Momentum Drive (Patreon)

Note : This one is a bit more work in progress than the others, don't hesitate to tell me what you think of it, it's still a technology/propulsion system I am hammering out of the kinks in. Also chapter 4 has been written, and I'm drowning in paperwork because my health insurance expired.

The Momentum Drive is the mainstay of spaceship propulsion throughout the galaxy. It allows for a ship to 'move' at a fixed speed at low energy costs, by putting the ship in a so called 'drive bubble'. Technically, the bubble itself has no kinetic energy and is something of a pocket dimension, when it collapses the object inside's speed is returned to its realspace equivalent. Conventional propulsion within the bubble will not affect it in any way, the objects within will, for the wider universe, move with the bubble, however within the objects will still move normally, as if in a parallel dimension, and the normal laws of motion will reapply when they leave it. A railgun slug moving at one percent the speed of light entering a bubble moving at ten percent of lightspeed moving exactly against it would, for the brief moment it is within it, be moving at nine percent of lightspeed in the direction the bubble is going, then when it exits it, return to its previous vector, and, as far as the wider universe is concerned, now retreading its previous path, as entering the bubble made it move backward, however briefly.

The object projecting the bubble however, ALWAYS move at the speed of that bubble, no matter what, as it is anchored around it. Interestingly enough, on can, as far as the wider universe is concerned, slow down a ship this way. It's momentum is technically the same, but it is moving forward within a bubble that, in and of itself, is moving slower, and since the bubble is centered around the object, it cannot 'move' at its actual velocity. Some compare it to running on a treadmill that itself is a vehicle driving you around, and collapsing the bubble as jumping off of the treadmill.

An active Momentum Drive is almost impossible to hide to sensors, similar to shields or active wards. When two drive bubbles meet, the lesser one (drive bubble strength is calculated through a host of equations, which can be broadly simplified it's internal volume multiplied by its drive rating) collapses and is absorbed by the stronger one, which forms the basis of combat boarding pods and missile attacks as well as the governing principle of anti-missile missiles.

Objects entering drive bubbles behave more or less as standard. From an external point of view they are suddenly moving with the bubble in whatever direction it is, as if they had instantly picked up its momentum, but from within the bubble they are behaving entirely as normal in relation to the other objects within. This can lead to strange quirks, and there have been attempts to weaponize the phenomena for defence against kinetic attack, but it proved too expensive, finnicky and unreliable to make a viable weapon.

Momentum Drives are classified by 'drive rating', corresponding to the maximum percentage of lightspeed at which they are capable of moving. Theoretically this could rise higher than the speed of light, though this has not been achieved yet.

The lower the drive rating, the cheaper it is in terms of fuel and the longer its service life, as well as the lower its maintenance costs. As such, lower drive ratings are favored for civilian vessels.

The standard drive ratings are as follow :

1 : Also called the 'minimum drive', used by gate freighters, one jumpers and ore haulers. Considered extremely ineffective for ships expected to do multiple jumps and visiting several worlds, as it can take over two days at that speed to make it in system from the jump limit.

2-5 : The so called 'freighter range', most interstellar freighters are within those bounds, with non imperial/older imperial freighters averaging at 3 and modern, top of the line imperial freighters usually having a standard of 5.

6-10 : The 'patrol range'. Most non imperial warships, imperial or non imperial patrol vessels or pirates are within that range, as are courier vessels and fast traders.

11-15 : The 'military range'. This is the range most Imperial warships operates at, though there are exceptions. Class 15 drives are the maximum the Empire uses for combat vessels, though some support ships like naval couriers have Class 16s.

16+ : The 'missile range'. Outside of advanced imperial naval couriers and certain spy vessels, only missiles have a drive of Class 16 and above. Most missiles oscillate between Class 20 and Class 30, with the Empire having recently rolled out a brand new array of Class 35 missiles and torpedoes, the 'Arrowhead' and 'Halberd' respectively.