Gravitation Drive

The Gravitation Drive is the main method of interstellar travel throughout The Fields.

How it Works
The Gravitation Drive is an advanced piece of engineering and knowing the intricacies of it would take decades of study. However knowing how the Gravitation Drive works in a basic manner gives you an idea of the limitations of the device.

The basic premise of the Gravitation Drive is that it removes the ship from spacetime and moves it to the target destination, navigating its way by the gravitational pull of the target. This means two things: One, the travel of a ship from one system to another is instantaneous since the travel is happening outside of time. Two, the primary limitation for travelling with the Gravitation Drive is the gravitational signature of the target body.

When a ship engages its Gravitation Drive the drive will erect a displacement field around the ship which allows it to pass outside of spacetime. The supercomputer will then begin its collosal workload of determining every significant piece of mass inside and outside the displacement field. Once it has it can creating a navigational solution and move the ship outside of spacetime and shunt it back in at a target point in front of the target mass.

Limitations
Since the Gravitational Drive works on the gravitational signature of the target then there has to be a clear gravitational pull from the target. It can only work on celestial bodies and it can only work on the dominant one in the system. For example if a ship wanted to travel from Proxima Centauri to Io, a moon of Jupiter, it would first have to jump to the Sun, then to Jupiter, then to Io. The ship would then have to use sub-light engines to navigate the space above Io, either to a spaceport or a satellite station.

The other main limitation of the Gravitation Drive is the complete lack of military application. The average 'slug' from a sub-light driver gun, is about 10kg. If this were to pass only 1m from the ship, it would exert the same gravitational pull as a sun sized star 10 light years away. In even a small space battle there are so many errant mass projectiles floating in space that it is impossible to get an accurate navigational solution.

Multi-Drive Ships
MD ships are a relic of the past that still exist. In the early days of space travel Gravitation Drives couldn't project a displacement field very far, so engineers rigged ships with 2-6 Gravitation Drives, depending on their size, in order to progress space travel. In recent years we have developed the technology to project a displacement field to cater all but the largest ships in The Fields. Still these old vessels still travel the skies, the main disadvantage of MD ships is the increased load times for a suitable navigational solution. There is also a minor issue of the ship tearing itself apart during transit.

Blind Jumps
No shipwright would ever allow a Gravitation Drive to blind jump, it is a dangerous and reckless maneuver that has a very low success rate. However once the ship has left the dockyard it is in the sole control of the Captain and his Chief Engineer.

Many small or old ships have some form of blind jump capability. Mostly it is for escaping the authorities but some especially impatient captains have been known to blind jump small impossible to miss trips.

For instance, if a ship needed to land on a planetoid from high orbit. There would be very little danger in simply jumping the distance toward the surface because the gravitational pull of the target would be so much more massive than anything else the computer wouldn't need much of a navigational solution.