Jump Travel

All FTL engines are jump drives which use hydrogen fuel to create a singularity bubble. The engine expands this bubble to encompass the entire ship and then it shifts into a parallel universe. During a jump the ship remains in this alternate dimension contained within the singularity bubble. Eventually this bubble will dissipate, meld into the previous dimension, and the ship will have traveled, or jumped, a certain distance.

The distance jumped depends on the state of the alternate dimension which they entered, ranging from 1 to 6 parsecs. Currently there are six known alternate dimensions, each with a unique time space dilation state. A ship always remains approximately 5 days (GST) in this alternate dimension while in jump space, however the actual distance traveled depends on which dimension (or jump level state) of jump space they entered.

Regardless if a ship jumped 6 parsecs or less than 1 parsec, they always remain 5 days in jump. Multiple jumps are possible, however a ship will have to come out of jump space, replot a course, and jump again (after refueling, if needed). Note there is a seventh alternate dimension which exists, but no known means to travel to and from this dimension is possible using jump technology.

The hydrogen fuel spent on a jump is per parsec distance. Ships can refuel at spaceports or opt instead to skim the high atmosphere of gas giants for hydrogen, or from water sources on a planet. It takes 1+d4 hours to refuel by skimming the atmosphere of a gas giant (or collecting water from planets) and the fuel will always remain unrefined. Unrefined fueling takes 60 minutes at a starport (includes time for processing the fuel into a more usable state). Refined fueling takes only 30 minutes at starport.

Using unrefined fuel for jumps can be a risky proposition if trying to make multiple jumps through deep space. The amount of fuel needed to create and maintain the singularity bubble can be significantly increased using unrefined fuel. If the ship does not land in a system with a plentiful source of hydrogen, it may potentially run out and be essentially stuck. This is especially treacherous if trying to re-jump within deep space.

The singularity bubble which the ship travels through during a jump is highly susceptible to gravity. Unexpected gravity forces can distort the bubble bringing the ship into its previous dimension prematurely, or potentially alter its course. Because of this all ships attempting to make a jump need to get out of the 100 Diameter Threshold Limit (100DLT) of a system. The obvious gravity diameter to gain distance from is the system star itself but most planets are already close to being outside this 100 diameter limit (commonly 1 AU). In such cases, the planet a ship is orbiting and other neighboring gas giants that are the 100DLT of concern.

Ships will usually take a specific route to another system by a direct vector to get beyond the 100 diameter threshold and avoid drifting into other outer planet gravity paths. Hence, particular vectors from a planet to different destination systems can be predicted somewhat. Naval and police ships take advantage of this ‘broadcasting of routes’, including pirates.

Additionally these routes may take them relatively close to small planetoids, asteroids, or moons (ships will easily get beyond their diameter limit quickly). Pirates will also use the cover of larger planetary bodies to attempt an ambush. Most captains are very nervous when attempting to get beyond the 100DLT, as it is an opportune time to run into pirates (or law enforcement if smuggling goods).

If a ship jumps into a system, they are already at the 100 diameter threshold for that system. They can hold position, calculate the next jump, and travel onwards to another system. For pirates, this is a useful tactic. Since most initial jump destinations can be predicted some by vector movement to the 100DLT, many will sacrifice cargo space for additional fuel so they can make a double jump quickly. If they needing to refuel at a local system gas giant, they must get beyond the 100 diameter threshold again and this can cost the pirate critical hours if being pursued.

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