It is possible.
Direction:
Like Jarraff said, to have the missile system fire up, for instance, make sure the computer screen that says "MIS" is pointing down, where it normally points aft (toward the rear of the ship).
Manual shots vs. AI-driven Weapon Pods:
You cannot use logic to manually fire homing missiles. On the other hand, this might be a rare opportunity where you can use a AI weapon pod to fire multiple homing missiles at once. To do so, you'll want to keep the AI pointed forward in the missile weapon pod, and to control the target, you'll want to set the AI to target your selected target. Plus, if it's a pod, you'll want to put most of the pod/turret's equipment "under the skin" of the ship. As in building the ship with a hollow area, down into which the weapon pod reaches deep.
Slave systems:
To get long-range homing missiles you'll want to slave beam to the missile system. To create heat-seeking swarm missiles that target friend and foe, you'll slave a missile system to another missile system. You can also slave a pulse system to a missile main system to create a high-power, slow-moving "nuke" missile. Most prefer the beam slave, because it's got precise control over what is fired upon and is a faster missile. On the other hand, firing multiple low-damage heat-seeking swarm missiles before firing the big missile systems can distract anti-missile systems with decoy missiles. "Nuke" missiles are not as favored, because their relatively slow speed makes them highly susceptible to anti-missile fire even with decoy missiles. However, "Nukes" are very powerful.
Powering shots:
It's important to track how much power each missile shot requires, and make sure there is enough power storage in the weapon pod itself to handle that shot. I'll leave it to the rest of the forum to talk about power generation to sufficiently recharge the power storage between shots, a popular and well-covered subject.
Pros vs. Cons:
Missiles are subject to being shot down by AMS (Anti Missile System) automated turrets, which are on many ships.
A human player currently does not yet get any warning when a missile is on the way, unless it is fired in the same sector, in which case, the target can see the "contrail" and missile flare, but gets no other indication unless they see their automated AMS turrets engage. (Flare as in the visual indication of a missile, not a missile defense heat device.)
Missile systems fire relatively slowly and have large power requirements. (Exception: When slaved with a cannon slave system, the missile system becomes a dumb-rocket, rapid-fire weapon system that looks like a big, relatively slow cannon system with missile-looking shots instead of the less-obvious cannon shots.)
You can create a multiple-output MLRS (Multiple-Launch Rocket System) with guided missiles by designating multiple outputs for the same main weapon computer. However, this is not recommended, because each additional output block after the first one adds a 10% power cost to the overall weapon system. Most builders would instead recommend creating a MLRS out of multiple independent guided missile systems. (Think: Building a whole weapon hotbar out of missiles on a row of your MLRS.)
An AI-driven weapon pod or turret can fire multiple weapon systems all at the same time, as long as enough power is available, so you can create a MLRS on a turret/weapon pod where the AI fires all missiles at once. (If you want to create a simulation of a MLRS where each missile fires by itself, before the next, you would need to reduce power storage so that only one or two missiles fire at once. This can create a nice effect. However, if the first missile system recharges before the pod reaches the last individual missile systems of the MLRS, some of the missile systems might never fire, as it starts firing the first missiles at the beginning of the MLRS instead of continuing to the end of the list.)
AMS turrets that automatically destroy missiles are worth mentioning again as a con. No other weapon system can be intercepted like missiles.
Another con is that to maintain lock, you need to keep your target in your sights. This can be challenging in large vessels, because they turn so slowly. AI-driven turrets don't have this problem so much, mostly due to the fact that most turrets can turn much faster than a large vessel, and so it is easy for a turret to keep a target in its sights. Perhaps more importantly, as far as I know, AI gets an instant target lock, versus the multi-second lock that a manually-targeted guided missile requires.
One of the biggest pros of missile systems with beam slave is the immense range. You can basically snipe a missile at a distant target. I'm not sure of the exact range, but I think it's at least two sectors. Not only is firing ship hard to see from multiple sectors away, but when the missile is fired more than one sector away, the target cannot currently see the missile or its contrail. However, as far as I know, automated AMS turrets will attempt to engage a long-range missile once it closes in range of those AMS turrets, no matter how far away it was fired from.
