In most sci-fi (graphic) novels and films, they often depict the design of the cockpit or captain's bridge in a rather unusual way. A smaller ship such as a fighter or a transport ship usually comes with a bridge near the nose of the spacecraft, while a larger ship such as a battleship or destroyer comes with a bridge located near the rear. Is there any basis for the bizarre (inconsistent) design, or simply is it just copycatting by younger laid-back writers?
Short answer: because they often draw inspiration from real-world craft, which have varying cockpit/bridge locations.
A picture is worth a thousand words:
- Single-seat fighters
- In-atmosphere VTOL
- Capital ships
- Passenger transport
- Private craft/status symbols
- Naboo royal starship (Star Wars)
- Random yacht from Google image search
- Ships with no windows
From a design point you have reasons for the three cases :
- Fighters and small craft are... small, with few choices about where you put things like engine, thrusters, weapons... By being in the front, the pilot can see up, front and have a better view on what is below the craft, in front of him. The further back he sit, the less he'll see under his craft body, specialy if some components that you want to put in front of him, like the engine, are big. Radar and the like, or a glass floor might change this but you still can't see through the body and sometime your eyes are still quite important. Also, if you take a hit, you are out anyway.
- Cargo don't matter. Put the bridge back, front, up, down... that's for show. Plowing the space line at the front of your ship is somewhat more glorious.
- Heavy warships are different : most detection will be made through screens (radar, dradis...) so there is no need to have a favorable, direct, view on the space around you. You want your bridge in a somewhat secure location and the risk of taking a hit on your front is slightly higher than in the middle of your ship. Of course it depend on your battle technologies : laser at the front, Startrek style or space-broadsides Warhammer 40k Style.
- Heavier battleships, if big enough, might have secondary and/or specialized bridges/headquarters either close to the place where their function apply (like engineering, strategic command, barracks...) or just to prevent having both the captain and his second in command at the same location in case of problems. It would also allow for different hierarchies to apply and not muddy the water too much between people : if the ship captain has only indirect authority over the soldiers on his board, it's better if the military officer have their own headquarter on the ship. This could be called not putting all your bridges in the same basket.
Then, you have public familiarity and authors' lack of creativity. But there are at least basic logic in the designs.
Spacecraft are generally based on equivalent scale sea going ships
Small power boats tend to have a short bow, then the controls, then the rest of the boat, mostly consisting of the engine. Larger boats tend to have either a central (military) or aft (commercial) bridge.
If we go back to the days of sailing boats, both small and large boats would have control at the back, why? On small boats the controls are simply a stick on a foil and a piece of rope, on large boats it's a wheel attached to a chain attached to a foil and a lot of shouting. Short chain of command, short chain of control.
Let's take a small boat and add power. You now have a choice, you can put the engine at the front and the helm at the back, but there's no reason to do that, better to put the engine right in front of the drive. Now you have a second choice, put the helm on top of the engine or in front of the engine, putting the helm on top raises the centre of mass unnecessarily which will reduce stability, so put him in front. This gives your standard prow, pilot, engine configuration that stuck through to small spacecraft, it's basically a pilot sitting in front of an engine and not much more.
With larger ships there's no reason to change the fundamental layout, from a high bridge at the back, the commander can see both what's going on ahead of and around him, the state of his entire ship and cargo, and have an overview of what the crew are doing. Everything that's of interest to him is within a single field of view. To transfer this into starships? Well the military are nothing if not traditionalists and having the bridge away from the leading edge affords a certain amount of protection simply from the presence of the bulk of the ship ahead.
While you could experiment with moving the bridge or cockpit around, there's no real need to. It's better to keep the command and control chains short, which makes fault finding easier.
The question isn't "Why isn't the bridge at the front" but rather, "Why is the Enterprise bridge high up in the saucer section, not down between the nacelles, behind the main deflector dish, about 10m from engineering?"
Since everyone has already answered "why" in very convincing ways, we should look at the "where should it be" in realistic SF.
The "Starfury" fighter from the TV show "Babylon 5" does it best. The pilot is more or less in the centre of the spacecraft, and the spacecraft itself is centered on a large "X" shaped platform with the engines at the ends of the X to provide long movement arms for manoeuvre.
For most other realistic spacecraft, the cockpit is usually in the "nose" in order to allow the crew a full field of view. This illustration is of a space tug concept from the mid 1970's, and the crew module is on top of a thrust core and flanked by some auxiliary fuel tanks:
MOTV space tug concept
For larger spacecraft and especially military vehicles, the crew will most likely be encased in an armoured capsule near the centre of the craft. Since one of the major dangers of long range space travel is radiation exposure, being in the centre of the cart surrounded by the bulk of the spaceship's structure and reaction mass tanks provides a great deal of radiation protection without requiring large amounts of extra shielding.
Im modern naval ships this is known as the "Combat Information Centre (CIC)" and everything runs from there. A "Weather Bridge" might still be situated in the nose of the craft to allow for delicate manoeuvres such as docking at a space station, but this will not be the primary centre of operations (and indeed may sit unmanned most of the time. If your story requires a place for junior rating to goof off on watch, this might be it).
Because the reader/viewer sees it as normal
As Euphoric and others say in the comments, it's conventional that small spaceships are based on aircraft, and larger craft are based on ocean-going ships.
Although not explicitly stated anywhere, this positioning reinforces the perception of scale to the viewer.
For small craft: there isn't much place else to put the cabin and still have an effective small craft.
For large vessels: doesn't matter where you place it too much but on the trailing edge of the vessel for safety.
