In my opinion every writer who wants to write inter-space system stores needs a way to break the speed of light. Einstein said that the speed of light is the fastest anything can go. But taking four years to go from the Earth to the nearest star takes a bit from the story. Yes, I know about how time slows down as you go faster so the people traveling that distance won't think it's 4 years, but what about the people on Earth and in that other star system? The people on the ship may be the main characters but I want my characters to interact with the people they knew when they left the star system, not their 10 generation descendants.
So I break the most fundamental law of the universe, the speed of light.
My ships do this by means of what I call a star drive. I know it's not an original name and I don't know who used it first but it's used a lot. But the name fits how it works. Einstein also said that anything with mass curves space. The Star Drive takes advantage of this. Every one knows that to get to the end of two streets that intersect you cut the corner traveling directly from the start to the end. The star drive cuts the corner caused by the curvature of space. If it's going to get anywhere it needs a large curve, only a star or something more massive can provide this. A star at each end of the trip is required to provide a big enough curve.
Ships equipped with the Star Drive dive towards the star as close as their shields can handle and then make the transition into the space beneath the curve.
The closer to the star they can get the more the curved the curve is and the faster they make the trip. Ships also curve space and the Star Drive uses this to add to the effects. So the larger the ship the faster the trip.
One of the problems with the star drive is during the transition periods to the space beneath the curve. During the transition from one gravity well of one star to another and the effects of the curved space itself increased the effective mass of the ship enormously. With this effective increase in mass the momentum also increases. Any change in direction of the ship during the transition period would be very dangerous. Maneuvering thrusters would be working on turning the ship at opposite ends while the middle is still trying to go straight ahead. Depending on the condition of the Star Drive installed in the ship this could last anywhere from 10 seconds to an hour. This of course leaves the ship very vulnerable to attack.
My ships use a variety of different engines. There's the regular liquid rocket engines, used mostly for maneuvering thrusters. But interstellar ships usually have three different types of engines installed. The biggest is the Star Drive, which is explained above. The second biggest is the anti-matter drives. These take hydrogen and anti-matter to produce a high thrust for the ship. The last is the anti-gravity system. This works directly with the Star Drive and in modern engines is part of the star drive. It is only good for lift off from a planet and station keeping, only providing a vertical force away from the gravity well its working in. The closer to the gravity well the more effective it is. The anti-gravity system is the one used to bring the ship close enough to a star to activate the star drive.
Not much to say about shields except there's two major types. One that deflects mass, the other deflects light. Large ships, like carriers and dreadnoughts carry shields powerful enough to deflect almost anything shot at them. Only the main guns on a dreadnought or ship destroy can break through by brute force.
Weapons have evolved past smart guided missiles (though fighters still use them) to rail guns, lasers and enormous ship-killing torpedoes.
A rail gun is just a basic projectile gun. It's a barrel with magnets at regular intervals down the tube. A charged shell is loaded into the barrel and the magnets are turned on. When the shell passes a magnet it switches polarity to repel the shell instead of attracting it. This causes the shell to fire at a high velocity.
The rail shot gun carried by the KSS Skate is just a 27 small barrels that spread out by 10 degrees to provide a large field of fire.
Not much to say, its a beam of light, like you see in all the movies.
Because the shields of large ships are almost impossible to penetrate by smaller ships these large missiles were developed. The first generation of these missiles was just guided rockets carrying a large warhead. The ship carrying these torpedoes was equipped with a shield bore cannon. On a strike run these attacking ship would fire the shield bore to open up a hole in the shields and fire the rocket through the hole. The ships had to get very close or else the missile would miss the hole and explode on the shields, doing minor damage to the target and having a good chance of destroying the attacking ship.
The second type of torpedo is the type used by the Skate. The shield bore laser is built into the nose of the torpedo. The shield bore in the torpedoes is smaller and weaker then the one carried on the older ships. The skate is equipped with an advanced sensor array to analyze the fluctuating pattern of a target ship and guild the torpedoes to the weakest spot. As soon as the torpedo passes through the shields the skate would then redirect the warhead to the best target.
Stealth technology is becoming very advanced in our days. The B-2 bomber is larger then the stealth fighter but its harder to detect. That's a big difference in only one generation of stealth technology. From what I've seen the B-2 relies on a continuous curve to give it this advantage, so the smaller of my ships use this to help them hide from their enemies. They even go so far as to withdraw all their turrets into the ship and anything else that would break the curved outline. Conventional sensors can not pick up these ships.
The larger ships don't use this technology; most of them are around 2 km long. A continuous curve for a ship this size would still produce enough of a flat surface to reflect radar. The other reason is that larger ships are used as a show of force. A show of force is much more impressive if they can be seen.
Radar and infrared are still used. When a ship doesn't have its rail-gun or laser turrets retracted, radar can still be used to detect them. They also work well on fighters. But with stealth technology two new sensor types have been developed: a mass sensor and a magnetic ion radar.
The mass sensor detects the curves in space caused by anything with mass. It's not very accurate and can only detect objects greater then 20,000 tons. Fighters, missiles and the newer torpedo ships fall beneath this limit. It has a range of about 150,000,000 km (1 au).
The magnetic ion radar is an active system. It works similar to radar but not quite. Radar detectors, detects the presence of radar waves. The magnetic ion radar looks for the absence. The magnetic ion detector firsts makes a special ion by containing many electrons inside a positive charge. It then sends these ions out at about a quarter of the speed of light. These ions have a half-life of about a half second. When they decay then send out radio waves in all directions. If a ship is in the way then the radio waves won't get back to the sensor. The sensor will detect this absence in radio waves and detect the ship. The sensors can detect when there is still only a sixteenth of the ions still in space giving this system a range of 150,000 km (0.1 au). Each set of ions sent out has a different frequency and only the sensor knows which ones are still active. The frequency sent out is close to the same frequencies that super hot hydrogen gives off. This means that for ships near a star won't detect these sensors. But since the differing frequency is known only by the sensor it will still detect it.
I am not a physicist and I know that most of the above science wouldn't hold water. I'm a Computer Scientist who likes to write science fiction. I needed a science base and that's what I've provided. Just because it doesn't match current physic theories doesn't mean I can't use it. So basically what I'm saying is that I don't want emails telling me that I'm all wrong and that my science is stupid, its there to help move the story along not to provide a window on the universe.