jump drive
operational description
"jump drives" enable a spaceship to "jump", that is, transit from one location in physical space to another location in physical space without transiting physical space itself. when this event is viewed externally the ship and all its properties simply disappears, reappearing roughly one week later in another location. when jump is experienced internally no motion is felt, but observes report the outside world "fading away" or "draining away into a whirlpool" or the view simply graying out. during jump nothing can be seen outside any external windows until the jump is completed. upon precipitation at the destination observers report the sudden appearance of stars and space, or the slow fading of the gray until a normal view is seen, or the starts sometimes "spinning back". there is no minimum jump distance - a ship could jump a few inches - but jump drives are rated by the number of parsecs across which they may transit a ship. presently the upper limit for controlled jumps to intended destinations is 6 parsecs, achieved by using tech 15 jump drives. jumps beyond 6 parsecs are easily accomplished but have uncontrolled and unpredictable results.
jump drives and maneuver drives are very similar. while maneuver drives bend real-space-time, jump drives breach it.
jump drives generate a jump field (calibrated to match she ship's size and shape) and jump capacitors store and then discharge electrical power to breach a point in real-space-time located within the jump field. once this breach is achieved the jump drives pour hydrogen into the breach. this induces the hydrogen to fuse within the breach, which drives the breach "wider" and "longer" towards a target destination point (determined by the ship's navigation systems). at the moment that the target destination point in real-space-time is also breached, jump occurs and continues until the ship itself precipitates at the target destination point. during jump the jump drives are shut down and left unpowered and require no engineering attention other than preservative maintenance.
charging jump drives emit a high-speed rotor mechanica sound, a high-pitched whine as the capacitors charge, and a loud roaring while the fusing fuel enlarges the breach. as jump is about to initiate the sound of the fusing fuel becomes more distant. upon jump entry all jump drive sounds cease.
physical description
jump drives consist two separate field generators, each a flask with internally nested counter-rotators (two for jump 1, three for jump 2, etc), internal capacitor banks above and below the rotors, and external real-space guide fins, joined by a ship calibration mesh grid which, depending on tech level and manufacturer and materials, may be heavy or thin or narrow or wide. one of these units is enough to generate a jump field but a pair or more of these assemblies, while more expensive, allows more accuracy in jump destination navigation. fuel lines, wide enough to handle the fuel flow necessary to drive the expansion of the jump breach, lead into the top of each field generator.
normal operations
jump drive operations are uncomplicated, requiring only a set of destination coordinates supplied by the ship's navigator using the navigation systems, the application of electrical power and the lighting off of the field generator rotators, the opening of hydrogen fuel valves, and the jump sequence start signal initiated from the bridge which actuates the real-space-time breach charge and the flow of fuel into the breach. larger ships will have engineering control panels to centralize and coordinate these procedures but smaller ships routinely have nothing in engineering but a power breaker and a fuel valve. engineering 1, or mechanical 1 and electronics 1, are sufficient for routine jump operations.
maintenance
jump drives rotators are heavy, complex, and sensitive, but are not fragile. other moving parts requiring maintenance include those associated with fuel transfer and electrical power application. field generator internal maintance is the same as that of any rotating machinery. external maintenance consists of keeping the field generator radiators and mesh grid clean and un-dinged, and replacing any electrical components that fail or fuel valves that wear out. engineering 1, or mechanical 1 and electronics 1, are sufficient for these routine tasks.
refit/overhaul
jump drive field generator rotators must be rebalanced each year, and the field generators must be carefully calibrated to each other, to their grids, and to the ship on which they are mounted. this rebalancing and calibration must be performed during annual overhauls or or the not only will the jump drives begin to lose accuracy in intended destination but also may lose "power" - a jump 2 drive may become capable only of jumping 1 parsec, but still require all the fuel necessary to jump 2 parsecs. the task of rebalancing/recalibrating jump drives is rated UNUSUAL and requires both a qualified engineer and a qualified navigator. while those with skill level 1 or 2 may attempt it and may succeed the results cannot be guaranteed. skill level 3 for both engineer and navigator are necessary for guaranteed accuracy in jump. shipyard overhaul is sufficiently experienced (usually) to calibrate without testing. field testing proof of calibration usually consists of a short jump to an empty in-system target zone.
overhaul facilities may refit/overhaul jump drives to their technological level - i.e. an otherwise unsupported tech 13 yard can refit/overhaul a jump 5 drive to perform jump 4, the jump limit for tech 13.
damage control
even for a small ship executing a small jump, expanding the jump breach requires a large volume of hydrogen fuel. if the fuel system should be damaged or break while this evolution is in progress the engineering space will rapidly cool to the point of uninhabitability and all breathable air will be displaced in a moment.
jump drives that take physical damage may be repaired by any mechanic or, if the internals of a field generator have been disrupted, by any electronics tech. the task rating of such repairs depends on the level of damage. but the drives will then require re-calibration, and the task of re-calibrating them from being damaged is rated VERY DIFFICULT. this calibration is otherwise identical to that described in refit/overhaul.
abnormal operations
purified fuel is necessary to minimize navigational inaccuracies as the jump fuel is expanding the real-space-time breach. these inaccuracies are best implemented by the game referee. a suggested rule is impurities in fuel will introduce 6d6 AU inaccuracy in the final destination point.
jump drives which are operated past their refit/overhaul schedules begin to suffer in range and accuracy. these inaccuracies are best implemented by the game referee. a suggested rule for operations past refit/overhaul is, roll d6. if the result is less than the number of months past due, then 1) the jump drive will be reduced in range by 1 parsec, and 2) for each month past due roll another d6, and this result is the final inaccuracy in AU. these rolls are modified by both navigator and engineering skill level. example: a ship is 4 months past refit/overhaul. the navigator is skill level 2 and the engineer is skill level 1. the ship jumps. the player rolls d6 and gets a 1, adds 2 for the navigator, and adds 1 for the engineer, for a result of 4. jump accuracy is normal. later, 5 months past refit/overhaul, the ship jumps again. this time the player again rolls a 1, adds 2 for the navigator and 1 for the engineer, for a total of 4, less than the 5 months the ship is past refit/overhaul, therefore the jump will be 1 parsec short and the shorter jump will be inaccurate. the player then rolls 3d6, for 12, and subtracts 2 for the navigator and 1 for the engineer, for a result of 9. therefore the actual destination of this jump will be 9 AU distant from theintended destination. this reduction in range and inaccuracy accumulates without limit.
if jump is attempted with damaged or uncalibrated jump drives then the final destination is completely unpredictable. resolving the final destination is best implemented by the game referee. the old rule of d6d6 determining direction in hexsides and distance in parsecs of actual destination from intended destination seems appropriate.
normally two "turns" are required to charge the jump capacitors and charge the hydrogen fuel into the real-space-time breach. "fast jump" reduces this time to one turn, however this requires electrical power connections and fuel lines sufficient to handle the greater input of power and fuel. most civilian ships do not have this heavy-duty gear installed, while most military and scout ships do. "fast jump" by military/scout ships requires no task check. for a civilian ship the task of attempting fast jump is rated UNUSUAL, with failure resulting in electrically and/or mechanically damaged jump drives and possibly a failed jump.
(optional. jump may be initiated anywhere, and the destination point may be anywhere. jump is very sensitive, however, to gravitic fields. initiating jump within 100d of any major gravity source renders jump navigation calculations inaccurate. jump precipitation within 100d of a major gravity source will on arrival result in electrostatic feedback into the jump drive field generators. if the capacitors are unable to absorb this charge they will overload and burst, damaging or even destroying their electrical components and rendering the jump drives non-functional.)