Re: Real Space Combat Help:

At 01:06 AM 4/9/97 -0500, you wrote:
>	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.

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
particle
>beam weapons?

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
space
>combat?  Nuke or kinetic kill?

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
warship
>before going into combat (the crew would be in space suits).  Why would
>that help?

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
that is)?

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.

Allan Goodall:	agoodall@sympatico.ca 
"You'll want to hear about my new obsession.
 I'm riding high upon a deep depression. 
 I'm only happy when it rains."    - Garbage