Sublight Drives
Sublight Drives
Sublight drives move spacecraft through realspace. These engines provide more energy output than repulsorlift engines—which, since they require a large mass such as a planet for their antigrav engines to operate, are inappropriate for flights into deep space—and work much differently than their hyperdrive counterparts.
Though many varieties of sublight drives exist throughout the galaxy—solid chemical booster rockets, atomic drives, light sails, ramjets—by far the most popular in the Empire is the Hoersch-Kessel ion engine. Originally brought into this part of the galaxy countless millennia ago by alien merchants, today almost all of the major ship manufacturers put Hoersch-Kessel-style motors into their vessels.
The Hoersch-Kessel is extremely efficient and extremely powerful. For most efficient use, the engine draws energy from power cells or generators. However, it can be converted to break down and draw power from uranium, other heavy metals, or virtually any substance. Liquid reactants, energy conversion cells, and even ion-collector pods are regularly employed for power.
Another point in the Hoersch-Kessel’s favor is its versatility. The basic technology is simple, making it easy to construct drives for specific performance standards. A small version is used in starfighters and other high-performance vessels; larger engines can be produced for bigger ships. Not all H-K drives are identical: while each engine relies upon the same technological theory, different manufacturers all have their own variations, each attempting to produce the most efficient design.
Because of its widespread use throughout the galaxy, most ship mechanics know the H-K well; it is easy to find someone to fix it when it breaks down. It’s also easy to find replacement parts for most small and mid-size Hoersch-Kessels, though larger or specialized ships may have to have parts manufactured.
The H-K doesn’t break down often—it has few moving parts. However, for maximum efficiency, the engine’s intake and firing cells require precise adjustment and alignment, and must be “tuned up” periodically. If this maintenance is ignored for too long, the engine can be severely damaged or even ruined.
Unlike hyperdrive engines, which propel vessels through hyperspace, the H-K moves ships in realspace via a fusion reaction which breaks down fuel into charged particles. The resulting energy hurls from the vessel, providing thrust. The ship’s direction is controlled by changing the exhaust’s direction with baffles or so-called “vectrals,” or by smaller H-K engines employed as lateral thrusters.
While the H-K’s thrust is mildly radioactive and dangerous at extremely close ranges, it is safe enough to use in an atmosphere. The H-K’s most dangerous emissions are normally stopped by a series of collector coils, which are “scrubbed” and replaced during regular maintenance. Maintenance personnel routinely wear radiation-proof clothing (and smart ones have periodic anti-radiation inoculations as well). For situations where the H-K cannot be used, a ship relies on its repulsorlift engines.
Source: REUP:416