given those resources, I may have more dV fuel/accelerant than you
@:) at that point. This, of course, is highly tech-dependent.
I think it's hard to imagine the attacker having the upper hand,
fuel-wise, in this situation. Assuming the planet has fuel resources
and assuming it's prepared to defend itself, one would expect significant
quantities of fuel to be in orbit around the planet. I would think it would
boil down to the question of whether the attacking fleet can carry more fuel
than the planet. That seems unlikely.
> I think it's hard to imagine the attacker having the upper hand,
Its not just `more fuel' that's the issue; its dV that's a real problem. Ships
will require reaction mass in the near future, that's
a given. You can have /immense/ amounts of fuel floating around in
orbit or you can use the upper atmosphere to scoop to use for fuel; you still
may not be ready to use it whenever the attacker drops down the well. If
water's the reaction mass of choice, the attacker can probably find massive
quantities flying around in your system, drop in, set up a mobile base and
throw fuel down the well at regular intervals (makes a good weapon, too).
The /real/ question is who can generate the most dV. At the bottom of
the well, as we've mentioned previously, its going to take a /lot/
more fuel to generate the same dV as well-assisted passes from
outside. This can and probably /will/ make more difference than the
raw amount of fuel available.
> Alex Williams writes:
@:) > I think it's hard to imagine the attacker having the upper
@:) > hand, fuel-wise, in this situation.
@:) Its not just `more fuel' that's the issue; its dV that's a real @:)
problem.
@:) The /real/ question is who can generate the most dV. At the
@:) bottom of the well, as we've mentioned previously, its going to
@:) take a /lot/ more fuel to generate the same dV as well-assisted
@:) passes from outside. This can and probably /will/ make more
@:) difference than the raw amount of fuel available.
It's true that it's the delta-v that's important. Also that people
at the bottom of a gravity well have more trouble producing it (at least in
the 'out' direction). On the other hand, people in low orbit are actually
pretty far out of the gravity well and it's not terribly difficult to get
yourself into an orbit where your planet's gravity is almost undiscernable.
People coming in from the outside will have the
ability to generate more v. But probably not more delta-v. So
they'll be zipping in and everyone will know exactly where they're
going and delta-v becomes less important on the part of the defenders.
If they come in a lower speed they will have better control over where they're
going and more ability to steer but so will the defenders.
> In message <335293F4.2781@alf.dec.com> you wrote:
> Samuel Penn wrote:
If the target is trying to be stealthy, then he's got no active sensors which
are most likely to detect gauss attacks. If you have detected him anyhow, then
I'd say hitting with gauss would be doable. If he can see it coming, then
effective range depends on muzzle velocity of the gauss weapon. Anything out
to a few seconds range could probably be hit (it also comes down to how
quickly the target can move out the way).
> > Further, I might even have as good, or better, acceleration (and
It also comes down to weapon systems we both mount, and relative tech. Also,
there's going to be big differences in tactical skills of attacker and
defender, and attacker could also have much better knowledge of the defenders
systems and plans, then the defender does of the attacker (it's easier to plan
an attack you know you're going to make, then it is to plan a defence when you
don't know who, what or when an attack will occur).