Having a small craft makes it easy to see its relationship to other objects and with small craft the difference of being at the front end or the back end of craft that is 10 metres in length isn't that drastic. Smaller craft generally have a high thrust-to-mass ratio and are generally more nimbly and respond to input quicker. The pilot needs to be able to gather information quickly and respond quickly, the cabin/bridge in a prominent place with unrestricted view would be best for accomplishing this.
But traditionally for craft where drag is a concern the cabin is generally at the opposite end of the 'prime mover' in a streamlined configuration. A missile doesn't have a pilot but its avionics and warhead are at the front of the frame; there is need to have the thrust to come out one side and still have low drag. This necessitates that the warhead is at the front of the missile.
In space, drag is not a concern but you still have to worry about thrust vectors and your mass. If a major amount of your mass is hanging off-axis of your thrust vector, it is going to go in circles. Therefore is still an advantage to having the mass in-line with the engine, and again if you have small craft it is almost a necessity that the cabin/bridge is at the opposite end of the engine.
With massive vessels, they usually have a support role where drag is not the primary concern, fulling their role or supporting smaller craft is the primary concern.
No matter the placement of the bridge it would be almost impossible for a pilot to make distance and speed judgments for the far edges of their vessel. Additionally these vessels have a low thrust-to-mass ratio and respond slowly to inputs, so waiting for reports or data to make maneuvering decisions can be tolerated, assuming the pilot is not reckless.
When a vessel becomes so massive, the change to the centre of mass due to the placement of the bridge becomes so small that they can be effectively placed anywhere. But with massive vessels come with high inertia, it is not easy to stop the vessel, so having your command structure placed away from the leading edge your vessel means the vessel might have a chance to limp in-to or away from action during a collision rather than being put out of commission instantly.
Massive vessels tend to be under their own power in 'safe' areas where threats can be planned for and there is lots of room to maneuver. The bridge doesn't need to be placed in the perfect spot as the pilot doesn't need to know exactly where the edge of the vessel is because he has plenty of error tolerance. A cargo ship is rarely, if ever, piloted straight in to dock by its own power. There are a host of tugs and mooring facilities that safely guide the vessel to port without relying on the pilot's knowledge of his blind spots.
Location to engineering areas isn't probably a major design criteria for bridge placement, not in modern or future times. Even in modern, mid-sized vessels the prime movers can be mid-ship with transmissions and screws towards the back. And with electrical-motor driven craft, engineering can be anywhere. e.g. nuclear subs can have two fission vessels one port and one aft to balance the weight.
A great source of space ship designs are space engineers, there are tons of people that have designed different space ships both of the larger and smaller kind.
The trend I see in this matter is that the small ships have the bridge in the front because it gives a better view and it is more practical to put the cargo bays behind the bridge.
On the larger ships the bridge is basically anywhere, but most of the time directly in front of the main propulsion and power-plant (don't know if it is to decrease the distance for maintenance) and the fighter/cargo/crew bays in in-front of the bridge.
The location on the larger vessels is not important because most is controlled by displaying values on screens and using cameras for maneuvers. There are few designs that actually have a usable window on the bridge, but on the smaller ships and fighters, it is few that have a camera to assist.
If it's a small ship, like a one-man fighter or "space motorbike", it would save space to put the cockpit at or near the front.
Assuming your propulsion technology involves throwing reaction mass out of the back of the ship to make it go forwards, you need nozzles for that on the back. These need to be connected to the actual engines, the components which accelerate the reaction mass using whatever technology is being used (rockets, ion engines, whatever). It's far easier to put these right next to the nozzles, so you've got engines at the back now taking up a good amount of space.
Then you need to power those engines, so you've got fuel tanks and they should probably be close to the engines too in order to reduce the amount of plumbing you need. Maybe you need a fusion reactor or something as well.
So put that all nicely together at the back, what's left? Stick the pilot at the front! Maybe the pilot has some more stuff in front of them - small thrusters for steering/docking perhaps, or the mounting for the ship's radar/lidar/other system allowing you to spot things before you crash into them. But the bulk of a little ship like that's going to be at the back. If you tried to put the pilot between, say, the engines and the fuel tanks, you'd just have to sit them amidst a load of fuel pipes. Doesn't seem very practical does it!
Obviously this does rely on having suitable protection from impact by little bits of rock/debris you might find in the space environment against the cockpit canopy.
I also suspect pilots might prefer it this way, as there's a psychological need to be able to see out, even if in space things are likely to not be very visible using the naked eye. You'd have detection screens everywhere, but you'd still want to be able to see where you're going, and it would be very useful for trying to dock with something after an equipment failure.
Big ships, on the other hand, have more room for a spacious room to command the ship from, big screens to display what's going on, redundant detector systems for docking... big spaceships are likely to be more like big submarines.
So actually, you could argue that a typically-depicted one man spacecraft is a cross between a modern fastjet fighter and a submersible. Hmm.
For surface ships, elevating the pilot sufficiently to allow visibility around much of the vessel is extremely helpful during low-speed maneuvering where side clearance around the entire vessel may be an issue. The further back the pilot is located, the more of the ship the pilot will be able to see at once.
For aircraft, a similar approach might be helpful during low-speed maneuvering on the ground, but having the pilot's head above the top of the main fuselage would add a huge amount of drag. Further, in most situations a pilot will either be on the ground in an area where precise maneuvering isn't required, will have a crew on the ground to assist, or will be traveling fast enough that anything the pilot might see that isn't completely in front of the aircraft will have either hit the aircraft or missed it by the time the pilot can react. Being able to see straight ahead is important for a pilot, and thus requires that any opaque objects forward of the pilot be located below the line of sight.
For spaceships which are not designed for use in atmospheres, an "elevated" bridge (or better yet, a pair of such bridges on opposite sides of the craft) would probably more useful than a bridge in line with everything else. For ships which might need to land, however, minimizing drag would be important.