Does anyone know if it is possible to have weapons that are not in turrets?
I would like to have some weapons only be fixed in the direction the ship if facing.
i.e., the macross cannon, starblazers wave motion gun, and rockets and guns on fighters that can only launch from the front.
what kind of lousy designer would design a ship that does not allow you to shoot at something while at the same time running away ?
Many science fiction universes have ships with linear accelerator type guns or rail guns running down the long-axis of the hull. Presumably there would be a small ability to steer the beam from the muzzle.
Of course in reality the ship cold simply point where it wanted regardless of the direction of motion.
I had thought about making the entire ship the turret, but that limits you to one weapon, and it flies sideways a lot of the time 
that is silly, how can such ships fight to run away ?
Most modern fighter planes can only attack when facing forward, unless they use missiles, and even then, they are fired forward.
You attack head on, where your profile is minimal, not side on, where it is largest.
Xwings attack from the front, as do TIE fighters, as do Colonial Vipers, as do Cylons.
Watch the main cannon fire from Macross or the wave motion gun from starblazers. Even the death star had to be facing in a certain direction to use it’s main gun.
There is no reason why a spacecraft has to point in the direction it is moving. Using realistic movement, in fact, a ship would usually be pointing at right angles to the direction of movement.
The only reason for fixed guns would be if the universe in question allowed for powerful weapons that were too large to fit in a turret. Linear accelerators, for example, or rail guns.
Cyclotrons are another weapon that might require pointing the ship after a fashion—the emitters would need to be at a tangent, so you could spin the spacecraft and attack targets in many arcs of fire.
Anyway, it’s common in many cool universes (B5, Starblazers, Traveller, etc).
Regarding Terrestrial craft, it is an entirely different thing since in space ships can pivot regardless of the direction they travel in.
Plus many of the Rebel ship models quite clearly have spinal mounts.
One day…
yeah it doesnt have to move in the direction it is firing but usualy you are gonna want to see where you are going, ( or have motion sickness from hell wich i guess zero G ships will have regardless :P)
turrets would be much more preferable 
The computers required for targeting don’t care 
Weight saving, space saving, better protection from continuous armour, smaller profile, better reliability from fewer moving parts, less required power are all good reasons for having fixed-orientation weapons, but not all of them apply in GSB-space.
GSB assumes full battlefield visibility, so a smaller profile isn’t a benefit.
GSB assumes uniform armour protection, so better continuous armour protection isn’t a benefit.
GSB has on/off damage degradation (a weapon works perfectly until it doesn’t, and turrets don’t jam), so reliability isn’t a benefit.
It looks like GSB assumes that turrets consume no power, so that wouldn’t be a benefit.
Weight saving should be a benefit, and so should armour values; 40% or more of a weapon mount weight is in the turret, and even more if it is is armoured. Plus a turret is much larger than the weapon it houses, so takes more armour to cover it. So you could tweak it so that a fixed weapon weighs 50% of a turreted weapon, but only counts as half a module for armour value purposes.
Space saving is another benefit; you should be able to fit two fixed weapons into the space taken by a weapon-plus-turret, even if both fixed weapons are fully mounted inside the hull. Yes - I know that the GUI shows the weapons hangin unprotected outside the ships in GSB, but if that really were the case, why do I have to take your armour down to start damaging you weapons; the turrets and weapons must have armour on them that you can’t see.
BUT, you lose all the directional benefits. So fixed weapon configurations would work better for rocket fighters (which steer the fighter) and frigate/cruiser missiles (which steer themselves), and for sheer push-through-and-never-mind-the-losses tactics (I load up three frigates with 8 fixed ion cannon each and set them on a cruiser, assuming that one of them will survive long enough to get in range and take down the cruiser shields and armour).
You can see the trade-off in modern missile-equiped naval vessels; some mount missiles on swiveling mounts so that the missiles are pointed the right way when they are fired, but some are now moving to fixed mounts firing more manouverable missiles. You can also see it in fighter planes; some have external gun mounts that include a small degree of movement, trading greater weight and drag against a better field of fire.
so, basically the death-weapon of the Aggressor-class destroyer from FoC? if it can only turn one way, than i’ll go with that. 
Got to say - I’d been thinking about this for a while.
Clearly a non-turret weapon would need to be seriously powerful (to offset the slowness of aiming), and mainly used against larger ships. I think it would also mean that the turn rate of ships would be much more important - though the pilot AI would need to know to point the ship at targets…
generally you can only turret mount light weapons,GSB doesnt take that in question
all heavy guns need to be atleast partially mounted into the hull itself,limiting their aiming abilities to only few degrees, but such weapons are usually much much more powerful
as for myself,im all in favor of fixed weapons in GSB… as i mentioned earlier i like ships built around weapon systems, like Homeworld ion cannon frigates or the dreadnoughts from Mass Effect
it gives the “heavy” weapon a “heavy” feel
what would be great is if you could have several variants of each of the weapons… you could mount a turreted version,fixed (few degree aim) heavier version,and several modifications of both (power,range,turn speed,refire,etc) with each variant having its advantages and disadvantages
i dont really see such a feature often and thats why i like Space Empires so much… 2 different games in same universe but Starfury has firing arcs,and SE5 has mount sizes… combined it would make for some interesting variations
furthermore ships with bonuses,affinities and disadvantages for various types of weaponry and equipment would give it some more options…
for example a bombardment cruiser built around a single huge volley fire torpedo launcher facing front,and lined with small turret slots for anti-frigate “cavalry strikes”
or a cruiser designed for frontline duty able to carry several heavy turreted weapons, but lacking the tracking equipment to make small turreted weapons effective against small targets and/or not strong enough powergrid to make full use of a fixed heavy weapon
you got the idea,possibilities here are basically endless and i think it would enhance the gameplay by introducing more complex tactics… ofcourse you would probably need more ship types and variants of them to cope with this
possibly a ship tunning feature for the upcomming campaign?